Comparison of Velocity Vector Imaging Echocardiography With Magnetic Resonance Imaging in Mouse Models of Cardiomyopathy

Abstract

Background Myocardial strain imaging using echocardiography can be a cost-effective method to objectively quantify ventricular wall motion but few studies have compared strain measured with echocardiography against MRI in small animals. Methods and Results We compared circumferential (CS) and radial strain (RS) measured with echocardiography (vector velocity imaging [VVI]) to displacement encoding with stimulated-echo (DENSE) MRI in two mouse models of cardiomyopathy. In 3 month old mice with gene targeted deficiency of cardiac myosin binding protein-C (cMyBP-C−/−, n=6) or muscle LIM protein (MLP−/−, n=6), and wild-type (WT) mice (n=8), myocardial strains were measured at three cross-sectional levels and averaged to obtain global strains. There was modest correlation between VVI and MRI measured strains, with global CS yielding stronger correlation compared to global RS (CS R2 = 0.4452 vs. RS R2 = 0.2794, both p<0.05). Overall, strain measured by VVI was more variable than MRI (p<0.05) and the limits of agreement were slightly, but not significantly (p=0.14) closer for global CS than RS. Both VVI and MRI strain measurements showed significantly lower global CS strain in the knockout groups compared to the wild-type. The VVI (but not MRI) CS strain measurements were different between the two knockout groups (−14.5 ± 3.8% vs. −6.6 ± 4.0%, cMyBP-C−/− vs. MLP−/− respectively, p<0.05). Conclusions Measurements of LV circumferential and radial strains are feasible in small animals using 2D echocardiography. VVI and MRI strain measurements correlated modestly and the agreement between the modalities tended to be greater for circumferential than radial strain. Although VVI and MRI strains were able to differentiate between wild-type and knockout mice, only global circumferential VVI strain differentiated between the two models of cardiomyopathy.

Diagnostic Concordance of Echocardiography and Cardiac Magnetic Resonance–Based Tissue Tracking for Differentiating Constrictive Pericarditis From Restrictive Cardiomyopathy

“…47,48 Despite these limitations, the correlation between tissue tracking strain values from both techniques is similar to previously published data for both modalities. 6,49 Moreover, the substantial concordance in patient characterization suggests potential diagnostic value.…”

“…Specifically the recent growth in tissue tracking software allows myocardial functional data to be extracted from both echocardiography and CMR images with equal ease and accuracy. [6][7][8] An emphasis on intermodalbetween May 2006 and May 2013. This included 28 patients with CP, 30 patients with RCM, and 34 control patients who had no structural or functional abnormality on echocardiography or CMR.…”

High field magnetic resonance imaging of rodents in cardiovascular research

“…In their work, Azam et al demonstrated that although echocardiographic vector velocity imaging seemed to be feasible and accurate, strains measured with DENSE method were more variable than those measured with MRI with similar variability for radial and circumferential strains [12].…”

Hemodynamic Assessment of a Murine Heterotopic Biventricularly Loaded Cardiac Transplant in vivo Model

“…Thus, it should be stressed that further analyses of the proposed model should be performed in terms of diagnostic assessment methods, including not only ultrasonography but also MRI. Yet, at this point of acute analysis, it was more important to use noninvasive methods only, with no additional stress from MRI contrast enhancement and prolongation of the postoperative anesthesia time, yet still reliable data acquisition [23,24,25]. …”