T1-weighted axial visual rating scale for an assessment of medial temporal atrophy in Alzheimer's disease.

BACKGROUND The most-widely used visual rating scale (VRS) for medial temporal atrophy is the T1-weighted (T1W) coronal VRS developed by Scheltens et al. However, it is often difficult to use the T1W-coronal VRS in cases with limitations in obtaining T1W-coronal images. To overcome this issue, we modified the T1W-coronal VRS onto the axial plane. OBJECTIVE The purposes of this study were to validate our T1W-axial VRS by examining its compatibility with the original T1W-coronal VRS and by investigating the correlation with the cognitive functions and hippocampal volumes. METHODS Participants were 50 patients with Alzheimer's disease dementia and 30 elderly with normal cognition. We transposed each component of the T1W-coronal VRS onto T1W-axial images (i.e., the largest height of the hippocampal formation into the width of the medial temporal lobe). The compatibility of T1W-axial VRS with T1W-coronal one was determined using the kappa value. The correlations of T1W-axial VRS with cognitive performance or the hippocampal volumes were analyzed with age, gender, and education as covariates. RESULTS The kappa value between the T1W-axial and T1W-coronal VRS was 0.772 (p < 0.045). The T1W-axial VRS showed a significant correlation with the scores of cognitive functions, including verbal memory tests (-0.601, p < 0.001 for the left). Furthermore, the T1W-axial VRS also correlated well with hippocampal volumes (-0.576, p < 0.001). CONCLUSIONS The T1W-axial VRS showed good agreement with T1W-coronal VRS and correlated well with cognitive functions as well as hippocampal volumes, which suggests that the T1-axial VRS may replace the original T1W-coronal one.