Background: Callosal Angle (CA) and Evans Index (EI) are considered as imaging biomarkers
to diagnose normal-pressure hydrocephalus using traditional MR measurement methods.
Objective: The current study aimed to evaluate the differential diagnostic value of CA and EI in
Mild Cognitive Impairment (MCI) and Alzheimer’s Disease (AD).
Methods: Five-hundred and two subjects were selected from the Alzheimer's Disease Neuroimaging
Initiative (ADNI) database, which included 168 Normal Controls (NC), 233 MCI and 101 AD
patients. The structural MR images were interactively applied with multiplanar reconstruction to
measure the CA and EI.
Results: CA presented no significant difference among NC, MCI and AD groups (H value = 3.848,
P value = 0.146), and EI demonstrated higher value in MCI and AD groups than that in NC groups
(P = 0.000 and 0.001, respectively). MCI group had significant larger EI (0.29±0.04) than
(0.27±0.03) NC group in 70-75 years old sub-groups. ROC showed that the area under the curve
was 0.704±0.045 for NC-MCI in 70-75 years old groups. The correlation analysis indicated that EI
was significantly negatively related to MMSE scores of MCI patients (r = -0.131, P = 0.046).
Conclusion: EI might serve as a screening imaging biomarker for MCI in 70-75 years old patients,
and show limited differential value for the diagnosis of AD. CA could present no diagnostic value
for MCI and AD in the current study.