Full-field swept-source optical coherence tomography and neural tissue classification for deep brain imaging.

Ilan Felts Almog,Fu‐Der Chen,Suhan Senova,Wesley D Sacher,Anton Fomenko,Elise Gondard,Andres M Lozano,Joyce K S Poon

doi:10.1002/jbio.201960083

Abstract

Optical coherence tomography can differentiate brain regions with intrinsic contrast and at a micron scale resolution. Such a device can be particularly useful as a real‐time neurosurgical guidance tool. We present, to our knowledge, the first full‐field swept‐source optical coherence tomography system operating near a wavelength of 1310 nm. The proof‐of‐concept system was integrated with an endoscopic probe tip, which is compatible with deep brain stimulation keyhole neurosurgery. Neuroimaging experiments were performed on ex vivo brain tissues and in vivo in rat brains. Using classification algorithms involving texture features and optical attenuation, images were successfully classified into three brain tissue types.

Highlights

Neurosurgical interventions have evolved to provide effective treatment for a variety of disabling conditionsIlan Felts Almog and Fu Der Chen contributed to the study.including tumors [1], epilepsy [2], dystonia [3] and Parkinson's disease [4,5,6]
An endoscopic FF-Optical coherence tomography (OCT) system demonstrated by Benoit a la Guillaume et al provided sufficient resolution to resolve neurons, but its imaging depth was limited to tens of microns [46], whereas the structures of interest for neurosurgeical procedures are at least 1 mm thick
We have presented the first demonstration of FF-Swept-source OCT (SS-OCT) with >1 μm wavelength light as well as the first demonstration of such a system with an endoscopic probe which can be inserted several millimeters into tissue

Summary

| INTRODUCTION

Ilan Felts Almog and Fu Der Chen contributed to the study. including tumors [1], epilepsy [2], dystonia [3] and Parkinson's disease [4,5,6]. Different brain regions are identified by the electrophysiological pattern of neuronal activity, or by the patient's behavioral response to electrical stimulation at the implanted electrode [13,14,15] Such iterative recordings and stimulation are lengthy procedures and require an expertise in electrophysiology which might not be available in all neurosurgical centers. The wavelength coincides with one of the biological optical windows, providing longer imaging depth in tissue [37,38,39,40] Such specification is critical in detecting upcoming vascular structures for surgical guidance applications. An endoscopic FF-OCT system demonstrated by Benoit a la Guillaume et al provided sufficient resolution to resolve neurons, but its imaging depth was limited to tens of microns [46], whereas the structures of interest for neurosurgeical procedures are at least 1 mm thick. Image processing algorithms were developed and applied to the obtained images for the differentiation of brain regions

| MATERIALS AND METHODS

| Experimental procedures

Findings

| RESULTS

| CONCLUSION