Spiral CT angiography of aortic dissection

Spiral CT angiography (CTA) is one of the newest imaging techniques used for the evaluation of aortic dissection. Current spiral CT scanners with high-performance tubes and subsecond scanning allow increased regions of coverage. Large volumes of data are rapidly acquired through the aorta during maximum contrast enhancement. Multiplanar reformat (MPR), curved planar reformat (CPR), and 3-D rendering techniques including shaded surface display (SSD) and maximum intensity projection (MIP) are then applied to the data to generate CT angiographic images of the aorta. Emergent spiral CTA may be performed in patients with suspected aortic dissection who are hemodynamically stable. Postprocessing is performed immediately following data acquisition and can provide additional information for aortic dissection diagnosis and clinical management. The technique, applications, and limitations of spiral CTA for the evaluation of aortic dissection will be discussed relative to the role of other imaging modalities.