The use of diffusion-tensor imaging to assess microstructural integrity of white matter of patients with Alzheimer’s disease

Abstract

Objective. To compare diffusion-tensor imaging (DTI) measures in different anatomic regions of the brain in patients with an isolated Alzheimer's disease (AD) and patients with AD and small-vessel disease (SVD).Material and methods. 20 AD patients, aged 66 (±10), of whom 11 AD patients had an isolated neurodegenerative process and 9 patients, who were diagnosed with AD+SVD, were examined. A research was made on a 3 T Siemens Magnetom Skyra MR-scanner. All participants underwent the same imaging protocol, which included standard clinical- and diffusion tensor pulse sequences. With an MR-image processing software package Olea Medical Sphere 3.0, fractional anisotropy (FA), mean diffusivity (MD), axial and radial diffusivity (AxD and RxD) were measured in different brain regions.Results. Significant differences in DTI measures (FA, MD, AxD, RxD), indicating more severe white matter microstructural damage in AD+SVD patients, compared with patients with an isolated AD, were observed in middle thalamic radiation, upper and lower longitudinal bundles, posterior part of cingulate gyrus and genu of corpus callosum.Conclusion. DTI is an informative method, highly sensitive in detecting difference in white matter microstructural integrity of brain tissue in individuals with an isolated AD and patients with AD+SVD.

Keywords

• dementia
• alzheimer's disease
• small-vessel disease
• magnetic resonance imaging
• diffusion-tensor imaging