Comparison of Two-Dimensional Speckle and Tissue Velocity Based Strain and Validation With Harmonic Phase Magnetic Resonance Imaging

Two-dimensional (2-D) strain (ε_2-D) on the basis of speckle tracking is a new technique for strain measurement. This study sought to validate ε_2-D and tissue velocity imaging (TVI)–based strain (ε_TVI) with tagged harmonic-phase (HARP) magnetic resonance imaging (MRI). Thirty patients (mean age 62 ± 11 years) with known or suspected ischemic heart disease were evaluated. Wall motion (wall motion score index 1.55 ± 0.46) was assessed by an expert observer. Three apical images were obtained for longitudinal strain (16 segments) and 3 short-axis images for radial and circumferential strain (18 segments). Radial ε_TVI was obtained in the posterior wall. HARP MRI was used to measure principal strain, expressed as maximal length change in each direction. Values for ε_2-D, ε_TVI, and HARP MRI were comparable for all 3 strain directions and were reduced in dysfunctional segments. The mean difference and correlation between longitudinal ε_2-D and HARP MRI (2.1 ± 5.5%, r = 0.51, p <0.001) were similar to those between longitudinal ε_TVI and HARP MRI (1.1 ± 6.7%, r = 0.40, p <0.001). The mean difference and correlation were more favorable between radial ε_2-D and HARP MRI (0.4 ± 10.2%, r = 0.60, p <0.001) than between radial ε_TVI and HARP MRI (3.4 ± 10.5%, r = 0.47, p <0.001). For circumferential strain, the mean difference and correlation between ε_2-D and HARP MRI were 0.7 ± 5.4% and r = 0.51 (p <0.001), respectively. In conclusion, the modest correlations of echocardiographic and HARP MRI strain reflect the technical challenges of the 2 techniques. Nonetheless, ε_2-D provides a reliable tool to quantify regional function, with radial measurements being more accurate and feasible than with TVI. Unlike ε_TVI, ε_2-D provides circumferential measurements.