CT) is a noninvasive radionuclide-based whole body imaging technique which combines both a Positron Emission Tomography (PET) scanner and an x-ray Computed Tomography (CT) scanner in a single gantry system. In PET, functional images are obtained which denotes spatial distribution of metabolic or biochemical activity in the body. These images are aligned with anatomical images obtained by CT sca...

combined pet/ct scanners now play a major role in medicine for in vivo imaging in oncology, cardiology, neurology, and psychiatry. as the performance of a scanner depends not only on the scintillating material but also on the scanner design, with regards to the advent of newer scanners, there is a need to optimize acquisition protocols as well as to compare scanner performances on an objective ...

Purpose: Compton spectroscopy is a widely accepted tool for measuring the primary X-ray spectra of a diagnostic computed tomography (CT) system. The aim of this work is to spectroscopically detect CT X-ray photons subjected to 90-degree Compton scattering for accurate modelling of CT beam-shaping filtration, which necessary for computation of radiation exposure and for other research applicatio...

introduction: in 2000, the unscear reported that ct constitutes 5% of all the medical x-ray  examinations and it contributes 34% of the resultant collective dose worldwide. children are more  sensitive to the ionizing radiations than adults. so, routine quality control tests are expected to be  carried out periodically on the ct scanners. the aim of this research was to estimate the effective  ...

A pelvimetry examination is sometimes prescribed to a pregnant woman at the end of her pregnancy in order assess dimensions pelvis prior childbirth. This has long been performed by using X-ray, but now increasingly being replaced CT-scan The objective this study radiation doses received during practical CT Hitashi Supria 16-slice scanner. were estimated Monte Carlo (MC)-based simulation with GA...

The authors describe a low-cost CT scanner integrated with a radiotherapy simulator and designed for treatment planning. The standard rotational gantry and x-ray tube of the simulator are used with a multiwire xenon lonization chamber and simple current-proportional readout system to measure patient attenuation, avoiding problems associated with diagnostic CT scanners in treatment planning. Al...

Three-dimensional computer models of dental arches play a significant role in prosthetic dentistry. The microfocus X-ray CT scanner has the advantage of capturing precise 3D shapes of deep fossa, and we propose a new method of measuring the three-dimensional morphology of a dental impression directly, which will eliminate the conversion process to dental casts. Measurement precision and accurac...

This paper presents the results of evaluating the use of X-ray CT data for attenuation correction of PET data. This method of attenuation correction is intended for use with a combined volume-imaging PET/CT scanner for oncology. We discuss four possible methods of scaling the attenuation map from the CT energies to the required PET attenuation map at 511 keV. Results are presented on the testin...

A state of the art X-ray micro-CT scanner takes about 20 seconds to acquire a full dataset, which is too slow to capture the rapidly beating heart of small animals. We have been working to develop the first electron-beam micro-CT (EBMCT) prototype for cardiac imaging of the mice and rats. In this paper, we describe the background on electron-beam CT (EBCT) and emphasize the needs for EBMCT. The...