Imaging
MP
A 3 Tesla magnetic resonance imaging scanner (Siemens Trio Magnetom) was used to obtain structural brain images. The imaging sessions were hosted by the Berlin Center for Advanced Neuroimaging (BCAN; Berlin, Germany). We ran a T1-weighted 3D magnetization-prepared rapid gradient echo (MP RAGE) sequence (TR = 2500 ms, echo time = 4.77 ms, flip angle = 7°, 192 sagittal slices, field of view = 256 × 256 mmFreesurfer (version 5.3.) on Linux CentOS6 (× 86) was used to automatically segment subcortical volumes. The processing of T1 weighted images included motion correction, averaging, removal of non-brain tissue compartments and Talairach transformationVolumetric measures were given in cubic millimeters. Freesurfer values for the left and the right thalamus hemisphere were combined to obtain a single variable for the entire thalamus. The Freesurfer variable ‘EstimatedTotalIntraCranialVol’ served as a measure for intracranial volume. (