Introduction: Crosstalk is a leakage of X-ray or light produced in a matrix of X-ray detectors or array of photodiodes in one element to other elements affecting on image contrast and spatial resolution. In this study, we assessed X-ray crosstalk in a computed tomography (CT) scanner with small detector elements to estimate the effect of various parameters such as X-ray tube voltage, detector e...

According as the progress of medical technique, X-ray imaging systems have been progressed. Especially, X-ray CT imaging system have been improved and widely used as general diagnostic methods nowadays in Japan. However, the doses for patients of X-ray CT imaging are relatively higher than of other Xray examinations. The dose estimations and optimizations on X-ray CT are very important for medi...

PURPOSE Attenuation correction with an X-ray CT image is a new method to correct attenuation on SPECT imaging, but the effect of the registration errors between CT and SPECT images is unclear. In this study, we investigated the effects of the registration errors on myocardial SPECT, analyzing data from a phantom and a human volunteer. METHODS Registerion (fusion) of the X-ray CT and SPECT ima...

With wide industrial application, computerized tomography (CT) is a rapidly developing technique that is especially useful for imaging and measuring multi-component and multi-phase processes. Tomographic measurements can be obtained by using different sensors, such as X-ray, ultrasonic, optical and microwave sensors, as well as electrical impedance electrodes [6]. X-ray, ultrasonic and microwav...

introduction: variable resolution x-ray (vrx) ct is a new type of ct that can image objects at various spatial resolutions. in a vrx ct scanner, the spatial resolution increases at the cost of reduction in the field of view (fov). an important factor that limits the spatial resolution of the vrx ct is the effect of focal spot size. also, the optimum magnification is different at each incident a...

background: a variable resolution x-ray (vrx) ct scanner provides a great increase in the spatial resolution. in vrx ct scanners, the spatial resolution of the system and its field of view (fov) can be changed according to the object size. one of the main factors that limit the spatial resolution of vrx ct scanner is the effect of the x-ray focal spot. materials and methods: a theoretical study...

Introduction: The purpose of the current study was to investigate the effect of X-ray spectra on the sensitivity of a polymer gel dosimeter imaged with a conventional computed tomography (CT) scanner. Material and Methods: The whole process of CT imaging of an irradiated polymer gel was simulated by MCNPX Monte Carlo (MC) code. The imaging of polyacrylamide gel was accomplished by means of a co...

Background: In CT systems, the machine utilizes a bowtie filter to shape the X-ray beam and remove lower energy photons. The shape of this bowtie filter is complicated and its geometry is often not available in detail. These renders the CT dose index (CTDI) to have different values in measurement versus Monte Carlo simulation studies and other analytical calculations especially in dosimetry of ...

Generally, computerised tomography (CT) is an X-ray based non-destructive testing method that was developed for medical purposes in the seventies and introduced for industrial applications during the eighties. CT produces maps of the X-ray linear attenuation coefficient of an object’s interior; presented either as cross section images (two-dimensional CT) or as volume information (three-dimensi...

Radiologic Procedure Rating Comments RRL* CT abdomen and pelvis without and with contrast 2 ☢ ☢ ☢ ☢ X-ray abdomen 2 ☢ ☢ CT abdomen and pelvis without contrast 2 ☢ ☢ ☢ ☢ CT abdomen and pelvis with contrast 2 ☢ ☢ ☢ ☢ X-ray contrast enema 2 ☢ ☢ ☢ X-ray cystography 2 ☢ ☢ ☢ MRI pelvis without and with contrast 2 MRI may be indicated if urethral diverticulum is suspected. O MRI pelvis without contras...