Three-dimensional free breathing whole heart cardiovascular magnetic resonance T ₁ mapping at 3 T

Background: This study demonstrates a three-dimensional (3D) free-breathing native myocardial T ₁ mapping sequence at 3 T. Methods: The proposed sequence acquires three differently T ₁ -weighted volumes. The first two volumes receive a saturation pre-pulse with different recovery time. The third volume is acquired without magnetization preparation and after a significant recovery time. Respiratory navigator gating and volume-interleaved acquisition are adopted to mitigate misregistration. The proposed sequence was validated through simulation, phantom experiments and in vivo experiments in 12 healthy adult subjects. Results: In phantoms, good agreement on T ₁ measurement was achieved between the proposed sequence and the reference inversion recovery spin echo sequence (R ² = 0.99). Homogeneous 3D T ₁ maps were obtained from healthy adult subjects, with a T ₁ value of 1476 ± 53 ms and a coefficient of variation (CV) of 6.1 ± 1.4% over the whole left-ventricular myocardium. The averaged septal T ₁ was 1512 ± 60 ms with a CV of 2.1 ± 0.5%. Conclusion: Free-breathing 3D native T ₁ mapping at 3 T is feasible and may be applicable in myocardial assessment. The proposed 3D T ₁ mapping sequence is suitable for applications in which larger coverage is desired beyond that available with single-shot parametric mapping, or breath-holding is unfeasible.