نتایج جستجو برای: computed tomography dose reduction
تعداد نتایج: 1018046 فیلتر نتایج به سال:
Background: Paranasal sinus disease is one of the most common problems of patients that refer to ENT centers. Adding to clinical examination imaging plays an important role in diagnosis and treatment. Also the imaging of paranasal sinuses is necessary before surgery. Although computed tomography is the modality of choice for these areas, it has some disadvantages which the most important one is...
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...
Background and Aim: The objective of this study was to measure and compare the tissue absorbed dose in thyroid gland, salivary glands, eye and skin in maxillofacial imaging with panoramic, conventional linear tomography, cone beam computed tomography (CBCT) and computed tomography (CT).Materials and Methods: Thermoluminescent dosimeters (TLD) were implanted in 14 sites of RANDO phantom to measu...
PURPOSE To evaluate the effect of introduction of iterative reconstruction as a mandated software upgrade on radiation dosimetry in routine clinical practice over a range of computed tomography examinations. METHODS Random samples of scanning data were extracted from a centralised Picture Archiving Communication System pertaining to 10 commonly performed computed tomography examination types ...
With the advent of multi-slice computed tomography (CT) scanner and the sophisticated CT reconstruction algorithm, CT Angiography (CTA) is increasingly used to evaluate patient with vascular diseases (Fleischmann et al., 2006; Chow & Rubin, 2002; Rubin at al., 2001). It has many advantages over the conventional catheter angiograms: 1) non-invasiveness, 2) short acquisition time, 3) multiple vie...
PURPOSE The aim of this study was to investigate the potential dose reduction in the uterus as a result of lead apron protection during thoracic CT scans. Moreover, the distribution of the radiation dose in the uterus was determined in order to obtain information about the ratio of internally and externally scattered radiation. MATERIALS AND METHODS The uterus doses during thoracic CT were de...
An efficient noise treatment scheme has been developed to achieve low-dose CT diagnosis based on currently available CT hardware and image reconstruction technologies. The scheme proposed includes two main parts: filtering in sinogram domain and smoothing in image domain. The acquired projection sinograms were first treated by our previously proposed Karhunen-Loeve (K-L) domain penalized weight...
Use of computed tomography (CT) as a medical diagnostic imaging tool has increased in recent decades because of its technical advances in data acquisition speed and image reconstruction technology. The increased reliance on CT was accompanied by increased patient exposure to ionizing radiation, however, and concerns among radiologic professionals and the public regarding CT dose resulted in inc...
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