Cerebral angiography is advisable in some cases prior to surgery for a brain tumor. This technique allows the most accurate and precise delineation of the blood vessels supplying both the tumor and the surrounding brain. It can allow preoperative planning that may be instrumental in preventing a neurological deficit following surgery. The technique involves passing a small catheter from an artery in the groin and injecting contrast material into the arteries supplying the tumor and brain. This produces a "roadmap" of these vessels that can be incorporated into a stereotactic database for use before and during surgery.

Two special techniques used during cerebral angiography are embolization and WADA testing. Embolization is useful preoperatively in treating some meningiomas. It involves deposition of particles into the inside of the blood vessels supplying the tumor. In cases where the blood supply is difficult to access surgically, embolization can diminish this blood supply and make surgery less technically challenging. WADA testing can be used when it is desirable to know which areas of the brain are active in speech and language function. This may be useful when a tumor involves the regions of the temporal or frontal lobes that are responsible for these functions.