Image-guided radiation therapy using cone-beam computed tomography (CBCT) is becoming routine practice in modern radiation therapy. The purpose of this work was to develop an imaging QA program for CT and CBCT units in our department, based on the American College of Radiology (ACR) CT accreditation phantom. The phantom has four testing modules, permitting one to test CT number accuracy, slice ...

During the last years, a number of novel X-ray imaging and data processing methods have been developed. This work gives an overview of some recent CT-developments: 1) High resolution CT: State of the art laboratory CT-systems are able to reach resolutions down to 0.7 μm (or even lower) and voxels sizes down to 50 nm. Several applications of high-resolution CT are presented and discussed. 2) Qua...

This article discusses CT radiation dose, the measurement of CT dose, and CT image quality. The most commonly used dose descriptor is CT dose index, which represents the dose to a location (e.g., depth) in a scanned volume from a complete series of slices. A weighted average of the CT dose index measured at the center and periphery of dose phantoms provides a convenient single-number estimate o...

X-ray computed tomography (CT) systems with high resolution (also known as micro-CT systems) have been developed over the last two decades and have been used with great success in small animal studies. A micro-CT scanner is based on the same underlying physical principle as a clinical CT scanner, but it is designed for higher-resolution imaging. It produces three-dimensional (3D) tomographic da...

OBJECTIVE High-resolution MRI methods have been used to evaluate carotid artery atherosclerotic plaque content. The purpose of this study was to assess the performance of high-resolution MRI in evaluation of the quantity and pattern of mineral deposition in carotid endarterectomy (CEA) specimens, with quantitative micro-CT as the gold standard. METHODS AND RESULTS High-resolution MRI and CT w...

The purpose of this work is measurement of the system presampling MTF of a variable resolution x-ray (VRX) CT scanner. In this paper, we used the parameters of an actual VRX CT scanner for simulation and study of effect of different focal spot sizes on system presampling MTF by Monte Carlo method (GATE simulation software). Focal spot size of 0.6 mm limited the spatial resolution of the system ...

Conformal proton radiation therapy requires accurate prediction of the Bragg peak position. Protons may be more suitable than conventional x-rays for this task since the relative electron density distribution can be measured directly with proton computed tomography (CT). However, proton CT has its own limitations, which need to be carefully studied before this technique can be introduced into r...

BACKGROUND Direct comparison of CT and magnetic resonance (MR) perfusion techniques has been limited and in vivo assessment is affected by physiological variability, timing of image acquisition, and parameter selection. OBJECTIVE We precisely compared high-resolution k-t SENSE MR cardiac perfusion at 3 T with single-phase CT perfusion (CTP) under identical imaging conditions. METHODS We use...

We present our methodology for the three-dimensional anatomical and geometrical description of soft tissues, relevant for orthopaedic surgical applications and musculoskeletal biomechanics. The technique involves the segmentation and geometrical description of muscles and neurovascular structures from high-resolution computer tomography scanning for the reconstruction of generic anatomical mode...

Background: For almost a decade, virtual reality (VR) has been employed in otology simulation. The realism and accuracy of traditional three-dimensional (3D) mesh models the middle ear from clinical CT have suffered because their low resolution. Although micro-computed tomography (micro-CT) imaging overcomes resolution issues, its usage platforms limited due to high computational requirements. ...