Real‐time MR imaging of myocardial regional function using strain‐encoding (SENC) with tissue through‐plane motion tracking

Abstract

Purpose: To implement real-time myocardial strain-encoding (SENC) imaging in combination with tracking the tissue displacement in the through-plane direction. Materials and Methods:SENC imaging was combined with the slice-following technique by implementing three-dimensional (3D) selective excitation. Certain adjustments were implemented to reduce scan time to one heartbeat. A total of 10 volunteers and five pigs were scanned on a 3T MRI scanner. Spatial modulation of magnetization (SPAMM)-tagged images were acquired on planes orthogonal to the SENC planes for comparison. Myocardial infarction (MI) was induced in two pigs and the resulting SENC images were compared to standard delayed-enhancement (DE) images. Results:The strain values computed from SENC imaging with slice-following showed significant difference from those acquired without slice-following, especially during systole (P Ͻ 0.01). The strain curves computed from the SENC images with and without slice-following were similar to those computed from the orthogonal SPAMM images, with and without, respectively, tracking the tag line displacement in the strain direction. The resulting SENC images showed good agreement with the DE images in identifying MI in infarcted pigs. Conclusion:Correction of through-plane motion in realtime cardiac functional imaging is feasible using slice-following. The strain measurements are more accurate than conventional SENC measurements in humans and animals, as validated with conventional MRI tagging.

Strain‐encoded (SENC) magnetic resonance imaging to evaluate regional heterogeneity of myocardial strain in healthy volunteers: Comparison with conventional tagging

“…The SENC values of healthy volunteers in our study are very close to the normal SENC values obtained in the studies of Ibrahim et al (18) and Korosoglou et al (19). The longitudinal SENC values in the study of Garot et al (10) are much lower than the longitudinal SENC values in this study.…”

Strain-Encoded CMR for the Detection of Inducible Ischemia During Intermediate Stress

“…Because the displacement is higher during peak stress, the absence of through-plane motion correction is expected to underestimate strain values to a higher extent during stress, resulting in an underestimation of the calculated strain reserves. Throughplane motion tracking is, however, now available with new implementations of the SENC pulse sequence (15), which may allow for more accurate estimation of strain in future studies. Emphasizing pathophysiologic aspects between myocardial strain response and lumen narrowing, the decrease of strain rate in our study was shown to precede that of myocardial strain in the ischemic cascade.…”

Comparison of strain measurement from multimodality tissue tracking with strain-encoding MRI and harmonic phase MRI in pulmonary hypertension

“…LV and RV regional function can be assessed from cardiac magnetic resonance (CMR) imaging through myocardial tagging [9][10][11] as well as real-time myocardial strain encoding (SENC) [12,13] or direct tissue encoding sequences (DENSE) [14]. Myocardial tagging and SENC have quantitative value, but have not yet gained widespread clinical use, in part because of expertise of specific sequences, additional scanning time and the need for complex post-processing analysis.…”