MR angiographic source images for depicting surgical topography of anterior communicating artery aneurysm.

BACKGROUND

This study evaluated the usefulness of magnetic resonance (MR) angiography on preoperative depiction of surgical topography around anterior communicating artery aneurysms.

METHODS

Twenty cases of anterior communicating artery aneurysms, nine ruptured and 11 unruptured, were included. MR angiographic source images and projection images were obtained by three-dimensional (3D) time-of-flight techniques. Conventional angiography was performed by femoral artery catheterization. By comparing the topography based on these angiograms to that confirmed during surgery, we evaluated the information provided by MR angiography that was beneficial during surgery.

RESULTS

MR angiographic source images could visualize cerebral and nerve tissues around the aneurysms in all 20 cases. In five cases, the source images provided additional useful information to that from conventional angiography. It included visualization of aneurysmal domes in the gyrus rectus in two cases and aneurysmal adhesion to the optic nerve or chiasma in three cases. These findings were considered to have contributed to successful aneurysmal surgery. The remaining 15 cases, however, had such typ ical anatomy around the aneurysm that clipping was conventionally performed without additional information from the source images.

CONCLUSIONS

MR angiographic source images have a distinguishing feature in defining neural tissue-vascular relationships and can significantly improve preoperative depiction of surgical topography. They would be useful only when there are still questions after careful reading of conventional angiography.