Improving tractography in brainstem cavernoma patients by distortion correction.

Area of Science:

• Neurosurgery
• Medical Imaging
• Neuroscience

Background:

• Resection of brainstem cerebral cavernous malformations (CCM) risks damaging critical neural pathways like the corticospinal tract (CST).
• Accurate pre- and intraoperative visualization of these tracts is crucial for surgical planning and minimizing neurological deficits.
• Diffusion tensor imaging (DTI) tractography in the brainstem is challenged by distortions from magnetic field inhomogeneities and eddy currents.

Purpose of the Study:

• To evaluate the efficacy of cranial distortion correction (CDC) in improving CST tractography accuracy for patients with brainstem CCM.
• To quantify the impact of CDC on the anatomical localization and integrity of the CST in this patient cohort.

Main Methods:

• The study included 25 patients who underwent brainstem CCM resection; 24 had experienced hemorrhage.
• Anatomically based CST tractography was performed before and after applying CDC.
• Accuracy was assessed by anatomical plausibility, aberrant fiber detection, and measurements relative to anatomical landmarks.

Main Results:

• CDC significantly improved CST tractography precision, aligning it more closely with anatomical expectations.
• The CST was located more ventrally after CDC (1.5 ± 0.6 mm closer to the basilar artery; 1.7 ± 0.6 mm closer to the clivus).
• Aberrant fibers were reduced by 44% post-CDC, with no detectable motor deficits related to irregular fiber resection.

Conclusions:

• CDC is an effective method for correcting DTI tractography distortions in the brainstem, particularly for CCM patients.
• This correction enhances the anatomical accuracy of CST visualization, supporting safer and more precise surgical interventions.
• Improved tractography through CDC aids in preserving neurological function during brainstem lesion resection.