Table 5.
MRIa measurements (measured at all 4 time points: t0: baseline; t1: 6 months; t2: 12 months & t3: 18 months)
| TYPE OF MRI MEASUREMENT / SCAN | Main technical details of the Siemens protocols |
|---|---|
| Grey matter volume assessment [108] | MP2RAGEb; duration: 8.22 min; voxel size: 1 mm isotropic; 176 slices; FOVc: 256x240x176 mm; TRd/TEe: 5000/2.98 ms; TI1f/TI2g: 700/2500 ms; flip angle 1/2: 4/5 degrees |
|
Functional MRI Tonal working memory task [109] |
EPIh; duration: 20.00 min; voxel size: 2.5 mm isotropic; 54 slices; FOV: 210x210x135 mm; multiband accelerator factor: 3; TR/TE: 1350/31.6 ms |
|
Resting state functional MRI Allows to measure activity in the Default Mode Network (DMN) reflecting global functional connectivity of the brain [110] |
EPI; duration: 10.31 min; voxel size: 2.5 mm isotropic; 54 slices; FOV: 210x210x135 mm; multiband accelerator factor: 3; TR/TE: 1350/31.6 ms |
|
White matter assessment Allows to compute i.a. Fractional Anisotropy for evaluating white matter integrity reflecting structural connectivity [111]. |
DTIi; duration 7.38 min; voxel size: 1.5 mm isotropic; 84 slices; FOV: 222x222x126 mm; multiband accelerator factor: 3; TR/TE: 5163/109.2 ms; b-values: 0/1500 s/mm2; 65 directions, anterior to posterior phase encoding direction followed by a reverse direction for distortion correction; b-values: 0/ s/mm2) |
| Blood perfusion assessment [112] | ASLj; duration 6.10 min; voxel size: 2.5 × 2.5 × 3.0 mm; 36 slices; FOV: 220x220x129 mm; TR/TE: 3640/21.0 ms; flip angle: 90 degrees |
a MRI: Magnetic Resonance Imaging
b MP2RAGE: Magnetization-Prepared 2 Rapid Acquisition Gradient Echoes
c FOV: Field Of View
d TR: Time to Repetition
e TE: Time to Echo
f TI1: Inversion Time 1
g TI2; Inversion Time 2
h EPI: Echo Planar Imaging
i DTI: Diffusion Tensor Imaging
j ASL: Arterial Spin Labeling