[The Development of a Normal Database of Elderly People for Use with the Statistical Analysis Software Easy Z-score Imaging System with 99mTc-ECD SPECT].

We created a new normal database of elderly individuals (Tsukuba-NDB) for easy Z-score Imaging System (eZIS), a statistical imaging analysis software, comprised of 44 healthy individuals aged 75 to 89 years. The Tsukuba-NDB was compared with a conventional NDB (Musashi-NDB) using Statistical Parametric Mapping (SPM8), eZIS analysis, mean images, standard deviation (SD) images, SD values, specific volume of interest analysis (SVA). Furthermore, the association of the mean cerebral blood flow (mCBF) with various clinical indicators was statistically analyzed. A group comparison using SPM8 indicated that the t-value of the Tsukuba-NDB was lower in the frontoparietal region but tended to be higher in the bilateral temporal lobes and the base of the brain than that of the Musashi-NDB. The results of eZIS analysis by Musashi-NDB in 48 subjects indicated the presence of mild decreases in cerebral blood flow in the bilateral frontoparietal lobes of 9 subjects, precuneus and posterior cingulate gyrus of 5 subjects, lingual gyrus of 4 subjects, and near the left frontal gyrus, temporal lobe, superior temporal gyrus, and lenticular nucleus of 12 subjects. The mean images showed that there were no visual differences between both NDBs. The SD images intensities and SD values were lower in Tsukuba-NDB. Clinical case comparison and visual evaluation demonstrated that the sites of decrease in blood flow were more clearly indicated by the Tsukuba-NDB. Furthermore, mCBF was 40.87 ± 0.52 ml/100 g/min (mean ± SE), and tended to decrease with age. The tendency was stronger in male subjects than female subjects. Among various clinical indicators, the platelet count was statistically significantly correlated with CBF. In conclusion, our results suggest that Tsukuba-NDB, which is incorporated into a statistical imaging analysis software, eZIS, is sensitive to changes in cerebral blood flow caused by Cranial nerve disease, dementia and cerebrovascular accidents, and can provide precise diagnosis of these brain diseases in the rapidly aging Japanese population.