Diagnostic utility of hippocampal size and mean diffusivity in amnestic MCI

Area of Science:

• Neuroimaging
• Neurology
• Radiology

Background:

• Hippocampus atrophy is common in mild cognitive impairment (MCI).
• Diffusion tensor imaging (DTI) detects subtle brain tissue changes in neuropsychiatric diseases, including MCI.

Purpose of the Study:

• To compare the diagnostic accuracy of hippocampus volumetry and DTI measures for detecting MCI.
• To evaluate the sensitivity and specificity of these methods in differentiating MCI patients from controls.

Main Methods:

• High-resolution MRI for hippocampus volumetry and co-registered DTI scans were performed on 18 MCI patients and 18 controls.
• Region-of-interest-based mean diffusivity (MD) and fractional anisotropy (FA) were calculated for the hippocampus.
• Receiver operating characteristic (ROC) analyses and logistic regression were used to estimate diagnostic properties.

Main Results:

• Left hippocampus parameters showed higher predictive power than right-sided measures.
• At 80% specificity, left hippocampus volume (HV) had low sensitivity (50%).
• Left hippocampal MD (89% sensitivity) and FA (78% sensitivity) demonstrated superior diagnostic accuracy for MCI detection.

Conclusions:

• DTI-derived left hippocampal parameters are more sensitive than volumetric measures for detecting subtle hippocampal abnormalities in MCI.
• DTI offers a valuable tool for the early diagnosis of mild cognitive impairment.