Quantitative assessment of cerebral blood flow in patients with Alzheimer's disease by SPECT

Abstract

This study evaluated an automated analysis of SPECT brain imaging in patients with Alzheimer's disease (AD).

Methods: Patients [n = 81; mean age, 69.9 +/- 10.6 yr (mean +/- s.d.)] with a clinical diagnosis of probable AD (NINCDS-Alzheimer's Disease and Related Disorders Association criteria) underwent 99mTc-ethyl cysteine dimer SPECT imaging. After imaging registration and data extraction using three-dimensional stereotactic surface projections, a pixel-wise comparison of ethyl cysteine dimer uptake was performed using a reference database of 10 cognitive intact controls of comparable age.

Results: When individual cases were compared to the normal database, temporo-parietal regional cerebral 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 correlation with an overall level of cognitive decline, as assessed by the Mini Mental State Examination and by the cognitive section of the Cambridge Mental Disorders of the Elderly Examination. In addition, there were significant region-specific correlations between left temporo perfusion deficit and language performance and between right parietal rCBF reduction and praxis.

Conclusion: These results indicate that this observer-independent analysis of SPECT data enables objective and semiquantitative assessment of the magnitude and extent of cortical perfusion abnormalities in patients with AD.