Intracanalicular aneurysm of the anterior inferior cerebellar artery revealed by multi-detector CT angiography.

A 62-year-old woman had sudden-onset headache and posterior neck pain, and a subarachnoid hemorrhage was revealed by unenhanced CT. Both multi-detector CT angiography and digital subtraction angiography were performed and revealed a small intracanalicular aneurysm of the left anterior inferior cerebellar artery. The patient underwent successful retrosigmoid craniectomy and trapping of the aneurysm. This case shows the ability of multi-detector CT angiography to indicate bony landmarks that can alter the surgical approach.