Real‐time fast strain‐encoded magnetic resonance imaging to evaluate regional myocardial function at 3.0 Tesla: Comparison to conventional tagging

Abstract

Purpose:To compare the utility of the real-time technique fast strain-encoded magnetic resonance imaging (fast-SENC) for the quantification of regional myocardial function to conventional tagged magnetic resonance imaging (MRI). Materials and Methods:Healthy volunteers (N ϭ 12) and patients with heart failure (N ϭ 7) were examined using tagged MRI and fast-SENC at 3.0T. Circumferential strain was measured using fast-SENC in six endo-and six subepicardial regions in the basal-, mid-, and apical-septum and the basal-, mid-, and apical-lateral wall from the fourchamber view. These measurements were plotted to tagging, in corresponding myocardial segments.Results: Peak systolic strain (Ecc) and early diastolic strain rate (Ecc/second) acquired by fast-SENC correlated closely to tagged MRI (r ϭ 0.90 for Ecc and r ϭ 0.91 for Ecc/second, P Ͻ 0.001 for both). Both fast-SENC and tagging identified differences in regional systolic and diastolic function between normal myocardium and dysfunctional segments in patients with heart failure (for fast-SENC: Ecc ϭ -21.7 Ϯ 2.7 in healthy volunteers vs. -12.8 Ϯ 4.2 in hypokinetic vs. 0.6 Ϯ 3.8 in akinetic/dyskinetic segments, P Ͻ 0.001 between all; Ecc/ second ϭ 104 Ϯ 20/second in healthy volunteers vs. 37 Ϯ 9/second in hypokinetic vs. -16 Ϯ 15/second in akinetic/ dyskinetic segments, P Ͻ 0.001 between all). Quantitative analysis was more time-consuming for conventional tagging than for fast-SENC (time-spent of 3.8 Ϯ 0.7 minutes vs. 9.5 Ϯ 0.7 minutes per patient, P Ͻ 0.001). Conclusion:Fast-SENC allows the rapid and accurate quantification of regional myocardial function. The information derived from fast-SENC during a single heartbeat seems to be superior or equal to that acquired by conventional tagging during several heart cycles and prolonged breathholds.

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.…”

“…In other MR tagging studies the interobserver variability was approximately the same as in our study using MR tagging (24,25). However, despite the use of harmonic phase (HARP) concepts (26), the data analysis of tagged images is still more time-consuming and is often confounded by noise artifacts due to inadequate image quality (19).…”

“…The rate of early relaxation was decreased in older subjects. A validation of SENC and MR tagging to assess diastolic function has been performed before (19). We presume that SENC may be superior to MR tagging in assessment of diastolic function as SENC does not suffer that much from rapid fading of tags, which limits interpretation of the whole cardiac cycle because RF pulses with ramped flip angles are applied to compensate for the tag fading caused by longitudinal relaxation and to maintain constant myocardial signal intensity throughout the cardiac cycle.…”

Identification and further differentiation of subendocardial and transmural myocardial infarction by fast strain-encoded (SENC) magnetic resonance imaging at 3.0 Tesla

“…SENC provides the objective colour-coded evaluation of circumferential and longitudinal myocardial strain and has been validated in clinical settings [15,16]. Fast SENC using a spiral acquisition enables MR data acquisition times as short as a single heartbeat [15].…”

Strain‐encoded MRI to evaluate normal left ventricular function and timing of contraction at 3.0 Tesla

“…Compared with 1.5T, they provide significant improvement in signal-to-noise ratio (SNR), especially for T1-dependent techniques such as SENC and fast-SENC MRI (9).…”