LOCATION OF LANGUAGE IN THE CORTEX - A COMPARISON BETWEEN FUNCTIONAL MR-IMAGING AND ELECTROCORTICAL STIMULATION

PURPOSE: To determine the accuracy of functional MR imaging in locatin g language areas for planning surgical resection. METHODS: Intraoperat ive photographs were digitized and overlaid on functional MR language maps, The sensitivity and specificity of functional MR imaging for ide ntifying language areas were determined for five different language ta sks by comparing functional MR areas of language activation with resul ts of electrocortical stimulation. A match was considered to occur if an activated area contacted, overlapped, or surrounded a language tag. The borders of the activation areas were extended by 1 and 2 cm to de termine whether the number of matches changed. Language and nonlanguag e tag matches were tabulated separately. RESULTS: Sensitivity/specific ity for all patients and all language tasks ranged from 81%/53% for ar eas that touched to 92%/0% for areas separated by 2 cm. Individual lan guage tasks were not as sensitive as a battery of language tasks combi ned. Location of language areas varied among subjects for a given task and among tasks for a given subject. CONCLUSION: Functional MR imagin g should be considered a useful presurgical planning tool for mapping cortical language areas, because it is sensitive, it provides increase d time for planning before surgery, and it is noninvasive.