Application of spiral CT angiography in aortic diseases

Objective To evaluate the diagnostic efficacy of spiral CT angiography (CTA) in the assessment of aortic diseases. Methods Spiral CT of the aorta was performed in 42 patients including aortic dissection、aneurysm、pseudoaneurysm、coarctation、interruption and arteritis by using 5.0 mm/s table speed and 3 or 5 mm collimation (pitch=1.67 or 1.0). Overlapping axial reconstructed images were used to create MPR、SSD and MaxIP images. Results MPR successfully clarified the extent of the intimal flap and intraluminal thrombus in 14 patients, it was useful to display the anatomy in the region of the arch; SSD showed the spiraling of the intimal flap, but failed to differentiate the true lumen from the false one. MaxIP had no additional information. SSD better showed the extent of aneurysm and the relationship between aneurysm and arterial branches in 22 AAA; MPR was useful to determine the extent of intraluminal thrombus while MaxIP depicted the calcification of aorta, position and anatomic relationship of the stent. Site of rupture of aorta and pseudoaneurysm were shown clearly with MPR. The anatomy of anomalousvessels in 3 cases with congenital aortic diseaseswere demonstrated with SSD, whereas MPR and MaxIP couldn't provide useful information. Conclusions Spiral CT angiography is a valuable tool in the assessment of aortic diseases and can provide more useful informations for the surgeons.