Emerging imaging techniques have recently enabled visualizing intracellular neurofibrillary tau tangles in human brains in vivo with PET tracers. Results confirm the current notion of the new tau tracer for in vivo labeling tau deposition and the agreement with the tau-pathological Braak stage in early stage of dementia. Recent studies have also identified brain atrophy regions including medial temporal lobe, especially hippocampus and entorhinal cortex, and posterior cingulate cortex as being more predictive of disease progression. The effects of multivitamin supplements on serum homocysteine level, and depression of Korean older adults with mild cognitive impairment (MCI) in care facilities is examined. An investigation was done on the impact of mild cognitive impairment (MCI) on incidence of early and long-term postoperative cognitive dysfunction (POCD) and MCI-related postoperative changes in cortical activity in patients after coronary artery bypass grafting (CABG).