The accuracy and reliability of 3D CT/MRI co-registration in planning epilepsy surgery

Clin Neurophysiol. 2009 Apr;120(4):748-53. doi: 10.1016/j.clinph.2009.02.002. Epub 2009 Mar 4.


Objective: To investigate the accuracy and reliability of 3D CT/MRI co-registration technique for the localization of implanted subdural electrodes in the routine epilepsy presurgical evaluation, in so doing assess its usefulness in planning the tailored resection of epileptic focus.

Methods: Four external anatomic fiducial makers were used for co-registration of volumetric pre-implant brain MRI and post-implant head CT using Curry 5.0 software in 19 epilepsy presurgical candidates. The location of subdural electrodes derived from the co-registration was compared to that obtained by intra-operative digital photographs by using gyral/sulcal patterns and cortical vasculature as anatomic markers.

Results: The mean localization error was 4.3+/-2.5 mm in all 19 patients. However, the mean localization error was 3.1+/- 1.3 mm in 13 patients with all four reliable fiducial markers; whereas the mean localization error was 6.8+/-2.4 mm in 6 patients with two or three reliable fiducial markers.

Conclusion: Visualization of subdural electrode positions on a patient's cortex can be accurately performed in the routine clinical setting by 3D CT/MRI co-registration. However, the accuracy of co-registration is dependent upon having reliable surface fiducial markers. In practice, confirmation of location accuracy, such as with intra-operative digital photographs, is necessary for planning of tailored resective surgery.

Significance: The combination of 3D CT/MRI co-registration and intra-operative digital photography techniques provides a practical and effective algorithm for the localization and validation of implanted subdural electrodes.

MeSH terms

  • Adolescent
  • Adult
  • Electroencephalography
  • Epilepsies, Partial / pathology
  • Epilepsies, Partial / surgery*
  • Female
  • Humans
  • Imaging, Three-Dimensional / methods*
  • Magnetic Resonance Imaging / methods*
  • Male
  • Middle Aged
  • Patient Care Planning
  • Photography
  • Preoperative Care
  • Registries*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Tomography, X-Ray Computed / methods*
  • Young Adult