A three‐dimensional free‐breathing sequence for simultaneous myocardial T₁ and T₂ mapping

Abstract

Purpose: The aim of this study was to develop, test and validate a 3D free‐breathing technique for simultaneous measurement of native myocardial T1 and T2. Methods: The proposed 3D technique acquires five fat‐suppressed electrocardiogram‐triggered respiratory navigator‐gated spoiled gradient echo volumes in an interleaved manner. Four volumes are prepared using a combination of nonselective saturation and T2 preparation. One volume is acquired with fully recovered longitudinal magnetization for accuracy during parametric fitting. Performance of the technique was validated through numerical simulations, phantom experiments and in vivo experiments in 15 healthy human subjects. Results: Simulations and phantom experiments show that the measured T1 and T2 are largely insensitive to heart rate. In vivo whole‐heart maps with a voxel size of 1.5 × 1.5 × 16 mm3 were acquired without parallel imaging within ~ 8 min including respiratory gating efficiency. The in vivo parametric maps were homogeneous (coefficients of variation of left ventricle myocardium were 6.0% ± 0.8% and 10.2% ± 3.4% for T1 and T2 maps, respectively), with an average T1 value of 1470 ± 59.2 ms and T2 value of 41.6 ± 1.8 ms Conclusions: The proposed 3D technique allows for measurement of whole‐heart T1 and T2 with preserved accuracy and precision in a single scan.

Accelerated free‐breathing whole‐heart 3D T2 mapping with high isotropic resolution

“…Finally, the proposed fast and efficient framework holds promise for wider cardiac applications, such as high‐resolution motion‐compensated 3D T 1 mapping and 3D joint T 1 ‐T 2 mapping, both of which will be investigated in future work.…”

3D free‐breathing cardiac magnetic resonance fingerprinting

“…20 More recently, 3D free-breathing T 1 /T 2 mapping has been achieved using T2prep, saturation recovery pulses and respiratory diaphragmatic navigators; however, this can lead to long and unpredictable scan times. 21 All of the above are steady-state approaches, often sampling discrete points along the relaxation curves and relying on simplified exponential models.…”

Single breath-hold saturation recovery 3D cardiac T1 mapping via compressed SENSE at 3T

“…The sequence begins with proton density (PD) images to avoid T1 effects from prior saturation pulses (first block). Full signal recovery is ensured by waiting a minimum of 6 s between the PD readouts [12,26]. The second block consists of images acquired at saturation time (TS) 1 and at TS1+RR interval (TS3).…”