FIGURE 2.

Diffusion tensor image analysis along the perivascular space (ALPS) indexes are correlated with the mean standardized uptake value ratios (SUVRs) of ¹⁸F‐AV‐45 PET images and ¹⁸F‐APN 1607 position emission tomography (PET) images and Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Assessment Battery (CERAD‐NAB) total scores. (A) ALPS‐indexes showed a significant correlation with CERAD‐NAB total scores after adjusting for age, sex, years of education, and APOE4 genotype (R ² = 0.35, p < 0.01). (B) ALPS‐indexes showed a significant correlation with the mean SUVRs of ¹⁸F‐AV‐45 PET images after adjusting for age, sex, years of education, and APOE4 genotype (R ² = 0.12, p = 0.02). (C) ALPS‐indexes showed a significant correlation with the mean SUVRs of ¹⁸F‐APN 1607 PET images after adjusting for age, sex, years of education, and APOE4 genotype (R ² = 0.27, p < 0.01). Dotted lines indicate the 95% confidence intervals. (D) Combined fitting curves from the SUVRs of the ¹⁸F‐AV‐45 PET image, SUVRs of the ¹⁸F‐APN1607 PET image, ALPS‐indexes, and gray matter volume (GMV) ratios in the precuneus region. The values of regional SUVRs in the ¹⁸F‐AV‐45 PET images and ¹⁸F‐APN1607 PET images were scaled to 0–100%, with 0% representing the minimal value and 100% representing the maximal value. The original ALPS‐indexes and regional GM ratios were reversed, with 100% representing the minimal value and 0% representing the maximal value. This normalization procedure made the higher values of abnormalities in regional SUVRs, GMV ratios, and ALPS‐indexes represent the more severe disease state. AD = Alzheimer disease; NC = normal control.