Abstract
Aim: Atrophy of the medial temporal lobe (MTL) is one of the anatomical hallmarks of Alzheimer's disease (AD). Transcranial sonography (TCS) is able to visualize and measure the MTL.
Study aimed to test the digital image analysis of the MTL TCS image in patients with AD compared to healthy controls. Methods: Patients with AD and healthy controls were enrolled to the study.
MTL and the surrounding space were imaged in the coronal plane on TCS from both sides in all enrolled subjects. All images were encoded and evaluated using B-Mode Assist software by counting the black/white ratio of the MTL.
The receiver operating characteristic curve, optimal cut-off value, sensitivity, specificity, and positive and negative predictive values were statistically evaluated. Results: A total of 78 subjects were enrolled to the study during 6 months; 31 patients with AD (14 males, mean age 76.2 +/- 5.8 years) and 47 healthy controls (21 males, mean age 75.5 +/- 6.4 years).
A significantly lower value of MTL black/white ratio was found in patients with AD compared with healthy controls (1.63 +/- 0.75 vs. 3.43 +/- 1.01; P < 0.001). The optimal cut-off value of MTL black/white ratio for differentiation between patients with AD and healthy controls was 2.5 with a sensitivity of 90.3%, specificity of 87.2%, positive predictive value of 82.3% and negative predictive value of 93.2%.
Conclusion: Digital image analysis of the TCS MTL images enables the measurement of the black/white ratio as a marker of MTL atrophy in patients with AD.