Evaluation of the Computed Tomographic Angiography for the Diagnosis of the Ruptured Cerebral Aneurysm

We retrospectively evaluated computed tomographic angiography (CTA) as the first choice of imaging for diagnosing ruptured cerebral aneurysms among 219 consecutive patients with non-traumatic subarachnoid hemorrhage (SAH) at our hospital between January 2001 and December 2004. We found ruptured cerebral aneurysms in 203 patients, and the first diagnostic method was Digital Subtraction Angiography (DSA) in 34 patients and CTA in 169. Complementary DSA was indicated in 27 of the latter group (CTA+DSA group), and the remaining 142 patients (CTA group) were treated based solely on CTA findings. We found that 22% of the CTA+DSA group (n=6) and 4.9% of the CTA group (n=7) (P<0.01) had aneurysms at the distal portions of major vessels. The outcomes of the 2 groups did not significantly differ, and the diagnosis was incorrect in only 1 patient in the CTA group. These findings indicated that the probability of misdiagnosing multiple aneurysms is higher when they are barely visible on CTA images, and thus physicians should strive to acquaint themselves with progress in diagnostic modalities and select the most appropriate strategy for individual patients with aneurysmal SAH.