Validation of two accelerated 4D flow MRI sequences at 3 T: a phantom study

European Radiology Experimental

Table 5 4D flow measurements with GRAPPA2 and k-t-GRAPPA5 sequences of the flow volumes and mean velocities in pulsatile flow in comparison with 2D flow phase-contrast sequences

2D flow PC			4D flow PC GRAPPA2			4D flow PC k-t-GRAPPA5
Flow volume, L/min	Mean velocity, cm/s	Peak velocity, cm/s	Flow volume, L/min	Mean velocity, cm/s	Peak velocity, cm/s	Flow volume, L/min	Mean velocity, cm/s	Peak velocity, cm/s
2.7	35	69	2.7	36	72	2.7	35	72
3.6	47	98	3.6	47	100	3.7	48	102
4.4	58	123	4.3	57	120	4.7	58	123
5.7	71	149	5.4	70	147	5.7	71	149
Correlation coefficient R (p value)*			1.0	1.0	1.0	0.99	0.99	0.99
Limits of agreement*			-0.18, 0.38	-1.63, 2.13	-5.8, 5.8	-0.38, 0.18	-1.23, 0.73	-5.8, 2.3

2D two-dimensional, 4D four-dimensional, cm/s centimetres per second, GRAPPA generalised autocalibrating partially parallel acquisition, L/min litres per minute, PC phase-contrast
*Correlation coefficients and limits of agreement between the 4D flow PC GRAPPA2 and k-t-GRAPPA5 with the 2D flow PC sequences used as the reference standard