Self‐navigated isotropic three‐dimensional cardiac T 2 mapping

Purpose To implement and characterize an isotropic three‐dimensional cardiac T 2 mapping technique. Methods A self‐navigated three‐dimensional radial segmented balanced steady‐state free precession pulse sequence with an isotropic 1.7‐mm spatial resolution was implemented at 3T with a variable T 2 preparation module. Bloch equation and Monte Carlo simulations were performed to determine the influence of the heart rate, B 1 inhomogeneity and noise on the T 2 fitting accuracy. In a phantom study, the accuracy of the pulse sequence was studied through comparison with a gold‐standard spin‐echo T 2 mapping method. The robustness and homogeneity of the technique were ascertained in a study of 10 healthy adult human volunteers, while first results obtained in patients are reported. Results The numerical simulations demonstrated that the heart rate and B 1 inhomogeneity cause only minor deviations in the T 2 fitting, whereas the phantom study showed good agreement of the technique with the gold standard. The volunteer study demonstrated an average myocardial T 2 of 40.5 ± 3.3 ms and a <15% T 2 gradient in the base‐apex and anterior‐inferior direction. In three patients, elevated T 2 values were measured in regions with expected edema. Conclusion This respiratory self‐navigated isotropic three‐dimensional technique allows for accurate and robust in vitro and in vivo T 2 quantification. Magn Reson Med 73:1549–1554, 2015. © 2014 Wiley Periodicals, Inc.