Three-Dimensional and Micro-Scale Brain Functional Imaging by Functional Optical Coherence Tomography Combined with Fourier Imaging

Abstract

Functional optical coherence tomography (fOCT) has been developed as a three-dimensional (3D) and micro-scale brain functional imaging technique. The brain functional signal obtained from fOCT is based on changes in OCT signal intensities before and after a given stimulation. However, it is difficult to accurately calculate the functional signals since the signals are usually contaminated with lots of physiological noises e.g. heartbeat and respiration. In this study, in order to remove such noises, we proposed a combination of fOCT and Fourier imaging, which uses periodic stimulation and extracts a component at the stimulus frequency in acquired OCT signals. The proposed method was applied to cat early visual cortex and visualized the first clear maps of 3D brain function by fOCT. The functional maps obtained by fOCT were compared with the neural response properties and showed statistically significant correlations (ρ_T = 0.0318, p = 1.29 x 10^-11). Therefore, the combination of fOCT and Fourier imaging is promising to improve detection accuracy of fOCT, suggesting the utility for clinical diagnosis of brain dysfunction.