The preoperative targeting of proper implantation sites can be accomplished by the indirect and direct methods. The indirect method uses computer tomography, magnetic resonance imaging, or ventriculography to locate the anterior and posterior commissures and then employs predetermined coordinates and distances from the intercommissural line to define the target area. Subsequent histologically defined atlas maps can also be used to verify the target area. The direct method provides visualization and targeting of deep nuclei by applying stereotactic preoperative MRI, which unlike the indirect method, takes into account the anatomic variation of the nuclei’s size, position, and functional segregation amongst individuals.