Spiral CT angiography and 3D reconstruction in patients with aortic coarctation

The objective of this study was to assess the reliability of spiral CT angiography (CTA) and 3D reconstruction in patients with aortic coarctation (CoA). Eighteen patients with suspected or surgically proven coarctation were examined by spiral CT. In addition to the axial slices, 3D reconstructions, such as shaded surface display (SSD) and maximum intensity projection (MIP), were used to determine the diameters of the CoA and the pre- and poststenotic aorta and to visualise the collateral vessels. Diameters derived from cardiac catheterization were compared with those from CTA in 8 patients. The degree of aortic stenosis was correlated with blood pressure gradients (BPG) in 12 patients. The difference between the diameters of the CoA and the pre- and poststenotic aorta derived from MIP and angiography was not statistically significant (p = 0.69). With SSD the internal thoracic artery was detected in 16 and the posterior intercostal artery in 13 cases. The degree of aortic stenosis correlated poorly with the BPG (r = 0.51, r2 = 0.26). CTA with 3D reconstruction represents a reliable noninvasive technique for the assessment of the degree of CoA and the visualisation of collateral vessels. It may serve as a follow-up investigation after intervention or surgical treatment.