CT ANGIOGRAPHY OF INTRACRANIAL ANEURYSMS - ADVANTAGES AND PITFALLS

Objective: To determine the clinical usefulness of computed tomography (CT) angiography in the evaluation of cerebral aneurysms. Materials a nd Methods: From October 1994 through April 1996, 26 patients with 30 surgical proven intracranial aneurysms underwent both CT angiography a nd catheter cerebral angiography. The findings of the two methods were reviewed independently and then compared with each other. Results: Co mparing with catheter angiography, CT angiography was superior in demo nstrating the aneurysmal neck in seven aneurysms but was inferior in o ne. The thrombosed part and calcification of aneurysms were clearly de monstrated on CT angiograms. CT angiography also aided in differentiat ing tight vascular loops from aneurysms. On CT angiograms, one posteri or communicating arterial aneurysm was overlooked and another anterior choroidal artery aneurysm was misinterpreted as a posterior communica ting artery aneurysm. Of note were two patients in whom the infundibul um of the orbitofrontal artery was misinterpreted as the anterior comm unicating artery aneurysm. Conclusion: CT angiography can compliment c onventional catheter angiography for its better demonstration of the 3 -dimensional anatomy. It can provide surgical information about the ne ck, calcification and thrombosed part of an aneurysm and its relation to adjacent structures. However, caution is advocated because CT angio graphy may fail to demonstrate small but important vessels such as pos terior communicating: anterior choroidal and orbitofrontal arteries. R ecognition of the limitations of CT angiography is important in minimi zing interpretation errors. (C) 1997 Elsevier Science Ireland Ltd.