Which multiband factor should you choose for your resting-state fMRI study? The Emory Multiband Dataset

Introduction
------------
The Emory Multiband Dataset was collected to examine the impacts of multiband acceleration on resting-state fMRI. We collected factors of 2, 3, 4, 6, 8, 9, and 12 with 2-mm isotropic resolution, and additionally 2 mm and 3.3 mm single-band acquisitions, from thirty-two subjects.

Acquisition Protocols
---------------------
The acquisition protocols included 6-min scans with AP phase encoding:
* single-band with 3.3 mm voxel size (TR 3.0 s)
* single-band with 2 mm voxel size (TR 5.67)
* multiband with factors 2 (TR 2.85), 3 (TR 1.91), 4 (TR 1.44), 6 (TR 0.962), 8 (TR 0.736), 9 (TR 0.675), 12 (TR 0.512).

In addition:
* MB 3 with PA phase encoding; we used this PA SBRef in topup and did not use the bold series (which contained 8 volumes).

sub-28 and sub-31 do not have MB9 acquisitions.

Flip angles were set to achieve the Ernst angle.

Each participant's data is from a single session in the same scanner, and two scanners with identical hardware specifications and software version were used throughout the study (MAGNETOM PrismaFit, software version E11C, Siemens Healthcare, Erlangen, Germany). A thirty-two channel head coil was used.

Example processing scripts are available from the Brain Research in Imaging Statistics Kit at https://github.com/thebrisklab

Task Description: "rest"
--------------------------
Participants were asked to lay motionless and look at a cross-hair during resting-state scans.

Defacing
--------
Pydeface was used on all anatomical images to ensure de-identification of subjects. The code can be found at https://github.com/poldracklab/pydeface