Functional MR in the evaluation of dementia: correlation of abnormal dynamic cerebral blood volume measurements with changes in cerebral metabolism on positron emission tomography with fludeoxyglucose F 18.

PURPOSE To determine whether magnetic susceptibility functional MR imaging of cerebral blood volumes provides information similar to fludeoxyglucose F 18 positron emission tomography (PET) brain images in patients undergoing evaluation for dementia.

METHODS Ten subjects were studied with both PET and functional MR. Clinical diagnoses included probable Alzheimer disease (n = 5), possible Alzheimer disease (n = 1), Pick disease (n = 2), and primary progressive aphasia (n = 2). The studies were quantitatively evaluated by coregistration of PET and functional MR images followed by regression analyses of corresponding regions of interest. Qualitatively, each brain was categorized into eight regions, and each was classified as normal or abnormal by visual inspection.

RESULTS Correlation coefficients between registered functional MR and PET images were excellent (mean, r = 0.58) in most of the cerebrum. Significant correlations were observed in 72 of 74 brain sections. Qualitatively, 16 brain regions were judged to be abnormal by both MR imaging and PET; 46 regions were normal by both; 10 regions were abnormal by PET only; and 8 regions were abnormal only by functional MR. The concordance between functional MR and PET was 78%, which was highly significant.

CONCLUSION Cerebral blood volumes images derived from magnetic susceptibility (functional MR) provide information similar to fludeoxyglucose F 18 PET images in demented patients undergoing evaluation for dementia.