The Application Of High-field Intraoperative Magnetic Resonance Imaging On Stereotactic Biopsy And Microsurgical Resection Of Lesions Involving Hand Motor Area

Objective To explore the applied effects of high-field intraoperative magnetic resonance imaging (iMRI) on multi-image fusion guided stereotactic biopsy of hand motor area brain lesions. And study the methods and applications of intraoperative magnetic resonance imaging (iMRI)-guided functional neuronavigation combined with intraoperative neurophysiological monitoring (IONM) for microsurgical resection of lesions involving hand motor area.Method In the first part,12patients with hand motor area brain lesions were performed by conventional MRI, diffusion tensor imaging (DTI) and blood oxygenation level dependent-functional magnetic resonance imaging (BOLD-fMRI) with1.5T intraoperative MRI system before operation. The digital image data and preoperative PET/CT image data were transferred into BrainLAB planning workstation and all kinds of images were automatically fused. We used the BrainLAB software to reconstruct corticospinal tract (CST) and hand motor activation areas and three-dimensional display the anatomic relationship of CST and brain lesions. Leksell surgical planning workstation was used to help to choose the best target site and the reasonable needle track. The1.5T iMRI was used to effectively monitor the intracranial condition during brain biopsy procedure. In the second part,16patients with brain lesions adjacent to hand motor area were enrolled in the study. All the patients were examined by conventional MRI, DTI and BOLD-fMRI with1.5T high-field intraoperative MRI system. Conventional MRI, DTI and BOLD-fMRI data were integrated into neuronavigation system for intraoperatively locating lesions, CST and hand motor activation areas. Besides, intraoperative neurophysiological monitoring (IONM), including somatosensory evoked potentials (SEP), motor evoked potentials (MEP) and electrocorticogram (ECoG), was carried out to further map hand motor area and epileptogenic focus. High-field iMRI was used to update the anatomical and functional imaging date and verify the extent of lesion resection.Results In the first part, needle biopsies were successfully performed in all12cases and pathological diagnosis were explicitly obtained in12patients. No patient suffered from significant complications during or after surgery. In the second part, brain shifting during the functional neuronavigation was corrected by iMRI in5patients. Finally, total lesion resection was achieved in13cases, subtotal resection in3cases. Lesions in3cases were not further resected because the residual lesions were immediately adjacent to hand motor area. At3-18months after the operation, the hand motor function improved or unchanged in all the16cases, and no patients had a persistent neurological deficit. The postoperative seizure improvement has achieved Engel Ⅱ level or above in9cases of brain lesions complicated with secondary epilepsy.Conclusion With the help of high-field iMRI, multi-image fusion guided stereotactic brain biopsy conduces to achieving the purpose of higher positive rate of biopsy and lower incidence of complications. The method with this design combining MRI-DTI fusion images with the frame-based stereotactic biopsy can play a significant role in intracranial lesions of hand motor areas. Intraoperative MRI. functional neuronavigation and neurophysiological monitoring technique are complementary in microsurgery of brain lesions involving hand motor area. Combined using these techniques can obtain precise location of lesions and hand motor functional structures, and allow a maximum resection of lesion and minimization of postoperative neurological deficit.