Magnetom 7t scanner

We first re-analyzed the dataset from a whole body 7 T MAGNETOM scanner (Siemens Healthcare) used and described already in Becker et al. (2012) (link). The scanner was equipped with gradients with a peak amplitude of 70mT/m and a maximum slew rate of 200 T/m/s (SC72, Siemens Healthcare, Erlangen, Germany). Diffusion weighting gradients were applied along 60 different directions at a b-value of 1000 s/mm². 7 interspersed non-diffusion weighted S₀ images were acquired. The scan was repeated 4 times. An optimized monopolar Stejskal–Tanner sequence according to Morelli et al. (2010) (link) together with the ZOOPPA approach described in Heidemann et al. (2012) (link) has been used for the scan. The experiment was performed using a single channel transmit, 24-channel receive phased array head coil (Nova Medical, Wilmington, MA, USA). 91 slices with 10% overlap were acquired at a field-of-view (FoV) of 143 × 147 mm² resulting in an isotropic high resolution of 800 μm. Further imaging protocol parameters were: TR 14.1 s, TE 65 ms, BW 1132Hz/pixel, ZOOPPA acceleration factor of 4.6. A healthy adult volunteer was scanned four times using this protocol in one session after obtaining written informed consent in accordance with the ethical approval from the University of Leipzig. Total acquisition time was 65 min. We used the raw diffusion weighted data.

Participants were scanned on a research-dedicated Siemens 7T Magnetom scanner in the Clinical Research Center on the National Institutes of Health Campus (Bethesda, MD). Partial T2*-weighted functional image volumes were acquired using a gradient echo planar imaging (EPI) sequence with a 32-channel head coil (47 slices; 1.6 × 1.6×1.6 mm; 10% interslice gap; TR, 2 s; TE, 27 ms; matrix size, 126 × 126; FOV, 192 mm). Oblique slices were oriented approximately parallel to the base of the temporal lobe and were positioned such that they covered the occipital, temporal, and parietal cortices, and as much as possible of frontal cortex. After the functional imaging runs, standard MPRAGE (magnetization-prepared rapid-acquisition gradient echo) and corresponding GE-PD (gradient echo–proton density) images were acquired, and the MPRAGE images were then normalized by the GE-PD images for use as a high-resolution anatomical image for the following fMRI data analysis (Van de Moortele et al., 2009 (link)).

We imaged with a concentric ring trajectory-based MRSI sequence on a 7 T Magnetom scanner (Siemens Healthcare, Erlangen, Germany) with a 32-channel receive array coil (Nova Medical, Wilmington, MA, USA), featuring a 64 × 64 × 39 matrix with 3.4 mm³ isotropic resolution [15 (link)]. The acquisition took 15 min with 450 ms TR and 1.3 ms acquisition delay, covering a manually placed 220 × 220 × 133 mm³ field of view (FOV) [10 (link), 15 (link)]. More details are found in Supplementary Table 2, which reports MRS parameters in the MRSinMRS standard [16 (link)]. We additionally obtained 7 T 0.8 mm3 isotropic T1-weighted MP2RAGE in 8:02 min and 0.8 mm3 isotropic fluid-attenuated inversion recovery (FLAIR) in 8:10 min.
Clinical 3 T MRI consisted of FLAIR, T2-weighted MRI, and pre- and post-contrast T1-weighted MRI (Gadoteridol, 0.1 mmol/kg).