A multi-center inter-manufacturer study of the temporal stability of phase-contrast velocity mapping background offset errors

Table 2 Variability results of background offsets

Scanner	1	2	3
ROI	1 2 3 4	1 2 3 4	1 2 3 4
Long-term (stdev cm/s)	0.07 0.07 0.07 0.08	0.18 0.18 0.17 0.21	0.16 0.08 0.07 0.12
Long-term (pk-pk cm/s)	0.35 0.29 0.28 0.37	0.64 0.62 0.60 0.86	0.61 0.34 0.30 0.48
Session (pk-pk cm/s)	0.25 0.16 0.28 0.20	0.47 0.48 0.40 0.50	0.19 0.21 0.19 0.23
Cine (Sc) (stdev cm/s)	0.12 0.13 0.12 0.12	0.06 0.05 0.05 0.05	0.06 0.08 0.04 0.07
Spatial (Ss) (stdev cm/s)	0.94 1.0 1.1 1.2	0.20 0.18 0.32 0.21	0.23 0.32 0.22 0.28

The “Long-term” rows include all 40 scans over the 8 weeks. The “Session” row is the largest peak-to-peak variation between the 5 scans in each week. The 4 ROIs were placed at 4 locations consistently for each scan as explained in Methods. The spatial standard deviation within each single ROI is shown in the spatial row. The values in bold font are quoted in the Results as the worst-case. The symbols Sc and Ss are used in the Discussion.

ISSN: 1532-429X