Intraoperative quantitative functional brain mapping using an RGB camera.

Charly Caredda,Laurent Mahieu-Williame,Bruno Montcel,Jacques Guyotat,Raphaël Sablong,Laure Alston,Michaël Sdika

doi:10.1117/1.nph.6.4.045015

Abstract

.Intraoperative optical imaging is a localization technique for the functional areas of the human brain cortex during neurosurgical procedures. However, it still lacks robustness to be used as a clinical standard. In particular, new biomarkers of brain functionality with improved sensitivity and specificity are needed. We present a method for the computation of hemodynamics-based functional brain maps using an RGB camera and a white light source. We measure the quantitative oxy and deoxyhemoglobin concentration changes in the human brain cortex with the modified Beer–Lambert law and Monte Carlo simulations. A functional model has been implemented to evaluate the functional brain areas following neuronal activation by physiological stimuli. The results show a good correlation between the computed quantitative functional maps and the brain areas localized by electrical brain stimulation (EBS). We demonstrate that an RGB camera combined with a quantitative modeling of brain hemodynamics biomarkers can evaluate in a robust way the functional areas during neurosurgery and serve as a tool of choice to complement EBS.

Highlights

Noninvasive functional brain mapping is an imaging technique used to localize the functional areas of the patient brain
We propose in our study to complement the intrinsic optical imaging approaches with statistical analyses inspired by the blood oxygenation level-dependent (BOLD) Functional magnetic resonance imaging (fMRI) method
A quantitative and noninvasive method for imaging the oxygenated hemoglobin concentration changes (Δ1⁄2HbO2) and deoxygenated hemoglobin concentration changes (Δ1⁄2Hb) of a human exposed cortex using a digital RGB camera was demonstrated in the present report

Summary

Introduction

Noninvasive functional brain mapping is an imaging technique used to localize the functional areas of the patient brain. After patient craniotomy, a brain shift invalidates the relevance of neuronavigation to intraoperatively localize the functional areas of the patient brain.[2] In order to prevent any localization error, intraoperative MRI has been suggested but it complicates the surgery gesture which makes it rarely used. For these reasons, electrical brain stimulation (EBS)[3] is the gold standard for the identification of brain functional areas.

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