16 channel knee coil

MRI was performed on a 3T system (Phillips Achieva/Phillips Ingenia 3T, Philips Healthcare). A 16-channel knee coil (Philips Healthcare) was used to acquire the brain scans. The imaging protocol included time-of-flight (ToF) imaging (repetition time (TR)/echo time (TE)=20/4 ms, flip angle (FA)=20°, matrix=332×212), DW-MRI (TR/TE=2600/76 ms, FA=90°, b-value=0, 1000 s/mm², number of signal averages (NSA)=6, matrix=144×144), PW-MRI (TR/TE=1500/20.1 ms, FA=40°, 60 dynamics, matrix=320×320), T2-weighted FLAIR imaging (TR/TE=11000/125 ms, inversion time=2800 ms, FA=90°, echo train length (ETL)=27, matrix=288×288) and susceptibility-weighted imaging (SWI) (Fast Field Echo based sequence, TR/TE=31/7.2 ms, ETL=4, matrix=480×480, NSA=2). SWI was used to rule out the possibility of hemorrhage. For PW-MRI, 0.2 mmol/kg of gadobutrol (Gadavist, Bayer Healthcare Pharmaceuticals, Leverkusen, Germany) was injected intravenously (IV) via the femoral catheter after the second of 60 dynamic scans (total scan time=90 s).

MR images were acquired at baseline and follow-up with a 3.0 T MR scanner (Philips Achieva, NL) using a 16-channel knee coil. Participants were positioned in supine with knees relaxed and slightly flexed. MR sequences included: (i) a proton density-weighted 3D VISTA sequence (repetition time/echo time [TR/TE] 1300/27 ms; field of view [FOV] 150 mm²; 0.35 mm isotropic; echo train length 64 ms; scan time 6 min 11 s); (ii) sagittal short-tau inversion recovery (STIR) sequence (TR/TE 3,850/30 ms; FOV 160 mm²; slice thickness 2.5 mm; slice gap 1.2 mm; inversion time 180 ms; voxel size 0.45 × 0.50 × 2.5 mm); and (iii) axial proton-density turbo spin-echo (TSE) sequence (TR/TE 3,850/34 ms; FOV 140 mm²; slice thickness 2.5 mm; slice gap 2.0 mm; voxel size 0.5 × 0.55 × 2.5 mm).