Background: In patients with Alzheimer’s disease (AD), cerebral blood flow (CBF) is
decreased from the early stages. CBF in AD is currently estimated from Z-scores using statistical
analysis. However, the Z-score is not considered the impaired area ratio.
Methods: In the present study, a novel indicator, ΣzS, associated with brain surface area and Zscores,
is defined and the association with regional CBF has been estimated using Mini-Mental State
Examination (MMSE) scores, which indicate the severity of cognitive impairment in patients with
Results: A negative correlation was detected between ΣzS in the posterior cingulate gyrus and the
subset numbers 1, 2, and 5 of the total MMSE scores. Furthermore, a negative correlation was detected
between the total MMSE score and ΣzS in Brodmann area 30, which is a subdivided area of
Conclusion: These results suggest that ΣzS may be a useful indicator of CBF metabolism, and thus
may improve the current understanding of cognitive function in patients with AD.