A dosimetry system using commercially available pin silicon photodiodes as the sensor is evaluated for in-phantom dose measurements in x-ray CT and other diagnostic radiology. System sensitivity measured as a function of the effective energy of x rays was between 0.37 and 0.49 V/mGy at an effective energy range between 23.5 and 72 keV. The minimum detectable organ dose with 25% uncertainty was ...

Background: Bisphosphonates (BPs) are used extensively for managing the osteoporosis. There are some controversies on atypical fractures of femur that associated with increase in cortical thickness (CT) and BPs’ use. In this study, the effects of alendronate consumption were studied on femoral CT as a predictor for atypical fracture.   Methods: Forty nine post-menopausal women age...

Introduction: The objective of this work is to study the ability of MRI normoxic polymer gel dosimetry system to be used to verify the calculated dose distribution, in a simple geometry, in clinical radiotherapy. Materials and Methods:  Initially, 2 liters of the normoxic MAGAT polymer gel was prepared and then poured into two cylindrical Perspex phantom (simu...

background: the sporadic cases of radiation-activated multiple sclerosis (ms) has been previously described, with a few studies focused on the relationship between radiation and the risk of ms. the aim of our study was to evaluate the association between history of x-ray radiation and ms.   methods : this case-control study was conducted on 150 individuals including 65 ms patients and 85 age- a...

The purpose of this study is to investigate the potential use of Ir-192 as the source for real time imaging during HDR (High Dose Rate) brachytherapy treatment. Phantom measurement was performed to determine outside of the body dose. Monte Carlo code, EGSnrcMP egs_inprz, was used for the simulation to calculate the outside of the body x-ray signal for CT reconstruction. Matlab code was develope...

In diagnostic X-ray computed tomography (CT) imaging, some applications, such as dose measurement using the Monte Carlo method and material decomposition dual/multi-energy approaches, rely on accurate knowledge of energy spectrum beam. this regard, detectors providing an estimation could greatly impact quality CT imaging patient-specific dosimetry. The aim study is to estimate intrinsic efficie...

Accurate treatment planning in radiotherapy essentially decreases damage to healthy tissue surrounding the tumor. Due plans use a direct, highly collimated, narrow beam with high intensity treat small area tumors, researchers have studied microbeam radiation therapy extensively. Using synchrotron as source may help limit damage, but using computerized simulations and dosimetry is still necessar...