Navigator acceptance window width does not affect accuracy and precision in free-breathing 2D cardiac MR fingerprinting of the myocardium at 3T.

We implemented and characterized a free-breathing 2D cardiac joint T1-T2 MR fingerprinting technique at 3T named PARMA that includes a lung-liver navigator to minimize through-plane motion. We assessed the effect of rejected navigators on the relaxation times. Joint T1-T2 maps with four different navigator acceptance window widths (NAWWs from ±4mm to ±32mm) were acquired in 6 healthy volunteers and compared to clinical routine techniques. The accuracy and precision of the maps resulting from the different NAWWs did not significantly differ, suggesting that the NAWW can be chosen as a balance between navigator inefficiency and through-plane motion.