Background: Preclinical cardiovascular research is the foundation for our understanding and broad
knowledge of heart function and cardiovascular diseases. Reliable cardiac imaging
modalities are the basis for applicable results. Past studies show that two-dimensional
echocardiography has limitations compared with cardiac magnetic resonance imaging
in rats. This study was performed to validate a completely new technology of four-dimensional
echocardiography by comparing it to the gold standard of cardiac magnetic resonance
imaging and the widely used method of two-dimensional echocardiography.
Methods: Assessment of heart function and left ventricular volumes was performed in 20 rats
using four-dimensional echocardiography, cardiac magnetic resonance imaging and two-dimensional
echocardiography. 5 rats underwent a ligation of the superior and inferior vena cava
to induce low cardiac output two weeks prior to cardiac imaging.
Results: Four-dimensional echocardiography and cardiac magnetic resonance imaging measurements
show a strong correlation in end-diastolic volume (r = 0.983, p ≤ 0.001), end-systolic volume (r = 0.970, p≤0.001) and left ventricular ejection
fraction (r = 0.952, p < 0.001) in both groups (control and diseased). Two-dimensional echocardiography
underestimates end-diastolic volume but not end-systolic volume, which leads to a
significant underestimation of left ventricular ejection fraction.
Conclusion: Four-dimensional echocardiography and cardiac magnetic resonance imaging provide
similar consistent results concerning left ventricular volumes and systolic function.
In addition, our results confirmed that two-dimensional echocardiography is the least
reliable imaging modality of the three, showing higher variance and larger standard
deviation than four-dimensional echocardiography and cardiac magnetic resonance imaging.
