Current Medical Imaging - Volume 6, Issue 2, 2010

As one of the most commonly used medical imaging modalities, x-ray computed tomography (CT) continues to play an important role in current diagnostic imaging. This hot topic issue of CMIR summarizes some new developments in nonconventional x-ray CT imaging techniques. In the past decades, significant research efforts on CT have been made in the direction of low-dose, fast imaging, improved image quality and multi Read More

Cone-beam dedicated breast CT scanners have been developed to provide 3D images of the breast with sub millimeter isotropic resolution, no breast compression, and dose equivalent to mammography. This article will first review the system design and hardware components used in dedicated breast CT, followed by a review of scanner performance and image quality investigations. Proposed reconstruction algorithms Read More

Cone-beam computed tomography (CBCT) is an emerging medical imaging modality used for various clinical applications. However, radiation dose to patients is a major limiting factor for its utility in some applications such as daily patient setup and future adaptive therapy in radiotherapy. In this article, we summarize recent development for dose reduction in CBCT. In particular, we discuss several noise reduction strategies for lo Read More

X-ray cone-beam computed tomography (CBCT) is widely used nowadays, mainly for its large volume coverage and hardware compatibility with open-gantry x-ray imaging systems. As the size of x-ray illumination increases, an inevitable and adverse effect is the boost of scatter contamination on the x-ray images, which becomes one of the fundamental limitations of CBCT imaging. The large scatter signals in CB Read More

Phase sensitive imaging theoretically allows for a drastic reduction in x-ray dose while simultaneously achieving comparable or better spatial and contrast resolution compared to traditional x-ray absorption based imaging. Several techniques exist to extract the phase information from an x-ray signal, including x-ray interferometry, diffraction enhanced imaging, in-line holography, coded aperture x-ray imaging, and grating-b Read More

The combination of functional and anatomical information through dual-modality imaging has brought about a revolution in the diagnostic and prognostic impact of noninvasive in vivo imaging. As the current marketplace shows, one of the best means of combining anatomical and functional imaging methods is to integrate the two modalities around a common table or bed, and perform the two scans sequentially while the su Read More

Over the past few years, computed tomography (CT) reconstruction theory has undergone a rapid development. Since Katsevich published his paper on exact and efficient helical cone-beam CT reconstruction in 2002, intensified research efforts have been made in this field. Various analytic algorithms have been proposed for exact reconstruction from many kinds of projection data. Among them, region-of-interest (ROI) or v Read More

A new image reconstruction algorithm, prior image constrained compressed sensing (PICCS), will be reviewed in this paper. PICCS enables accurate image reconstruction with high contrast-to-noise ratio from undersampled projection data sets. Several clinically relevant applications are reviewed to demonstrate how the new algorithm can be utilized to: reduce radiation dose, provide high quality four dimensional cone beam CT im Read More