To evaluate the usefulness of MDCT angiography in the diagnosis of vertebrobasilar artery dissection.

Between July 2003 and December 2005, 39 patients who underwent MDCT angiography and digital subtraction angiography with a history of suspicious vertebrobasilar artery dissection were selected. A blind interpretation of images was made by two observers, retrospectively. A diagnosis of dissection in MDCT angiography was made according to the following criteria: presence of an intimal flap, aneurysmal dilatation, abrupt or tapered luminal narrowing, alternatively dilated and narrowed lumen. The sensitivity and specificity of MDCT angiography in depicting vertebrobasilar artery dissection were determined.

43 vertebrobasilar artery dissections were diagnosed by MDCT angiography in 39 patients. The interobserver agreement was good (kappa=0.92). A diagnosis was made by the presence of an intimal flap (n=16, 36%), abrupt or tapered luminal narrowing (n=16, 36%), aneurysmal dilatation (n=13, 30%), alternatively dilated and narrow lumen (n=14, 32%). The sensitivities and specificities of MDCT angiography were 91%, 88% as determined by the first radiologist, and were 89%, 87% as determined by a second radiologist, respectively.

MDCT angiography is a useful method for the diagnosis of vertebrobasilar artery dissection.