MAPPING OF THE CORTICAL MOTOR HAND AREA WITH FUNCTIONAL MR-IMAGING AND MR IMAGING-GUIDED LASER-INDUCED INTERSTITIAL THERMOTHERAPY OF BRAIN-TUMORS - WORK-IN-PROGRESS

PURPOSE: To localize the cortical motor hand area with functional magn etic resonance (MR) imaging before and after MR imaging-guided laser-i nduced interstitial thermotherapy of tumors in the precentral brain re gion to control energy delivery and to improve safety. MATERIALS AND M ETHODS: Functional MR images were obtained in eight patients (five men , three women; aged 27-63 years) while they flexed their fingers. MR i maging-guided laser-induced interstitial thermotherapy was terminated when there was less than 8-12 mm between the border of the laser-induc ed lesion and the motor hand area anterior aspect. RESULTS: Seven pati ents had a statistically significant localized change in signal intens ity in the central region of the contralateral hemisphere. This area w as a spotlike circumscribed focus in three patients and scattered over a larger zone in four patients. Persistent deficits did not occur aft er thermotherapy in any patient. In three patients, onset of reversibl e perifocal edema in the motor hand area coincided with the developmen t of hemiparesis, which completely resolved. No patient had activity w ithin the tumor on functional MR images. CONCLUSION: Functional MR ima ging findings can be used to prevent neurologic damage during MR imagi ng-guided laser-induced interstitial thermotherapy.