Free-breathing multislice native myocardial T₁ mapping using the slice-interleaved T₁ (STONE) sequence

Purpose To develop a novel pulse sequence for free-breathing, multislice, native myocardial T₁ mapping. Methods The slice-interleaved T₁ (STONE) sequence consists of multiple sets of single-shot images of different slices, acquired after a single nonselective inversion pulse. Each slice is only selectively excited once after each inversion pulse to allow sampling of the unperturbed longitudinal magnetization in the adjacent slices. For respiratory motion, a prospective slice-tracking respiratory navigator is used to decrease through-plane motion followed by a retrospective image registration to reduce in-plane motion. STONE T₁ maps were calculated using both a two-parameter and three-parameter fit model. The accuracy and precision of the STONE sequence for different T₁, T₂, and inversion pulse efficiency were studied using numerical simulations and phantom experiments. T₁ maps from 14 subjects were acquired with the STONE sequence and T₁s were compared to the MOdified Look-Locker Inversion recovery sequence (MOLLI). Results In numerical simulations and phantom experiments, the STONE sequence using a two-parameter fit model yields more accurate T₁ times compared to MOLLI, with similar high precision. The three-parameter fit model further improves the accuracy, but with a reduced precision. The native myocardial T₁ times were higher in the STONE sequence using two- or three-parameter fit compared to MOLLI. The standard deviation of the T₁ times was lower in the STONE T₁ maps with a two-parameter fit compared with MOLLI or a three-parameter fit. Conclusion The STONE sequence allows accurate and precise quantification of native myocardial T₁ times with the additional benefit of covering the entire ventricle. Magn Reson Med 74:115-124, 2015.