Hippocampal volume from T1 MRI as an atrophy biomarker: automated calculation and Scheltens' scale correlation

Scheltens' discrete scale is widely used for assessing brain atrophy but has limitations in subjectivity and tracking patient progression over short periods. Automated brain volumetry offers a more objective imaging approach for diagnosing neurodegenerative diseases. This retrospective study aims to correlate Scheltens' scale assessments with hippocampal and cerebrum volumes measured by volBrain, enhancing patient care.

This study involved 106 participants, including healthy volunteers and patients with mild cognitive impairment, all scanned using a standardized MRI protocol. Two radiologists assessed medial temporal lobe atrophy, while volBrain automated the volumetric measurements. Reliability between raters was evaluated using the intra-class correlation coefficient and Kappa analysis. Shapiro-Wilk test performed to evaluate the normality of data distribution, Spearman's, Kruskal-Wallis, and Dunn's ad hoc tests used to compare the Scheltens' scale with volumetric data. Receiver operating characteristic analysis performed for the radiologist evaluations and ordinal logistic regression used to model the probability of Schelten's scores with relative hippocampal volumes.

Raters had almost perfect agreement. Scheltens' scale correlations with hippocampus volumetric measurements were strongly significant, but correlations with cerebrum volumetric measurements were weak. Automated brain volumetric software presented 82% sensitivity and 100% specificity. Ordinal logistic regression presented overall model significance.

This study suggests that hippocampus relative volume is a sensitive biomarker for atrophy evaluation toward an advanced, medial lobe atrophy scale, providing clinicians with a precise and objective tool.