Analysis and Visualization Methods for Detecting Functional Activation Using Laser Speckle Contrast Imaging

AbstractPrevious studies have used regional cerebral blood flow (CBF) hemodynamic response to measure brain activities. In this work, we used a laser speckle contrast imaging (LSCI) apparatus to sample the CBF activation in somatosensory cortex (S1BF) with a repetitive whisker stimulation. Traditionally, the CBF activations were processed by depicting the change percentage above baseline. Thus, there is a limitation on the influence of different methods to detect activations in LSCI. First, principal component analysis (PCA) was performed to denoise the CBF signal. As the signal of the first principal component (PC1) showed the highest correlation with the S1BF CBF response curve, PC1 was used in the following analysis. Then we used fast Fourier transform (FFT) to evaluate the frequency properties of the LSCI images and the activation map was generated based on the amplitude of the central frequency. Furthermore, Pearson ’s correlation coefficient (C-C) analysis and a general linear model (GLM) were performed to estimate the S1BF activation based on the time series of PC1. We found that GLM performed better in identifying activation than C-C. Additionally, the activation maps generated by FFT were similar to those obtained by GLM. Particularly, the superficial vein and arterial vessels separated the activation region as segmented activated areas, and the regions with unresolved vessels showed a common activation for whisker stimulation. Our research analyzed the extent to w...

Source: Microcirculation - September 8, 2022 Category: Research Authors: Peng Hu, Bochao Niu, Hang Yang, Yang Xia, Donna Chen, Chun Meng, Ke Chen, Bharat Biswal Tags: ORIGINAL ARTICLE Source Type: research