Black‐blood native T 1 mapping: Blood signal suppression for reduced partial voluming in the myocardium

Purpose To study the feasibility of black‐blood contrast in native T 1 mapping for reduction of partial voluming at the blood–myocardium interface. Methods A saturation pulse prepared heart‐rate‐independent inversion recovery (SAPPHIRE) T 1 mapping sequence was combined with motion‐sensitized driven‐equilibrium (MSDE) blood suppression for black‐blood T 1 mapping at 3 Tesla. Phantom scans were performed to assess the T 1 time accuracy. In vivo black‐blood and conventional SAPPHIRE T 1 mapping was performed in eight healthy subjects and analyzed for T 1 times, precision, and inter‐ and intraobserver variability. Furthermore, manually drawn regions of interest (ROIs) in all T 1 maps were dilated and eroded to analyze the dependence of septal T 1 times on the ROI thickness. Results Phantom results and in vivo myocardial T 1 times show comparable accuracy with black‐blood compared to conventional SAPPHIRE (in vivo: black‐blood: 1562 ± 56 ms vs. conventional: 1583 ± 58 ms, P = 0.20); Using black‐blood SAPPHIRE precision was significantly lower (standard deviation: 133.9 ± 24.6 ms vs. 63.1 ± 6.4 ms, P < .0001), and blood T 1 time measurement was not possible. Significantly increased interobserver interclass correlation coefficient (ICC) (0.996 vs. 0.967, P = 0.011) and similar intraobserver ICC (0.979 vs. 0.939, P = 0.11) was obtained with the black‐blood sequence. Conventional SAPPHIRE showed strong dependence on the ROI thickness (R 2 = 0.99). No such trend was observed using the black‐blood approach (R 2 = 0.29). Conclusion Black‐blood SAPPHIRE successfully eliminates partial voluming at the blood pool in native myocardial T 1 mapping while providing accurate T 1 times, albeit at a reduced precision. Magn Reson Med 78:484–493, 2017. © 2016 International Society for Magnetic Resonance in Medicine