Spatial Variation of BOLD Contrast in the Activated ROI Is Correlated with Voxel-Wise Gray Matter Volume Fraction

Wanyong Shin¹, Hong Gu¹, Qihong Zou¹, Pradeep Kurup¹, Yihong Yang¹

In this study, we investigate spatial variations of BOLD contrast (β) within individual subjects and correlate it with voxel-wise T1 and fractional volume (fv) of each tissue component using a new brain segmentation technique, FRASIER. Our data show that spatial variation within individual subjects in a ROI activated by a visual task is highly correlated with T1 and fractional volume of GM, as well as resting-state fluctuation amplitude (RSFA). The dependency (slop of the linear regression), however, varies over subjects. These findings may be used to calibrate BOLD signals for improving sensitivity and specificity in detecting brain activity.