A Validation of Two-Dimensional In Vivo Regional Strain Computed from Displacement Encoding with Stimulated Echoes (DENSE), in Reference to Tagged Magnetic Resonance Imaging and Studies in Repeatability

Abstract

Fast cine displacement encoding with stimulated echoes (DENSE) has comparative advantages over tagged MRI (TMRI) including higher spatial resolution and faster post-processing. This study computed regional radial and circumferential myocardial strains with DENSE displacements and validated it in reference to TMRI, according to American Heart Association (AHA) guidelines for standardized segmentation of regions in the left ventricle (LV). This study was therefore novel in examining agreement between the modalities in 16 AHA recommended LV segments. DENSE displacements were obtained with spatiotemporal phase unwrapping and TMRI displacements obtained with a conventional tag-finding algorithm. A validation study with a rotating phantom established similar shear strain between modalities prior to in vivo studies. A novel meshfree nearest node finite element method (NNFEM) was used for rapid computation of Lagrange strain in both phantom and in vivo studies in both modalities. Also novel was conducting in vivo repeatability studies for observing recurring strain patterns in DENSE and increase confidence in it. Comprehensive regional strain agreements via Bland–Altman analysis between the modalities were obtained. Results from the phantom study showed similar radial-circumferential shear strains from the two modalities. Mean differences in regional in vivo circumferential strains were −0.01 ± 0.09 (95% limits of agreement) from comparing the modalities and −0.01 ± 0.07 from repeatability studies. Differences and means from comparison and repeatability studies were uncorrelated (p>0.05) indicating no increases in differences with increased strain magnitudes. Bland–Altman analysis and similarities in regional strain distribution within the myocardium showed good agreements between DENSE and TMRI and show their interchangeability. NNFEM was also established as a common framework for computing strain in both modalities.

Myocardial strain in healthy adults across a broad age range as revealed by cardiac magnetic resonance imaging at 1.5 and 3.0T: Associations of myocardial strain with myocardial region, age, and sex

“…On the other hand, other authors, including Augustine et al,18 using feature‐tracking, Neizel et al19 using SENC, and Kuznetsova et al20 using echocardiography found that women had similar circumferential and longitudinal strain to men. DENSE,1 tagging,8 phase contrast MR,10 and feature tracking21 use different techniques to analyze strain, which could account for some of the differences in strain values observed using these different methods 22…”

Analytic signal phase-based myocardial motion estimation in tagged MRI sequences by a bilinear model and motion compensation

“…In that work, a coarse-to-fine B-spline scheme allows for the effective and robust computation of the displacement, and also a pyramidal refinement scheme helps to deal with large motions. From the myocardial motion field, various further studies have been realized in order to extract motion-related information, such as myocardium segmentation (Dietenbeck et al, 2014), local deformation (Kar et al, 2014;Oubel et al, 2012), and local region tracking (Arif et al, 2014;Luo et al, 2014;Sun et al, 2011). For these information extraction methods, the key point is to estimate an accurate myocardium motion field.…”

Magnetic Resonance Imaging of Myocardial Deformation and Scarring in Coronary Artery Disease.

“…Although there were significant differences between the scar and control groups, the AUC was small, preventing the use of radial strain for diagnostics. The high variability of radial strain in healthy individuals has also been demonstrated in other studies [148].…”