Table 1. 3T brain MRI anatomical acquisition protocols.

Each of the 7 sites used one of 3 different Siemens scanner models (Skyra, Verio and TrioTim), necessitating 3 model-specific protocols for each of the 3 pulse sequences.

	3D T2 FLAIR			3D T1 MPRAGE			2D PD T2
Scanner manufacturer	Siemens Skyra	Siemens Verio	Siemens TrioTim	Siemens Skyra	Siemens Verio	Siemens TrioTim	Siemens Skyra	Siemens Verio	Siemens TrioTim
Operation system version	Syngo MR D13	Syngo MR B17	Syngo MR B17	Syngo MR D13	Syngo MR B17	Syngo MR B17	Syngo MR D13	Syngo MR B17	Syngo MR B17
Coil	20, 32, or 64 Channel*	32 Channel	32 Channel	20, 32, or 64 Channel*	32 Channel	32 Channel	20, 32, or 64 Channel*	32 Channel	32 Channel
Acceleration factor for parallel imaging	2	2	2	2	2	2	3	3	3
Orientation	Sagittal	Sagittal	Sagittal	Sagittal	Sagittal	Sagittal	Axial	Axial	Axial
Field of view (cm)	25.6×25.6	25.6×25.6	25.6×25.6	25.6×25.6	25.0×25.0	25.0×25.0	21.7×24.0	21.7×24.0	21.7×24.0
Matrix size	512×512	512×512	512×512	256×256	256×256	256×256	232×256	232×256	232×256
Number of slices	176	176	176	176	176	176	108	108	108
Repetition time (msec)	4800	4800	4800	1900	1900	1900	3000	3000	3000
Echo time (msec)	353	354	355	2.52	2.52	2.52	11/101	11/101	11/101
Flip angle (degrees)	120	120	120	9	9	9	150	150	150
Voxel size (mm)	0.5×0.5×1.0	0.5×0.5×1.0	0.5×0.5×1.0	1.0×1.0×1.0	0.977×0.977×1.0	0.977×0.977×1.0	0.9375×0.9375×3.0	0.9375×0.9375×3.0	0.9375×0.9375×3.0
Scan time (mins)	6:53	7:00	7:00	4:15	4:16	4:16	1:57	2:15	2:15
Number of signal averages	1	1	1	1	1	1	1	1	1

Key: FLAIR = fluid-attenuated inversion recovery, MPRAGE = magnetization-prepared rapid acquisition gradient echo, PD = proton density.

^*Brigham and Women’s Hospital = 20-channel, University of California San Francisco = 64 channel (the other two Skyra sites = 32 channel).