32 channel receive coil

All MRI examinations were performed on a 7 T human MRI scanner (Siemens, Erlangen, Germany) equipped with a 32-channel receive coil.
The mGRE data for mapping the $T_2^{\mathrm{*}}$ decay curves were acquired with an in-house developed pulse-sequence (van Gelderen et al., 2012 (link)). Echo times (TEs) ranged from 2.3 to 62.7 ms. Thirty-eight echoes (positive read gradient only) were acquired with an echo spacing of 1.6 ms. Repetition time (TR) was 1 s and flip angle (FA) was 70°. Fifteen slices with 1.5 mm slice thickness and 25% gap between slices were measured per scan, with an in-plane resolution of 1.5 × 1.5 mm and a FOV of 240 × 180 mm (the acquisition matrix size is 160 × 120). The slices were parallel to the plane of the anterior and posterior commissure line and captured a section of the corpus callosum. Five signal averages were acquired within a total scan time of 10 min.
Whole brain 3D T₁-weighted magnetization-prepared rapid gradient echo (T₁-MPRAGE) was acquired before (pre-gad T₁) and after (post-gad T₁) contrast injection (0.1 mmol/kg gadobutrol; Bayer Healthcare, Leverkusen, Germany).

Postmortem MRI scans from MS brains were acquired as previously described.²⁷ (link) Briefly, formalin-fixed brains were positioned in a Fomblin-filled container and were scanned in a 7-T MRI scanner (Siemens) equipped with a birdcage-type transmit coil and a 32-channel receive coil. A 3D T1w magnetization-prepared rapid gradient echo (T1-MP2RAGE, repetition time = 2200 ms, echo time = 3.04 ms, flip angle = 7°, nominal resolution 0.6 × 0.6 × 0.6 mm³, acquisition time: 6 min, 35 s) and a 3D high-resolution multigradient-echo (GRE, repetition time = 60 ms, echo times = 6.09, 15.99, 25.89, and 35.79 ms, flip angle = 10°, nominal resolution 0.42 × 0.42 × 0.42 mm³, acquisition time: 2 h, 15 min) T2∗w sequence were acquired. Pre- and post-mortem MRI scans were registered by linear/affine registration using an in-house software.