Magnetic resonance angiographic source images for depicting topography and surgical planning for middle cerebral artery aneurysms: technique application.

PURPOSE

To evaluate the usefulness of magnetic resonance (MR) angiographic source images for determining the feasibility of M1 segment control via the distal approach in pterional craniotomy for middle cerebral artery (MCA) aneurysms.

METHODS

MR angiographic source and conventional angiographic source images were obtained in 40 patients with MCA aneurysms. Each aneurysm was treated surgically using a pterional craniotomy. We initially approached the aneurysm distally. When this was judged inappropriate, the approach was altered to proximally. We compared the topography based on these angiograms to that confirmed during surgery.

RESULTS

MR angiographic source images visualized the aneurysm, the M1 and M2 segments of the MCA, the insula, and the frontal and temporal opercula in all 40 patients. In 22 (55%) of them, the distal portion of the M1 segment was recognized from the posterolateral perspective between the aneurysmal neck and the insular surface. These aneurysms were successfully clipped via the distal approach after definite proximal control of the MCA was obtained.

CONCLUSIONS

It was concluded that MR angiographic source images have a distinguishing feature in defining cerebral tissue-vascular relationships and that they are useful in the surgical planning for MCA aneurysms.