CT angiography: expanded clinical applications.

In this essay, the potential of vascular imaging with helical CT is explored. The speed and ease with which volumes of interest can be depicted with high resolution and the ability of CT to resolve small differences in electron density allow imaging of vascular territories with IV injection of iodinated contrast materials. Vascular and combined vascular/soft-tissue/bone imaging make CT a powerful clinical tool. The technique is predominantly used for evaluation of atherosclerotic disease of the carotid bifurcation, the renal arteries, and the major abdominal vessels. A variety of display options, such as surface rendering and maximum intensity projection (MIP), have different advantages and are often complementary. The time taken to produce clinically acceptable images has been markedly reduced to between 15 and 30 min. Some of the limitations are related to the length of vascular coverage, the contrast load, and the need for exact timing. On the other hand, the technique is not affected by flow artifacts. CT angiography is now a reliable and practical clinical test that may be a useful adjunct to conventional CT.