Helical CT evaluation of aortic aneurysms and dissection: a pictorial essay.

The relative noninvasive nature, easy accessibility, convenience and accuracy of helical CT in the rapid evaluation of not only the aorta and its branches, but the entire thorax/abdomen, makes it the best suited imaging modality for use in evaluation of aortic aneurysms and dissection. Excellent vascular opacification, the advantage of reconstructing overlapping scans without respiratory misregistration, multiplanar reconstruction and 3D rendering of the vessels highlight the benefits of helical CT. Helical CT evaluation combines the advantages of conventional CT, giving true information about the exact transverse and longitudinal extent of the aneurysm, the vessel wall, luminal thrombus and structures around the aorta, and those of aortography in the form 3D volumetric information display. The purpose of this essay is to present a spectrum of aortic aneurysms and dissection to highlight the role of helical CT in their evaluation.