Comparison of spoiled gradient echo and steady‐state free‐precession imaging for native myocardial T 1 mapping using the slice‐interleaved T 1 mapping (STONE) sequence

• Published in: NMR in biomedicine Vol. 29; no. 10; pp. 1486 - 1496
• Main Authors: Jang, Jihye, Bellm, Steven, Roujol, Sébastien, Basha, Tamer A., Nezafat, Maryam, Kato, Shingo, Weingärtner, Sebastian, Nezafat, Reza
• Format: Journal Article
• Language: English
• Published: 01.10.2016
• ISSN: 0952-3480; 1099-1492
• DOI: 10.1002/nbm.3598

Abstract Cardiac T 1 mapping allows non‐invasive imaging of interstitial diffuse fibrosis. Myocardial T 1 is commonly calculated by voxel‐wise fitting of the images acquired using balanced steady‐state free precession (SSFP) after an inversion pulse. However, SSFP imaging is sensitive to B 1 and B 0 imperfection, which may result in additional artifacts. A gradient echo (GRE) imaging sequence has been used for myocardial T 1 mapping; however, its use has been limited to higher magnetic field to compensate for the lower signal‐to‐noise ratio (SNR) of GRE versus SSFP imaging. A slice‐interleaved T 1 mapping (STONE) sequence with SSFP readout (STONE–SSFP) has been recently proposed for native myocardial T 1 mapping, which allows longer recovery of magnetization (>8 R–R) after each inversion pulse. In this study, we hypothesize that a longer recovery allows higher SNR and enables native myocardial T 1 mapping using STONE with GRE imaging readout (STONE–GRE) at 1.5T. Numerical simulations and phantom and in vivo imaging were performed to compare the performance of STONE–GRE and STONE–SSFP for native myocardial T 1 mapping at 1.5T. In numerical simulations, STONE–SSFP shows sensitivity to both T 2 and off resonance. Despite the insensitivity of GRE imaging to T 2 , STONE–GRE remains sensitive to T 2 due to the dependence of the inversion pulse performance on T 2 . In the phantom study, STONE–GRE had inferior accuracy and precision and similar repeatability as compared with STONE–SSFP. In in vivo studies, STONE–GRE and STONE–SSFP had similar myocardial native T 1 times, precisions, repeatabilities and subjective T 1 map qualities. Despite the lower SNR of the GRE imaging readout compared with SSFP, STONE–GRE provides similar native myocardial T 1 measurements, precision, repeatability, and subjective image quality when compared with STONE–SSFP at 1.5T.