It is important during neurosurgical procedures to identify and preserve eloquent functional cortex adjacent to a resectable lesion. Resection of a lesion infiltrating vital cerebral cortex can be associated with postoperative neurological deficits if the surgeon cannot clearly distinguish between the infiltrating borders of a lesion and surrounding functionally eloquent tissue. Spatial relationships between a lesion and surrounding normal brain can change significantly from those determined by preoperative methods such as CT and MRI scans. Necessary intraoperative interventions such as cerebrospinal fluid drainage, osmotic diuresis and lesion debulking cause quantitatively unpredictable brain shift in three dimensions. Therefore functional localization in real time that can be performed in the operating room is desirable. However, intraoperative real-time functional mapping techniques now available cannot be used in many surgical situations and are not sufficiently reliable in all cases in which they are used.

We have developed an intraoperative approach that may permit reliable lesion localization and brain functional mapping in real time with minimal risk. This approach makes use of infrared technology to identify functionally active eloquent cortex and may differentiate abnormal tissue from normal cortex.

The goal of this study is to investigate the clinical use of intraoperative infrared (IR) neuroimaging to differentiate intracranial lesions from surrounding normal functionally important tissue in real time. Reliable real-time intraoperative functional mapping of eloquent cortex adjacent to lesions by this technique would improve the safety and effectiveness of many neurosurgical procedures.