MRI acquisition and processing
Structural brain measures were derived from a 3.0 Tesla Philips Achieva full-body MRI scanner with a 8-channel head coil at baseline and after 6 months. All scans were acquired on the same scanner with a standardized protocol that included a sagittal 3D T1-weighted sequence (TR/TE = 7.9/4.5 ms; 192 slices; FOV(mm) = 256x232; 1.00 mm isotropic voxels). Scan quality was visually checked.