BACKGROUND The Local Diagnostic Reference Levels (LDRLs) form an efficient, concise and powerful standard for optimizing the radiation protection of a patient. OBJECTIVES To calculate the Entrance Surface Doses (ESDs) received by patients undergoing PA chest X-ray examinations in major public hospitals in Addis Ababa, thereby to establish the first Ethiopian LDRLs as part of ongoing dose redu...

Introduction The present work describes a study in which, based on patient dose measurements, thermoluminescent dosimeters were used to obtain the diagnostic reference level arising from panoramic radiography. Materials and Methods Ten panoramic units and a sample of 15 patients per X-ray unit were studied. Two thermoluminescent dosimeter chips were placed on the skin surface of selected organs...

Introduction: Diagnostic reference level (DRL) is a useful tool for the promotion of optimization. The national DRLs (NDRLs) are useful, brief, and robust guidelines for optimizing radiation protection in a country. The aim of this study was to extract the local DRLs (LDRLs) for some common radiologic examination in Sabzevar county. Materials and Methods: There are eight radiology departments ...

Introduction: Medical uses of radiation have grown very rapidly over in the past two decades, medical uses represent the largest source of exposure to people, The most important methods in medical diagnosis are the useses of diagnostic radiology exams. Although the use of these methods is very beneficial for the treatment of patients, but ionizing radiation produces ion pairs, ...

PURPOSE The magnetic fields of linac-MR systems modify the path of contaminant electrons in photon beams, which alters patient skin dose. To accurately quantify the magnitude of changes in skin dose, the authors use Monte Carlo calculations that incorporate realistic 3D magnetic field models of longitudinal and transverse linac-MR systems. METHODS Finite element method (FEM) is used to genera...

background: in vivo dosimetry is a method for estimation of overall error in the delivered dose to the patients at the end of radiotherapy process. in this research, two methods for target dose calculation were evaluated on midline and central axis of photon beams in in vivo dosimetry of thorax fields. materials and methods: entrance and exit doses for anterior and lateral fields of thorax were...

introduction:  skin  sparing  is  one  of  the  most  desirable  characteristics  of  high  energy  photon  beams. however, the photons emerging from the target of linacs are contaminated by secondary  electrons  as  a  result  of  their  interactions  with  air,  collimators,  flattening  filter  and  any  other  objects in their path. this phenomenon tends to increase the skin dose received b...