Gyroscan intera 1.5t nova dual scanner

Brain imaging involved an T1-weighted scan and a DTI scan with a Philips Gyroscan Intera 1.5T Nova Dual scanner (Philips, Best, The Netherlands) at the Turku PET Centre. T1-weighted images were acquired following parameters: 3D FFE (flip angle 30°), SENSE 2, TR 25 ms, TE 4.6 ms, acquisition voxel size 1.17/1.17/1.00 mm, and reconstructed image size 256 × 256 × 256 with voxel size 1.09/1.09/1.0 (with 0.5 mm of gap between slices) mm. The DTI were acquired with the following parameters: SENSE 2, single-shot spin-echo echo-planar-imaging sequence (half-scan), 32 directions at b = 1000 s/mm², TR 4286 ms, TE 89 ms, acquisition voxel size 2.32/2.36/2.32 mm, and reconstructed image size 122 × 122 × 60 with voxels size isotropic 2.32 mm.

MRI scans were acquired on a 3 T Siemens Skyra scanner (Yale) and 3 T Philips Ingenuity TF PET/MR scanner or a Philips Gyroscan Intera 1.5 T Nova Dual scanner (Turku). Total brain volumes, derived from non-Gadolinium enhanced T1 sequences, were calculated using mixed voxel segmentation and normalized to head size^{31 (link)}. Automated lesion detection was performed on T2 weighted FLAIR sequences with the LPA algorithm available as part of the lesion segmentation toolbox (LST) (http://www.applied-statistics.de/lst.htm), followed by manual correction using itk-SNAP software version 3.x by three reviewers blinded to the patients’ genotype.