Iodine is commonly used as a contrast agent in nonmedical science and engineering, for example, to visualize Darcy flow in porous geological media using X-ray computed tomography (CT). Undesirable beam hardening artifacts occur when a polychromatic X-ray source is used, which makes the quantitative analysis of CT images difficult. To optimize the chemistry of a contrast agent in terms of the be...

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...

authors and five references. They should not have tables or figures and should relate solely to an article published in Circulation within the preceding 12 weeks. Only some letters will be published. Authors of those selected for publication will receive prepublication proofs, and authors of the article cited in the letter will be invited to reply. Replies must be signed by all authors listed i...

In computed tomography (CT) the quality of reconstructed images depends on several reasons: the quality of the set-up calibration; precision of the mathematical model, used in the reconstruction procedure; the reconstruction technique used; quality of the numerical implementation of the reconstruction algorithm. Most of fast reconstruction algorithms use the X-ray monochromaticity assumption. I...

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...

Coronary artery calcification quantification (scoring) has been done with electron beam CT (EBCT), but is now being done with spiral or helical CT. Many radiologists and cardiologists who do not have EBCT but do have access to spiral CT will now be able to do coronary artery calcification scoring, and will now need to know the spiral CT appearance of the coronary artery anatomy. This pictorial ...

authors and five references. They should not have tables or figures and should relate solely to an article published in Circulation within the preceding 12 weeks. Only some letters will be published. Authors of those selected for publication will receive prepublication proofs, and authors of the article cited in the letter will be invited to reply. Replies must be signed by all authors listed i...

Using the backprojection filtration (BPF) and filtered backprojection (FBP) approaches, respectively, we prove that with cone-beam CT the interior problem can be exactly solved by analytic continuation. The prior knowledge we assume is that a volume of interest (VOI) in an object to be reconstructed is known in a subregion of the VOI. Our derivations are based on the so-called generalized PI-se...

A Monte Carlo based computer model has been developed for electron beam computed tomography (EBCT) to calculate organ and effective doses in a humanoid hermaphrodite phantom. The program has been validated by comparison with experimental measurements of the CT dose index in standard head and body CT dose phantoms; agreement to better than 8% has been found. The robustness of the model has been ...