Mohammad Hashemi

Medical Physics Research Center, Mashhad University of Medical Sciences, Mashahd, Iran.

[ 1 ] - Assessment of Radiation Dose to the Lens of the Eye and Thyroid of Patients Undergoing Head and Neck Computed Tomography at Five Hospitals in Mashhad, Iran

Introduction: In recent years, the number of computed tomography (CT) scans, which is a high-dose technique, has increased significantly. Head and neck CT is performed frequently and thyroid, particularly in children, has always been considered a sensitive organ. In recent years, radiobiologists and health physicists have been more concerned about the safety of lenses of the eyes, as cataract i...

[ 2 ] - Quality assessment of conventional X-ray diagnostic equipment by measuring X-ray exposure and tube output parameters in Great Khorasan Province, Iran

Introduction: Regular implementation of quality control (QC) program in diagnostic X-ray facilities may affect both image quality and patient radiation dose due to the changes in exposure parameters. Therefore, this study aimed to investigate the status of randomly selected conventional radiographic X-ray devices installed in radiology centers of Great Khorasan Province, Iran, to produce the da...

[ 3 ] - An Empirical Transmitted EPID Dosimetry Method using a Back-Projection Algorithm

Background: The present study aimed to introduce a rapid transmission dosimetry through an electronic portal-imaging device (EPID) to achieve two-dimensional (2D) dose distribution for homogenous environments. Material and Methods: In this Phantom study, first, the EPID calibration curve and correction coefficients for field size were obtained from EPID and ionization chamber. Second, the...