An improved fMRI analysis for detecting motor cortex activity near brain tumors

摘要

Functional magnetic resonance images (fMRI) typically represent a correlation of the hemodynamic response in a region of the brain that is associated with a stimulus or task; and is used to elucidate areas of neural activity. An inadequate model of the hemodynamic response function (HRF) may prevent the detection of regional brain activity, particularly in brain regions distorted by tumor or other pathology. Thus, idealized HRFs may not provide good models of hemodynamic response in brain regions near a tumor, and subject-specific and/or region-specific HRFs are needed. Functional MR images from one brain tumor patient and three normal subjects were obtained with a GE 1.5 Tesla scanner. Right and left hands were exercised independently during 30 sec squeeze/rest blocks for 5min, during which 5 mm thick, echo planar images (5 slices) were obtained through the motor cortex. Generation of fMRI data using the Analysis of Functional Neurolmages (AFNI) (1) is outlined below.