Computer-assisted automatic localization of the human pedunculopontine nucleus in T1-weighted MR images: A preliminary study

Background: The pedunculopontine nucleus (PPN) is a new promising target of deep brain stimulation (DBS) for the treatment of Parkinson's disease. This study was to develop a method of computer-assisted automatic localization of the PPN in T1-weighted MR images. Methods: A 3D template of a segment of the brainstem containing the PPN was constructed. A knowledge-based, hierarchical method of template-to-subject registration was proposed to register the template to the subject's data to locate the subject's PPN. Results: Experiments were performed with both T1-weighted and proton density MR images acquired from 12 people. Preliminary results show that the proposed method can locate the PPN with an error of 1.83 ± 0.42 mm for its rostral pole and 1.57 ± 0.34 mm for its caudal pole. Conclusion: The proposed method is automatic, robust and accurate in the localization of the PPN, which demonstrates utility for preoperative surgical planning.