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1.  Role of Lesion-to-Background Activity Ratio and Background Activity in Optimization of Reconstruction Protocols for FDG PET/CT Images of Overweight Patients: A Phantom Study

Samira Rezvani, Pardis Ghafarian, Mehrdad Bakhshayesh Karam, Mohammadreza Ay
Peer-reviewed Journal Publication
Iranian Journal of Radiology,2023,

2.  Impact of random and scattered coincidences from outside of field of view on positron emission tomography/computed tomography imaging with different reconstruction protocols

Mahak Osouli Alamdari, Pardis Ghafarian, Arman Rahmim, Mehrdad Bakhshayesh-Karam, Mohammad Reza Ay
Peer-reviewed Journal Publication
Nuclear Science and Techniques,2023, V34,P 1-13

3.  Exploring ASL perfusion MRI as a substitutive modality for 18F-FDG PET in determining the laterality of mesial temporal lobe epilepsy

Hossein Rahimzadeh, Hadi Kamkar, Pardis Ghafarian, Narges Hoseini-Tabatabaei, Neda Mohammadi-Mobarakeh, Jafar Mehvari-Habibabadi, Seyed-Sohrab Hashemi-Fesharaki & Mohammad-Reza Nazem-Zadeh
Peer-reviewed Journal Publication
Neurological Sciences,2023

4.  Multimodality radiomics prediction of radiotherapy-induced the early proctitis and cystitis in rectal cancer patients: A machine learning study

Samira Abbaspour, Maedeh Barahman, Hamid Abdollahi, Hossein Arabalibeik, Ghasem Hajianfar, Mohammadreza Babaei, Hamed Iraji, Mohammadreza Barzegartahamtan, Mohammadreza Ay, Seied Rabi Mahdavi
Peer-reviewed Journal Publication
Biomedical Physics & Engineering Express,2023

5.  Accurate modeling and performance evaluation of a total‐body pet scanner using Monte Carlo simulations

Hadi Rezaei, Peyman Sheikhzadeh, Pardis Ghafarian, Habib Zaidi, Mohammad Reza Ay
Peer-reviewed Journal Publication
Medical Physics,2023, V 50,P6815-6827

6.  The effects of various penalty parameter values in Q.Clear algorithm for rectal cancer detection on 18F‑FDG images using a BGO‑based PET/CT scanner: a phantom and clinical study

Fatemeh Sadeghi, Peyman Sheikhzadeh* , Saeed Farzanehfar , Pardis Ghafarian*, Yalda Moafpurian and Mohammadreza Ay
Peer-reviewed Journal Publication
EJNMMI physics,2023,V 10,P 63

7.  List-mode quantitative joint reconstruction of activity and attenuation maps in Time-of-Flight PET

Hamidreza Hemmati, Alireza Kamali-Asl, Pardis Ghafarian, Arman Rahmim, Habib Zaidi, Mohammad Reza Ay
Peer-reviewed Journal Publication
Journal of Instrumentation,V 18,P P09041

8.  FEASIBILITY OF [64CU] CU-TRASTUZUMAB PET/CT IMAGING IN BREAST CANCER: A SYSTEMATIC REVIEW

Ali Abdulhasan Kadhim, Peyman Sheikhzadeh, Mehrshad Abbasi, Nasim Vahidfar, Saeed Afshar, Mohsen Bakhshi Kashi, Negisa Seyyedi, Mohammad Reza Ay
Peer-reviewed Journal Publication
Journal of Population Therapeutics and Clinical Pharmacology, 2023,V 30, P 2375-2385

9.  Phantom and clinical evaluation of Block Sequential Regularized Expectation Maximization (BSREM) Reconstruction Algorithm in 68Ga-PSMA PET/CT Studies

Fatemeh Sadeghi, Peyman Sheikhzadeh, Nima Kasraie, Saeed Farzanehfar, Mehrshad Abbasi, Yalda Salehi, Mohammad Reza Ay
Peer-reviewed Journal Publication
Physical and Engineering Sciences in Medicine, V 3,P 1297-1308

10.  Evaluation of deep-learning based partial volume correction of PET images without the use of anatomical information

Mohammad-Saber Azimi, Alireza Kamali-Asl, Mohammad-Reza Ay, Mahboube Sadat Hosseini, Fatemeh Khorshidi, Yalda Moafpourian, Hossein ARABI, Arman Rahmim, Habib Zaidi
Peer-reviewed Journal Publication
Journal of Nuclear Medicine, V 64, P971-P971

11.  Reproducibility of radiomics features in partial volume correction of PET images

Mohammad-Saber Azimi, Alireza Kamali-Asl, Mohammad-Reza Ay, Mahboube Sadat Hosseini, Fatemeh Khorshidi, Hossein ARABI, Arman Rahmim, Habib Zaidi
Peer-reviewed Journal Publication
Journal of Nuclear Medicine,V64,P994-P994

12.  Development of novel and low-cost readout electronics for large FOV gamma camera detector

Aram Radnia, Amirhossein Alikhani, Behnoosh Teimourian, Mahyar Youser Nejad, Mohammad Hossein Farahani, Fakhereh Pashaei, Arman Rahmim, Mohammad Reza Ay
Peer-reviewed Journal Publication
research squre,2023

13.  Evaluation and optimization of geometry parameters of GAGG scintillator-based Compton Camera for medical imaging by Monte Carlo simulation

Hajar Zarei, S Razaghi, Y Nagao, M Itoh, M Yamaguchi, N Kawachi, MR Ay, H Watabe
Peer-reviewed Journal Publication
Journal of Instrumentation,2023,V18, P01035

14.  Realizing 32-time Scan Duration Reduction of 18F-FDG PET Using a Cycle-GAN and Image Augmentation

Ali Ghafari, Peyman Sheikhzadeh, Negisa Seyyedi, Mehrshad Abbasi, Mohammad Reza Ay
Peer-reviewed Journal Publication
Frontiers in Biomedical Technologies

15.  Reducing scan time using time-of-flight protocol in clinical [18F] FDG-PET/CT imaging: A feasibility study

Roya Sharifpour, Pardis Ghafarian, Mehrdad Bakhshayesh-Karam, Carlos F Uribe, Arman Rahmim, Mohammad Reza Ay
Peer-reviewed Journal Publication
Iranian Journal of Nuclear Medicine,2022,P 1-16

16.  Impact of Various Image Reconstruction Methods on Joint Compensation of Respiratory Motion and Partial Volume Effects in Whole-Body 18F-FDG PET/CT Imaging: Patients with Non-Small Cell Lung Cancer

Pardis Ghafarian, Sahar Rezaei, Esmaeil Gharepapagh, Saeid Sarkar, Mohammad Reza Ay
Peer-reviewed Journal Publication
Iran South Med J 2022, 25(4): 355-370

17.  Endorectal ultrasound radiomics in locally advanced rectal cancer patients: despeckling and radiotherapy response prediction using machine learning

Samira Abbaspour, Hamid Abdollahi, Hossein Arabalibeik, Maedeh Barahman, Amir Mohammad Arefpour, Pedram Fadavi, Mohammadreza Ay & Seied Rabi Mahdavi
Peer-reviewed Journal Publication
Nuclear Medicine Communications,2022,V 43,P 1004-1014

18.  Generation of 18F-FDG PET standard scan images from short scans using cycle-consistent generative adversarial network

Ali Ghafari, Peyman Sheikhzadeh, Negisa Seyyedi, Mehrshad Abbasi, Saeed Farzenefar, Fereshteh Yousefirizi, Mohammadreza Ay, Arman Rahmim
Peer-reviewed Journal Publication
Physics in Medicine & Biology,2022,P 355-370

19.  Deep Learning Based Missing Information Recovery in Partial Ring Total Body PET Scanner

H Rezaei, P Sheikhzadeh, P Ghafarian, I Shiri, M Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING,2022,V49,S78-S79

20.  Development of Reconstruction Algorithm for High Resolution microPET Scanner Using Siddon-based System Matrix

S Hariri Tabrizi, B Teimourian, M Farahani, M Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING,2022,V49, S426-S426

21.  High Resolution PET Detector Design Using SiPM Array

A Radnia, M Farahani, M Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING,2022,V49,S450-S450

22.  Impact of Different Crystal Material on Performance Characteristics of Long Axial Field-Of-View PET Scanner: A Monte Carlo Simulation Study

H Rezaei, M Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING,2022,V49,S79

23.  Optimization of Time Coincidence Window and Energy Window for Dedicated Brain PET: A Simulation Study

T Zare, P Sheikhzadeh, A Rahmim, B Teimourian Fard, P Ghafarian, M Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING,2022,V49,S595

24.  Potential advantages of FDG‐PET radiomic feature map for target volume delineation in lung cancer radiotherapy

Zahra Falahatpour, Parham Geramifar, Seyed Rabie Mahdavi, Hamid Abdollahi, Yazdan Salimi, Alireza Nikoofar, Mohammad Reza Ay
Peer-reviewed Journal Publication
Journal of Applied Clinical Medical Physics,2022,V23

25.  The impact of Different Reconstruction Parameters along with TOF and PSF in PET/CT Imaging: Patient with Normal and High BMI

S Rezvani, P Ghafarian, M Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING,2022,V49,S594

26.  Comparison of The Performance of Denoising Filters in Improving The Quality of Low-Dose Brain PET Images With Two Dose Levels of 5% and 10%

Mohammad-Saber Azimi, Alireza Kamali-asl, Mohammad-Reza Ay, Hossein Arabi
Peer-reviewed Journal Publication
medical journal of mashhad university of medical sciences,2022, Vol 65

27.  Deep Learning-Based Partial Volume Correction in Standard and Low-Dose PET-CT Imaging

Mohammad-Saber Azimi, Alireza Kamali-Asl, Mohammad-Reza Ay, Navid Zeraatkar, Hossein Arabi
Peer-reviewed Journal Publication
arXiv preprint arXiv:2207.02553

28.  Comparative assessment of attention-based deep learning and non-local mean filtering for joint noise reduction and partial volume correction in low-dose PET imaging

Mohammad-Saber Azimi, Alireza Kamali-Asl, Mohammad-Reza Ay, Navid Zeraatkar, Mahboube Sadat Hosseini, Hossein ARABI, Habib Zaidi
Peer-reviewed Journal Publication
Journal of Nuclear Medicine, 2022, Vol 63, P 2729-2729

29.  Harmonization based on quantitative analysis of standardized uptake value variations across PET/CT scanners: a multicenter phantom study

Abbas Monsef, Mohammad Reza Ay, Peyman Sheikhzadeh, Parham Geramifar, Arman Rahmim, Pardis Ghafarian
Peer-reviewed Journal Publication
Nuclear Medicine Communications,2022,V43, P1004-1014

30.  A deep learning method for high-quality ultra-fast CT image reconstruction from sparsely sampled projections

Hamidreza Khodajou-Chokami, Seyed Abolfazl Hosseini, Mohammad Reza Ay
Peer-reviewed Journal Publication
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment,2022,Vol 1029

31.  Synergistic impact of motion and acquisition/reconstruction parameters on 18F-FDG PET radiomic features in non-small cell lung cancer: phantom and clinical studies

Seyyed Ali Hosseini,Isaac Shiri,Ghasem Hajianfar,Bahador Bahadorzade,Pardis Ghafarian,Habib Zaidi,Mohammad Reza Ay
Peer-reviewed Journal Publication
Medical Physics,2022

32.  Necessity of Development and Manufacturing of Dedicated Brain PET Scanners

Peyman Sheikhzadeh, Mohammadreza Ay
Peer-reviewed Journal Publication
Frontiers in Biomedical Technologies,2022,V9, p74-75

33.  PARS-NET: a novel deep learning framework using parallel residual conventional neural networks for sparse-view CT reconstruction

H Khodajou-Chokami, SA Hosseini, MR Ay
Peer-reviewed Journal Publication
Journal of Instrumentation,2022, Vol 17

34.  A novel approach for extracting functional brain networks involved in mesial temporal lobe epilepsy based on self organizing maps

Alireza Fallahi, Mohammad Pooyan, Jafar Mehvari Habibabadi, Seyed Sohrab Hashemi-Fesharaki, Narges Hoseini Tabatabaei, Mohammadreza Ay, Mohammad-Reza Nazem-Zadeh
Peer-reviewed Journal Publication
Informatics in Medicine Unlocked,2022, Vol 29, P 100876

35.  Statistical analysis of COVID-19 infection severity in lung lobes from chest CT

Mehdi Yousefzadeh, Mozhdeh Zolghadri, Masoud Hasanpour, Fatemeh Salimi, Ramezan Jafari, Mehran Vaziri Bozorg, Sara Haseli, Abolfazl Mahmoudi Aqeel Abadi, Shahrokh Naseri, Mohammadreza Ay, Mohammad-Reza Nazem-Zadeh
Peer-reviewed Journal Publication
Informatics in Medicine Unlocked,2022,P 100935,

36.  Leveraging Deep Neural Networks to Improve Numerical and Perceptual Image Quality in, Low-dose Preclinical PET Imaging

Mahsa Amirrashedi, Saeed Sarkar, Hojjat Mamizadeh, Hossein Ghadiri, Pardis Ghafarian, Habib Zaidi, Mohammad Reza Ay
Peer-reviewed Journal Publication
Computerized Medical Imaging and Graphics,2021,P 102010

37.  The Impact of Preprocessing on the PET-CT Radiomics Features in Non-small Cell Lung Cancer

Seyyed Ali Hosseini, Isaac Shiri, Ghasem Hajianfar, Pardis Ghafarian, Mehrdad Bakhshayesh Karam, Mohammad Reza Ay
Peer-reviewed Journal Publication
Frontiers in Biomedical Technologies,2021,V 8

38.  Accurate Monte Carlo Modeling and Performance Evaluation of a Total-body PET Scanner

Hadi Rezaei, Peyman Sheikhzadeh, Pardis Ghafarian, Habib Zaidi, Mohammad Reza Ay
Proceeding and Conference Record
2021 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC),P 1-3

39.  Temporal and extratemporal atrophic manifestation of temporal lobe epilepsy using voxel-based morphometry and corticometry: clinical application in lateralization of epileptogenic zone

Majdi Jber, Jafar Mehvari Habibabadi, Roya Sharifpour, Hengameh Marzbani, Masoud Hassanpour, Milad Seyfi, Neda Mohammadi Mobarakeh, Ahmedreza Keihani, Seyed Sohrab Hashemi-Fesharaki, Mohammadreza Ay, Mohammad-Reza Nazem-Zadeh
Peer-reviewed Journal Publication
Neurological Sciences,2021,P 1-21

40.  Introducing a novel Polyvinyl chloride/Tungsten composites for shielding against gamma and X-ray radiations

Tohid Abdolahzadeh1 , Jalil Morshedian1 , Shervin Ahmadi1 , Mohammad Reza Ay2,3 , Omid Mohammadi
Peer-reviewed Journal Publication
Iranian Journal of Nuclear Medicine,2021,vol 29- p 58-64

41.  Introducing the GammaPen: All-in-One Gamma Probe for Sentinel Lymph Node Biopsy

Aram Radnia, Hamed Abdollahzadeh, Behnoosh Teimourian, Mohammad Hossein Farahani, Mohammad Reza Ay
Peer-reviewed Journal Publication
Frontiers in Biomedical Technologies,2021

42.  Dynamic functional connectivity in temporal lobe epilepsy: a graph theoretical and machine learning approach

Alireza Fallahi, Mohammad Pooyan, Nastaran Lotfi, Fatemeh Baniasad, Leili Tapak, Neda Mohammadi-Mobarakeh, Seyed Sohrab Hashemi-Fesharaki, Jafar Mehvari-Habibabadi, Mohammad Reza Ay, Mohammad-Reza Nazem-Zadeh
Peer-reviewed Journal Publication
Neurological Sciences,2021,Vol 42

43.  A Deep Neural Network To Recover Missing Data In Small Animal Pet Imaging: Comparison Between Sinogram-And Image-Domain Implementations

Mahsa Amirrashedi, Saeed Sarkar, Hossein Ghadiri, Pardis Ghafarian, Habib Zaidi, Mohammad Reza Ay
Proceeding and Conference Record
2021 IEEE 18th International Symposium on Biomedical Imaging (ISBI)

44.  Standard-dose PET reconstruction from low-dose preclinical images using an adopted all convolutional U-Net

Mahsa Amirrashedi, Saeed Sarkar, Hossein Ghadiri, Pardis Ghafarian, Mohammad Reza Ay
Proceeding and Conference Record
Medical Imaging 2021: Biomedical Applications in Molecular, Structural, and Functional Imaging

45.  Development and characterization of an all-in-one gamma probe with auto-peak detection for sentinel lymph node biopsy based on NEMA NU3-2004 standard

Aram Radnia, Hamed Abdollahzadeh, Behnoosh Teimourian, Mohammad Hossein Farahani, Mohammad Esmaeil Akbari, Habib Zaidi, Mohammad Reza Ay
Peer-reviewed Journal Publication
Annals of Nuclear Medicine,2021,Vol 35,P 1-9

46.  Advances in Preclinical PET Instrumentation

Mahsa Amirrashedi, Habib Zaidi, Mohammad Reza Ay
Peer-reviewed Journal Publication
Elsevier,2020, V4,p403-426

47.  Measurement of Radiation Exposure to Caregivers of Patients with Thyroid Diseases Treated with Iodine-131: A Review

Ali Abdulhasan Kadhim, Peyman Sheikhzadeh, Saeed Farzanefar, Shima Yavari, Majdi Mousa Jber, Mohammad Reza Ay
Peer-reviewed Journal Publication
Frontiers in Biomedical Technologies,Vol 7,P 191-199

48.  Evaluation of gamma and electron radiations impact on vitamins for onion preservation

Salar Firouzi, Abdollah Khorshidi, Jamshid Soltani-Nabipour, Seyed Mohsen Zia Barzi, Mohammad Amani, Majid Sorouri, Mohammad Reza Ay
Peer-reviewed Journal Publication
Applied Radiation and Isotopes,2020

49.  Towards quantitative small-animal imaging on hybrid PET/CT and PET/MRI systems

Mahsa Amirrashedi, Habib Zaidi, Mohammad Reza Ay
Peer-reviewed Journal Publication
Clinical and Translational Imaging,2020

50.  Radiation Dose Assessment to Family Members Taking Care of Non-Cancerous Thyroid Patients Treated with I-131 Therapy in Nuclear Medicine Department

Ali Abdulhasan Kadhim, Peyman Sheikhzadeh, Saeed Farzanefar, Shima Yavari, Mohammad Reza Ay
Peer-reviewed Journal Publication
Radiation Protection Dosimetry,2020

51.  Deep-JASC: joint attenuation and scatter correction in whole-body 18F-FDG PET using a deep residual network

Isaac Shiri, Hossein Arabi, Parham Geramifar, Ghasem Hajianfar, Pardis Ghafarian, Arman Rahmim, Mohammad Reza Ay & Habib Zaidi
Peer-reviewed Journal Publication
European Journal of Nuclear Medicine and Molecular Imaging, 2020

52.  Guidelines for TMS/tES Clinical Services and Research through the COVID-19 Pandemic

Marom Bikson, Colleen A Hanlon, Adam J Woods, Bernadette T Gillick, Leigh Charvet, Claus Lamm, Graziella Madeo, Adrienn Holczer, Jorge Almeida, Andrea Antal, Mohammad Reza Ay,
Peer-reviewed Journal Publication
Brain Stimulation, Elsevier,2020

53.  Standard SPECT myocardial perfusion estimation from half-time acquisitions using deep convolutional residual neural networks

Isaac Shiri, Kiarash AmirMozafari Sabet, Hossein Arabi, Mozhgan Pourkeshavarz, Behnoosh Teimourian, Mohammad Reza Ay, Habib Zaidi
Peer-reviewed Journal Publication
Journal of nuclear cardiology: official publication of the American Society of Nuclear Cardiology,2020

54.  Performance evaluation of developed dedicated breast PET scanner and improvement of the spatial resolution by wobbling: a Monte Carlo study.

A Emami, H Ghadiri, P Ghafarian, P Geramifar, MR Ay
Peer-reviewed Journal Publication
Japanese journal of radiology,2020,P 1-10

55.  6th Anniversary Editorial

Mahnaz Kiani Mobareke, Mohmmadreza Ay
Peer-reviewed Journal Publication
Frontiers in Biomedical Technologies,Vol 7, P 1-2

56.  Novel preclinical PET geometrical concept using a monolithic scintillator crystal offering concurrent enhancement in spatial resolution and detection sensitivity: a simulation study

Amirhossein Sanaat , HosseinArabi , MohammadReza Ay and Habib Zaidi
Peer-reviewed Journal Publication
Physics in Medicine & Biology,2020

57.  Computationally efficient system matrix calculation techniques in computed tomography iterative reconstruction

Golshan Mahmoudi, Mohammad Reza Ay, Arman Rahmim, Hossein Ghadiri
Peer-reviewed Journal Publication
Journal of Medical Signals and Sensors,2020,Vol 10, p 1-11

58.  Corrigendum to" Targeted gold nanoparticles enable molecular CT imaging of head and neck cancer: An in vivo study

Sara Khademi, Saeed Sarkar, Ali Shakeri-Zadeh, Neda Attaran, Sharmin Kharrazi, Mohammad Reza Ay, Hosein Azimian, Hossein Ghadiri
Peer-reviewed Journal Publication
The International Journal of Biochemistry & Cell Biology,2020, Vol 10,P 1

59.  Molecular imaging approaches in the diagnosis of breast cancer: A systematic review and meta-analysis

Getu Ferenji Tadesse, Parham Geramifar, Pardis Ghafarian, Eshetu Ejeta Cheka, Eyachew Misgana Tegaw, Seifu Gizaw Feyisa, Ramin Sadeghi, Mohammad Reza Ay
Peer-reviewed Journal Publication
Iranian Journal of Nuclear Medicine,2020,Vol 28, P 1-13

60.  The impact of iterative reconstruction protocol, signal‑to‑background ratio and background activity on measurement of PET spatial resolution

Sahar Rezaei1,2 · Pardis Ghafarian3,4 · Mehrdad Bakhshayesh‑Karam3,4 · Carlos F. Uribe5 · Arman Rahmim6,7 · Saeed Sarkar2 · Mohammad Reza Ay1,2
Peer-reviewed Journal Publication
Japanese Journal of Radiology ,2020,

61.  Validation and evaluation of a GATE model for MAMMI PET scanner

Azadeh Emami, Pardis Ghafarian, Hossien Ghadiri, Parham Geramifar, Mohammad Reza Ay
Peer-reviewed Journal Publication
Iranian Journal of Nuclear Medicine,2020,Vol 28, P 33-38

62.  Novel preclinical PET geometrical concept using a monolithic scintillator crystal offering concurrent enhancement in spatial resolution and detection sensitivity: a simulation …

Amirhossein Sanaat, Hossein Arabi, Mohammadreza Ay, Habib Zaidi
Peer-reviewed Journal Publication
Physics in Medicine & Biology,2019,

63.  Joint compensation of motion and partial volume effects by iterativedeconvolution incorporating wavelet-based denoising in oncologic PET/CTimaging

Sahar Rezaei,Pardis Ghafarian,Abhinav K. JhaArman Rahmim,Saeed Sarkar,Mohammad Reza Ay
Peer-reviewed Journal Publication
physica media,2019,Vol 68,P 52-60

64.  Targeted gold nanoparticles enable molecular CT imaging of head and neck cancer: an in vivo study

Sara Khademi, Saeed Sarkar, Ali Shakeri-Zadeh, Neda Attaran, Sharmin Kharrazi, Mohammad Reza Ay, Hosein Azimian, Hossein Ghadiri
Peer-reviewed Journal Publication
The international journal of biochemistry & cell biology,2018,Vol 114

65.  Sparse-view statistical image reconstruction with improved total variation regularization for X-ray micro-CT imaging

G Mahmoudi, MR Fouladi, MR Ay, A Rahmim, H Ghadiri
Peer-reviewed Journal Publication
Journal of Instrumentation, 2019, Vol 14

66.  NEMA NU‐4 2008 Performance Evaluation of Xtrim‐PET: A prototype Si PM‐based preclinical scanner

Mahsa Amirrashedi, Saeed Sarkar, Pardis Ghafarian, Reza Hashemi Shahraki, Parham Geramifar, Habib Zaidi, Mohammad Reza Ay
Peer-reviewed Journal Publication
Medical physics,2019

67.  A novel approach to automatic position calibration for pixelated crystals in gamma imaging

Salar Sajedi, Navid Zeraatkar, Sanaz Kaviani, Hadi Khanmohammadi, Saeed Sarkar, Hamid Sabet, Mohammad Reza Ay
Peer-reviewed Journal Publication
Iranian Journal of Nuclear Medicine,2019,Vol 27

68.  Dual-energy CT imaging of nasopharyngeal cancer cells using multifunctional gold nanoparticles

Hossein Ghadiri, Sara Khademi, Saeed Sarkar, Ali Shakeri-zadeh, Neda Attaran, Mohammad Reza Ay, Hosein Azimian, Razieh Solgi
Peer-reviewed Journal Publication
IET Nanobiotechnology, 2019

69.  The influence of misregistration between CT and SPECT images on the accuracy of CT-based attenuation correction of cardiac SPECT/CT imaging: Phantom and clinical studies

Leila Saleki, Pardis Ghafarian, Ahmad Bitarafan-Rajabi, Nahid Yaghoobi, Babak Fallahi, Mohammad Reza Ay
Peer-reviewed Journal Publication
Iranian Journal of Nuclear Medicine,2019,Vol 27,pp63-72

70.  Validation and evaluation of a GATE model for MAMMI PET scanner

Azadeh Emami, Pardis Ghafarian, Hossien Ghadiri, Parham Geramifar, Mohammad Reza Ay
Peer-reviewed Journal Publication
Iranian Journal of Nuclear Medicine,2019

71.  A Novel Method for Measuring the MTF of CT Scanners: A Phantom Study

Hamidreza Khodajou-Chokami, Seyed Abolfazl Hosseini, Mohammad Reza Ay, Ali Safarzadehamiri, Pardis Ghafarian, Habib Zaidi
Proceeding and Conference Record
2019 IEEE International Symposium on Medical Measurements and Applications

72.  MCNP-FBSM: Development of MCNP/MCNPX Source Model for Simulation of Multi-Slice Fan-Beam X-Ray CT Scanners

Hamidreza Khodajou-Chokami, Seyed Abolfazl Hosseini, Mohammad Reza Ay, Habib Zaidi
Proceeding and Conference Record
2019 IEEE International Symposium on Medical Measurements and Applications

73.  Direct attenuation correction of brain PET images using only emission data via a deep convolutional encoder-decoder (Deep-DAC)

Isaac Shiri, Pardis Ghafarian, Parham Geramifar, Kevin Ho-Yin Leung, Mostafa Ghelichoghli, Mehrdad Oveisi, Arman Rahmim, Mohammad Reza Ay
Peer-reviewed Journal Publication
European radiology,2019,pp1-3

74.  Development and preliminary results of Xtrim-PET, a modular cost-effective preclinical scanner

Salar Sajedi, Navid Zeraatkar, Mohsen Taheri, Sanaz Kaviani, Hadi Khanmohammadi, Saeed Sarkar, Hamid Sabet, Mohammad Reza Ay
Peer-reviewed Journal Publication
2019, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

75.  Deep-Fill: Deep Learning Based Sinogram Domain Gap Filling in Positron Emission Tomography

Isaac Shiri, Peyman Sheikhzadeh, Mohammad Reza Ay
Peer-reviewed Journal Publication
arXiv preprint arXiv:1906.07168

76.  Design, optimization and performance evaluation of BM-PET: A simulation study

Peyman Sheikhzadeh, Hamid Sabet, Hossein Ghadiri, Parham Geramifar, Pardis Ghafarian, Mohammad Reza Ay
Peer-reviewed Journal Publication
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

77.  PSFNET: ultrafast generation of PSF-modelled-like PET images using deep convolutional neural network

Isaac Shiri, Kevin Leung, Parham Geramifar, Pardis Ghafarian, Mehrdad Oveisi, Mohammad Reza Ay, Arman Rahmim
Peer-reviewed Journal Publication
Journal of Nuclear Medicine,2019,vol 60,pp 1369-1369

78.  HiResPET: high resolution PET image generation using deep convolution encoder decoder network

Isaac Shiri, Kevin Leung, Pardis Ghafarian, Parham Geramifar, Mehrdad Oveisi, Mohammad Reza Ay, Arman Rahmim
Peer-reviewed Journal Publication
Journal of Nuclear Medicine,2019,vol 60,pp 1368-1368

79.  Simultaneous Attenuation Correction and Reconstruction of PET Images Using Deep Convolutional Encoder Decoder Networks from Emission Data

Isaac Shiri, Kevin Leung, Pardis Ghafarian, Parham Geramifar, Mehrdad Oveisi, Mohammad Reza Ay, Arman Rahmim
Peer-reviewed Journal Publication
Journal of Nuclear Medicine,2019,vol 60

80.  Impact of image reconstruction methods on quantitative accuracy and variability of FDG-PET volumetric and textural measures in solid tumors

Ali Ketabi, Pardis Ghafarian, Mohammad Amin Mosleh-Shirazi, Seyed Rabi Mahdavi, Arman Rahmim, Mohammad Reza Ay
Peer-reviewed Journal Publication
European radiology,2019,vol 29,pp 2146-2156

81.  Techniques for generating attenuation map using cardiac SPECT emission data only: a systematic review

Getu Ferenji Tadesse, Parham Geramifar, Eyachew Misganew Tegaw, Mohammad Reza Ay,
Peer-reviewed Journal Publication
Annals of Nuclear Medicine ,21019,Vol 33,P 1-13

82.  Design and performance evaluation of high resolution small animal PET scanner based on monolithic crystal: a simulation study

A Sanaat, MS Zafarghandi, MR Ay
Peer-reviewed Journal Publication
Journal of Instrumentation,2019, Vol 14

83.  A full quantitative analysis of 18 MV photon beam from 2100 C/D-Varian clinical linear accelerator with and without flattening filter

SR Mahdavi, MR Ay, M Zabihzadeh, M Allahverdi, M Shahriari, M Hoseini-Ghahfarokhi
Peer-reviewed Journal Publication
International Journal of Radiation Research, 2019, Vol 17, P 137-146

84.  Design and performance evaluation of spheroid geometry for brain PET scanner using Monte Carlo modeling

Peyman Sheikhzadeh, Hossein Ghadiri, Parham Geramifar, Pardis Ghafarian, Mohammad Reza Ay
Peer-reviewed Journal Publication
Iranian Journal of Nuclear Medicine, 2019, Vol 27, P 32-37

85.  Monte Carlo-based optimization of a gamma probe system for sentinel lymph node mapping

Azadeh Nikoogoftar, Mojtaba Shamsaie, Navid Zeraatkar, Mohammad Reza Ay
Peer-reviewed Journal Publication
Iranian Journal of Nuclear Medicine,2019, Vol 27, p 8-14

86.  Resolution Recovery with Pre-Reconstruction Fourier Transforms Filtering for a High Resolution Animal SPECT System

Reza Hashemi Shahraki, Isaac Shiri, Parham Geramifar, Afshin Akbarzadeh, Amir Hossein Sanaat, Mohammad Reza Ay
Peer-reviewed Journal Publication
Frontiers in Biomedical Technologiesو2018Vol 5, P 74-80

87.  Advantages and disadvantages of removed flattening filter Linac: A Monte Carlo study on full quantitative dosimetric data of 18 MV-Varian Linac

Mansour Zabihzadeh, Seyed Rabee Mahdavi, Mohammad Reza Ay, Mojtaba Hoseini-Ghahfarokhi
Peer-reviewed Journal Publication
Iranian Journal of Medical Physics, 2018, Vol 15, P 446

88.  Conventional Voxel in Tomographic Reconstruction Based upon Plane-Integral Projections–Use It or Lose It?

Hojjat Mahani, Gholamreza Raisali, Alireza Kamali-Asl, Mohammad Reza Ay
Peer-reviewed Journal Publication
Iranian Journal of Medical Physics, 2018, Vol 15, P 269-269

89.  Conventional Voxel in Tomographic Reconstruction Based upon Plane-Integral Projections–Use It or Lose It?

Hojjat Mahani, Gholamreza Raisali, Alireza Kamali-Asl, Mohammad Reza Ay
Proceeding and Conference Record
Iranian Journal of Medical Physics,2018, V ol 15, P 261

90.  Evaluation of effect of gold nanorods and spherical gold nanoparticles of different sizes on X-ray attenuation in computed tomography

Sara Khademi, Hossein Ghadiri, Saeed Sarkar, Sharmin Kharrazi, Seyed Mohammad Amini, Ali Shakeri-Zadeh, Mohammad Reza Ay
Peer-reviewed Journal Publication
Iranian Journal of Medical Physics,2018, Vol 15, P 354

91.  Evaluation of multifunctional targeted gold nanoparticles on X-ray attenuation in nasopharyngeal cancer cells by X-ray imaging

Sara Khademi, Hossein Ghadiri, Saeed Sarkar, Ali Shakerizadeh, Neda Attaran, Sharmin Kharrazi, Mohammad Reza Ay
Peer-reviewed Journal Publication
Iranian Journal of Medical Physics, 2018, Vol 15, P 355

92.  Fast System Matrix Calculation in CT Iterative Reconstruction

Golshan Mahmoudi, Mohammad Reza Ay, Hossein Ghadiri
Peer-reviewed Journal Publication
Iranian Journal of Medical Physics, 2018, Vol 15, P 150-150

93.  Recovery of missing data in partial geometry PET scanners: Compensation in projection space vs image space

Seyedehsamaneh Shojaeilangari, C Ross Schmidtlein, Arman Rahmim, Mohammad Reza Ay
Peer-reviewed Journal Publication
Medical physics, 2018, Vol 45, P5437-5449

94.  Impact of image reconstruction methods on quantitative accuracy and variability of FDG-PET volumetric and textural measures in solid tumors

Ali Ketabi, Pardis Ghafarian, Mohammad Amin Mosleh-Shirazi, Seyed Rabi Mahdavi, Arman Rahmim, Mohammad Reza Ay
Peer-reviewed Journal Publication
European radiology,2018,pp1-11

95.  F-18-PSMA vs. Ga-68-PSMA11; S-value Estimation in XCAT BMIs Using GATE Monte Carlo Code

M Fallahpoor, N Vahidfar, G Divband, F Kalantari, M Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING,2018, Vol 45,P S737-S737

96.  Monte Carlo simulation of MAMMI PET system and performance evaluation using GATE toolkit

A Emami, H Ghadiri, P Ghafarian, P Geramifar, M Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING,2018, Vol 45, P S714-S714

97.  Uncertainties in effective dose estimation for CT transmission scan in total body PET-CT imaging with Auto mA3D tube current modulation

Y Salimi, MR Deevband, P Ghafarian, MR Ay
Peer-reviewed Journal Publication
International Journal of Radiation Research, Vol 16, p 465-472

98.  Folic acid-cysteamine modified gold nanoparticle as a nanoprobe for targeted computed tomography imaging of cancer cells

Sara Khademi, Saeed Sarkar, Ali Shakeri-Zadeh, Neda Attaran, Sharmin Kharrazi, Mohammad Reza Ay, Hossein Ghadiri
Peer-reviewed Journal Publication
Materials Science and Engineering: C,2018 ,Vol.89

99.  Reconstruction/segmentation of attenuation map in TOF-PET based on mixture models

Hamidreza Hemmati, Alireza Kamali-Asl, Pardis Ghafarian, Mohammad Reza Ay
Peer-reviewed Journal Publication
Annals of nuclear medicine, 2018, Vol.26, pp 1-11

100.  Capturing Bone Signal in MRI of Pelvis, as a Large FOV Region, Using TWIST Sequence and Generating a 5-Class Attenuation Map for Prostate PET/MRI Imaging

Mehdi Shirin Shandiz, Hamid Saligheh Rad, Pardis Ghafarian, Khadijeh Yaghoubi, Mohammad Reza Ay
Peer-reviewed Journal Publication
Molecular imaging, 2018, Vol 17

101.  Concept design and Monte Carlo performance evaluation of HeadphonePET: a novel brain-dedicated PET system based on partial cylindrical detectors

P Sheikhzadeh, H Sabet, H Ghadiri, P Geramifar, P Ghafarian, MR Ay
Peer-reviewed Journal Publication
Journal of Instrumentation, 2018, Vol 13 ,P07008

102.  An alternative mathematical modeling of the scintillation camera and framework for performance analysis of gamma-ray positioning algorithms

Behnoosh Teimourian Fard, Mojtaba Shamsaei Zafarghandi, Soheil Hosseini, Hamid Sabet, Mohammad Reza Ay
Peer-reviewed Journal Publication
Iranian Journal of Nuclear Medicine, 2018, v.26, P.112-126

103.  The influence of using different reconstruction algorithms on sensitivity of quantitative 18F-FDG-PET volumetric measures to background activity variation

Ali Ketabi, Pardis Ghafarian, Mohammad Amin Mosleh-Shirazi, Seyed Rabi Mahdavi, Mohammad Reza Ay
Peer-reviewed Journal Publication
Iranian Journal of Nuclear Medicine, 2018, Vol.26, pp 87-97

104.  Mixture model based joint-MAP reconstruction of attenuation and activity maps in TOF-PET

H Hemmati, A Kamali-Asl, P Ghafarian, MR Ay
Peer-reviewed Journal Publication
Journal of Instrumentation, 2018, Vol.13

105.  Cardiac contraction motion compensation in gated myocardial perfusion SPECT: A comparative studyRobotic system for SPECT imaging

Narges Salehi, Arman Rahmim, Emad Fatemizadeh, Afshin Akbarzadeh, Mohammad Hossein Farahani, Saeed Farzanefar, Mohammad Reza Ay
Peer-reviewed Journal Publication
Physica Medica, 2018, Vol.49, pp 77-82

106.  Generic high resolution PET detector block using 12× 12 SiPM array

Salar Sajedi, Navid Zeraatkar, Mohsen Taheri, Sanaz Kaviani, Hadi Khanmohammadi, Saeed Sarkar, Hamid Sabet, Mohammad Reza Ay
Peer-reviewed Journal Publication
Biomedical Physics & Engineering Express, 2018, Vol 4

107.  A novel dual energy method for enhanced quantitative computed tomography

A Emami, H Ghadiri, A Rahmim, MR Ay
Peer-reviewed Journal Publication
Journal of Instrumentation, 2018, Vol.13

108.  Evaluation of size, morphology, concentration, and surface effect of gold nanoparticles on X-ray attenuation in computed tomography

Sara Khademi, Saeed Sarkar, Sharmin Kharrazi, Seyed Mohammad Amini, Ali Shakeri-Zadeh, Mohammad Reza Ay, Hossein Ghadiri
Peer-reviewed Journal Publication
Physica Medica, 2018, Vol 45,pp 127-133

109.  Evaluating the Impact of Various Parameters on the Gamma Index Values of 2D Diode Array in IMRT Verification

Keyvan Jabbari, Fakhereh Pashaei, Mohammad R Ay, Alireza Amouheidari, Mohammad B Tavakoli
Peer-reviewed Journal Publication
Journal of medical signals and sensors, Vol 8 , P31-38

110.  Is correction for metallic artefacts mandatory in cardiac SPECT/CT imaging in the presence of pacemaker and implantable cardioverter defibrillator leads?

Zahra Etemadi, Pardis Ghafarian, Ahmad Bitarafan-Rajabi, Hadi Malek, Mohammad Reza Ay
Peer-reviewed Journal Publication
Iranian Journal of Nuclear Medicine, 2018, Vol 26, P 35-46

111.  Quantification and Reduction of Respiratory Induced Artifact in Attenuation Correction of PET Data using Respiration Averaged CT: A Simulation and Phantom Study

Fatemeh Sadat Fatemi Nasrollahi, Pardis Ghafarian, Parham Grramifar, Mohammad Reza Ay
Peer-reviewed Journal Publication
Frontiers in Biomedical Technologies, 2017, Vol 3, pp 49-59

112.  Quantification and reduction of respiratory induced artifacts in positron emission tomography/computed tomography using the time-of-flight technique

Roya Sharifpour, Pardis Ghafarian, Arman Rahmim, Mohammad R Ay
Peer-reviewed Journal Publication
Nuclear medicine communications

113.  A Generic, Scalable, and Cost-Effective Detector Front-End Block for PET

Salar Sajedi, Navid Zeraatkar, Mohsen Taheri, Sanaz Kaviani, Hadi Khanmohammadi, Saeed Sarkar, Hamid Sabet, MR Ay
Proceeding and Conference Record
2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), P 1-3

114.  Development of a Preclinical PET System Based on Pixelated LYSO Crystals and SiPM Arrays

Navid Zeraatkar, Salar Sajedi, Sanaz Kaviani, Mohsen Taheri, Hadi Khanmohammadi, Saeed Sarkar, Mohammad Reza Ay
Proceeding and Conference Record
2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), P 1-3

115.  A Comparison Study on Two Novel Statistical Reconstruction Algorithms Developed for Slit-Hole Collimation Data in Small Animal SPECT Imaging

H Mahani, G Raisali, A Kamali-Asl, M Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, 2017, Vol 44, P S434-S434

116.  Cardiac contraction motion compensation in gated Myocardial Perfusion SPECT

N Salehi, M Farahani, E Fatemizadeh, S Farzanefar, M Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, 2017

117.  Design optimization of partial cylindrical PET scanner based on trapezoid-shaped block detector and monolithic crystals using Monte Carlo simulation

P Sheikhzadeh, H Ghadiri, P Geramifar, P Ghaffarian, M Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, 2017

118.  Development of low dose CT protocols with acceptable CT image quality for CTAC of PET data: Phantom Study

Z Mojabi, P Ghafarian, H Ghadiri, M Bakhshayeshkaram, M Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, 2017

119.  Evaluation of the Impact of Using TOF Technique on Metal Artifact Reduction in PET/CT Images

R Sharifpour, P Ghafarian, MR Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, 2017

120.  Grid block design based on monte carlo simulated dosimetry, the linear quadratic and Hug–Kellerer radiobiological models

Somayeh Gholami, Hassan Ali Nedaie, Francesco Longo, Mohammad Reza Ay, Sharifeh A Dini, Ali S Meigooni
Peer-reviewed Journal Publication
Journal of medical physics, 2017, Vol 42, pp 213

121.  Is the averaged SUV from several hottest voxels an alternative to SUV peak for quantification of large heterogeneous or small lesions in oncological PET imaging?

A Ketabi, P Ghafarian, S Masjoodi, MA Mosleh-Shirazi, MR Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, 2017

122.  Monte Carlo Based Performance estimation of breast PET due to reduction of the ring diameter

A Emami, H Ghadiri, P Ghafarian, M Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, 2017

123.  Optimal quantitative SUV metrics over wide range of lesion sizes in advanced image reconstruction (TOF and PSF) for PET

I Shiri, P Ghafarian, S Ashrafinia, A Bitarafan-Rajabi, M Ay, A Rahmim
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, 2017, Vol 44, P S427-S428

124.  Optimization of the crystal thickness for a monolithic LYSO animal PET detector with anger and CSE positioning method using Monte Carlo simulation

A Sanaat, M Shamsaie, B Teymorian, R Hoshemi, M Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, 2017, Vol 44, p 431-432

125.  Quantification and Reduction of respiratory induced errors in attenuation correction of PET data using respiration averaged CT: a simulation study

P Ghaffarian, F Fatemi, P Geramifar, M Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, 2017

126.  Simultaneous High-Sensitivity High-Resolution Molecular SPECT Imaging with Spinning Slit-Hole Collimator: A Monte Carlo Simulation Study

M Ay, H Mahani, G Raisali, A Kamali-Asl
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, 2017, Vol 44, P S389-S390

127.  Sub-centimeter lesion detectability in Point-spread function (PSF) and Time of flight (TOF) reconstructed PET images

I Shiri, P Ghafarian, A Bitarafan-Rajabi, M Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, 2017, Vol 44, P S438-S439

128.  The Influence of Crystal Material and Size on the Sensitivity of Recently Developed SiPM Based Animal PET Scanner: a Monte Carlo Study

P Ghahramani, N Zeraatkar, N Vosoughi, MR Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, 2017, Vol 44, PS429-S430

129.  Volume-based assessment of different image reconstruction algorithms and thresholds for FDG-PET/CT based on dose-painting concept

P Ghafarian, A Ketabi, MA Mosleh-Shirazi, MR Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, 2017, Vol 44, P S758-S758

130.  Compton scatter tomography in TOF-PET

Hamidreza Hemmati, Alireza Kamali-Asl, Mohammadreza Ay, Pardis Ghafarian
Peer-reviewed Journal Publication
Physics in Medicine & Biology,2017, Vol 62, pp 7641

131.  Development and calibration of a new gamma camera detector using large square Photomultiplier Tubes

N Zeraatkar, S Sajedi, B Teimourian Fard, S Kaviani, A Akbarzadeh, MH Farahani, S Sarkar, MR Ay
Peer-reviewed Journal Publication
Journal of Instrumentation,2017, Vol 12

132.  Development and validation of an accurate GATE model for NeuroPET scanner

Peyman Sheikhzadeh, Hamid Sabet, Hossein Ghadiri, Parham Geramifar, Hojjat Mahani, Pardis Ghafarian, Mohammad Reza Ay
Peer-reviewed Journal Publication
Physica Medica, 2017,Vol.40, pp59-65

133.  Spinning slithole collimation for high-sensitivity small animal SPECT: Design and assessment using GATE simulation

Hojjat Mahani, Gholamreza Raisali, Alireza Kamali-Asl, Mohammad Reza Ay
Peer-reviewed Journal Publication
Physica Medica, 2017, Vol 40, pp 42-50

134.  Implementation of absolute quantification in small‐animal SPECT imaging: Phantom and animal studies

Shabnam Khorasani Gerdekoohi, Naser Vosoughi, Kaveh Tanha, Majid Assadi, Pardis Ghafarian, Arman Rahmim, Mohammad Reza Ay
Peer-reviewed Journal Publication
Journal of applied clinical medical physics, 2017, Vol 18, pp 215-223

135.  How crystal configuration affects the position detection accuracy in pixelated molecular SPECT imaging systems?

Hojjat Mahani, Gholamreza Raisali, Alireza Kamali-Asl, Mohammad Reza Ay
Peer-reviewed Journal Publication
Nuclear Science and Techniques, 2017, Vol 28, pp 47

136.  Implementation of absolute quantification in small-animal SPECT imaging: Phantom and animal studies

Shabnam Khorasani Gerdekoohi, Naser Vosoughi, Kaveh Tanha, Majid Assadi, Pardis Ghafarian, Arman Rahmim, Mohammad Reza Ay
Peer-reviewed Journal Publication
MEDICAL IMAGING, 2017, pp 1-9

137.  Evaluation of radiation exposure to staff and environment dose from [18F]-FDG in PET/CT and cyclotron center using thermoluminescent dosimetry

S Zargan, P Ghafarian, A Shabestani Monfared, AA Sharafi, M Bakhshayeshkaram, MR Ay
Peer-reviewed Journal Publication
Journal of biomedical physics & engineering, 2017,Vol 7

138.  Quantification of the impact of TOF and PSF on PET images using the noise-matching concept: clinical and phantom study

M Shekari, P Ghafarian, S Ahangari, MR Ay
Peer-reviewed Journal Publication
Nuclear Science and Techniques, 2017, Vol 28, pp 167

139.  Collimator-Detector Response Compensation in Molecular SPECT Reconstruction using STIR Framework?

Hojjat Mahani, Gholamreza Raisali, Alireza Kamali-Asl, Mohammad Reza Ay
Peer-reviewed Journal Publication
Iranian Journal of Nuclear Medicine and Molecular Imaging, 2017, Vol 25, pp 26-34

140.  Impact of Time-of-Flight and Point-Spread-Function for Respiratory Artifact Reduction in PET/CT Imaging: Focus on Standardized Uptake Value

Roya Sharifpour, Pardis Ghafarian, Mehrdad Bakhshayesh-Karam, Hamidreza Jamaati, Mohammad Reza Ay
Peer-reviewed Journal Publication
Tanaffos ,2017,Vol 16, pp 127

141.  Monte Carlo optimization of crystal configuration for pixelated molecular SPECT scanners

Hojjat Mahani, Gholamreza Raisali, Alireza Kamali-Asl, Mohammad Reza Ay
Peer-reviewed Journal Publication
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2017, Vol 844, pp 1-6

142.  Single STE-MR Acquisition in MR-Based Attenuation Correction of Brain PET Imaging Employing a Fully Automated and Reproducible Level-Set Segmentation Approach

Anahita Fathi Kazerooni, Mohammad Reza Ay, Saman Arfaie, Parisa Khateri, Hamidreza Saligheh Rad
Peer-reviewed Journal Publication
Molecular Imaging & Biology, 2017, Vol 19, pp 143-152

143.  A hybrid tracking system for image-guided spine surgery using a tracked mobile C-arm: a phantom study

P. Ghobadi, A. Ahmadian, H. saberi, M.R. Ay, M. Addolghafar and K. Amini
Peer-reviewed Journal Publication
Turk J Elec Eng & Comp Sci, 2017, Vol. 25, pp 434-448.

144.  Development and Evaluation of Image Reconstruction Algorithms for a Novel Desktop SPECT System

Navid Zeraatkar, Arman Rahmim, Saeed Sarkar, Mohammad Reza Ay
Peer-reviewed Journal Publication
Asia Oceania Journal of Nuclear Medicine and Biology,2017, Vol 5,pp 120

145.  New approach for calibration of pixelated scintillation detectors of intraoperative gamma cameras

Afshin Akbarzadeh, Valiallah Saba, Mohammad Reza Ay
Peer-reviewed Journal Publication
Iranian Journal of Nuclear Medicine and Molecular Imaging, 2017, Vol. 25, No. 1, pp 34-42.

146.  MR-guided attenuation map for prostate PET-MRI: an intensity and morphologic-based segmentation approach for generating a five-class attenuation map in pelvic region

M. Shandiz, H. Saligeh Rad, P. Ghafarian, M. Bakhshaysh Karam and M.R. Ay
Peer-reviewed Journal Publication
Ann Nucl Med. 2017, Vol 31, pp 29-39

Abstract:

PURPOSE:

Prostate imaging is one of the major application of hybrid PET/MRI systems. Inaccurate attenuation maps (µ-maps) derived by direct segmentation (SEG) in which the cortical bone is ignored and the volume of the air in cavities is underestimated is the main challenge of commercial PET/MRI systems for the quantitative analysis of the pelvic region. The present study considered the cortical bone and air cavity along with soft tissue, fat, and background air in the µ-map of the pelvic region using a method based on SEG. The proposed method uses a dedicated imaging technique that increases the contrast between regions and a hybrid segmentation method to classify MR images based on intensity and morphologic characteristics of tissues, such as symmetry and similarity of bony structures.

PROCEDURES:

Ten healthy volunteers underwent MRI and ultra-low dose CT imaging. The dedicated MR imaging technique uses the short echo time (STE) based on the conventional sequencing implemented on a clinical 1.5T MRI scanner. The generation of a µ-map comprises the following steps: (1) bias field correction; (2) hybrid segmentation (HSEG), including segmenting images into clusters of cortical bone-air, soft tissue, and fat using spatial fuzzy c-means (SFCM), and separation of cortical bone and internal air cavities using morphologic characteristics; (3) the active contour approach for the separation of background air; and (4) the generation of a five-class μ-map for cortical bone, internal air cavity, soft tissue, fat tissue, and background air. Validation was done by comparison with segmented CT images.

RESULTS:

The Dice and sensitivity metrics of cortical bone structures and internal air cavities were 72 ± 11 and 66 ± 13 and 73 ± 10 and 68 ± 20 %, respectively. High correlation was observed between CT and HSEG-based µ-maps (R 2 > 0.99) and the corresponding sinograms (R 2 > 0.98).

CONCLUSIONS:

Currently, pelvis µ-maps provided by the current PET/MRI systems and the ultra-short echo time and atlas-based methods tend to be inaccurate. The proposed method acceptably generated a five-class μ-map using only one image.

KEYWORDS:

MRI-base attenuation correction; Morphologic characteristics-based segmentation; PET/MRI; Prostate imaging; STE pulse sequence

147.  Development and characterization of a compact hand-held gamma probe system, SURGEOGUIDE, based on NEMA NU3-2004 standards

S. Kaviani, N. Zeraatkar,S. Sajedi, N. Gorjizadeh, M.H. Farahani, P. Ghafarian,G. El Fakhri, H. Sabete and M.R. Ay
Peer-reviewed Journal Publication
Journal of Instrumentation, 2016, Vol 11

148.  Effect of TOF and PSF in detection of lymph node metastases in head and neck of PET/CT images

P Ghafarian, A Ketabi, A Doroudinia, M Bakhshayesh Karam, MR Ay
Proceeding and Conference Record
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING, 2016, Vol 43, pp s507

149.  Design and development of a dedicated portable gamma camera system for intra-operative imaging

S. Kaviani, N. Zeraatkar, S. Sajedi, A. Akbarzadeh, N. Gorjizadeh, M. H. Farahani, B. Teimourian, P. Ghafarian, H. Sabet and M.R. Ay
Peer-reviewed Journal Publication
Phys Med. 2016 Jul;32(7):889-97. doi: 10.1016/j.ejmp.2016.06.004. Epub 2016 Jun 23

Abstract

PURPOSE:

We developed a high performance portable gamma camera platform dedicated to identification of sentinel lymph nodes (SLNs) and radio-guided surgery for cancer patients. In this work, we present the performance characteristics of SURGEOSIGHT-I, the first version of this platform that can intra-operatively provide high-resolution images of the surveyed areas.

METHODS:

At the heart of this camera, there is a 43×43 array of pixelated sodium-activated cesium iodide (CsI(Na)) scintillation crystal with 1×1mm(2) pixel size and 5mm thickness coupled to a Hamamatsu H8500 flat-panel multi-anode (64 channels) photomultiplier tube. The probe is equipped with a hexagonal parallel-hole lead collimator with 1.2mm holes. The detector, collimator, and the associated front-end electronics are encapsulated in a common housing referred to as head.

RESULTS:

Our results show a count rate of ∼41kcps for 20% count loss. The extrinsic energy resolution was measured as 20.6% at 140keV. The spatial resolution and the sensitivity of the system on the collimator surface was measured as 2.2mm and 142cps/MBq, respectively. In addition, the integral and differential uniformity, after uniformity correction, in useful field-of-view (UFOV) were measured 4.5% and 4.6%, respectively.

CONCLUSIONS:

This system can be used for a number of clinical applications including SLN biopsy and radiopharmaceutical-guided surgery.

Keywords:

Sentinel lymph node (SLN), Lymphoscintigraphy, SURGEOSIGHT-I, Breast cancer, Intra-operative gamma camera

150.  Design, optimization and performance evaluation of BM-PET: A simulation study

Peyman Sheikhzadeh, Hamid Sabet, Hossein Ghadiri, Parham Geramifar, Pardis Ghafarian, Mohammad Reza Ay
Peer-reviewed Journal Publication
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

151.  Design and Assessment of a Novel SPECT System for Desktop Open-Gantry Imaging of Small Animals: a Monte Carlo Study

N. Zeraatkar, M. H. Farahani, S. Sarkar, A. Rahmim and M.R. Ay
Peer-reviewed Journal Publication
Med Phys. 2016 May;43(5):2581. doi: 10.1118/1.4947127

Abstract

PURPOSE:

Given increasing efforts in biomedical research utilizing molecular imaging methods, development of dedicated high-performance small-animal SPECT systems has been growing rapidly in the last decade. In the present work, we propose and assess an alternative concept for SPECT imaging enabling desktop open-gantry imaging of small animals.

METHODS:

The system, PERSPECT, consists of an imaging desk, with a set of tilted detector and pinhole collimator placed beneath it. The object to be imaged is simply placed on the desk. Monte Carlo (MC) and analytical simulations were utilized to accurately model and evaluate the proposed concept and design. Furthermore, a dedicated image reconstruction algorithm, finite-aperture-based circular projections (FABCP), was developed and validated for the system, enabling more accurate modeling of the system and higher quality reconstructed images. Image quality was quantified as a function of different tilt angles in the acquisition and number of iterations in the reconstruction algorithm. Furthermore, more complex phantoms including Derenzo, Defrise, and mouse whole body were simulated and studied.

RESULTS:

The sensitivity of the PERSPECT was 207 cps/MBq. It was quantitatively demonstrated that for a tilt angle of 30°, comparable image qualities were obtained in terms of normalized squared error, contrast, uniformity, noise, and spatial resolution measurements, the latter at ∼0.6 mm. Furthermore, quantitative analyses demonstrated that 3 iterations of FABCP image reconstruction (16 subsets/iteration) led to optimally reconstructed images.

CONCLUSIONS:

The PERSPECT, using a novel imaging protocol, can achieve comparable image quality performance in comparison with a conventional pinhole SPECT with the same configuration. The dedicated FABCP algorithm, which was developed for reconstruction of data from the PERSPECT system, can produce high quality images for small-animal imaging via accurate modeling of the system as incorporated in the forward- and back-projection steps. Meanwhile, the developed MC model and the analytical simulator of the system can be applied for further studies on development and evaluation of the system.

152.  Is Grid Therapy Useful for all Tumors and Every Grid Block Design?

S. Gholami, H. Nedaie, F. Longo, M. R. Ay, S. Wright and A. S. Meigooni
Peer-reviewed Journal Publication
J Appl Clin Med Phys. 2016 Mar 8;17(2):6015

Abstract

Grid therapy is a treatment technique that has been introduced for patients with advanced bulky tumors. The purpose of this study is to investigate the effect of the radiation sensitivity of the tumors and the design of the grid blocks on the clinical response of grid therapy. The Monte Carlo simulation technique is used to determine the dose distribution through a grid block that was used for a Varian 2100C linear accelerator. From the simulated dose profiles, the therapeutic ratio (TR) and the equivalent uniform dose (EUD) for different types of tumors with respect to their radiation sensitivities were calculated. These calculations were performed using the linear quadratic (LQ) and the Hug-Kellerer (H-K) models. The results of these calculations have been validated by comparison with the clinical responses of 232 patients from different publications, who were treated with grid therapy. These published results for different tumor types were used to examine the correlation between tumor radiosensitivity and the clinical response of grid therapy. Moreover, the influence of grid design on their clinical responses was investigated by using Monte Carlo simulations of grid blocks with different hole diameters and different center-to-center spacing. The results of the theoretical models and clinical data indicated higher clinical responses for the grid therapy on the patients with more radioresistant tumors. The differences between TR values for radioresistant cells and radiosensitive cells at 20 Gy and 10 Gy doses were up to 50% and 30%, respectively. Interestingly, the differences between the TR values with LQ model and H-K model were less than 4%. Moreover, the results from the Monte Carlo studies showed that grid blocks with a hole diameters of 1.0 cm and 1.25 cm may lead to about 19% higher TR relative to the grids with hole diameters smaller than 1.0 cm or larger than 1.25 cm (with 95% confidence interval). In sum-mary, the results of this study indicate that grid therapy is more effective for tumors with radioresistant characteristics than radiosensitive tumors.

153.  Reduction of Respiratory Induced Artefact in PET/CT Images using TOF Reconstruction

R. Sharif Pour, P. Ghafarian, A. Doroudinia, M. Bakhshayesh Karam and M. R. Ay
Published Abstract
ACNM 2016

Abstract

Objectives:

The aim of this study was to investigate the effect of time-of-flight (TOF) and point-spread function (PSF) for quantitative and qualitative PET/CT image analysis in relation to decrease respiratory artifact in diaphragmatic region.

Methods:

29 patients with uptake time 61±2 min and injection of 327.5 MBq (range 261–350 MBq) 18F-FDG were scanned with Discovery 690 GE PET/CT scanner, equipped with 64-slice CT. All of the lesions were in the diaphragmatic region including: the lung lower lobes, liver and stomach in patients with extended white band artefact. For quantitative measurement NEMA phantom were also utilized. The PET images were retrospectively reconstructed using HD (Fully 3D Iterative Reconstruction)+PSF and TOF+ PSF algorithm with various iterations, subsets and post smoothing filters. A semi-quantitative analysis was performed using SUVmax and SUVmean with 50% threshold. We also considered image quality using coefficient of variance (COV) in the liver in clinical study, the signal-to-noise ratio (SNR) and contrast to background measurements in each lesions. The PET/CT images reviewed by two expert physicians.

Results:

In the phantom study, SUVmean illustrated the more convenient value in related to SUVmax when TOF+PSF algorithm applied with increase of post filter from 4.4 mm to 6.4mm. In clinical study, the COV was decreased 7.4%±1.3% when TOF+PSF were compared with non-TOF image. The SUVmax trend to higher value with relative difference 11.3% (range: 0.5%–25.1%) when TOF and non-TOF images were evaluated. It was interesting that using appropriate TOF reconstruction parameter increased the SNR up 65.6% (Range: 7.0%–194.7%). The combination of TOF and PSF decreased the lesion size on PET images 33.0%, 25.7% and 24.5% in sagital, coronal and axial view respectively when compared with HD+PSF algorithm. According to balance among the SNR, contrast, noise and visual assessment, the optimal images were obtained with TOF+PSF with FWHM between 5.2 to 6.4 mm.

Conclusion:

A little overestimation in SUVmax versus to SUV mean 50% was observed, when PSF with combination of either VPHD or TOF was used. TOF with PSF improved white band artifact in diaphragmatic region remarkably, increased lesion delectability, and altered lesion size in PET images. It is noteworthy that the variation in SUV and lesion size is strongly dependent to the proximity of the lesions to the artefact region and it is highly recommended that to attain optimal image quality, combination of low iteration number and utilizing appropriate Gaussian filter is necessary because noise and false positive findings could be dominant with small-FWHM post filter.

154.  Hybrid Imaging, PET/CT, in HANDBOOK OF SMALL ANIMAL IMAGING, Preclinical Imaging, Therapy, and Applications

M.R. Ay and N. Ghazanfari
Book Chapter
George C. Kagadis et al. , Editors. 2016, Tylor & Francis Books, Inc.
Mohammad Reza Ay and Nafiseh Ghazanfari
Introduction to Combining MRI with PET

155.  Introducing the HeliGuide: Urea Breath Tests System for Detecting Helicobacter Pylori

Aram Radnia, MohammadHossein Farahani, C Hoorvash, MohammadReza Ay
Peer-reviewed Journal Publication
Frontiers in Biomedical Technologies,2015, Vol 2,pp 115-117

156.  How gamma camera’s head-tilts affect image quality of a nuclear scintigram?

Hojjat Mahani, Alireza Kamali-Asl, MohammadReza Ay
Peer-reviewed Journal Publication
Frontiers in Biomedical Technologies, 2015, Vol 1

157.  The influence of PET and CT misalignment due to respiratory motion on the cardiac PET/CT imaging: a simulation study

Pardis Ghafarian, MohammadReza Ay
Peer-reviewed Journal Publication
Frontiers in Biomedical Technologies,2015, Vol 1

158.  Acceptance Test of the first Hospital Cyclotron for Production of PET tracers in Iran

P. Ghafarian, S. M. Khamesi1, M. R. Golrokh Nodehi and M. R. Ay
Published Abstract
World Congress on Medical Physics & Biomedical Engineering, 7-12 June 2015, Toronto, Canada, p 518

159.  An alternate mathematical modeling of image formation, and framework for performance analysis of positioning algorithms in the scintillation camera

S. Hosseini, M. H. Farahani and M. R. Ay
Published Abstract
World Congress on Medical Physics & Biomedical Engineering, 7-12 June 2015, Toronto, Canada, p 103

160.  Can Pacemaker and ICD degrade CT-Based Attenuation Corrected cardiac SPECT images?

Z. Etemadi, A. Bitaran Rajabi, H. Malek, P. Ghafarian, N. Zeraatkar and M.R. Ay
Published Abstract
World Congress on Medical Physics & Biomedical Engineering, 7-12 June 2015, Toronto, Canada, p 132

161.  Correction of Metal Artefacts Induced from Pacemaker and ICD Leads in CT-Based Attenuation Correction of Cardiac SPECT data

M. R. Ay, Z. Etemadi, A. Bitarafan-Rajabi, H. Malek, N. Zeraatkar and P. Ghafarian
Published Abstract
World Congress on Medical Physics & Biomedical Engineering, 7-12 June 2015, Toronto, Canada, p 522

162.  Design, modeling and performance evaluation of a small animal Micro-CT scanner: A Monte Carlo study

S. Nezhaddehghani1, S. Sarkar, and M. R. Ay
Published Abstract
World Congress on Medical Physics & Biomedical Engineering, 7-12 June 2015, Toronto, Canada, p 97

163.  Generating a four-class attenuation map for MR-based attenuation correction of PET data in pelvis region using an automatic segmentation protocol

H. Saligheh Rad, M. Shirin Shandiz, P. Ghafarian, M. H. Arabi, M. Bakhshayeshkaram, N. Shafiei and M. R. Ay
Published Abstract
World Congress on Medical Physics & Biomedical Engineering, 7-12 June 2015, Toronto, Canada, p 201

164.  Generation of 4-Class Attenuation Map for MRI Based Attenuation Correction of PET Data in the Head Area Using a Novel Combination of STE/DIXON-MRI and FCM Clustering

P. Khateri, H. Saligheh Rad, A. Homayoun Jafari, A. Fathi, A. Akbarzadeh, M. Shojae Moghadam, A. Aryan, P. Ghafarian and M.R. Ay
Published Abstract
World Congress on Medical Physics & Biomedical Engineering, 7-12 June 2015, Toronto, Canada, p 371

165.  Impact of Point spread function modeling on tumor quantification in clinical PET/CT imaging

S. Ahangari1, P. Ghafarian, M. Bakhshayeshkaram and M. R. Ay
Published Abstract
World Congress on Medical Physics & Biomedical Engineering, 7-12 June 2015, Toronto, Canada, p 133

166.  Measurement of Photon and Neutron Dose Distribution in Cyclotron Bunker During F18 and N13 Production

P. Ghafarian, S. M. Khamesi, M. R. Golrokh Nodehi and M.R. Ay
Published Abstract
World Congress on Medical Physics & Biomedical Engineering, 7-12 June 2015, Toronto, Canada, p 606

167.  Monte Carlo Simulation of X-ray Spectra in Computed Tomography Scanner using GATE

M. R. Ay, S. Nezhaddehghani1, and S. Sarkar
Published Abstract
World Congress on Medical Physics & Biomedical Engineering, 7-12 June 2015, Toronto, Canada, p 331

168.  Optimal Pixelated Crystal for a Molecular SPECT Scanner: A GATE Monte Carlo Study

M. R. Ay, H. Mahani, G. Raisali, and A. Kamali-Asl
Published Abstract
World Congress on Medical Physics & Biomedical Engineering, 7-12 June 2015, Toronto, Canada, p 200

169.  Spinning Knife-Edge Slit-Hole: a Novel Collimation for High-Sensitivity Molecular SPECT

H. Mahani, G. Raisali, A. Kamali-Asl and M.R. Ay
Published Abstract
World Congress on Medical Physics & Biomedical Engineering, 7-12 June 2015, Toronto, Canada, p 200

170.  The Impact of time of flight algorithm and PSF modeling on standard uptake value in clinical PET/CT imaging

M. Shekari, P. Ghafarian, M. Bakhshayeshkaram and M. R. Ay
Published Abstract
World Congress on Medical Physics & Biomedical Engineering, 7-12 June 2015, Toronto, Canada, p 132

171.  TLD Measurement of Absorbed Dose of Workers in PET/CT Department

P. Ghafarian, S. Zargan, A. Shabestani Monfared, A. Sharafi, M. Bakhshayeshkaram and M.R. Ay
Published Abstract
World Congress on Medical Physics & Biomedical Engineering, 7-12 June 2015, Toronto, Canada, p109

172.  Generation of MR-Based Attenuation Correction Map of PET Images in the Brain Employing Joint segmentation of Skull ans Soft and Soft-Tissue from Single Short-0TE MR Imaging

Anahita Fathi Kazeroni, Mohammad Hadi Arabi, M.R.Ay
Book Chapter
Spring International Publishing Switzerland, 2015

173.  An optimal Grid block design for spatially fractionated radiation therapy

S. Gholami S , H. Nedaie, F. Longo, M. R. Ay, AS. Meigooni
Published Abstract
ESTRO 2015

174.  Generation of a Four-Class Attenuation Map for MRI-Based Attenuation Correction of PET Data in the Head Area Using a Novel Combination of STE/Dixon-MRI and FCM Clustering

P. Khateri, H. Saligheh Rad, A. H. Jafari, A. Fathi Kazerooni, A. Akbarzadeh, M. Shojae Moghadam, A. Aryan, P. Ghafarian, M. R. Ay
Peer-reviewed Journal Publication
Mol Imaging Biol. 2015 Dec;17(6):884-92. doi: 10.1007/s11307-015-0849-1

Abstract

PURPOSE:

The aim of this study is to generate a four-class magnetic resonance imaging (MRI)-based attenuation map (μ-map) for attenuation correction of positron emission tomography (PET) data of the head area using a novel combination of short echo time (STE)/Dixon-MRI and a dedicated image segmentation method.

PROCEDURES:

MR images of the head area were acquired using STE and two-point Dixon sequences. μ-maps were derived from MRI images based on a fuzzy C-means (FCM) clustering method along with morphologic operations. Quantitative assessment was performed to evaluate generated MRI-based μ-maps compared to X-ray computed tomography (CT)-based μ-maps.

RESULTS:

The voxel-by-voxel comparison of MR-based and CT-based segmentation results yielded an average of more than 95 % for accuracy and specificity in the cortical bone, soft tissue, and air region. MRI-based μ-maps show a high correlation with those derived from CT scans (R (2) > 0.95).

CONCLUSIONS:

Results indicate that STE/Dixon-MRI data in combination with FCM-based segmentation yields precise MR-based μ-maps for PET attenuation correction in hybrid PET/MRI systems.

KEYWORDS:

Attenuation correction; Attenuation map; FCM technique; PET/MRI; STE pulse sequence

175.  Impact of the Radiation Sensitivity of Tumor and Geometric Design of the GRID Block On the Clinical Response of Grid Therapy

S. Gholami, AS. Meigooni, H. Nedaie, F. Longo M. R. Ay
Published Abstract
Med. Phys. 42, 3440 (2015); http://dx.doi.org/10.1118/1.4924823

Abstract

Purpose:

The spatially fractionated radiation therapy (Grid therapy) is a novel technique that has been recently introduced for treatments of the patients with advanced bulky tumors. The purpose of this study is to investigate the effect of the radiation sensitivity of tumor and Grid block design on the clinical response of the Grid therapy.

Methods:

The Geant4 toolkit is used to simulate a Varian2100C linear accelerator with the block-based Grid. The dose profile has been utilized to calculate the Therapeutic Ratio (TR) and Equivalent Uniform Dose (EUD) for different types of tumors. These calculations were performed with respect to their radiation sensitivities using Linear Quadratic model (LQ). Clinical responses of few hundred patients from different publications that were treated with Grid therapy, have been used to validate correlation between tumor radiation sensitivity and clinical response of Grid therapy. Moreover, the influence of Grid design on clinical response of this radiation technique was investigated with using Monte Carlo simulation of a Grid block with different hole-diameters of 0.5 cm, 0.75 cm, 1.25 cm, and 1.5 cm. The Geometrical Sparing Factor (GSF) was considered to compare the results from different Grid designs.

Results:

The higher clinical response of Grid therapy for more radio-resistant tumors was confirmed in both theoretical assumptions and clinical outcomes. In addition, the results indicate that the Grid hole diameter have more effect on increasing the TR in comparison with the hole center-to-center distance effect. From this Monte Carlo study, a Grid design with the hole diameter between 1.25 cm and 1.5 cm with GSF value of 0.90 is recommended.

Conclusion:

Grid Therapy is more effective for more radio-resistant tumors.The optimum results of the Grid therapy depend on selection of the appropriate Grid design.This study is a first step toward clarifying some important aspects in a clinical response of spatially fractionated radiation therapy.

176.  Monte Carlo Calculation of Neutron Doses to Organs of a Female Undergoing A Pelvic 18 MV Irradiation

M. Zabihzadeh, S.R. Mahdavi, M.R. Ay and Z. Shakarami
Peer-reviewed Journal Publication
Biomedical & Pharmacology Journal, 2015, Vol. 8, pp 65-71

177.  Monte Carlo-based Assessment of the Trade-off between Spatial Resolution, Field-of-View and Scattered Radiation in the Variable Resolution X-ray CT Scanner

H. Arabi, A.R. Kamali Asl, M. R. Ay and H. Zaidi
Peer-reviewed Journal Publication
Phys Med, 2015, Vol. 31, pp 510-516

178.  Optimizing Image Reconstruction Parameters in Time of Flight PET/CT Imaging: a Phantom Study

M. Shekari, P. Ghafarian, S. Ahangari, H. Ghadiri, M. Bakhshayeshkaram and M.R. Ay
Peer-reviewed Journal Publication
2015, Vol. 2, No. 3, pp 146-154

179.  The Effects of Backscattered Radiation into Beam Monitor Chamber: Study of 6 and 18 MV Conventional and Removed Flattening Filter Clinical Accelerator

M. Zabihzadeh, S.R. Mahdavi, M.R. Ay and Z. Shakarami
Peer-reviewed Journal Publication
BIOSCIENCES BIOTECHNOLOGY RESEARCH ASIA, 2015, Vol. 12, pp 25-36

180.  The Impact of Point Spread Function Modeling on Scan Duration in PET Imaging

S. Ahangari, P. Ghafarian, M. Shekari, H. Ghadiri, M. Bakhshayeshkaram and M.R. Ay
Peer-reviewed Journal Publication
Frontiers in Biomedical Technologies, 2015, Vol. 2, No. 3, pp 137-145

181.  Design and development of small fieldof view portable gamma camera for localization of sentinel lymph nodes

V. Moji, N. Zaratkar, S. Sajedi, A. Akbarzadeh, B. Timourian, M.H. Farahani and M. R. Ay
Published Abstract
18th Iranian Conference of Nuclear Medicine, Tehran, Iran, 12-14 November 2104, pp. 70

182.  Development of a hybrid small animal SPECT/CT scanner:a Monte Carlo study

S. Nerzhaddehghani, S. Sarkar and M.R. Ay
Published Abstract
18th Iranian Conference of Nuclear Medicine, Tehran, Iran, 12-14 November 2104, pp. 71

183.  Experimental measurement of absorbed dose using TLD for radiation workers in PET/CT department

S. Zargan, A. Monfared, P. Ghafarian, A. K. Sharafi, M. Bakhshayesh karam and M.R. Ay
Published Abstract
18th Iranian Conference of Nuclear Medicine, Tehran, Iran, 12-14 November 2104, pp. 157

184.  Monte Carlo-based characterization of HiReSPECT scanner: a dedicatd small animal SPECT imaging system

H. Mahani, G. Raisali, A. Kamali asl and M.R. Ay
Published Abstract
18th Iranian Conference of Nuclear Medicine, Tehran, Iran, 12-14 November 2104, pp. 73

185.  Optimizing the acquisition time in whole body PET/CT imaging

S. Ahanghari, P. Ghafarian, M. Sherkari, M. Bakhshayesh karam and M.R. Ay
Published Abstract
18th Iranian Conference of Nuclear Medicine, Tehran, Iran, 12-14 November 2104, pp. 75

186.  Performance evaluation of surgical gamma probe for sentinel lymph node localization based on NMA NU3-2004 standard

N. Gorjizadeh, S. Farzanehfar, A. Kaviani, N. Zeraatkar, M. H. Farhani, S. Sajesi and M.R. Ay
Published Abstract
18th Iranian Conference of Nuclear Medicine, Tehran, Iran, 12-14 November 2104, pp. 77

187.  Quantification of inter-crystal scatter and penetration in HiReSPCT: a dedicated small animal SPCT imaging systm

H. Mahani, G. Raisali, A. Kamali asl and M.R. Ay
Published Abstract
18th Iranian Conference of Nuclear Medicine, Tehran, Iran, 12-14 November 2104, pp. 78

188.  A Fully Automated and Reproducible Level-set Segmentation Approach for Generation of MR-Based Attenuation Correction Map of PET Images in the Brain Employing Single STE-MR Imaging Modality

Fathi, M. H. Arbabi, M.R. Ay and H. Saligheh Rad
Published Abstract
PSMR 2014 MR-PET Workshop, Kos Island, Greece, 19-21 May 2014, EJNMMI Physics 2014, 1(Suppl 1):A48

189.  A hybrid method for generation of attenuation map for MR-based attenuation correction of PET data in prostate PET/MR imaging

M. Shirin Shandiz, M. H. Arabi, P. Ghafarian, M. Bakhshayesh Karam , H. Saligheh Rad and M.R. Ay
Published Abstract
PSMR 2014 MR-PET Workshop, Kos Island, Greece, 19-21 May 2014, EJNMMI Physics 2014, 1(Suppl 1):A77

190.  MR-Based Attenuation Map Generation in Short-TE MR Images of the Head Employing Spatial Fuzzy C-Means Clustering Approach

M. H. Arabi, A. Fathi, P. Khateri, M.R. Ay and H. Saligheh Rad
Published Abstract
PSMR 2014 MR-PET Workshop, Kos Island, Greece, 19-21 May 2014, EJNMMI Physics 2014, 1(Suppl 1):A49

191.  A Novel Segmentation Approach for Implementation of MRAC in Head PET/MRI Employing Short-TE MRI and 2-Point Dixon Method in a Fuzzy C-Means Framework

P. Khateri, H. Saligeh Rad, A.H. Jafari and M.R. Ay
Peer-reviewed Journal Publication
Nuclear Instrumentation Methods in Physics Research A, 2014, Vol. 734, No. 8, pp 171-174

192.  Classification of bones from MR images in torso PET-MR imaging using a statistical shape model

M. R. Ay, A. Akbarzadeh, A. Ahmadian and H. Zaidi
Peer-reviewed Journal Publication
Nuclear. Instrumentation Methods in Physics Research A, 2014, Vol. 734, pp 196-200

Abstract

There have been exclusive features for hybrid PET/MRI systems in comparison with its PET/CT counterpart in terms of reduction of radiation exposure, improved soft-tissue contrast and truly simultaneous and multi-parametric imaging capabilities. However, quantitative imaging on PET/MR is challenged by attenuation of annihilation photons through their pathway. The correction for photon attenuation requires the availability of patient-specific attenuation map, which accounts for the spatial distribution of attenuation coefficients of biological tissues. However, the lack of information on electron density in the MR signal poses an inherent difficulty to the derivation of the attenuation map from MR images. In other words, the MR signal correlates with proton densities and tissue relaxation properties, rather than with electron density and, as such, it is not directly related to attenuation coefficients. In order to derive the attenuation map from MR images at 511 keV, various strategies have been proposed and implemented on prototype and commercial PET/MR systems. Segmentation-based methods generate an attenuation map by classification of T1-weighted or high resolution Dixon MR sequences followed by assignment of predefined attenuation coefficients to various tissue types. Intensity-based segmentation approaches fail to include bones in the attenuation map since the segmentation of bones from conventional MR sequences is a difficult task. Most MR-guided attenuation correction techniques ignore bones owing to the inherent difficulties associated with bone segmentation unless specialized MR sequences such as ultra-short echo (UTE) sequence are utilized. In this work, we introduce a new technique based on statistical shape modeling to segment bones and generate a four-class attenuation map. Our segmentation approach requires a torso bone shape model based on principle component analysis (PCA). A CT-based training set including clearly segmented bones of the torso region of 20 clinical studies was designed. Using this training set, a bone atlas was trained taking advantage of PCA analysis. Our active shape segmentation technique uses the trained shape model to segment bones from user defined initial seed points. The segmentation algorithm was evaluated using 10 clinical datasets (aligned MR and CT pairs). The resulting attenuation maps were compared to corresponding attenuation maps derived from CT resulting in a mean relative difference less than 7%.

Keywords:

PET/MRI; MR bone segmentation; Attenuation correction; Whole-body imaging

193.  Derivation of attenuation map for attenuation correction of PET data in the presence of nanoparticulate contrast agents using spectral CT imaging

H. Ghadiri, MB Shiran, HR Soltanian-Zadeh, A. Rahmim, H. Zaidi and M.R. Ay
Peer-reviewed Journal Publication
Annals of Nuclear Medicine, 2014, Vol. 28, No. 6, pp 559-570

194.  Design and Development of a High Resolution Animal SPECT Scanner Dedicated for Rat and Mouse Imaging

S. Sajedi , N. Zeraatkar, V. Moji, M. H. Farahani, S. Sarkar, H. Arabi, B. Teymoorian, P. Ghafarian, A. Rahmim and M.R. Ay
Peer-reviewed Journal Publication
Nuclear. Instrumentation Methods in Physics Research A, 2014, Vol. 741, pp 169-176

195.  Experimental Evaluation of the Performance of HiReSPECT Scanner: a High-Resolution SPECT System for Small Animal Imaging

A. M. Pashazadeh, K. Tanha, F. Jafarian Dehkordi, M. Assadi, V. Moji , N. Zeraatkar and M.R. Ay
Peer-reviewed Journal Publication
Frontiers in Biomedical Technologies, 2014, Vol. 1, No. 3, pp 222-227

196.  How Gamma Camera’s Head-Tilts Affect Image Quality of a Nuclear Scintigram?

H. Mahani, A. Kamali-Asl, M.R. Ay
Peer-reviewed Journal Publication
Frontiers in Biomedical Technologies, 2014, Vol. 1, No. 4, pp 265-270

197.  Performance Evaluation of Newly Developed High Resolution Dual Head Animal SPECT System Based on NEMA NU2 2007 Standard

V. Moji, N. Zeraatkar, M.H. Farahani, M. Aghamiri, S. Sajedi, B. Teymorian, P. Ghafarian , S. Sarkar and M.R. Ay
Peer-reviewed Journal Publication
J Appl Clin Med Phys, 2014, Vol. 15, No. 6, pp 267-278

198.  Positron Emission Tomography: Physics, Instrumentation, Scanners and New Horizons

M.R. Ay and P. Geramifar
Book Chapter
2014, Royan Pazhoh, Inc., Tehran, Iran, ISBN-13: 9786007108543

199.  Quantification of PET and CT misalignment errors due to bulk motion in cardiac PET/CT imaging: Phantom and clinical studies

P. Ghafarian, M.R. Ay, A. Fard-Esfahani, A. Rahmim and H. Zaidi
Peer-reviewed Journal Publication
Frontiers in Biomedical Technologies, 2014, Vol. 1, No. 3, pp 159-167

200.  Resolution-Recovery-Embedded Image Reconstruction for a High-Resolution Animal SPECT System

N. Zeraatkar, S. Sajedi, M. H. Farahani, H. Arabi, S. Sarkar, P. Ghafarian, A. Rahmim and M.R. Ay
Peer-reviewed Journal Publication
Phys Med, 2014, Vol. 30, No. 7, pp 774-781

201.  The Influence of PET and CT Misalignment due to Respiratory Motion on the Cardiac PET/CT Imaging: a Simulation Study

P. Ghafarian, M.R. Ay
Peer-reviewed Journal Publication
Frontiers in Biomedical Technologies, 2014, Vol. 1, No. 4, pp 252-257

202.  Optical Flow Based Method for Generation of Virtual Average CT: A Simulation Study Using 4D XCAT Phantom

P. Geramifar, M. Shamsaie Zafarghandi and M.R. Ay
Published Abstract
European Association of Nuclear Medicine Annual Congress, 19-23 October 2013, Lyon, France. Eur J Nucl Med Mol, Vol 20, Issue 2

203.  Performance Evaluation of a Small Field of View Portable Gamma Camera for Localization of Sentinel Lymph Nodes

N. Gorjizadeh, N. Zeraatkar, A. Kaviani, S. Farzaneh far, M. H. Farahani, A. Akbarzadeh, S. Sajedi, B. Teimourian and M.R. Ay
Published Abstract
European Association of Nuclear Medicine Annual Congress, 19-23 October 2013, Lyon, France. Eur J Nucl Med Mol, Vol 20, Issue 2

204.  SURGEOGUIDE: a Gamma Probe for Localization of Sentinel Lymph Nodes

M.R. Ay, N. Zeraatkar, N. Gorjizadeh, S. Sajedi, H. Arabi, M. H. Farahani, B. Teimourian
Published Abstract
European Association of Nuclear Medicine Annual Congress, 19-23 October 2013, Lyon, France. Eur J Nucl Med Mol, Vol 20, Issue 2

205.  The Influence of Misalignment Artifact Due to Global and Respiratory Motion on Interpretation of Cardiac PET/CT Examination: Clinical and Phantom Studies

P. Ghafarian and M.R. Ay
Published Abstract
European Association of Nuclear Medicine Annual Congress, 19-23 October 2013, Lyon, France. Eur J Nucl Med Mol, , Vol 20, Issue 2

206.  Variation in Thoracic Lesions SUVmax as a Function of Respiratory Phase Based on the Optical Flow Motion Estimation: A Simulation Study Using 4D XCAT Phantom

P. Geramifar, M. Shamsaie Zafarghandi and M.R. Ay
Published Abstract
European Association of Nuclear Medicine Annual Congress, 19-23 October 2013, Lyon, France. Eur J Nucl Med Mol, Vol 20, Issue 2

207.  K-edge ratio method for identification of multiple nanoparticulate contrast agents by spectral CT imaging

H Ghadiri, M. R. Ay , M. B. Shiran, H. R. Soltanian-Zadeh and H Zaidi
Peer-reviewed Journal Publication
Br J Radiol. 2013 Sep; 86(1029): 20130308

208.  A fast and hardware mimicking analytic CT simulator

H Ghadiri, M B Shiran, H R Soltanian-Zadeh, A Rahmim and M R Ay
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Seoul, South Korea, 2013, pp 1-5

Abstract:

Different algorithms have been utilized for x-ray computed tomography (CT) simulation based on Monte Carlo technique, analytic calculation, or combination of them. Software packages based on Monte Carlo algorithm provide sophisticated calculations but the time consuming nature of them limits its applicability. Analytic calculation for CT simulation has been also evaluated in recent years. Due to ignoring basic physical processes, analytic methods have limited applications. In this study, a hardware mimicking algorithm has been developed to accurately model the CT imaging chain using analytic calculation. The model includes x-ray spectrum generation according to the pre-defined scanning protocol. The detector is designed to acquire the data either in integral or spectral modes. CT geometry can be used as parallel or fan beam with different sizes. Poisson noise model was applied to the acquired projection data. Varieties of projection-based computerized phantoms have been designed and implemented in the simulator. CT number and background noise of the simulated images have been compared with experimental data. On average, the relative difference between simulated and experimental HUs are 8.3%, 7.5%, and 8.0% for bone; 12.1%, 10.3%, and 7.8% for contrast agent; and 16.6%, 3.6%, and 5.2% for the background at 80 kVp/500 mAs, 120 kVp/250 mAs, and 140 kVp/125 mAs, respectively. The relative difference between simulated and experimental noise values vary between 2% to slightly less than 26%. For scanning and image generation with a computer equipped with Intel Core2 Quad CPU and 2.0 GB of RAM, the simulator takes about 32 seconds for generating a 512×512 single slice image when it is adjusted to acquire 900 projection angles with 20 mm slice thickness and 140kVp/200 mAs scanning protocol. The simulation time is independent of photon intensity.

209.  A Novel Segmentation Approach for Implementation of MRAC in Head and Neck PET/MRI Imaging Employing Short-TE MRI and 2-Point Dixon Method in Fuzzy C-Means Framework

P. Khateri, H. Salighe Rad, A.H. Jafari and M.R. Ay
Published Abstract
PSMR 2013 MR-PET Workshop, Jülich, Germany, 6-7 May –2013

210.  Classification of bones from MR images in torso PET-MR imaging using a statistical shape model

M.R. Ay, Akbarzadeh A, Ahmadian and Zaidi H
Published Abstract
PSMR 2013 MR-PET Workshop, Jülich, Germany, 6-7 May –2013

211.  A new energy mapping algorithm based on spectral CT images: application in PET/CT attenuation correction

H. Ghadiri, M.B. Shiran, H.R. Soltanian-Zadeh and M.R. Ay
Published Abstract
Iranian Congress of Nuclear Medicine, Shiraz, Iran, May 1-3, 2013

212.  Performance evaluation of HiReSPECT a dedicated animal SPECT system using modified NEMA standards

V.Moji, M. Aghamiri, H. Farahani, N. Zeratkar, S. Sajedi, B. Teymorian and M.R. Ay
Published Abstract
Iranian Congress of Nuclear Medicine, Shiraz, Iran, May 1-3, 2013

213.  Spatial Resolution and System Sensitivity in a Tilted-Head Planar-SPECT: a Monte Carlo Study

H. Mahani, A. R. Kamali-Asl, V. Moslemi, M.R. Ay
Published Abstract
Iranian Congress of Nuclear Medicine, Shiraz, Iran, May 1-3, 2013

214.  3D Prior Image Constrained Projection Completion for X-ray CT Metal Artifact Reduction

A. Mehranian, M. R. Ay, A. Rahmim and H. Zaidi
Peer-reviewed Journal Publication
IEEE Trans Nuclear Sciences, 2013, Vol. 60, No. 5, pp 3318-3332

215.  A novel non-linear recursive filter design for extracting high rate pulse features in nuclear medicine imaging and spectroscopy

S. Sajedi, A. Kamali Asl, M. R. Ay, M.H. Farahani and A. Rahmim
Peer-reviewed Journal Publication
Medical Engineers & Physics , 2013, Vol. 35, No.6, pp. 754-764

216.  An ordered-subsets proximal preconditioned gradient algorithm for edge-preserving PET image reconstruction

A. Mehranian, A. Rahmim, M. R. Ay, F. Kotasidis and H. Zaidi
Peer-reviewed Journal Publication
Medical Physics 2013, Vol. 40, No. 5, pp 052503-14

217.  EBT GHAFCROMIC film dosimetry in compensator-based intensity modulation radiation therapy

S. Vaezzadeh, M. Allahverdi, H. Nedaei, M. R. Ay, A. Shirazi and M. Yarahmadi
Peer-reviewed Journal Publication
Medical Dosimetry , 2013, Vol. 38, pp. 176-183

218.  Evaluation of whole-body MR to CT deformable image registration

A. Akbarzadeh, D. Gutierrez, A. Baskin, M. R. Ay, A. Ahmadian, N. Riahi Alam, K. Lövblad and H. Zaidi
Peer-reviewed Journal Publication
J Appl Clin Med Phys, 2013, Vol. 14, No. 4, pp 238-253

219.  Experimental assessment of the influence of beam hardening filters on image quality and patient dose in volumetric 64-slice x-ray CT scanners

M. R. Ay, A. Mehranian, A. Maleki, H. Ghadiri,P. Ghafarian and H. Zaidi
Peer-reviewed Journal Publication
Phys Med , 2013, Vol. 29, pp. 249-260

220.  MRI-guided attenuation correction in whole-body PET/MR: Assessment of the effect of bone attenuation

A. Akbarzadeh, M. R. Ay, A. Ahmadian, N. Riahi Alam and H. Zaidi
Peer-reviewed Journal Publication
Annals of Nuclear Medicine, 2013, Vol. 27, pp. 152-162

221.  Respiratory-Induced Errors in Tumor Quantification and Delineation in CT Attenuation Corrected PET Images: Effects of Tumor Size, Tumor Location and Respiratory Trace - A Simulation Study Using the 4D XCAT Phantom

P. Geramifar, M. Shamsaie Zafarghandi, P. Ghafarian, A. Rahmim and M. R. Ay
Peer-reviewed Journal Publication
Molecular Imaging & Biology, 2013, Vol. 15, No. 6, pp 655-665

222.  Smoothly Clipped Absolute Deviation (SCAD) Regularization for Compressed Sensing MRI Using an Augmented Lagrangian Scheme

A. Mehranian, H. Salighe Rad, A. Rahmim, M. R. Ay and H. Zaidi
Peer-reviewed Journal Publication
Magnetic Resonance Imaging, 2013, Vol. 31, No. 8, pp 1399-1411

223.  X-ray CT metal artifact reduction using wavelet domain L0 sparse regularization

A. Mehranian, M. R. Ay, A. Rahmim and H. Zaidi
Peer-reviewed Journal Publication
IEEE Trans Med Imaging, 2013, Vol. 32, No. 9, pp 1707-1722

224.  An Innovative Rotation-Based Iterative Resolution Recovery for HiReSPECT™: a Dedicated Small Animal SPECT System

N. Zeraatkar, M. H. Farahani, H. Arabi, S. Sarkar, S. Sajedi, N. Naderi, P. Ghafarian, A. Rahmim and M.R. Ay
Published Abstract
European Association of Nuclear Medicine Annual Congress, 27-31 October 2012, Milan, Itly. Eur J Nucl Med Mol, S386-S387

225.  Design and Development of a High Resolution Small Animal Imaging System for Mice and Rat

M.R. Ay , H. Arabi, M. H. Farahani, N. Zeraatkar, S. Sarkar, S. Sajed, N. Naderi and P. Ghafaian
Published Abstract
European Association of Nuclear Medicine Annual Congress, 27-31 October 2012, Milan, Itly. Eur J Nucl Med Mol, S441

226.  Determination of Attenuation Map at 511 keV Employing 3D Short Echo-Time MR Imaging in the Head Area: Application in MR-Based AC of PET data

P. Khareti, H. Salighe Rad, and M.R. Ay
Published Abstract
European Association of Nuclear Medicine Annual Congress, 27-31 October 2012, Milan, Itly. Eur J Nucl Med Mol, S369

227.  Digital signal processing unit for nuclear detection system

S. Sajedi, M.R. Ay, M. H. Farahani, N. Zeraatkar, H. Arabi, and N. Naderi
Published Abstract
European Association of Nuclear Medicine Annual Congress, 27-31 October 2012, Milan, Itly. Eur J Nucl Med Mol, S498

228.  Evaluation of the influence of respiratory motion misalignment between PET and CT data on diagnosis of heart defects using 4D XCAT phantom and STIR reconstruction

M. Sedighpoor, P. Ghafarian, A. Emami, M.R. Ay
Published Abstract
European Association of Nuclear Medicine Annual Congress, 27-31 October 2012, Milan, Itly. Eur J Nucl Med Mol, S515

229.  Quantification of the influence of misregistration between CT and SPECT images on the accuracy of CT-based attenuation correction of cardiac images in hybrid SPECT/CT systems

L. Saleki, A. Bitarafan-Rajabi, N. Yaghobi, B. Falahi, and M.R. Ay
Published Abstract
European Association of Nuclear Medicine Annual Congress, 27-31 October 2012, Milan, Itly. Eur J Nucl Med Mol, S518

230.  Standardized Uptake Value-Based Evaluations of Respiratory-Induced Errors in CTAC PET Images: A Simulation Study Using 4D XCAT Phantom

P. Geramifar, M. Shamsaie Zafarghandi, M.R. Ay
Published Abstract
European Association of Nuclear Medicine Annual Congress, 27-31 October 2012, Milan, Itly. Eur J Nucl Med Mol, S403

231.  SURGEOSIGHT-TM: An Intraoprative Hand Held Gamma Camera for Precise Localization of Sentine Lymph Nodes

M.R. Ay , H. Arabi, M. H. Farahani, N. Zeraatkar, S. Sarkar, S. Sajed, N. Naderi and P. Ghafaian
Published Abstract
European Association of Nuclear Medicine Annual Congress, 27-31 October 2012, Milan, Itly. Eur J Nucl Med Mol, S385

232.  The influence of crystal material and size on the performance of partial-rotating dual head small animal PET scanners: Quantitative evaluation using Monte Carlo modeling

N. Ghazanfari, M.R. Ay, S.Sarkar and G.Loudos
Published Abstract
European Association of Nuclear Medicine Annual Congress, 27-31 October 2012, Milan, Itly. Eur J Nucl Med Mol, S442

233.  The influence of resolution recovery during image reconstruction on quantitative brain SPECT imaging

A. Emami-Ardekani, F. Kalantari, H. Rajabi, M.R. Ay, A. Fard, M. Eftekhari
Published Abstract
European Association of Nuclear Medicine Annual Congress, 27-31 October 2012, Milan, Itly. Eur J Nucl Med Mol, S500

234.  Smoothly Clipped Absolute Deviation (SCAD) Regularization for Compressed Sensing MRI Using an Augmented Lagrangian Scheme

Mehranian A, H. Salighe Rad, M.R. Ay , Rahmim A, and Zaidi H
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Anaheim, CA, USA, 2012, pp 3646-3653

Abstract:

Compressed sensing (CS) in magnetic resonance imaging (MRI) enables the reconstruction of MR images from highly undersampled k-spaces, and thus substantial reduction of data acquisition time. In this context, edge-preserving and sparsity-promoting regularizers are used to exploit the prior knowledge that MR images are sparse or compressible in a given transform domain and thus to regulate the solution space. In this study, we introduce a new regularization scheme by iterative linearization of the non-convex clipped absolute deviation (SCAD) function in an augmented Lagrangian framework. The performance of the proposed regularization, which turned out to be an iteratively weighted total variation (TV) regularization, was evaluated using 2D phantom simulations and 3D retrospective undersampling of clinical MRI data by different sampling trajectories. It was demonstrated that the proposed regularization technique substantially outperforms conventional TV regularization, especially at reduced sampling rates.

235.  Generation of attenuation map for MR-based attenuation correction of PET data in the head area employing 3D short echo time MR imaging

P. Khareti, H. Salighe Rad, A. Fathi and M.R. Ay
Published Abstract
Proc. PSMR Conference, Isola de Elba, Italy 26-30 May , p. 70, 2012

236.  3D Calculation of Absorbed Dose for 131I Targeted Radiotherapy: A Monte Carlo Study

E. Saeedzadeh, S. Sarkar, A. Abbaspour Tehrani-Fard, M.R. Ay, H.R. Khosravi, G. Loudos
Peer-reviewed Journal Publication
Radiation Protection Dosimetry, 2012, 150, pp. 298-305

237.  3D TV-Based Compressed MR Image Reconstruction Using a Primal Dual Algorithm

A. Mehranian, H. S. Rad, M.R. Ay, and A. Rahmim
Published Abstract
Proc. Intl. Soc. Mag. Reson. Med., vol. 20, pp. 4228, 2012

238.  A novel energy mapping approach for CT-based attenuation correction in PET

B. Teimourian , M. R. Ay, M. Shamsaei-Zafarghandi, P. Ghafarian, H. Ghadiri and H. Zaidi
Peer-reviewed Journal Publication
Med Phys 2012, Vol. 39, No. 4, pp 2078-2089

239.  A proximal splitting algorithm for TV-regularized PET image reconstruction

A. Mehranian, A. Rahmim, and M.R. Ay
Published Abstract
Proc. Asia Oceania Congress of Nucl. Med. & Biology, vol. 20 (suppl. 1), p. 43, 2012

240.  An Ordered-Subsets Proximal Preconditioned Gradient Algorithm for Total Variation Regularized PET Image Reconstruction

Mehranian A, M.R. Ay, Rahmim A, and Zaidi H
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Anaheim, CA, USA, 2012, pp 3375-3382

241.  Development of a fully 3D image reconstruction for a pinhole animal SPECT

M. Khamesi, A. Kamali Asl, M. Masoudi, N. Zeraatkar, and M.R. Ay
Published Abstract
Proc. Asia Oceania Congress of Nucl. Med. & Biology, vol. 20 (suppl. 1), p. 122, 2012

242.  Development of image reconstruction code with collimator-detector response function compensation for a preclinical SPECT scanner

N. Zeraatkar, M. H. Farahani, H. Arabi, S. Sarkar, S. Sajedi, A. Rahmim, and M.R. Ay
Published Abstract
Proc. Asia Oceania Congress of Nucl. Med. & Biology, vol. 20 (suppl. 1), p. 36, 2012

243.  Generalized 4D AB-OSEM direct parametric imaging: application to PiB-PET

A. Rahmim, Y. Zhou, J. Price, J. Tang, L. Lu, M.R. Ay, G. Smith, V. Sossi, and D. Wong
Published Abstract
J. Nucl. Med., vol. 53 (suppl. 1): 313, 2012

244.  Generation of attenuation map for MR-based attenuation correction of PET data in the head area employing 3D short echo time MR imaging

P. Khateri, H. Saligeh Rad, A, Fathi and M.R. Ay
Peer-reviewed Journal Publication
Nuclear. Instrumentation Methods in Physics Research A, 2012, Vol. 702, No.21, pp. 133-136

245.  High resolution small animal SPECT: HiReSPECT for preclinical imaging

H. Arabi, M. H. Farahani, N. Zeraatkar, S. Sarkar, S. Sajedi, A. Rahmim, P. Ghafarian and M.R. Ay
Published Abstract
Proc. Asia Oceania Congress of Nucl. Med. & Biology, vol. 20 (suppl. 1), p. 93, 2012

246.  HiReSPECT an in house high resolution SPECT imaging system

M.R. Ay
Published Abstract
Proc. Asia Oceania Congress of Nucl. Med. & Biology, vol. 20 (suppl. 1), p. 10, 2012

247.  Impact of miscentering on patient dose and image noise in x-ray CT imaging: Phantom and clinical studies

M.A. Habibzadeh, M.R. Ay, A.R. Kamali Asl, H. Ghadiri and H. Zaidi H
Peer-reviewed Journal Publication
Phys Med Vol. 28, 2012, pp. 191-199

248.  Implementation of data acquisition board with digital signal processing capability for nuclear imaging and spectrometry devices

S. Sajedi, M. H. Farahani, H. Arabi, N. Zeraatkar, and M.R. Ay
Published Abstract
Proc. Asia Oceania Congress of Nucl. Med. & Biology, vol. 20 (suppl. 1), p. 39, 2012

249.  QCT technique optimization by dual energy CT

A. Emami, H. Ghadiri, P. Ghafarian and M.R. Ay
Published Abstract
Proc. Asia Oceania Congress of Nucl. Med. & Biology, vol. 20 (suppl. 1), p. 125, 2012

250.  Quantification of the influence of respiratory motion induced misalignment between PET and CT data on diagnosis of heart disease in cardiac PET/CT imaging

M. Sedigpoor, M.R. Ay, P. Ghafarian, P. Farnia
Published Abstract
Proc. Asia Oceania Congress of Nucl. Med. & Biology, vol. 20 (suppl. 1), p. 129, 2012

251.  Quantitative assessment of the influence of crystal material and size on the performance of rotating dual head small animal PET scanners: Monte Carlo modeling

N. Ghazanfari, S. Sarkar, G. Loudos, M.R. Ay
Peer-reviewed Journal Publication
Hellenic Journal of Nuclear Medicine, 2012, Vol. 15, No. 1, pp. 33-39

252.  The accuracy of dual energy mapping approach in CTAC in presence of low concentration of contract agent

H. Ghadiri, M.B. Shiran, H. Zaidi, H. Soltanian Zadeh and M.R. Ay
Published Abstract
Proc. Asia Oceania Congress of Nucl. Med. & Biology, vol. 20 (suppl. 1), p. 60, 2012

253.  The influence of opening angels and collimator material on the spatial resolution of pinhole collimator in animal SPECT imaging

M. Masoudi, A. Kamali Asl, M. Khamesi, H. Arabi and M.R. Ay
Published Abstract
Proc. Asia Oceania Congress of Nucl. Med. & Biology, vol. 20 (suppl. 1), p. 122, 2012

254.  The infuence of resolution recovery by using collimator detector response during 3D OSEM image reconstruction on 99mTc-ECD brain SPET images

F. Kalantari, H. Rajabi, M. R. Ay, A. Fard Esfahani, M. Eftekhari, B. Fallahi, A. Emami Ardekani
Peer-reviewed Journal Publication
Hellenic Journal of Nuclear Medicine, 2012, Vol. 15, No. 2, pp. 91-96

255.  A novel energy mapping approach in CT-based attenuation correction of PET data using multi-energy CT imaging

Ghadiri H, Shiran MB, M.R. Ay, Soltanian-Zadeh H and Zaidi H
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Valencia, Spain, 23-29 October 2011, p. 2510-2515

256.  A Novel Phantom for Accurate Performance Assessment of Bone Mineral Measurement Techniques: DEXA and QCT

A. Emami, H. Ghadiri, M.R. Ay, S. Akhlagpour, A. Eslami, P. Ghafarian and S. Taghizadeh
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Valencia, Spain, 23-29 October 2011, p. 3441-3445

257.  Characterization of scattered radiation profile in volumetric 64-slice x-ray CT scanner: A Monte Carlo study

Najafi Darmian A, M.R. Ay, Ghafarian P, Pouladian M, Shirazi A, Ghadiri H, Akbarzadeh A and Zaidi H
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Valencia, Spain, 23-29 October 2011, p. 2692–2696

258.  Generalized inter-frame and intra-frame motion correction in dynamic PET imaging

H. Mohy-ud-Din, N. Karakatsanis, C. Endres, M. R. Ay, D. F. Wong, and A. Rahmim
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Valencia, Spain, 23-29 October 2011, p. 3858-3862

259.  Impact of tissue classification on the accuracy of MR-based attenuation correction in PET-MRI

Akbarzadeh A, M.R. Ay, Ahmadian A, Riahi Alam N and Zaidi H
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Valencia, Spain, 23-29 October 2011, p. 2524–2530

260.  Metal artifact reduction in CT-based attenuation correction of PET using Sobolev sinogram restoration

Mehranian A, M.R. Ay, Rahmim A and Zaidi H
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Valencia, Spain, 23-29 October 2011, P. 2936-2942

261.  Sparsity constrained sinogram inpainting for metal artifact reduction in x-ray computed tomography

Mehranian A, M.R. Ay , Rahmim A, and Zaidi H
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Valencia, Spain, 23-29 October 2011, p. 3694–3699

262.  B-spline based free form deformation thoracic non-rigid registration of CT and PET images

Khodadad D, Ahmadian A, M.R. Ay, Esfahani AF, Banaem HY and Zaidi H
Proceeding and Conference Record
International Conference on Graphic and Image Processing (ICGIP 2011), 1-3 October 2011, Cairo, Egypt, Proc. SPIE, Vol. 8285, pp 82851K

263.  A Novel Phantom for Accurate Performance Assessment of Bone Mineral Measurement Techniques: DEXA and QCT

A. Emami, H. Ghadiri, M.R. Ay, S. Akhlagpour, A. Eslami, P. Ghafarian and S. Taghizadeh
Proceeding and Conference Record
5th Kuala Lumpur International Conference on Biomedical Engineering, 20-23 June 2011, Kuala Lumpur, Malaysia, IFMBE Proceedings 35, p. 47-50

264.  Monte Carlo Characterization of Scattered radiation profile in Volumetric 64 slice CT using GATE

A. Najafi Darmian, M.R. Ay, M. Pouladian, A. Shirazi, H.Ghadiri and A. Akbarzadeh
Proceeding and Conference Record
5th Kuala Lumpur International Conference on Biomedical Engineering, 20-23 June 2011, Kuala Lumpur, Malaysia, IFMBE Proceedings 35, p. 694-697

265.  Quantification of Inter-crystal Scattering and Parallax Effect in Pixelated High Resolution Small Animal Gamma Camera: A Monte Carlo Study

F. Adibpour, M.R. Ay, S. Sarkar and G. Loudos
Proceeding and Conference Record
5th Kuala Lumpur International Conference on Biomedical Engineering, 20-23 June 2011, Kuala Lumpur, Malaysia, IFMBE Proceedings 35, p. 708-711

266.  Quantitative Assessment of the influence of crystal material and size on the Inter Crystal Scattering and Penetration effect in pixilated dual head small animal PET scanner

N. Ghazanfari, M.R. Ay, N. Zeraatkar, S. Sarkar and G. Loudos
Proceeding and Conference Record
5th Kuala Lumpur International Conference on Biomedical Engineering, 20-23 June 2011, Kuala Lumpur, Malaysia, IFMBE Proceedings 35, p. 712-715

267.  Accurate Monte Carlo modeling and performance assessment of the X-PET™ subsystem of the FLEX Triumph™ preclinical PET/CT scanner

N. Zeratkar, M.R. Ay, A Kamaliasl and H. Zaidi
Peer-reviewed Journal Publication
Medical Physics, 2011, Vol. 38, No 3, pp 1217-1225

268.  Assessment of the impact of applying attenuation correction on the accuracy of activity recovery in TC99m-ECD brain SPECT of healthy subject using statistical parameter mapping

F. Vedaei, M.R. Ay, A. Kamali asl, F. Kalantari
Published Abstract
3th International Congress of Nuclear Medicine, Tehran, Iran, 2011, pp 92

269.  Assessment of the impact of applying attenuation correction on the accuracy of activity recovery in Tc99m-ECD brain SPECT of healthy subject using Statistical Parametric Mapping (SPM)

F. Vedaei, A. Kamali asl, F. Kalantari, M. Ansari, M.R. Ay
Peer-reviewed Journal Publication
Iranian Journal of Nuclear Medicine, 2011, 19, pp. 52-59

270.  Assessment of the influence of crystal material and size on the performance of dual head small animal PET scanners

N. Ghazanfari, M.R. Ay, S. Sarkar and G. Lodous
Published Abstract
3th International Congress of Nuclear Medicine, Tehran, Iran, 2011, pp 108

271.  Bone material decomposition by energy resolved CT-based attenuation correction of PET

H. Ghadiri, M. Shiran, M.R. Ay, H. Zaidi, H. Soltanian Zadeh
Published Abstract
3th International Congress of Nuclear Medicine, Tehran, Iran, 2011, pp 98

272.  Comparative assessment of energy-mapping approaches in CT-based attenuation correction for PET

M. R. Ay, M. Shirmohammad, S. Sarkar, A. Rahmim, H. Zaidi
Peer-reviewed Journal Publication
Molecular Imaging & Biology, 2011, Vol. 13, pp. 187-198

273.  Correction of contrast agent induced srtifacts in CT-based attenuation correction of cardiac PET data using a semi-automated segmentation algorithm

P. Ghafarian, M.R. Ay and J. Hassani
Published Abstract
3th International Congress of Nuclear Medicine, Tehran, Iran, 2011, pp 110

274.  CT-based attenuation correction on the FLEX Triumph™ preclinical PET/CT scanner

R. Prasad, M.R. Ay, O. Ratib and H. Zaidi
Peer-reviewed Journal Publication
IEEE Trans Nuclear Sciences, 2011, Vol. 58 pp 66-75

275.  Investigation of Time-of-Flight Benefits on the LYSO-Based PET/CT Scanner: A Monte Carlo Study Using GATE

P. Geramifar, M.R. Ay, M. Shamsaie Zafarghandi, S. Sarkar, G. Loudos, A. Rahmim
Peer-reviewed Journal Publication
Nuclear. Instrumentation Methods in Physics Research A , 2011 Vol. 641, pp. 121-127

276.  Is Metal Artifact Reduction Mandatory in Cardiac PET/CT Imaging in the Presence of Pacemaker and Implantable Cardioverter Defibrillator leads?

P. Ghafarian, S.M.R. Aghamiri, M.R. Ay, A. Rahmim, T. Schindler, O. Ratib and H. Zaidi
Peer-reviewed Journal Publication
European Journal of Nuclear Medicine and Molecular Imaging, 2011, Vol. 38, No. 2, pp 252-262

277.  Is percentage error of bone density determined by DEXA technique influenced by density?

A. Emami, H. Ghadiri, M.R. Ay, S. Akhlagpour, P. Ghafarian and S. Taghizadeh
Published Abstract
3th International Congress of Nuclear Medicine, Tehran, Iran, 2011, pp 88

278.  Monte Carlo estimation of electron contamination in a 18MV clinical photon beam

M. Allahverdi, M. Zabih Zadeh, M.R. Ay, S.R. Mahdavi, M. Shahriari ,A. Mesbahi and H. Alijanzadeh
Peer-reviewed Journal Publication
Iranian Journal of Radiation Research, 2011, Vol. 9 pp 15-28

279.  Monte Carlo-based evaluation of inter-crystal scatter and penetration in the PET subsystem of three GE Discovery PET/CT scanners

N. Zeraatkar, M. R. Ay, P. Ghafarian, S. Sarkar, P. Geramifar, and A. Rahmim
Peer-reviewed Journal Publication
Nuclear. Instrumentation Methods in Physics Research A, 2011, Vol. 659, pp. 508-514

280.  Novel detector design for reducing inter-cell x-ray cross-talk in the variable resolution x-ray CT scanner: A Monte Carlo study

H. Arabi, A Kamaliasl, M.R. Ay and H. Zaidi
Peer-reviewed Journal Publication
Medical Physics, 2011, Vol. 30 pp. 1389-1396

281.  Photon scatter and penetration in parallel hole collimator in preclinical Gamma Camera: A Monte Carlo study

F. Adibpour, M.R. Ay, S. Sarkar and G. Lodous
Published Abstract
3th International Congress of Nuclear Medicine, Tehran, Iran, 2011, pp 147

282.  Qualitative and quantitative assessment of metal artefacts arising from implantable cardiac pacing devices in oncological PET/CT studies: A phantom study

M.R. Ay, A. Mehranian, M. Abdoli, P. Ghafarian and H. Zaidi
Peer-reviewed Journal Publication
Molecular Imaging & Biology, 2011, Vol. 13, pp. 1077-1088

283.  Quantification of bremsstrahlung images with respect to post radioemoblization liver dosimetry

M.R. Teimoori, Sh. Akhlagpour, M.R. Ay, F. Kalantari and M. Amoui
Published Abstract
3th International Congress of Nuclear Medicine, Tehran, Iran, 2011, pp 103

284.  The influence of misalignment between PET and CT images on the accuracy of CT-based attenuation correction in thorax imaging: a simuation study

A. Anvari, M.R. Ay and B. Fallahi
Published Abstract
3th International Congress of Nuclear Medicine, Tehran, Iran, 2011, pp 190

285.  Use of optimization transfer for enhanced direct 4D parametric imaging in myocardial perfusion PET

A. Rahmim, J. Tang, H. Muhy-ud-Din, M.R. Ay, and M. A. Lodge
Published Abstract
Society of Nuclear Medicine (SNM) Annual Meeting, 2011, San Antonio, Texas, USA, J. Nucl. Med., vol. 52 (Supplement 1): 265, 2011

286.  4D Respiratory motion-corrected Rb-82 myocardial perfusion PET imaging

A. Rahmim, J. Tang, M.R. Ay and F. M. Bengel
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Knoxville, Tennessee, 2010, pp. 3312-3316

287.  A new method for experimental characterization of scattered radiation in 64-slice CT scanner

A. Akbarzadeh, M.R. Ay ,H. Ghadiri, S.Sarkar
Peer-reviewed Journal Publication
Biomedical Imaging and Intervention Journal, 2010, 6(1):e3

288.  A Novel Approach for Implementation of Dual Energy Mapping Technique in CT-Based Attenuation Correction Using Single kVP Imaging: A Feasibility Study

B. Teimourian, M.R. Ay, H. Ghadiri, M. Shamsaei Zafarghandi and H. Zaidi
Proceeding and Conference Record
12th Mediterranean Conference on Medical and Biological Engineering and Computing (MEDICON 2010), Chalkidiki, Greece, MEDICON 2010, IFMBE Proceedings 29, pp. 220–223, 2010

289.  A Novel Model for Monte Carlo Simulation of Performance Parameters of the Rodent Research PET (RRPET) Camera Based on NEMA NU-4 Standards

N. Zeraatkar, M.R. Ay, A. Kamali-Asl and H. Zaidi
Proceeding and Conference Record
12th Mediterranean Conference on Medical and Biological Engineering and Computing (MEDICON 2010), Chalkidiki, Greece, MEDICON 2010, IFMBE Proceedings 29, pp. 311–314, 2010

290.  A Virtual Sinogram Method to Reduce Dental Metallic Implant Artefacts in CT-based Attenuation Correction for PET

M. Abdoli, M.R. Ay, A. Ahmadian and H. Zaidi
Peer-reviewed Journal Publication
Nuclear Medicine Communication, 2010, 31, 22-31

291.  Accurate 3D Dosimetry for Internal Radiotherapy by Considering the Effect of Nonuniform Activity Distribution

E. Saeedzadeh, A. Abbaspour, S. Sarkar, M.R. Ay, H.R. Khosravi
Published Abstract
The International Congress of Nuclear Medicine, Mashhad, Iran, Iranian Journal of Nuclear Medicine, Vol. 18, Supp. 1, 2010, pp. 112

292.  Accurate 3D-Dosimetry for Internal Radiotherapy with 131I Using GATE Monte Carlo Code

E. Saeed Zadeh, S. Sarkar, A. Abbaspour, M.R. Ay, H. Khosravi, G. Lodus
Published Abstract
9th Iranian Congress of Medical Physics, Tehran, Iran, 2010, pp 116

293.  Accurate Modeling for Monte Carlo Based Performance Evaluation of The PET Subsystem of the FLEX Triumph Priclinical PET/CT Scanner Using NEMA NU-4 Standard

N. Zeraatkar, M.R. Ay, A.R. Kamali-Asl, H. Zaidi
Published Abstract
10th Congress of the World Federation of Nuclear Medicine and Biology (WFNMB 2010), Cape Town, South Africa, South Africa, World Journal of Nuclear Medicine, Vol. 9, Supp. 1, 2010, pp. S-163
Nominated as one of the best submitted abstracts

294.  Advances in Multimodality Molecular Imaging Instrumentation

M.R. Ay
Published Abstract
The International Congress of Nuclear Medicine, Mashhad, Iran, Iranian Journal of Nuclear Medicine, Vol. 18, Supp. 1, 2010, pp. 77

295.  Assessment of the Influence of Crystal Material and Size on the Sensitivity of Dual Head Small Animal PET Scanner

N. Ghazanfari, M.R. Ay, S. Sarkar and G. Loudos
Published Abstract
The International Congress of Nuclear Medicine, Mashhad, Iran, Iranian Journal of Nuclear Medicine, Vol. 18, Supp. 1, 2010, pp. 120

296.  Assessment of the Influence of PET and CT Data Misalignment Errors in Cardiac PET/CT Examination: Patient and Phantom Studies

P. Ghafarian, S.M.R. Aghamiri, M.R. Ay, A. Fard Esfahani and H. Zaidi
Published Abstract
The International Congress of Nuclear Medicine, Mashhad, Iran, Iranian Journal of Nuclear Medicine, Vol. 18, Supp. 1, 2010, pp. 81

297.  Calculation Of Scattered Radiation Profile In 64 Slice CT Scanners Using Experimental Measurement

A. Akbarzadeh, M.R.Ay ,H.Ghadiri, S.Sarkar
Peer-reviewed Journal Publication
Iran J. Medical Physics , 2010, 6, 1-10

298.  Coronary calcium score scan-based attenuation correction in cardiovascular PET imaging

P. Ghafarian, S.M.R. Aghamiri, M.R. Ay, B. Fallahi, A. Rahmim, T. Schindler, O. Ratib and H. Zaidi
Peer-reviewed Journal Publication
Nuclear Medicine Communication, 2010, Vol. 31, No 9, pp 780-787

299.  Coronary Calcium Score Scan-Based Attenuation Correction in Viability PET Examination: A Feasibility Study

P. Ghafarian, S.M.R. Aghamiri, M.R. Ay, B. Fallahi, A. Rahmim, T. Schindler, O. Ratib and H. Zaidi
Published Abstract
10th Congress of the World Federation of Nuclear Medicine and Biology (WFNMB 2010), Cape Town, South Africa, World Journal of Nuclear Medicine, Vol. 9, Supp. 1, 2010, pp. S-16

300.  CT2MCNP: An Integrated Package for Constructing Patient-Specific Voxel-Based Phantoms Dedicated for MCNP(X) Monte Carlo Code

A. Mehranian, M.R. Ay and H. Zaidi
Proceeding and Conference Record
12th Mediterranean Conference on Medical and Biological Engineering and Computing (MEDICON 2010), Chalkidiki, Greece, MEDICON 2010, IFMBE Proceedings 29, pp. 319–322, 2010

301.  Effects of Crystal Pixel Size and Collimator Geometry on the Performance of a Pixelated Crystal Gamma Camera Using Monte Carlo Simulation

M. Rasouli, A. Takavar, M.R. Ay, S. Saber, and G. Loudos
Peer-reviewed Journal Publication
Journal of Nuclear Medicine Technology, 2010, Vol. 38, No 4, pp 199-204

302.  Evaluation of Dose Distribution in Co-60 Machine Using Radicromic Film and Monte Carlo

M. Mollazadeh, , M. Allahverdi, T. Pourfallah, N. Riahi Alam, M.R. Ay
Published Abstract
16th Conference of Biomedical Engineering, Tehran, Iran, 2010, PP. 157

303.  Evaluation of MRI-based Polymer Gel Dosimetry for Measurement of CT Dose Index (CTDI) on 64 slices CT Scanners

L. Karimi-Afshar, N. Riahi Alam, M.R.Ay, M. Allahverdi, T. Purfallah, H. Hashemi, A. Farahani, B. Efie, M. Bakhteiari
Peer-reviewed Journal Publication
Iran J. Medical Physics , 2010, 6, 59-70

304.  Experimental Measurement of Modulation Transfer Function (MTF) in Five Commercial CT Scanners

S.M. Akbari, M.R. Ay, A. Kamali Asl, H. Ghadiri and H. Zaidi
Proceeding and Conference Record
12th Mediterranean Conference on Medical and Biological Engineering and Computing (MEDICON 2010), Chalkidiki, Greece, MEDICON 2010, IFMBE Proceedings 29, pp. 351–354, 2010

305.  Impact of Metal Artifact Reduction on Cardiac FDG-PET/CT Studies in the Presence pf pacemaker and Implantable Cardio Verter Defibrator Leads

P. Ghafarian, S.M.R. Aghamiri, M.R. Ay, A. Fard Esfahani, A. Rahmim, T.H. Schindler, O. Ratib and H. Zaidi
Published Abstract
The International Congress of Nuclear Medicine, Mashhad, Iran, Iranian Journal of Nuclear Medicine, Vol. 18, Supp. 1, 2010, pp. 104

306.  Implementation and Comparison of to Empirical Methods for Calculation of MTF in CT

M. Akbari, M.R. Ay, A. Kamali Asl, H. Ghadiri
Published Abstract
16th Conference of Biomedical Engineering, Tehran, Iran, 2010, PP. 155

307.  Measurement of scattered radiation in a volumetric 64-slice CT scanner using three experimental techniques

A. Akbarzadeh, M. R. Ay, H. Ghadiri, S. Sarkar and H. Zaidi
Peer-reviewed Journal Publication
Physics Medicine and Biology, 2010, 55, 2269-2280

308.  Optimization of weighted virtual sinogram-based metal artifact reduction in CT-based attenuation correction of PET data using a genetic algorithm

M. Abdoli, M.R. Ay, A. Ahmadian, R.A. Dierckx and H. Zaidi
Published Abstract
European Association of Nuclear Medicine Annual Congress, 9-13 October 2010, Vienna, Austria. Eur J Nucl Med Mol Imaging, Vol 37, Suppl. 1, (2010)

309.  Performance Assessment and Optimization of Pixelated Gamma Camera with Small Field of View: A Monte Carlo Study

F. Adibpour, M.R. Ay, S. Sarkar and G. Loudos
Published Abstract
The International Congress of Nuclear Medicine, Mashhad, Iran, Iranian Journal of Nuclear Medicine, Vol. 18, Supp. 1, 2010, pp. 116

310.  Quantification and Correction of Metallic Artifact Arising from Implantable cardiac Pacing Devices in PET/CT Studies: A Phantom Study

M.R. Ay, A. Mehranian, P. Ghafarian, M. Abdoli and H. Zaidi
Published Abstract
10th Congress of the World Federation of Nuclear Medicine and Biology (WFNMB 2010), Cape Town, South Africa, South Africa, World Journal of Nuclear Medicine, Vol. 9, Supp. 1, 2010, pp. S-20
Nominated as one of the best submitted abstracts

311.  Quantification of Inter Crystal Scatter and Parallax Events in LYSO-Based Discovery RX PET/CT Scanner: A Monte Carlo Study

N. Zeraatkar, M.R. Ay, S. Sarkar, A. Rahmim, P. Geramifar
Published Abstract
10th Congress of the World Federation of Nuclear Medicine and Biology (WFNMB 2010), Cape Town, South Africa, South Africa, World Journal of Nuclear Medicine, Vol. 9, Supp. 1, 2010, pp. S-158
Nominated as one of the best submitted abstracts

312.  Quantification of Inter-Crystal Scatter and Penetration Events in GE Discovery RX PET/CT Scanner: a Monte Carlo Simulation

N. Zeraatkar, M.R. Ay, S. Sarkar, P. Geramifar and A. Rahmim
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Knoxville, Tennessee, 2010, pp. 2403-2408

313.  Quantification of Respiratory Induced Artifact in CT-Based Attenuation Correction of PET Data: A Simulation Study

Z. Anvari, M.R. Ay, B. Fallahi, F. Buther
Published Abstract
The International Congress of Nuclear Medicine, Mashhad, Iran, Iranian Journal of Nuclear Medicine, Vol. 18, Supp. 1, 2010, pp. 79

314.  Quantifying the effect of anode surface roughness on diagnostic x-ray spectra using Monte Carlo simulation

A. Mehranian, M.R. Ay, N. Riahi and H. Zaidi
Peer-reviewed Journal Publication
Medical Physics, 2010, 37, 742-752

315.  Quantitative Assessment if Inter-Crystal Scatter and Penetration in the PET Subsystem of the FLEX Triumph Preclinical Multi-Modality Scanner

H. Arabi, N. Zeratkar, M.R. Ay, H. Zaidi
Published Abstract
The International Congress of Nuclear Medicine, Mashhad, Iran, Iranian Journal of Nuclear Medicine, Vol. 18, Supp. 1, 2010, pp. 40

316.  Reduction of dental filling metallic artefacts in CT-based attenuation correction of PET data using weighted virtual sinograms optimized by a genetic algorithm

M. Abdoli, M.R. Ay, A. Ahmadian, A. J. O. Dierckx and H. Zaidi
Peer-reviewed Journal Publication
Medical Physics, 2010, Vol. 37, No 12, pp 6166-6177

317.  The Effect of Nonuniform Activity Distribution in Three-Dimensional Dosimetry for Internal Radiotherapy with 131I

E. Saeed Zadeh, S. Sarkar, A. Abbaspour, M.R. Ay, H. Khosravi, G. Lodus
Published Abstract
10th Congress of the World Federation of Nuclear Medicine and Biology (WFNMB 2010), Cape Town, South Africa, South Africa, World Journal of Nuclear Medicine, Vol. 9, Supp. 1, 2010, pp. S-30

318.  The Influence of Patient Miscentering of Patient Dose and Image Noise in Two Commercial CT Scanners

M. Habibzadeh, M.R. Ay, A. Kamali Asl, H. Ghadiri
Published Abstract
16th Conference of Biomedical Engineering, Tehran, Iran, 2010, PP. 158

319.  The Influence of Patient Miscentering on Patient Dose and Image Noise in Two Commercial CT Scanners

M.A. Habibzadeh, M.R. Ay, A. Kamali Asl, H. Ghadiri and H. Zaidi
Proceeding and Conference Record
12th Mediterranean Conference on Medical and Biological Engineering and Computing (MEDICON 2010), Chalkidiki, Greece, MEDICON 2010, IFMBE Proceedings 29, pp. 327–330, 2010

320.  Virtual Dual Energy CT (VDECT): A Novel Approach for Improved Energy Mapping in CT-Based Attenuation Correction of PET Data

B. Teimourian, M.R. Ay, M. Shamsaei Zafarghandi, H. Ghadiri and H. Zaidi
Published Abstract
10th Congress of the World Federation of Nuclear Medicine and Biology (WFNMB 2010), Cape Town, South Africa, South Africa, World Journal of Nuclear Medicine, Vol. 9, Supp. 1, 2010, pp. S-33

321.  A Novel Application of MRI-Polymer Gel Dosimeter for Measurement of CTDI on X-Ray 64 Slices CT Scanner

L. Karimiafshar, N. Riyahi Alam, M.R. Ay, M. Alahverdi, T. Alahvirdi Pourfallah , H. Hashemi, A. Farahani,B. Rafiei and M. Bakhtiar
Proceeding and Conference Record
The World Congress on Medical Physics and Biomedical Engineering, Germany, Munich, 7-12 September 2009, IFMBE Proceedings 25, pp. 541-544

322.  CT-based attenuation correction on the FLEX Triumph™ preclinical PET/CT scanner

R. Prasad, M.R Ay, O. Ratib and H. Zaidi
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Orlando (FL) USA, 25-31 October 2009, 3357-3362

323.  Quantitative assessment of the effect of anode surface roughness on diagnostic x-ray spectra using Monte Carlo simulation

A. Mehranian , M.R. Ay, N. Riahi Alam and H. Zaidi
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Orlando (FL) USA, 25-31 October 2009, 2902-2907

324.  Reduction of dental filling metallic artifacts in CT-based attenuation correction of PET data using weighted virtual sinograms

M. Abdoli , M.R. Ay, A. Ahmadian and H. Zaidi
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Orlando (FL) USA, 25-31 October 2009, 2752-2755

325.  Comparative assessment of image- and virtual sinogram-based metal artefact reduction techniques for CT-based attenuation correction in PET

M. Abdoli, M.R. Ay, A. Ahmadian and H. Zaidi
Published Abstract
European Association of Nuclear Medicine Annual Congress, 10-14 October 2009, Barcelona, Spain. Eur J Nucl Med Mol Imaging, Vol 36, Suppl. 1, pp S226

326.  The Effect of Crystal Size on Position Detection Accuracy in PET Block Detectors: A Monte Carlo Study

S. Lashkari, S. Sarkar, M.R. Ay and A. Rahmim
Published Abstract
European Association of Nuclear Medicine Annual Congress, 10-14 October 2009, Barcelona, Spain. Eur J Nucl Med Mol Imaging, Vol 36, Suppl. 1, pp S409

327.  Challenges for Planning and Running a PET/CT and Cyclotron Facility

M.R. Ay
Published Abstract
International Congress of Nuclear Medicine and Molecular Imaging, Tabriz, Iran, 23-25 September, 2009, pp. 10

328.  CT Based Attenuation Correction in Cardiac PET/CT Using Calcium Score CT Image: A Feasibility Study

P. Ghafarian, S.M.R. Aghamiri, M.R. Ay, A. Rahmim and H. Zaidi
Published Abstract
International Congress of Nuclear Medicine and Molecular Imaging, Tabriz, Iran, 23-25 September, 2009, pp. 9

329.  Implementation and comparison of different energy mapping approaches in CT-based attenuation correction of PET

M.R.Ay, M. Shirmohammad, S. Sarkar, A. Rahmim, H. Zaidi
Published Abstract
International Congress of Nuclear Medicine and Molecular Imaging, Tabriz, Iran, 23-25 September, 2009, pp. 51

330.  Implementation of Dual Energy Mapping Techniques in CT-Based Attenuation Correction Method Using Single Energy Imaging: A Novel Approach for Reducing Patient Dose

B. Teimourian, M.R. Ay, M. Shamsaei Zafarghandi
Published Abstract
International Congress of Nuclear Medicine and Molecular Imaging, Tabriz, Iran, 23-25 September, 2009, pp. 52

331.  Strategies for Attenuation Correction in PET/CT and PET/MRI

M.R. Ay
Published Abstract
International Congress of Nuclear Medicine and Molecular Imaging, Tabriz, Iran, 23-25 September, 2009, pp. 8

332.  Validation of the GATE Monte Carlo Code in Evaluation of Organ Doses Calculation in Zubal Voxelized Phantom

E. Saeedzadeh, S. Sarkar, A. Abbaspour Tehrani-Fard, M.R. Ay, H.R. Khosravi
Published Abstract
International Congress of Nuclear Medicine and Molecular Imaging, Tabriz, Iran, 23-25 September, 2009, pp. 50

333.  Monte Carlo Estimation of Photoneotrons Contamination from High Energy Medical Accelerator in Treatment Room and Maze

M. Zabih Zadeh, M.R. Ay, M. Allahverdi, A. Mesbahi, S.R. Mahdavi and M. Shahriari
Published Abstract
10th Biennial ESTRO Conference on Physics and Radiation Technology for Clinical Radiotherapy, Maastricht, August 30 – September 3, 2009

334.  Metal Artifact Reduction in CT-Based Attenuation Correction of PET Data Using the Virtual Sinogram Concept

M. Abdoli, M.R. Ay, A. Ahmadian and H. Zaidi
Proceeding and Conference Record
3rd International Conference on Bioinformatics and Biomedical Engineering (IEEE iCBBE 2009), June 11th to 13th, 2009, 1-4, Beijing, China

335.  Quantification of PET and CT Data Misalignment Errors in Cardiac PET/CT: Clinical and Phantom Studies

P. Ghafarian and S.M.R. Aghamiri, M.R. Ay, A. Rahmim and H. Zaidi
Proceeding and Conference Record
3rd International Conference on Bioinformatics and Biomedical Engineering (IEEE iCBBE 2009), June 11th to 13th, 2009, 1-4, Beijing, China

336.  The Influence of X-ray Spectra Filtration on Image Quality and Patient Dose in the GE VCT 64-Slice Cardiac CT Scanner

M.R. Ay, A. Maleki, H. Ghadiri, P. Ghafarian, A. Ahmadian and H. Zaidi
Proceeding and Conference Record
The 3rd International Conference on Bioinformatics and Biomedical Engineering (IEEE iCBBE 2009), June 11th to 13th, 2009, 1-4, Beijing, China

337.  Evaluation of polymer gel dosimetry based on MRI imaging for measurement of CTDI in 64 slice CT scanner

L. Karimiafshar, N. Riahi Alanm and M.R. Ay
Published Abstract
1st Congress of Radiation Protection in Radiotherapy, Diagnostic and Interventional Radiology, 19-20 February 2009, Tehran, Iran

338.  PET/CT: Site Planning and Shielding Calculation

M.R. Ay
Published Abstract
1st Congress of Radiation Protection in Radiotherapy, Diagnostic and Interventional Radiology, 19-20 February 2009, Tehran, Iran, 43-44

339.  A Novel Dual Energy CT-Based Attenuation Correction Method in PET/CT Systems: A Phantom Study

B. Teymoorian, M.R. Ay, M. Shamsaei Zafarghandi and H. Ghadiri
Peer-reviewed Journal Publication
" Iranian Journal of Nuclear Medicine, 2009, 17, 42-49

340.  Differential Dose Volume Histograms of Gamma Knife in Presence of Inhomogeneities Using MRI- polymer Gel Dosimetry and MC Simulation

T. Allahverdi, M. Allahverdi, N. Riahi Alam, M.R. Ay, M. Zahmatkesh
Peer-reviewed Journal Publication
Medical Physics, 2009, 36,3002-3012

341.  Evaluation of Dose Delivery Accuracy of Gamma Knife Using MRI Polymer Gel Dosimeter in an Inhomogeneous Phantom

T. Allahverdi, M. Allahverdi, N. Riahi Alam, M.R. Ay, M. Zahmatkesh
Peer-reviewed Journal Publication
Journal of Physics: Conference Series 164, 2009, doi:10.1088/1742-6596/164/1/012066

342.  Monte Carlo Estimation of Photoneotrons Contamination from High Energy Medical Accelerator in Threatment Room and Maze: A Simplified Model

M. Zabih Zadeh, M.R. Ay, M. Allahverdi, A. Mesbahi, S.R. Mahdavi and M. Shahriari
Peer-reviewed Journal Publication
Radiation Detection Dosimetry, 2009, 135, 21-32

343.  Performance Comparison of Four Commercial GE Discovery PET/CT Scanners: A Monte Carlo Study Using GATE

P. Geramifar, M.R. Ay, M. Shamsaie Zafarghandi,G. Loudos, A. Rahmim
Peer-reviewed Journal Publication
Iranian Journal of Nuclear Medicine, 2009, 17, 26-33

344.  Performance evaluation of MRI-based PAGAT polymer gel dosimeter in an inhomogeneous phantom using EGSnrc code on a co-60 machine

T. Allahverdi, M. Allahverdi, N. Riahi Alam, M.R. Ay, M. Zahmatkesh and J.S. Ibbott
Peer-reviewed Journal Publication
Applied Radiation and Isotopes, 2009, 67, 186-191

345.  Verifying the accuracy of dose distribution in Gamma Knife unit in presence of inhomogeneities using PAGAT polymer gel dosimeter and MC simulation

T. Allahverdi, M. Allahverdi, N. Riahi Alam, M.R. Ay, M. Zahmatkesh
Peer-reviewed Journal Publication
Iranian J. of Radiation Research, 2009, 7, 49-56

346.  A novel approach for reducing dental filling artefacts in CT-based attenuation correction of head and neck oncologic PET/CT data

M. Abdoli, M.R Ay, A. Ahmadian, N. Sahba and H. Zaidi
Proceeding and Conference Record
4th European Congress of the International Federation of Medical and Biological Engineering, Antwerp, Belgium, 23-27 November 2008 ECIFMBE 2008, IFMBE Proceedings 22, pp. 492–495

347.  Comparative assessment of different energy mapping approaches in CT based attenuation correction: a patient study

M. Shirmohammad, M.R. Ay, A. Rahmim, S. Sarkar and H. Zaidi
Proceeding and Conference Record
4th European Congress of the International Federation of Medical and Biological Engineering, Antwerp, Belgium, 23-27 November 2008 ECIFMBE 2008, IFMBE Proceedings 22, pp. 496–499

348.  Comparative Assessment of Rotating Slat and Parallel Hole Collimator Performance in GE DST-Xli Gamma Camera: A Monte Carlo Study

N. Dehestani, S. Sarkar, M.R. Ay, M. Sadeghi and M. Shafaei
Proceeding and Conference Record
4th European Congress of the International Federation of Medical and Biological Engineering, Antwerp, Belgium, 23-27 November 2008 ECIFMBE 2008, IFMBE Proceedings 22, pp. 1062–1065

349.  Monte Carlo assessment of geometric, scatter and septal penetration components in high energy collimators

M. Shafaei, M.R. Ay, S. Sardari and H. Zaidi
Proceeding and Conference Record
4th European Congress of the International Federation of Medical and Biological Engineering, Antwerp, Belgium, 23-27 November 2008 ECIFMBE 2008, IFMBE Proceedings 22, pp. 2479–2482

350.  Reduction of Intravenous Contrast Related Artifacts in CT-based Attenuation Corrected PET Images

M.R. Ay, J.H. Bidgoli, P. Ghafarian and H. Zaidi
Proceeding and Conference Record
4th European Congress of the International Federation of Medical and Biological Engineering, Antwerp, Belgium, 23-27 November 2008 ECIFMBE 2008, IFMBE Proceedings 22, pp. 513–516

351.  The Influence of InterCrystal Scattering on Detection Efficiency of Dedicated Breast Gamma Camera: A Monte Carlo Study

M. Rasouli, M.R. Ay, A. Takavar, S. Lashkari and G. Loudos
Proceeding and Conference Record
4th European Congress of the International Federation of Medical and Biological Engineering, Antwerp, Belgium, 23-27 November 2008 ECIFMBE 2008, IFMBE Proceedings 22, pp. 2451–2454

352.  Characterization of Scatter and Penetration Using Monte Carlo Simulation in Ga-67 Imaging

M. Shafaee, M.R. Ay and D. Sardari
Published Abstract
9th ASIA Oceania Congress of Nuclear Medicine and Biology, Oct 31st - Nov 4th, 2008, New Delhi, India, Indian Journal of Nuclear Medicine, Vol 23, p.171

353.  A hybrid approach for accurate estimation of the scatter component in x-ray CT combining experimental measurements and Monte Carlo simulations

A. Akbarzadeh, M.R. Ay, H. Ghadiri, S. Sarkar and H. Zaidi
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Dresden, Germany, 19-25 October 2008, 3864-3867

354.  Monte Carlo Based Performance Assessment of Four Commercial GE Discovery PET/CT Scanners Using GATE

P. Geramifar, M.R. Ay, M. Shamsai Zafarghandi, G. Loudos, A. Rahmim
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Dresden, Germany, 19-25 October 2008, 3995-3999

355.  Rb-82 Cardiac PET Imaging with Resolution Modeling

A. Rahmim, J. Tang, M. A. Lodge, S. Lashkari, M.R. Ay, R. Lautamaki, B. M. W. Tsui, and F. Bengel
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference, Dresden, Germany, 19-25 October 2008, 3643-3650

356.  A novel energy mapping method for attenuation map generation at 511 keV in computed tomography based attenuation correction

M. Shirmohammad, M.R. Ay, A. Rahmim A, S. Sarkar and H. Zaidi
Published Abstract
European Association of Nuclear Medicine Annual Congress, 11-15 October 2008, Munich, Germany. Eur J Nucl Med Mol Imaging, Vol 35, Suppl. 2, S146
Nominated as one of the best submitted abstracts

357.  Monte Carlo Simulation of The GE LYSO-Based Discovery RX PET/CT Scanner Using GATE: a Validation Study

P. Geramifar, M.R. Ay, M. Shamsaii Zafarghandi,G. Lodous, A. Rahmim
Published Abstract
European Association of Nuclear Medicine Annual Congress, 11-15 October 2008, Munich, Germany. Eur J Nucl Med Mol Imaging, Vol 35, Suppl. 2, S175-176

358.  The Influence of Crystal Depth on Position Detection Accuracy and Detection Efficiency in PET Block Detector: A Monte Carlo Study

S. Lashkari, S. Sarkar, M.R. Ay and A. Rahmim
Published Abstract
European Association of Nuclear Medicine Annual Congress, 11-15 October 2008, Munich, Germany. Eur J Nucl Med Mol Imaging, Vol 35, Suppl. 2, S337-338

359.  A novel approach for experimental measurement of scatter profile and scatter to primary ratio in a 64-slice CT scanner

A. Akbarzadeh A, M.R. Ay, H. Ghadiri, S. Sarkar and H. Zaidi
Proceeding and Conference Record
4th Kuala Lumpur International Conference on Biomedical Engineering, 25-28 June 2008, Kuala Lumpur, Malaysia, IFMBE Proceedings Series, Vol. 21, pp 473-477

360.  The Influence of Crystal Material on Intercrystal Scattering and the Parallax Effect in PET Block Detectors: A Monte Carlo Study

S. Lashkari, S. Sarkar, M.R. Ay and A. Rahmim
Peer-reviewed Journal Publication
4th Kuala Lumpur International Conference on Biomedical Engineering, 25-28 June 2008, Kuala Lumpur, Malaysia, IFMBE Proceedings Series, Vol. 21, pp 633-636

361.  Comparative Assessment of Different Energy Mapping Methods for Generation of 511- keV Attenuation Map from CT Images in PET/CT Systems: A Phantom Study

M. Shirmohammad, M.R. Ay, H. Ghadiri, S. Sarkar and A. Rahmim
Proceeding and Conference Record
5th IEEE International Symposium on Biomedical Imaging: From Nano to Macro, 14-17 May, Paris, France, 2008, 644-647

362.  Monte Carlo Assessment of Time-of-Flight Benefits on The LYSO-Based Discovery RX PET/CT Scanner

P. Geramifar, M.R. Ay, M. Shamsayee, G. Lodous and A. Rahmim
Proceeding and Conference Record
5th IEEE International Symposium on Biomedical Imaging: From Nano to Macro, 14-17 May, Paris, France, 2008, 364-367

363.  Analytic System Matrix Resolution in PET: An Application to RB-82 Cardiac Imaging

A. Rahmim, M. Lodge, J. Tang, S. Lashkari and M.R. Ay
Proceeding and Conference Record
5th IEEE International Symposium on Biomedical Imaging: From Nano to Macro, 14-17 May, Paris, France, 2008, 1307-1310

364.  Analytic System Matrix Resolution Modeling in PET: An Application to Rb-82 Myocardial Perfusion Imaging

A. Rahmim, J. Tang, M. A. Lodge, S. Lashkari, M.R. Ay, R. Lautamaki, B. M. W. Tsui, and F. Bengel
Peer-reviewed Journal Publication
Physics in Medicine and Biology, 2008, 53, 5947-5965

365.  Comparing 511 keV attenuation maps obtained from different energy mapping methods for CT based attenuation correction of PET data

M. Shirmohammad, M.R. Ay, S. Sarkar and A. Rahmim
Peer-reviewed Journal Publication
Iran J. Medical Physics , 2008,5, 23-34

366.  Correction of oral contrast artefacts in CT-based attenuation correction of PET images using an automated segmentation algorithm

A. Ahmadian, M.R. Ay, J.H. Bidgoli, S. Sarkar and H. Zaidi
Peer-reviewed Journal Publication
European Journal of Nuclear Medicine and Molecular Imaging, 2008, 35, 1812-1823

367.  EGSnrc calculated and MRI-Polymer Gel Dosimeter Measured Dose Distribution of Gamma Knife in Presence of Inhomogeneities

P. Allahverdi, N. Riahi Alam, M. Allahverdi, M.R. Ay, M. Zahmatkesh M
Proceeding and Conference Record
International Congress of Medical physics, India, 2008

368.  Evaluation of Dose Delivery Accuracy of Gamma Knife Using MRI Polymer Gel Dosimeter in an Inhomogeneous Phantom

P. Allahverdi, N. Riahi Alam, M. Allahverdi, M.R. Ay, M. Zahmatkesh M
Proceeding and Conference Record
5th Congress on Radiotherpy Gel Dosimetry, 2008 , Greece, 399-403

369.  Improved clinical and quantitative dynamic Rb-82 cardiac imaging with resolution modelling

A. Rahmim, J. Tang, M. A. Lodge, S. Lashkari, M.R. Ay, R. Lautamaki, B. M. Tsui, and F. Bengel
Published Abstract
J. Nucl. Med., vol. 49 (Supplement 1): 62P, 2008

Abstract

Objectives:

To investigate, in the context of Rb-82 cardiac PET imaging, improvements in image quality obtained via a novel resolution modeling approach.

Methods:

An accurate resolution modeling approach was developed in which resolution degrading factors were modeled within reconstruction. A combined simSET/GATE Monte-Carlo tool was used to simulate Rb-82 cardiac acquisition. Time activity curves of myocardium, blood pool and other organs were measured from five healthy patients, and spline-smoothed to simulate the input activities. Multiple noise realizations within clinical (90sec delay, 5min) and quantitative dynamic (30sec delay, 10x12sec) imaging were simulated. For the former, defects were also simulated, and defect contrast vs. noise plots were assessed. For the latter, we performed compartmental analyses on the reconstructed image sequences, and the bias vs. variance for the K1 values were compared.

Results:

The reconstructed resolution was seen to improve from 5.1mm-7.7mm across the FoV to ~3.5mm nearly uniformly across the FoV. Hot and cold sphere contrast vs. noise trade-off curves were seen to substantially improve. Defect contrast vs. noise was significantly improved (75% to 63%, matched noise, true contrast 50%). For the dynamic sequence considered, with increasing post-smoothing, the results indicated increasing bias and decreasing variance in the compartmental extracted K1 values, and the trade-off curve was substantially improved with resolution modeling.

Conclusions:

Accurate resolution modeled reconstruction can significantly improve image quality in clinical and quantitative dynamic Rb-82 cardiac PET imaging.

370.  The Influence of Crystal Material on Intercrystal Scattering and the Parallax Effect in PET Block Detectors: A Monte Carlo Study

S. Lashkari, S. Sarkar, M.R. Ay, R. Rahmim
Peer-reviewed Journal Publication
Iran J. Medical Physics , 2008, 21, 67-76

371.  A hybrid approach for fast simulation of x-ray computed tomography

M.R. Ay, P. Ghafarian and H. Zaidi
Proceeding and Conference Record
Proceedings of IEEE Nuclear Science Symposium & Medical Imaging Conference, Honolulu, Hawaii, 28 October – 3 November 2007, Vol. 4, pp 3155-3160

372.  Correction of correction of PET images using an automated segmentation algorithm

J.H. Bidgoli, M.R. Ay, S. Sarkar, A. Ahmadian and H. Zaidi
Proceeding and Conference Record
Proceedings of IEEE Nuclear Science Symposium & Medical Imaging Conference, Honolulu, Hawaii, 28 October – 3 November 2007, Vol. 5, pp 3542-3547

373.  Impact of x-ray tube voltage, field size and phantom thickness on scattered radiation in diagnostic radiology: A Monte Carlo investigation

P. Ghafarian, M.R. Ay, H. Ghadiri, S. Sarkar and H. Zaidi
Proceeding and Conference Record
Proceedings of IEEE Nuclear Science Symposium & Medical Imaging Conference, Honolulu, Hawaii, 28 October – 3 November 2007, Vol. 5, pp 3830-3834

374.  Influence of energy indexing algorithm and electron substeps on MCNP4C electron transport: Application to simulation of x-ray spectra in diagnostic radiology and mammography

M.R. Ay, H. Ghadiri, P. Ghafarian, S. Sarkar and H. Zaidi
Proceeding and Conference Record
Proceedings of IEEE Nuclear Science Symposium & Medical Imaging Conference, Honolulu, Hawaii, 28 October – 3 November 2007, Vol. 5, pp 4006-4011

375.  Automatic Segmentation of Oral Contrast Enhanced CT Images for Artifact Free Attenuation Correction in PET/CT

M.R. Ay, J.H. Bidgoli, S. Sarkar and A. Ahmadian
Published Abstract
European Association of Nuclear Medicine Annual Congress, 13-19 October 2007, Copenhagen, Denmark. Eur J Nucl Med Mol Imaging, Vol 34, Suppl 2, S115

376.  Computed Tomography Based Attenuation Correction in PET/CT: Principles, Instrumentation, Protocols, Artifacts and Future Trends

M.R. Ay and S. Sarkar
Peer-reviewed Journal Publication
Iranian J. Nucl. Med., 2007, 15, 1-29

377.  Current status and new horizons in Monte Carlo simulation of x-ray CT scanners

H. Zaidi and M.R. Ay
Peer-reviewed Journal Publication
Medical & Biological Engineering & Computing , 2007, 45, 809-817

378.  Evaluation of Scatter and penetration in HEGP Collimator in DST Xli Gamma Camera During I131 Imaging

M. Shafaee, M.R. Ay, D. Sardari
Published Abstract
14th Iranian Nuclear Science Conference, Yazd, Iran, 2007, P.111

379.  Impact of x-ray tube settings and metallic leads on neurological PET imaging when using CT-based attenuation correction

M.R. Ay and H. Zaidi
Peer-reviewed Journal Publication
Nuclear. Instrumentation Methods in Physics Research A , 2007, 571, 411-417

380.  Validation and Performance Evaluation of Discovery Rx whole Body PET/CT Scanner Using GATE

P. Geramifar, M.R. Ay, M. Shamsaei
Published Abstract
14th Iranian Nuclear Science Conference, Yazd, Iran, 2007, P.33

381.  A Novel Hybrid Approach for Measurement of Bone Mineral Density and Content with High Signal to Noise Ratio

H. Ghadiri and M.R. Ay
Proceeding and Conference Record
Proceedings of World Congress on Medical physics and Biomedical Engineerin, Seoul, Korea, August 27 – September 1, 2006, pp. 1324-1327

382.  Impact of x-ray scatter when using CT-based attenuation correction in PET: A Monte Carlo investigation

H. Zaidi and M.R. Ay
Proceeding and Conference Record
Proceedings of IEEE Nuclear Science Symposium & Medical Imaging Conference, San Diego, USA, 29 October - 4 November 2006, Vol. 4; pp. 2161-2165

383.  Simulation-based assessment of the impact of contrast medium on CT-based attenuation correction in PET

M.R. Ay and H. Zaidi
Proceeding and Conference Record
Proceedings of IEEE Nuclear Science Symposium & Medical Imaging Conference. San Diego, USA, 29 October - 4 November 2006, Vol. 5; pp. 2731-2735
Recipient of 2006 IEEE Medical Imaging Conference Award

384.  Characterization of sources of artefact when using CT-based attenuation correction in PET

M.R. Ay and H Zaidi
Published Abstract
7th annual congress of the Swiss Society of Nuclear Medicine (SSNM), Lausanne, Switzerland, 1-3 June 2006, Nuklearmedizin Vol 45, p. A139

385.  Assessment of the impact of x-ray tube voltage on quantitative analysis of neurological PET when using CT-based attenuation correction

M.R. Ay and H Zaidi
Published Abstract
1st European conference in Molecular Imaging Technology, Marseille, France, 9-12 May 2006, p. 22

386.  Analytical and Monte Carlo modeling of x-ray spectra in mammography, in Emerging Technologies in Breast Imaging and Mammography

M.R. Ay and H. Zaidi
Book Chapter
J.S. Suri, R.M. Rangayyan, and S. Laxminarayan, Editors. 2006, American Scientific Publishers: Valencia, CA. ISBN: 1-58883-090-X, 2006, pp 25-44

DESCRIPTION

Breast cancer is the second leading cause of cancer deaths in women today (after lung cancer) and is the most common cancer among women, excluding non-melanoma skin cancers. According to the World Health Organization (WHO), more than 1.2 million people will be diagnosed with breast cancer this year worldwide. The American Cancer Society estimated that in 2005 approximately 211,240 women in the United States were diagnosed with invasive breast cancer (Stages I-IV). The chance of developing invasive breast cancer during a woman's lifetime is approximately 1 in 7 (13.4%). Another 58,490 women will be diagnosed with in situ breast cancer, a very early form of the disease. Though much less common, breast cancer also occurs in men. An estimated 1,690 cases were diagnosed in men in 2005. This year alone, the National Institutes of Health, the Centers of Disease Control (CDC), and the Department of Defense will collectively spend more than $850 million on breast cancer research. Today the literature of breast imaging technologies is clouded with uncertainty. There is no perfect method to tell which technique performs better or the best. It is also not clear how well the new progressing technologies are going to play a role in early breast cancer detection due partly because the emerging technologies have not established a clear strategy to achieve superior instrumentation for screening and diagnosis and for improving the sensitivity and specificity of the imaging or computer-aided diagnosis systems. This book is the first of its kind to address the issues on cutting edge emerging technologies for breast imaging and mammography. The book covers all facets of nature to image the breast, may it be light (optical), sound (ultrasound), magnetism, attenuation, microwave, electrical impedance, fusion of these modalities, and some of the very hot topics on Computer Aided Detection. The novelty of this book is due to the contributions of pioneers around the world. This book offers a very comprehensive and up-to-date perspective on the state of breast cancer screening instrumentation, diagnosis, and therapy and recommends steps for developing the most reliable breast cancer detection and therapeutic methods possible. This volume, for the first time, covers numerous topics on how to attack breast cancer from almost all different angles of medical imaging modalities such as X-ray, CT, MR, PET, SPECT, nuclear, ultrasound, microwave, optical, electrical impedance, thermal, infrared, and its fusion. Another novelty of this book is modeling breast cancer detection, diagnosis, and therapy in 3-D. The book begins with highlights on different kinds of breast cancer and its pathology and then introduces the engineers, scientists, innovators, and strategists to put their algorithms and designs for solving the number one killer problem in women’s health imaging. The book is divided into six parts: Part-I is dedicated to X-ray mammography and its applications, including modeling X-ray spectra, phase-contrast, and stereoscopic mammography. Part-II is dedicated to 3-D breast imaging and tomosynthesis, one of the most cutting-edge topics from pioneers. Part-III is dedicated to breast imaging using ultrasound and its applications. This involves detection, elastography, vibro-acoustography, breast biopsy, and breast cancer therapy using HIFU. Part-IV concentrates on some emerging techniques such as optical, microwave, electrical impedance tomography, nuclear, and infrared and thermal imaging techniques. Part-V is dedicated to some of the advanced computer-aided detection techniques applied to architectural distortion. Finally, the book concludes, in Part-VI, on the fusion of various modalities and some future predictions in the breast imaging area.

387.  Assessment of errors caused by x-ray scatter and use of contrast medium when using CT-based attenuation correction in PET

M.R. Ay and H. Zaidi
Peer-reviewed Journal Publication
European Journal of Nuclear Medicine and Molecular Imaging, 2006, 33 (11), 1301-1313

388.  Computed tomography-based attenuation correction in neurological positron emission tomography: evaluation of the effect of x-ray tube voltage on quantitative analysis

M.R. Ay and H. Zaidi
Peer-reviewed Journal Publication
Nuclear Medicine Communication, 2006, 27, 339-346

389.  MCNP4C-based Monte Carlo simulator for fan- and cone-beam x-ray CT: development and experimental validation

M.R. Ay, S. Sarkar, M. Shahriari, D. Sardari, and H. Zaidi
Proceeding and Conference Record
14th International Conference of Medical Physics. Biomedizinische Technik. 2005. Nuremberg, Germany, Sept. 14-17, 2005. 50 Suppl Part 1: pp. 360-361

390.  Assessment of different computational models for generation of x-ray spectra in diagnostic radiology and mammography

M.R. Ay, S. Sarkar, M. Shahriari, D. Sardari, and H. Zaidi
Peer-reviewed Journal Publication
Medical Physics, 32(6), pp. 1660-1675, 2005

391.  Development and validation of MCNP4C-based Monte Carlo simulator for fan- and cone-beam x-ray CT

M.R. Ay and H. Zaidi
Peer-reviewed Journal Publication
Physics in Medicine and Biology, 2005. 50(20): pp. 4863-4885

392.  Comparative assessment of different computational models for generation of x-ray spectra in diagnostic radiology and mammography

M.R. Ay, S. Sarkar, M. Shahriari, D. Sardari, and H. Zaidi
Proceeding and Conference Record
IEEE Nuclear Science Symposium & Medical Imaging Conference. 2004. Oct. 19-22, Rome, Italy. 4: pp. 4190-4194

393.  Estimating of patient dose in abdomen-pelvis CT exam as a function of scan techniques in single and multi-slice speiral CT by Monte Carlo method

M.R. Ay, S. Sarkar, M. Shahriari, and P. Ghafarian
Published Abstract
2th International Conference on Nuclear Science and Technology in Iran. Shiraz, Iran, 27-30 April 2004, p. 46

394.  Measurement of Organ Dose in Abdomen-Pelvis CT Exam as a Function of mA, KVp and Scanner Type by Monte Carlo Method

M.R. Ay, S. Sarkar, M. Shahriari and P. Ghafarian
Peer-reviewed Journal Publication
Iranian J. of Radiation Research, 1(4), 187-194, 2004

395.  Monte Carlo simulation of x-ray spectra in diagnostic radiology and mammography using MCNP4C

M.R. Ay, M. Shahriari, S. Sarkar, M. Adib and H. Zaidi
Peer-reviewed Journal Publication
Physics in Medicine and Biology, 49(19) pp. 4897-4917, 2004

396.  Measurement of organ dose in abdomen-pelvis CT exams as a function of mA, KVp and scanner type by Monte Carlo method

M.R. Ay, M. Shahriari, S. Sarkar, and P. Ghafarian
Published Abstract
3ed International Conference of The Effect of Low and Very Low Doses of Ionizing Radiation on Human Health. Tehran, Iran , 21-23 October 2003, p. 53

397.  Development of a Monte Carlo simulation package for scintillation cameras operation in single photon and coincidence imaging mode

M.R. Ay, M. Adib, and H. Zaidi
Published Abstract
Annual Congress of the European Association of Nuclear Medicine (EANM03). Amsterdam, The Netherlands, 23-28 August 2003, p. S326-S327

398.  Cyclotrons in nuclear medicine, in Comprehensive book on Radiology, Nuclear Medicine and Therapy Systems

M.R. Ay
Book Chapter
J. Shokohi, A.A. Ameri, and H.R. Sagha, Editors. 2003, Andishe Rafi Publisher: Tehran, Iran. pp. 1742-1756

399.  Image fusion in nuclear medicine

M.R. Ay
Published Abstract
7th Annual Meeting of Nuclear Medicine. Tehran, Iran, 2003: p. 45

400.  Introduction to PET and PET/CT systems, in Comprehensive book on Radiology, Nuclear Medicine and Therapy Systems

M.R. Ay
Book Chapter
J. Shokohi, A.A. Ameri, and H.R. Sagha, Editors. 2003, Andishe Rafi Publisher: Tehran, Iran. pp. 1757-1781

401.  Comparison of PET detectors

M.R. Ay
Published Abstract
6th Annual Meeting of Nuclear Medicine. Mashhad, Iran 2002, p. 31

402.  Steps toward building a PET center

M.R. Ay
Published Abstract
6th Annual Meeting of Nuclear Medicine. Mashhad, Iran 2002, p. 29

403.  Providing software for PET (Coincidence) 3D simulation using Monte Carlo method

M.R. Ay and M.E. Ashrafi
Published Abstract
International Conference on Radiation and its Role in Diagnosis and Treatment (FICR2000). Tehran, Iran, 14-18 October 2000, p. 51