Wanyong Shin1, Hong Gu2, Qihong
Zou2, Thomas Ross2, Yihong Yang2
1Radiology, Imaging
Institute, Cleveland Clinic, Cleveland, OH, United States; 2National
Institute on Drug Abuse, Baltimore, MD, United States
We present a method of voxel-wise group analysis using fractional volume of gray matter (fv,GM) as a covariant in a fMRI study with visual stimulation. The results show that a) Consistent functional activation is observed between conventional t-test and the t-test with fv,GM as a covariant, b) The size of the activated ROI and average t-score in the activated ROI are increased when using the covariate t-test with the same statistical threshold, and c) The slope of with respect to fv,GM is observed higher in V1 compared to V2, V3 and thalamus areas