Combined Diffusion Relaxometry: Phantom Validation and Ex Vivo Characterization of Alzheimer’s Disease Lesions

Motivation: There is a need for better characterization of white matter lesions in Alzheimer's disease and related disorders (ADRD) to distinguish between benign lesions and destructive lesions. Goal(s): Evaluate the utility of diffusion-T2 (D-T2) 2-dimensional MR in characterizing white matter abnormalities in post-mortem ADRD samples. Approach: We scanned a D-T2 phantom (spin-echo D-T2) and post-mortem ADRC brain samples (EPI D-T2), then we computed their 2D spectras. Results: We successfully validated our D-T2 protocol with the phantom. D-T2 spectra resolved tissue components of varying T2 and diffusion values in normal and abnormal white matter, revealing more information than 1D diffusion tensor imaging ADC outcomes. Impact: The D-T2 phantom can serve as a standard for validating D-T2 imaging protocols. Applying D-T2 to assess ADRD lesions could allow for more disease-specific diagnostics with MRI.