BACKGROUND AND PURPOSE Coronary calcification as detected by electron-beam CT measures the atherosclerotic plaque burden and has been reported to predict coronary events. Because atherosclerosis is a generalized process, coronary calcification may also be associated with manifest atherosclerotic disease at other sites of the vascular tree. We examined whether coronary calcification as detected ...

To achieve higher volume coverage at improved z-resolution in computed tomography (CT), systems with a large number of detector rows are demanded. However, handling an increased number of detector rows, as compared to today's four-slice scanners, requires to accounting for the cone geometry of the beams. Many so-called cone-beam reconstruction algorithms have been proposed during the last decad...

INTRODUCTION C-arm Cone Beam CT (CBCT) is a technology that is being integrated into many of the newer angiography systems in the interventional suite. Due to its ability to provide cross sectional imaging, it has opened a myriad of opportunities for creating new clinical applications. We review the technical aspects, current reported clinical applications and potential benefits of this technol...

While the expenses for computational power decrease, iterative reconstruction methods for x-ray computed tomography (CT) that allow the use of improved model assumptions, become more attractive. In applications for non-destructive testing one of the most common degradations of image quality with standard x-ray CT reconstruction methods is beam hardening. Techniques for beam hardening correction...

Purpose: Photon counting (PC) computed tomography (CT) can provide material selective CT imaging at lowest patient dose but it suffers from suboptimal count rate. A dynamic beam attenuator (DBA) can help with count rate by modulating x-ray beam intensity such that the low attenuating areas of the patient receive lower exposure, and detector behind these areas is not overexposed. However, DBA ma...

2 national X ray digital imaging center; Mianyang,China Abstract Beam Hardening effect would be induced due to broad energy spectrum of X-ray. Beam Hardening would lead to artifacts in CT reconstructed images, such as cupping artifact, streak artifact and metal artifact, so that the quality of CT image degrades. One efficient beam hardening correction method is building a mathematical law betwe...

C-arms are well suited for obtaining cone-beam projections intra-operatively. Due to the compact size of the detector used, the data are usually truncated within the field of view. As a result, direct application of a standard cone-beam reconstruction algorithm gives rise to undesirable artifacts and incorrect values in the reconstructed image volume. When prior information such as a pre-operat...

Certain regions of the body can be relatively difficult to image optimally by computed tomography (CT). The lower neck falls into this category. A routine transverse image at this level includes the shoulders, which can cause beam hardening [1] . Beam hardening reduces subject contrast and often produces streak artifacts between the shoulders [2, 3]. This image degradation is especially trouble...

For a micro-Computed Tomography (Micro-CT) system, the microfocus X-ray tube is an essential component because the spatial resolution of CT images, in theory, is mainly determined by the size and stability of the X-ray focal spot of the microfocus X-ray tube. However, many factors, including voltage fluctuations, mechanical vibrations, and temperature changes, can cause the size and the stabili...