Table 3.

Statistical results from exploratory measurements beyond the protocol.

Siemens		sample 1			sample 2			sample 3
		transv. aortic	obl. aortic	pulm	transv. aortic	obl. aortic	pulm	transv. aortic	obl. aortic	pulm
gradient amplitude	cm/s per mT/m	0.02	0.05	0.04	0.01	0.03	0.03	0.04	0.11	0.07
slew rate	cm/s per mT/m/s	2.28	0.85	-0.86	2.23	1.23	0.14	0.85	-0.34	0.3
r2		0.57	0.49	0.47	0.66	0.73	0.61	0.81	0.89	0.81

Results from beyond protocol variation by multiple regression of gradient amplitude and slew rate on velocity offset. All correlations found were highly significant (P < < 0.01) but not very strong and varied considerably among scanner samples of the same type. As an example, the data points of sample 2 are shown in Figure 5.