نتایج جستجو برای: field dose
تعداد نتایج: 1084576 فیلتر نتایج به سال:
Introduction: Radiotherapy is one of the effective methods in the treatment of cancer. In the recent methods of radiotherapy, intensity modulated radiotherapy (IMRT) technique by compensators is used. when photon beam passes the compensator, scattered photons can be generated within the compensator. The presence of scattered photons may complicate the design of compensators as...
Background: The purpose of this study was to evaluate nodal irradiation with conventional three-field's technique. Materials and Methods: Fifty patients with breast cancer were enrolled in this study. Computed tomography scans in the supine treatment position were imported into a treatment planning system. Levels I-III axillary and supraclavicular nodes were identified and their depths to the a...
introduction: coronary angiography and angioplasty procedures lead to significant radiation exposure of patients. in the current study, the average radiation dose to patients during angiography in the angiography department of shahid-madani hospital was determined. materials and methods: an image intensifier based angiography unit (philips bh 3000) was used for angiography procedures. the accur...
introduction: in 2000, the unscear reported that ct constitutes 5% of all the medical x-ray examinations and it contributes 34% of the resultant collective dose worldwide. children are more sensitive to the ionizing radiations than adults. so, routine quality control tests are expected to be carried out periodically on the ct scanners. the aim of this research was to estimate the effective ...
background: the aim of the study was to analyze the effective dose record of occupationally exposed radiation workers at bahawalpur institute of nuclear medicine and oncology department. materials and methods: annual effective doses of occupationally exposed workers were measured by film badge dosimetry by sending the dosimeters to radiation dosimetry laboratory (rdl), pakistan institute of nuc...
a lithium borate thermoluminescence dosimeter with 0.3 wt% of manganese impurityconcentration was prepared for high dose levels in the range of 1-30 kgy for gamma irradiation applications.the tld reader was used for read out purposes from ambient temperature to about 400°c with a heating rate of 6°c/sec. the pre- and post- irradiation anneal temperature was 300°c for 1.5 and 1 hours respectivel...
background: the aim of this study was to investigate clinical applications of mobile c-arms and consequent radiation risk,to increase medical attention on radiation protection, and to provide basic data for safe radiation use in the operating room. materials and methods: in this study, a total of 374 surgical operations, conducted using a portable fluoroscopic x-ray system from january to march...
introduction the purpose of this study was to estimate organ and effective doses in patients undergoing some common x-ray examinations in sabzevar, iran. the effective dose is one of the best parameters for describing the amount of radiation dose received by a patient undergoing any diagnostic x-ray examination. the public dose from x-ray examinations depends on various factors, and its contrib...
ct.scan examinations cause high patient absorbed dose from x-ray ionizing radiation. therefore it is necessary to obtain superficial dose profile in z-line. in this research 11 thermoluminecent dosimeter (tld), after calibration were located on z line perpendicular to slice thickness. ct.scan machines did x-ray exposures. the resultant dose profiles showed gussian shape apperience, which has se...
background: a study has been conducted to assess two useful radiation protection indices, the annual per-capita effective dose equivalent (aed) and the genetically significant dose (gsd), from conventional diagnostic radiography in 10 counties with more than 1,886,000 inhabitants in khorasan province in iran. materials and methods: the health centre authorities of khorasan province were asked t...
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