A path based approach to quantifying the progression of Alzheimer´s disease

Histological studies suggest that different pathological changes occur in the subfields of hippocampi in aging and in Alzheimer0s disease. The pathological changes due to Alzheimer´s disease follows a neural system and are consistent with subjects. The aim of this study is to study the path in vivo the changes in normal control, mild cognitive impairment and Alzheimers disease patients using high resolution MRI scanned at 3 Tesla. T1 weighted images were obtained from the ADNI database. The dataset consists of 11 control patients, 13 MCI patients, and 9 AD patients. The hippocampal subfields were segmented using the Freesurfer image-analysis suite (Version 6.0). The volume of the subfields and the path along the medial axis of the subfields were studied. The results suggest that the intensity along the medial axis shows more variation on the CA1 region than other subfields in cases of Alzheimer disease, MCI and normal control patients. The changes are more prominent in the early section of the CA1 suggesting the progressive nature of the disease. The mean intensity value along the medial axis of CA1 subfield shows change in AD, MCI and NC but similar change are not seen in other subfields.