MRI will be performed preoperatively, at 3 month, and at 12 months postoperatively on the same day as cognitive function testing. Training of all study personnel and MRI evaluation, and/or supervision of MRI evaluation, will be carried out by the Division of Neuroradiology at Basel University Hospital. Imaging will be performed using the institutional SIEMENS 3T TimTrio™ MRI scanner. The imaging sequence used is the whole brain quantitative MRI protocol comprised multi-parameter mapping based on 3D Fast Low Angle Shot (FLASH) MRI at 1 mm isotropic resolution (clinical standard at the University Hospital Basel). For our initial MRI analysis, we will assume that the same regions are relevant as those described in mild cognitive impairment (MCI) and Alzheimer's disease (AD), and a region of interest (ROI) analysis will be performed. In a second step, we will perform a whole brain analysis.