background:  this study presents patient specific and organ dose estimation in computed tomography (ct) imaging of thorax directly from patient ct image using monte carlo simulation.  patient's ct image is considered as the patient specific phantom and the best representative of patient physical index in order to calculate specific organ dose. materials and methods: egsnrc /beamnrc monte c...

computed tomographyrepresents about 10% of all diagnostic radiology procedures, but it isresponsible for almost 50% - 60% of exposure from diagnostic procedures. inhead ct, other critical organs such as eye lenses and thyroids are in theradiation field. therefore, dose assessment in these organs is very important.the aim of this study is to estimate the absorbed dose in critical organs ofpatien...

Introduction: Computed tomography is one of the most powerful tools for investigating thorax disease, because it shows progression of lung disease much clearer than chest radiography. Technical advances in CT scanners have led to some abilities for CT scanners such as coverage of larger volume, lower noise and ability for acquiring image in one respiratory phase. However, this will be accompani...

background marketing new radiography devices necessitates documenting their absorbed x-ray doses. since the current literature lacks studies on new devices, we assessed the doses of two new devices that had not previously been assessed. objectives the new devices were compared to the promax three dimensional (3d) scanner at two fields of view (fov) in nine critical head and neck tissues and org...

Computed tomography (CT) images contribute to high-quality medical diagnosis, but radiation dose can be quite high, requiring accurate assessment. CT index (CTDI) was developed for dosimetric purposes, scanners operated exclusively in axial mode. Nowadays, CTDI underestimate patient helical exams. AAPM report TG111 (2010) suggested a new metric which the patient's is obtained from profiles cons...

OBJECTIVE To assess the reduction of estimated radiation dose in abdominal computed tomography following the implementation of new scan protocols on the basis of clinical suspicion and of adjusted images acquisition parameters. MATERIALS AND METHODS Retrospective and prospective review of reports on radiation dose from abdominal CT scans performed three months before (group A - 551 studies) a...

Introduction: Head scans are the most frequently performed computed tomography (CT) examinations worldwide. However, there is growing concern over the probability of increased cancer risks among the exposed populations. Diagnostic reference levels (DRLs) identify radiation dose that is not commensurate with clinical objectives. The aim of this study was to establish DR...