Mohammad Keshtkar

Department of Medical Physics and Radiology, School of Medicine, Gonabad University of Medical Sciences, Gonabad, Iran.

[ 1 ] - Evaluation of the Entrance Surface Dose (ESD) and Radiation Dose to the Radiosensitive Organs in Pediatric Pelvic Radiography

Background Patients' dosimetry is crucial in order to enhance radiation protection optimization and to deliver low radiation dose to the patients in a radiological procedure. The aim of this study was to assess the entrance surface dose (ESD) and radiation dose to the radiosensitive organs in pediatric pelvic radiography. Materials and Methods The studied population included 98 pediatric patien...

[ 2 ] - Three-dimensional gel dosimetry for dose volume histogram verification in compensator-based IMRT

Background: Some tissues in human body are radiobiologically different from water and these inhomogeneity must be considered in dose calculation in order to achieve an accurate dose delivery. Dose verification in complex radiation therapy techniques, such as intensity‐modulated radiation therapy (IMRT) calls for volumetric, tissue equivalent and energy independent dosimeter. The purpose of this...

[ 3 ] - Application of Different methods for Reducing Radiation Dose to Breast during MDCT

The increased use of computed tomography (CT) and its high radiation dose have led to great concerns about its potential for radiation induced cancer risks. Breast is a radiosensitive tissue based on tissue weighting factors assigned by the International Commission on Radiological Protection (ICRP). Moreover, the dose is maximal on the surface of the patient. Therefore, strategies should be tak...

[ 4 ] - Synthesis and Cytotoxicity Assessment of Gold-coated Magnetic Iron Oxide Nanoparticles

Introduction: One class of magnetic nanoparticles is magnetic iron oxide nanoparticles (MIONs) which has been widely offered due to of their many advantages. Owing to the extensive application of MIONs in biomedicine, before they can be used in vivo, their cytotoxicity have to be investigated. Therefore, there is an urgent need for understanding the potential risks associated with MIONs.Materia...

[ 5 ] - Uncertainty Analysis in MRI-based Polymer Gel Dosimetry

Background: Polymer gel dosimeters combined with magnetic resonance imaging (MRI) can be used for dose verification of advanced radiation therapy techniques. However, the uncertainty of dose map measured by gel dosimeter should be known. The purpose of this study is to investigate the uncertainty related to calibration curve and MRI protocol for MAGIC (Methacrylic and Ascorbic acid in Gelatin I...