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from the VOI1). In a multi-center study so far, the normal Z score value has been reported as severity ≤ 1.19, extent 14.2 ≤ 2%, and ratio ≤ 2.2214). The MCI, AD, and DLB groups were analyzed by eZIS SVA calculate various numerical indices (severity, extent, ratio, and CIScore). Significant differences in the Z scores of the VOI1 and VOI2 were verified between the groups. Receiver operating character-istics (ROC) analysis was performed to calculate the area under the ROC curve (AUC). Addition-ally, the correlation between the CIScore and MMSE was assessed for the AD and DLB groups.Table 2 lists the numerical indices of all the groups, their means, and standard deviations. Mann-Whitney U test was performed for the numerical indices of each group, with p < 0.05 being the level of significance. In the MCI group, all severity, extent, and ratio values exceeded the normal range. When the MCI group was compared with the AD and DLB groups, both the severity and extent values were signifi-cantly high, and the ratio value was not signifi-cantly different. Box plots of the Severity and the CIScore are shown in Figure 2. When severity was 508Severity1.53†, ‡±0.333.38†±1.313.19‡±1.27†, ‡, §： significant differenceMCIADDLBTable 2　SVA index (mean±SD) in each groupExtent26.27±13.8068.72±20.4162.82±23.97Figure 2　Boxplot in each groupRatio4.29±2.405.84±2.733.88±1.25used for differentiating MCI from AD and DLB, the respective AUC values were 0.960 and 0.911. Like-wise, when the CIScore and VOI1 were used, the respective AUC values were 0.186, 0.641, 0.785, and 0.988 (Figure 3). When the CIScore was used for differentiating AD from DLB, the obtained AUC was 0.941. When the threshold value was set at 0.225, the accuracy, sensitivity, and specificity were 90.6%, 87.5%, and 93.7% (Figure 4). When chrono-logical changes of the SVA-A and CIScore in the MCI due to AD and MCI due to DLB cases were tracked, the chronological changes of the CIScore tended to decline (Figure 5). In all disease groups, no significant correlation between the CIScore and MMSE was observed (Figure 6).Compared with the MCI group, both the AD and DLB groups exhibited significantly increased severity and extent, and no significant difference was observed in the ratio. The obtained AUC also had high severity and extent, thus suggesting that severity and extent were useful indices for evalu-ating the conversion of MCI into other diseases in both the AD and DLB groups. The obtained AUC indicates that severity is more useful for differen-CIScore0.227±0.1300.358 §±0.1590.173 §±0.057VOI-18677±247815159±760724616±9125VOI-21771±5804826±21734226±1971ResultsDiscussion