Multi-echo SMS fMRI acquisition parameters (ds004499)

This OpenNeuro release (ds004499) comes from the Multimodal and Functional Imaging Laboratory (MAFIL) at CEITEC, Masaryk University in Brno. It was built to test multi-echo fMRI under different degrees of simultaneous multislice (multiband) acceleration and different flip angles. Every participant did the same block-design task seven times, each run with another combination of settings, so single-echo and multi-echo processing can be compared across acquisition protocols. The authors suggest it for testing and tuning fMRI processing pipelines. The data went public on OpenNeuro in January 2024; snapshot 1.0.4 from February 2026 only fixed the README.

Composition

There are 50 subjects, 23 female and 27 male, aged 18 to 41 (mean 28.98). Each has one T1-weighted MPRAGE, a gradient echo field map (two magnitude images and a phase difference), seven functional runs with three echo images each, and a physiological recording per run. The participants file names the recording device: a Siemens physiological recording unit or a BrainProducts BrainAmp MR ExG amplifier. The README does not state inclusion criteria or health status.

Acquisition

All scans were done on a 3 T Siemens Magnetom Prisma with a 64-channel head-neck coil, using the CMRR multiband EPI sequence. Field of view (192 x 192 mm), matrix (64 x 64), 48 axial slices of 3 x 3 x 3.5 mm, in-plane GRAPPA factor 2 and the three echo times (17.00, 34.64 and 52.28 ms) are the same in every run. The runs differ in multiband factor (1, 4, 6, 8), repetition time (3.05 s down to 0.4 s, giving 120 to 900 volumes in 6 minutes) and flip angle (80, 45 or 20 degrees). Run order was counterbalanced between ascending and descending.

Annotations

The task alternated checkerboard blocks with digits 1 to 4, answered with right-hand button presses, and rest blocks. There are no image labels.

Known limitations

No data descriptor paper is linked from the release, so the cohort description rests on the README and participants file. A 2021 Human Brain Mapping study by the same group (doi:10.1002/hbm.25698) used the same seven-run protocol in 26 volunteers; the release does not say whether those people are part of it. The single site and narrow age range limit generalization.