Biomarkers - metabolism, Magnetic Resonance Imaging - methods, Alzheimer Disease - psychology, Positron-Emission Tomography - methods, Aniline Compounds - metabolism, Entorhinal Cortex - pathology, Atrophy - pathology, Mild Cognitive Impairment - radionuclide imaging, Mild Cognitive Impairment - pathology, Alzheimer Disease - pathology, Ethylene Glycols - me...