نتایج جستجو برای: ray ct dose

تعداد نتایج: 689623  

Journal: :pollution 2015
raymond njinga sameul mamman

exposure to radiation from different types of television sets was measured to ascertain the levels of hazards posed to the human biological system. measurement of the annual radiation dose hazards was performed using a halogen-quenched gm tube with thin mica end window having a density of 1.5 mg/cm2, effective window diameter of 0.360 inch and side wall of 0.012 inch thick. the gm tube was plac...

Journal: :iranian journal of radiation research 0
r. paydar medical physics and biomedical engineering department, school of medicine, tehran university of medical sciences, tehran, iran a. takavar medical physics and biomedical engineering department, school of medicine, tehran university of medical sciences, tehran, iran m.r. kardan nuclear sciences research school, radiation applications research school, tehran, iran a. babakhani national radiation protection department, iranian nuclear regulatory authority, teheran iran m.r. deevband national radiation protection department, iranian nuclear regulatory authority, teheran iran s. saber pulmonary ward, shariati hospital, school of medicine, tehran university of medical sciences, tehran, iran

background: the radiation doses resulting from diagnostic x-ray examinations are routinely measured in terms of entrance surface dose (esd) and effective dose (ed). in this study, for the purpose of radiation protection, the radiation doses received from digital chest x-ray examination were evaluated in terms of esd and ed. material and methods: the ed was calculated by using the mcnp monte car...

Journal: :international journal of agricultural science, research and technology in extension and education systems 2012
ali benjavad talebi amin benjavad talebi

the purpose of the research was determine the effects of gamma ray on seed germination, seedling height and root length of rice (oryza sativa l. spp. indica cv. mr219) to identify the lethal dosage of the radiation. paddy seeds of mr219 were exposed to different doses of gamma radiations viz 50,100,150,200,250,300,350,400,450,500,600,700,800,900 and 1000 gy using 60co as the radiation source. t...

Journal: :iranian journal of radiation research 0
m. gupta department of physics, national institute of technology, kurukshetra-136119, india r.p. chauhan department of physics, national institute of technology, kurukshetra-136119, india

background: natural radioactivity in materials under certain conditions can reach the hazardous radiological levels. so, it becomes necessary to study the natural radioactivity in different materials to assess the dose for the population in order to know the health risks and to have a baseline for future changes in the environmental radioactivity due to human activities. materials and methods: ...

Journal: :iranian journal of medical physics 0
esen nsikan u dept. of physic, university of ibadan, nigeria

introduction high doses of ionizing radiation can lead to adverse health outcomes such as cancer induction in humans. although the consequences are less evident at very low radiation doses, the associated risks are of societal importance. this study aimed at assessing entrance skin doses (esds) in patients undergoing selected diagnostic x-ray examinations at public hospitals of akwa ibom state,...

Journal: :international journal of reproductive biomedicine 0
ali chaparian mahdi aghabagheri

background: pregnant women are sometimes exposed to ionizing radiation in radiology examinations for various reasons. in such cases, the radiation dose to the conceptus and subsequent risks should be estimated. objective: the purpose of this study was the calculation and presentation of fetal dose and subsequent risks resulted from different x-ray examinations. materials and methods: an analyti...

ژورنال: سنجش و ایمنی پرتو 2019

One of the most widely used diagnostic devices in medical imaging is computed tomography scanning with the use of X-ray ionization. After years of using this tool in the diagnosis and treatment, external doses of these beams can pose a risk of secondary cancer, which is significant in terms of radiation safety and protection. In this paper, using the Monte Carlo code MCNPX2.6 performed over thr...

Journal: :iranian journal of radiation research 0
b.aghahadi department of physics, harbin institute of technology, harbin 150080. p.r. china z. zhang department of national radiation protection, atomic energy organization of iran, tehran, iran s. zareh department of medical physics, tehran university of medical sciences, tehran,iran s. sarkar department of medical physics, tehran university of medical sciences, tehran,iran p.s.tayebi department of physics, heilongjiang university, harbin 150080,p.r. china

abstract   background: the x-ray machines used for radiodiagnosis should meet certain quality assurance (qa) programmes . these are necessary to have good quality radiographs at reasonably low exposure to patients.   materials and methods: dose reduction methods in abdomen x-ray examination were carried out in 10 hospitals in tehran. this paper presents the work, which was implemented on 200 pa...

2016
Nobuteru Kubo Jun-ichi Saitoh Hirofumi Shimada Katsuyuki Shirai Hidemasa Kawamura Tatsuya Ohno Takashi Nakano

The present study compared the dose-volume histograms of patients with Stage IIIA non-small cell lung cancer (NSCLC) treated with carbon ion radiotherapy with those of patients treated with X-ray radiotherapy. Patients with Stage IIIA NSCLC (n = 10 patients for each approach) were enrolled. Both radiotherapy plans were calculated with the same targets and organs at risk on the same CT. The trea...

2016
HAN CHEN

The goal in medical x-ray imaging is to obtain the image quality required for a given detection task, while ensuring that the patient dose is kept as low as reasonably achievable. The two most common strategies for dose reduction are: optimizing incident x-ray beams and utilizing energy information of transmitted beams with new detector techniques (spectral imaging). In this thesis, dose optimi...

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