Changes in medial temporal lobe in Alzheimer´s disease detected using transcranial sonography

Background Atrophy of the medial temporal lobe is one of the anatomical hallmarks of Alzheimer's disease (AD). Transcranial sonography (TCS) is able to visualize and measure the MTL. Purpose Study aims to test digital image analysis of MTL image in AD compared to healthy controls. Methods Patients with AD and healthy controls underwent TCS. The medial temporal lobe and the surrounding space was imaged in the coronal plane on TCS from both sides. All images were encoded and evaluated using B-Mode Assist software with counting the black/white ratio of the medial temporal lobe. The ROC curve, optimal cut-off value, sensitivity, specificity, positive and negative predictive values were statistically evaluated. Results Totally 78 subjects were enrolled to the study during 6 months; 31 AD patients (14 males, 76.2 ± 5.8 years) and 47 healthy controls (21 males, 75.5 ± 6.4 years). Significantly lower black/white ratio was found in AD patients compared with healthy controls (1.63 ± 0.75 vs 3.43 ± 1.01; P ˂ 0.001). The optimal cut-off value for differentiation between AD and healthy controls was 2.5 with a sensitivity 90.3%, a specificity 87.2%, a positive predictive value 82.3% and a negative predictive value 93.2%. Conclusion Digital image analysis of the TCS medial temporal lobe images enables to measure black/white ratio as a marker of MTL atrophy in AD patients. Study was supported by grant of Ministry of Health of the Czech Republic No. 16-28628A.