The dementias include a group of disorders characterized by most likely memory impairment and one or more additional cognitive deficits. Alzheimer’s disease (AD) is the most common (70%) type of dementia, also Sporadic-AD occurs after age 65 and is the most common form of Alzheimer’s disease, whereas mild cognitive impairment (MCI) is regarded as the predementia state, also Amnestic MCI is the prodromal stage of Alzheimer’s disease.
With the prospect of disease-modifying therapies, early detection of AD and accurate monitoring of its progression are important research goals.
Metrics derived from structural volumetric MRI, including atrophy within and beyond the MTL, PL, PFC,PP(cingulate gyrus) and … have improved diagnostic ability, and their utility will certainly be increased further by a standardization of acquisition and analysis methods, and by the development of robust algorithms for automated segmentation, which will guarantee that measures of hippocampal volumes, etc, are stable across laboratories worldwide.
Since new disease-modifying therapies in AD will likely be most beneficial before substantial neuronal loss and clinical impairment have occurred (in Amnestic MCI), advanced MR techniques hold promise as valuable tools for selecting candidates for clinical trials and as predictive markers of dementia progression in defined risk groups of patients.
There has been increased interest in applying advanced MR imaging modalities to differentiate MCI from AD: diffusion-tensor imaging to investigate structural connectivity and perfusion MRI to measure regional patterns of abnormality in cerebral perfusion. The resulting biomarkers could be used to they can be used to enrich trials, by improving patient selection and differentiating amnestic-MCI from sporadic AD patients for specific therapy selection. Also, some potential drugs have been known to cause adverse effects that present first on imaging, often before any clinical manifestation of the patient.
Therefore, the aim of the present baseline study is to find the best combination of MRI-derived biomarkers for differentiating amnestic-MCI from sporadic-AD and to find the most sensitive and specific imaging-based indicators for this purpose.