Approximately 1/3 of epilepsy patients have seizures that cannot be controlled with medication.  In these cases, either surgery or an implanted device in the brain may be able to improve seizure control.  To plan for the procedure, it is necessary to locate the exact source of the seizures by placing electrodes inside or over the surface of the brain.

MRI (Figure 1, Left) is the best imaging procedure for detail of the brain structure, but cannot be used once metal is in the brain.  CT (Figure 1, Right) can be used with metal, but does not provide detailed images of the brain. Merging these two images together (Figures 2 & 3) can provide detailed anatomical information, along with the exact location within the brain of the metal electrodes

The 3DQ Lab at Stanford uses the MRI from before the electrodes are implanted along with the CT from after the implantation to provide images that show the exact location of the electrodes in relation to the brain structure.