Comparison of Magnetoencephalography, Functional Magnetic Resonance Imaging, and Diffusion Tensor Imaging for Tractography for Localization of the Sensory-Motor Cortex |
Ji Hee Kim, Won Seok Chang, Dong Kyu Lee, Bong Soo Kim, Yong Gou Park, Yong Ho Lee, Jin Woo Chang |
Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Korea, Magnetoencephalography Room, Severance Hospital, Seoul, Korea, Korea Research Institute of Standard and Science, Daejeon, Korea |
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Abstract |
Objective Resection of brain tumors adjacent to eloquent areas is a challenge in neurosurgery. If maximal resection is desired without injury to eloquent areas, preoperative cortical mapping is necessary. The purpose of this study is to evaluate preoperative magnetoencephalography, functional magnetic resonance imaging, and diffusion tensor imaging for tractography for localization of the sensory-motor cortex.
Methods We assessed 11 patients who underwent resection of brain tumors located near the sensory-motor cortex at our institute from October 2010 to January 2011. All patients were taken preoperative magnetoencephalography, functional magnetic resonance imaging, and diffusion tensor imaging for tractography. Awake craniotomies were performed in some cases. Clinical outcomes were analyzed by neurologic examination, before the surgery and 14 days after surgery.
Results With functional magnetic resonance imaging, a central sulcus could not be defined in 3 cases in which the non-affected hemispheres of patients were examined, and it could not be defined in 8 cases in which the affected hemispheres were examined. With magnetoencephalography, a central sulcus could be localized in 10 cases in which the non-affected hemispheres of patients were examined, and in all cases in which the affected hemispheres were examined. In the examination of the affected hemispheres, magnetoencephalography and functional magnetic resonance imaging for localization of the sensory-motor cortex showed a significant difference. In diffusion tensor imaging for tractography, a central sulcus could be defined in 10 of the examined patients. Three patients underwent awake craniotomy with intraoperative cortical mapping, and the result corresponded to the localization identified with magnetoencephalography. All patients underwent gross total removal of the tumor. Neurologic deficit was aggravated postoperatively in 3 patients, and had not changed in 7 patients. 1 patient showed improved neurologic symptoms.
Conclusion There were three modalities for preoperative cortical mapping. Each of modality has different strengths and weaknesses. From the results, we recommend a combination of magnetoencephalography, functional magnetic resonance imaging, and diffusion tensor imaging for tractography for precise functional assessment of the brains affected by intracranial tumors. |
Key Words:
Magnetoencephalography, Functional magnetic resonance image, Diffusion tensor image, Tractography, KEY WORDS: Eloquent brain area, Central sulcus. |
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