نتایج جستجو برای: ct scan absorb dose thyroid shielding dose reduction
تعداد نتایج: 1024960 فیلتر نتایج به سال:
Background: Positron Emission Tomography-Computed Tomography (PET-CT) is a useful hybrid imaging modality in the diagnosis of various malignancies. This modality imposes almost 20 mSv radiation dose to the patient. The purpose of the present study was to evaluate the uncertainties in calculated CT effective dose in TUBE CURRENT MODULATION-activated scans by Impact-Dose software. Materials and ...
introduction in computed tomography (ct) technology, an optimal radiation dose can be achieved via changing radiation parameters such as ma, pitch factor, rotation time and tube voltage (kvp) for diagnostic images. materials and methods in this study, the brain, abdomen, and thorax scaning was performed using toshiba 16-slice scannerand standard aapm and ctdi phantoms. aapm phantom was used for...
Background In radiotherapy, especially when treating children, minimising exposure of healthy tissue can prevent the development adverse outcomes, including second cancers. this study we propose a validated Monte Carlo framework to evaluate complete patient during paediatric brain cancer treatment. Materials and methods Organ doses were calculated for treatment diffuse midline glioma (50.4 Gy w...
background: the anatomic position and proven radiosensitivity of the thyroid make it an organ of concern in dental x-ray examinations. a national radiation protection department (nrpd)-sponsored pilot study carried out in the dental radiology department of rums., to assess if the radiation dose in panoramic radiographies could be reduced without significant impairment of the subjective image qu...
BACKGROUND The aims of this study were to investigate the image quality and radiation exposure of pediatric protocols for cardiac CT angiography (CTA) in infants under one year of age. METHODOLOGY/PRINCIPAL FINDINGS Cardiac CTA examinations were performed using an anthropomorphic phantom representing a 1-year-old child scanned with non-electrocardiogram-gated (NG), retrospectively electrocard...
BACKGROUND Thyroid cancer incidence has increased significantly over the past three decades due, in part, to incidental detection. We examined the association between randomization to screening for lung, prostate, colorectal and/or ovarian cancers and thyroid cancer incidence in two large prospective randomized screening trials. METHODS We assessed the association between randomization to low...
The aim of this study was to assess effective doses of a lateral cephalogram radiograph with and without thyroid shield and compare the differences with the radiation dose of a hand-wrist radiograph. Thermoluminescent dosimeters were placed at 19 different sites in the head and neck of a tissue-equivalent human skull (RANDO phantom). Analogue lateral cephalograms with and without thyroid shield...
Recently, specific computed tomography (CT) scanners have been equipped with organ-based tube current modulation (TCM) technology. It is possible that organ-based TCM will replace the conventional dose-reduction technique of reducing the effective milliampere-second. The aim of this study was to determine if organ-based TCM could reduce radiation exposure to the breasts without compromising the...
a 22-year-old woman presented with acute left-sided pleuritic chest pain and dyspnea 6 days after surgery for revision of the stenotic central aortopulmonary shunt. she had a history of tetralogy of fallot (tof), pulmonary valve stenosis, ventricular septal defect and major aortopulmonary collateral artery. her waterston shunt was placed when she was 5 years old and stented and re-dilated after...
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