QUANTITATIVE ASSESSMENT OF CEREBRAL BLOOD-FLOW IN PATIENTS WITH ALZHEIMERS-DISEASE BY SPECT

This study evaluated an automated analysis of SPECT brain imaging in p atients with Alzheimer's disease (AD). Methods: Patients [n = 81; mean age, 69.9 +/- 10.6 yr (mean +/- s.d.)] with a clinical diagnosis of p robable AD (NINCDS-Alzheimer's Disease and Related Disorders Associati on criteria) underwent Tc-99m-ethyl cysteine dimer SPECT imaging. Afte r imaging registration and data extraction using three-dimensional ste reotactic surface projections, a pixel-wise comparison of ethyl cystei ne dimer uptake was performed using a reference database of 10 cogniti ve intact controls of comparable age. Results: When individual cases w ere compared to the normal database, temporo-parietal regional cerebra l blood flow (rCBF) abnormalities across different levels of dementia severity were clearly depicted on pixel-wise Z-score images. The rCBF reduction in cortical association areas showed a significant correlati on with an overall level of cognitive decline, as assessed by the Mini Mental State Examination and by the cognitive section of the Cambridg e Mental Disorders of the Elderly Examination. In addition, there were significant region-specific correlations between left temporo perfusi on deficit and language performance and between right parietal rCBF re duction and praxis. Conclusion: These results indicate that this obser ver-independent analysis of SPECT data enables objective and semiquant itative assessment of the magnitude and extent of cortical perfusion a bnormalities in patients with AD.