This recent study by Rutledge et al. compares 4D ultrasound (4D-US) with conventional M-mode and B-mode ultrasound for the assessment of LV function in a myocardial infarct model.
- Commonly used M-mode and B-mode echo measurements make geometric assumptions and limits accuracy, particularly in models where ventricular shape abnormalities occurs.
- Authors evaluated 4D echo in a mouse coronary artery ligation model.
- Compared conventional M-mode and B-mode measurements with 4D-US and verified with cardiac magnetic resonance (CMR) imaging.
- 4D-US provided close agreement in ESV and EF when compared with gold standard CMR; outperforming conventional US techniques.
- 4D echo data also showed lower inter-user variability; analysis completed by two blinded, independent sonographers.
- Using 4D data authors were able to perform standardized, clinically relevant wall motion severity index (WMSI) assessments, which correlated strongly (R=0.77) with histological analysis of infarct size.
- WMSI was calculated from 16 segments collected from 3 short axis views. Each segment was graded individually for wall motion, then averaged to provide an overall score.
4D-US is a reliable tool for the assessment of LV function after CAL, providing comparable measurements to CMR, but at a fraction of the time and cost. Furthermore, 4D echo enables easy standardization of WMSI measurements, shown to correlate with histological scar size.