High-resolution Infrared Thermal Imaging (ITI) for Simultaneous Functional Mapping of the Entire Craniotomy in Awake Patients

Functional activation of the cerebral cortex creates a robust increase in local temperature by increasing blood flow and metabolism because of neurovascular coupling. Changes in surface brain temperature while an awake patient performs a motor, sensory, or language task can be used to infer spatial patterns of activity to create functional maps. Awake neurosurgery is used in the management of drug-resistant epilepsy, glioma, and neurovascular malformation, in order to localize seizure and/or physiologic activity. Protection of key functional areas is imperative to avoiding postoperative neurologic deficits. Currently, direct electrical stimulation (DES) is the most commonly used method of intraoperative surgical mapping, which identifies functionally critical brain regions so they are not resected. However, DES has low spatial resolution (~1 cm), may provoke seizures, and can only test one area at a time. This project investigates a new method of intraoperative functional mapping based on infrared thermography, which has high resolution (~100 micron) and simultaneously monitors the entire exposed brain surface without risk for seizures. The Intraoperative Mapping System will be developed and tested on glioma patients, as tumors have relatively static impact on brain temperature compared to epileptogenic foci and vascular malformations. Preliminary data in motor and language mapping cases shows large (~0.5oC) positive thermal activation of contralateral motor cortex and language regions that have strong agreement with DES. Aim 1 will develop a mapping system (hardware and software) required to conduct real-time thermal-based brain mapping during awake craniotomy. We will optimize and integrate the infrared recording procedure within the surgical workflow, to maximize signal quality while minimizing treatment interference. The central piece is a mobile cart containing a powerful workstation and an articulating arm to locate the IR camera over the craniotomy. The compu