Table 2. Sequence parameters of structural MRI datasets at each data collection.
| Collection | FA | TI | TE | ES | BW | TR | PA | PF | SO | PE |
Reconstructed Resolution (mm)
|
Recontructed Image Dims
|
TA | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Label | ° | ms | ms | ms | Hz/Px | ms | RO | PE | SL | RO | PE | SL | min:sec | ||||
| The 3D MPRAGE (three dimensional magnetization prepared rapid acquisition gradient echo) sequence, or a vendor specific variant, was used to acquire all data. BW, bandwidth per pixel; Dims, dimensions; ES, echo spacing; FA, flip angle (indexed in degrees); PA, parallel acquisition; PE, phase encoding; PF, partial Fourier (halfscan); SO, Slice orientation; TA, Acquisition Time; TE, echo time; TI, inversion time; TR, repetition time; For parallel acquisitions; SS, SENSE acceleration in the slice direction; SP, SENSE acceleration in the phase encoding direction; GP, GRAPPA acceleration in the phase encoding direction; AP, ASSET acceleration in the phase encoding direction. For partial Fourier, the under-sampled dimension is listed with the under sampling factor; P, phase encoding. For slice orientation; S, sagittal; T, transverse (axial); C, coronal. For phase encoding direction; RL, right-to-left; AP, Anterior to posterior. Reconstructed resolution and image dimensions refer to the images after they have been reconstructed from the k-space data, the matrix size and resolution used for the acquisition may differ. For these categories, RO, read out direction; PE, phase encoding direction, and SL, slice direction. |
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| ABIDEII-BNI_1 | 9 | 900 | 3.10 | 6.7 | 240.5 | 2,500 | SS1.8 | — | S | AP | 1.06 | 1.06 | 1.06 | 256 | 256 | 193 | 5:34 |
| ABIDEII-EMC_1 | 16 | 350 | 4.24 | 10.26 | 81.4 | 1,664 | AP2 | — | S | AP | 0.90 | 0.90 | 0.90 | 256 | 256 | 186 | 5:40 |
| ABIDEII-ETH_1 | 8 | 1,150 | 3.90 | 7.9 | 188.3 | 3,000 | SP2.3 | — | T | RL | 0.90 | 0.90 | 0.90 | 256 | 256 | 180 | 5:46 |
| ABIDEII-GU_1 | 7 | 1,100 | 3.50 | 8.2 | 190 | 2,530 | GP2 | — | S | AP | 1.00 | 1.00 | 1.00 | 256 | 256 | 276 | 8:05 |
| ABIDEII-IU_1 | 8 | 1,000 | 2.30 | 7 | 210 | 2,400 | GP2 | P×7/8 | S | AP | 0.70 | 0.70 | 0.70 | 320 | 320 | 256 | 7:02 |
| ABIDEII-IP_1 | 30 | – | 5.60 | 25 | 141.7 | 2,500 | SP2+SS2 | — | S | AP | 1.00 | 1.00 | 1.00 | 240 | 240 | 170 | 4:37 |
| ABIDEII-KKI_1* (8 channels) | 8 | 1,000 | 3.70 | 8 | 191.5 | 3,500 | SS2 | — | C | RL | 1.00 | 1.00 | 1.00 | 256 | 200 | 200 | 8:08 |
| ABIDEII-KKI_1* (32 channels) | 8 | 900 | 3.70 | 8.2 | 192.9 | 3,000 | SP1.2+SS2 | — | T | RL | 0.95 | 0.95 | 1.00 | 224 | 224 | 150 | 4:24 |
| ABIDEII-KUL_3 | 8 | 900 | 4.60 | 9.4 | 130.6 | 2,000 | SP1.5+SS2.5 | — | C | RL | 0.98 | 0.98 | 1.20 | 256 | 256 | 182 | 1:43 |
| ABIDEII-NYU_1 | 7 | 1,100 | 3.25 | 7.4 | 200 | 2,530 | — | — | S | AP | 1.30 | 1.00 | 1.33 | 256 | 256 | 128 | 8:07 |
| ABIDEII-NYU_2 | 7 | 1,100 | 3.25 | 7.2 | 200 | 2,530 | — | — | S | AP | 1.30 | 1.00 | 1.33 | 256 | 256 | 128 | 8:07 |
| ABIDEII-ONRC_2 | 13 | 794 | 2.88 | 7.1 | 200 | 2,200 | GP3 | — | T | RL/AP † | 0.80 | 0.80 | 0.80 | 220 | 320 | 208 | 3:25 |
| ABIDEII-OHSU_1 | 10 | 900 | 3.58 | 8.2 | 180 | 2,300 | — | — | S | AP | 1.00 | 1.00 | 1.10 | 256 | 240 | 160 | 9:14 |
| ABIDEII-SDSU_1 | 8 | 600 | 3.17 | 8.136 | 244.1 | 2,683 ‡ | — | — | S | AP | 1.00 | 1.00 | 1.00 | 256 | 256 | 172 | 4:54 |
| ABIDEII-TCD_1 | 8 | 1,150 | 3.90 | 7.9 | 188.3 | 3,000 | SP2.3 | — | T | RL | 0.90 | 0.90 | 0.90 | 256 | 256 | 180 | 5:43 |
| ABIDEII-UCD_1 | 8 | 1,050 | 3.16 | 7.5 | 220 | 2,000 | GP2 | — | S | AP | 1.00 | 1.00 | 1.00 | 256 | 224 | 192 | 4:06 |
| ABIDEII-UCLA_1 | 9 | 853 | 2.86 | 6.7 | 240 | 2,300 | — | — | S | AP | 1.00 | 1.00 | 1.20 | 256 | 240 | 160 | 9:14 |
| ABIDEII-USM_1 | 9 | 900 | 2.91 | 6.8 | 240 | 2,300 | — | — | S | AP | 1.00 | 1.00 | 1.20 | 256 | 240 | 160 | 9:14 |
| ABIDEII-UCLA_Long | 9 | 853 | 2.86 | 6.7 | 240 | 2,300 | — | — | S | AP | 1.00 | 1.00 | 1.20 | 256 | 240 | 160 | 9:14 |
| ABIDEII-UPSM_Long | 7 | 1,000 | 3.93 | 9.4 | 130 | 2,100 | — | S | AP | 1.05 | 1.05 | 1.05 | 256 | 256 | 176 | 8:59 | |
*62 datasets of the KKI-1 collection were acquired with an 8-channel head coil, 149 datasets were acquired with a 32 channel coil and different scanning parameters. A list of the IDs with the corresponding head coil is provided in the ABIDE II website page for this collection as ‘Additional scan Information.’
† ONRC_2 has variable phase encoding direction, specific information for each dataset is provided in the release/website (http://fcon_1000.projects.nitrc.org/indi/abide/).
‡ SDSU has used a GE scanner that refers to TR as the amount of time between the RF pulses that are used to read out the lines of k-space (i.e., echo space). Here to be consistent across all collections we report TR using the Siemens convention that refers to TR as the time between sequential inversion recovery pulses. Based on the simple equation TR=TI+n*ES, where n is the number of actual (corrected for parallel imaging) phase encoding lines, we calculated the TR of SDSU to be 2,683 ms.