Accuracy of MR-guided stereotactic electrode implantation. 1. Preimplantation correlation with the Talairach system

The accuracy of stereotactic electrode implantation using MR guidance and a computerized imaging system was compared to the conventional Talairach system, using ventriculography and a stereotactic atlas. A combined methodology of two stereotactic approaches was used, with a modified Leksell and a Todd-Wells frame. The coordinates of temporo-limbic structures and the length of the AC-PC line were measured prior to implantation in 10 epileptic patients undergoing the combined procedure. Relative differences in single and three-dimensional values were obtained for 68 targets within the temporal lobe. Lengths of AC-PC lines were measured in 9 patients. Statistical differences were found for all temporal coordinates, but the AC-PC line did not differ significantly.