Longitudinal Volumetric Study for the Progression of Alzheimer's Disease from Structural MR Images

Alzheimer's Disease (AD) is primarily an irreversible neurodegenerative disorder affecting millions of individuals today. The prognosis of the disease solely depends on treating symptoms as they arise and proper caregiving, as there are no current medical preventative treatments. For this purpose, early detection of the disease at its most premature state is of paramount importance. This work aims to survey imaging biomarkers corresponding to the progression of Alzheimer's Disease (AD). A longitudinal study of structural MR images was performed for given temporal test subjects selected randomly from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. The pipeline implemented includes modern pre-processing techniques such as spatial image registration, skull stripping, and inhomogeneity correction. The temporal data across multiple visits spanning several years helped identify the structural change in the form of volumes of cerebrospinal fluid (CSF), grey matter (GM), and white matter (WM) as the patients progressed further into the disease. Tissue classes are segmented using an unsupervised learning approach using intensity histogram information. The segmented features thus extracted provide insights such as atrophy, increase or intolerable shifting of GM, WM and CSF and should help in future research for automated analysis of Alzheimer's detection with clinical domain explainability.