Data
70,278 bulk items are available, covering 65,156 participants.
Defined-instances run from 2 to 3, labelled using Instancing
2.
The values held within this field are coded links to files held within a bulk repository, not the actual data itself.
2 Instances
Instance 2 : Imaging visit (2014+)
65,081 participants, 65,081 items
Data not meaningful for statistical summary
Instance 3 : First repeat imaging visit (2019+)
5,197 participants, 5,197 items
Data not meaningful for statistical summary
Notes
Multiband diffusion brain images in NIFTI format.
The source DICOM images were acquired using the following parameters:
Resolution: 2x2x2 mm
Field-of-view: 104x104x72 matrix
Duration: 7 minutes (including 36 seconds phase-encoding reversed data)
10x b=0, 50x b=1000, 50x b=2000
SE-EPI with x3 multislice acceleration, no iPAT, fat saturation
For the two diffusion-weighted shells, 50 distinct diffusion-encoding directions were acquired (and all 100 directions are distinct). The diffusion prepraration is a standard ("monopolar") Stejskal-Tanner pulse sequence. This enables higher SNR due to a shorter echo time (TE=92ms) than than a twice-refocused ("bipolar") sequence. This improvement comes at the expense of stronger eddy current distortions, which are removed in the image processing pipeline.
The average size of these NIFTI datasets is 550MB per participant.