Functional MRI Incorporating Information on Voxel-Wise Tissue Volume Fractions
Yang Y, Gu H, Stein E, Zhan W
National Institute on Drug Abuse, NIH
Functional MRI using ultra-fast image acquisition techniques (e.g. EPI) typically has a spatial resolution of 2-4 mm. Partial volume effects are unavoidable in such image voxels, which would affect sensitivity and specificity of fMRI techniques. We present here a method to incorporate information on tissue volume fractions into fMRI, and therefore enhancing its spatial capability in detecting brain activity. BOLD and ASL perfusion activation maps were assessed in terms of statistical power and tissue volume fractions of gray matter, white matter, and CSF in each voxel. Using the information of tissue volume fractions, activation can be constrained primarily in gray matter.