The introduction of cone beam computed tomography into dentistry, and particularly into private offices, has raised a number of medicolegal issues. Among the issues raised are who may own and operate the machines, for what purposes should the machines be used, how broadly or narrowly should the field be collimated, does the full volume need to be interpreted and, if so, by whom? For images inte...

Cancer is a highly lethal disease that mainly treated by image-guided radiotherapy. Because the low dose of cone beam CT less harmful to patients, images are often used for target delineation in radiotherapy various cancers, especially breast and lung cancer. However, breathing heartbeat can cause position errors taken during different periods, also results insufficient imaging clarity, renderi...

Bai et al. recently proposed to acquire random fanbeam/cone-beam projections with a linear/planar detector from a circular scanning locus for controlled cardiac computed tomography (CT). After specifying a uniform acquisition geometry required by FBP (filtration-backprojection), we rebin the random fan-beam/cone-beam data via nearest-neighbor, quadrilateral and triangle-based linear interpolati...

For spiral cone-beam CT, parallel computing is an effective approach to resolving the problem of heavy computation burden. It is well known that the major computation time is spent in the backprojection step for either filtered-backprojection (FBP) or backprojected-filtration (BPF) algorithms. By the cone-beam cover method [1], the backprojection procedure is driven by cone-beam projections, an...

In x-ray micro-CT applications, it is useful to increase the field of view by offsetting a two-dimensional (2D) detector array. In this technical note, we briefly review the methods for image reconstruction with an asymmetric 2D detector array, elaborate on the use of an associated weighting scheme in the case of helical/spiral cone-beam scanning, and perform a series of numerical tests to demo...

We report on our first results on the use of Algebraic Reconstruction Techniques (ART) on helical cone-beam Computerized Tomography (CT) data. Two variants of ART have been implemented: a standard one which considers a single ray in an iterative step and a block version which groups several conebeam projections in calculating an iterative update. Both seem to produce high-quality reconstruction...