Analysis of chronic aortic regurgitation by 2D and 3D echocardiography and cardiac MRI

Abstract

Purpose The study compares the feasibility of the quantitative volumetric and semi-quantitative approach for quantification of chronic aortic regurgitation (AR) using different imaging modalities. Methods Left ventricular (LV) volumes, regurgitant volumes (RVol) and regurgitant fractions (RF) were assessed retrospectively by 2D, 3D echocardiography and cMRI in 55 chronic AR patients. Semi-quantitative parameters were assessed by 2D echocardiography. Results 22 (40%) patients had mild, 25 (46%) moderate and 8 (14%) severe AR. The quantitative volumetric approach was feasible using 2D, 3D echocardiography and cMRI, whereas the feasibility of semi-quantitative parameters varied considerably. LV volume (LVEDV, LVESV, SVtot) analyses showed good correlations between the different imaging modalities, although significantly increased LV volumes were assessed by cMRI. RVol was significantly different between 2D/3D echocardiography and 2D echocardiography/cMRI but was not significantly different between 3D echocardiography/cMRI. RF was not statistically different between 2D echocardiography/cMRI and 3D echocardiography/cMRI showing poor correlations (r < 0.5) between the different imaging modalities. For AR grading by RF, moderate agreement was observed between 2D/3D echocardiography and 2D echocardiography/cMRI and good agreement was observed between 3D echocardiography/cMRI. Conclusion Semi-quantitative parameters are difficult to determine by 2D echocardiography in clinical routine. The quantitative volumetric RF assessment seems to be feasible and can be discussed as an alternative approach in chronic AR. However, RVol and RF did not correlate well between the different imaging modalities. The best agreement for grading of AR severity by RF was observed between 3D echocardiography and cMRI. LV volumes can be verified by different approaches and different imaging modalities.

Keywords: 2D echocardiography; 3D echocardiography; Doppler echocardiography; aortic regurgitation; cardiac MRI.

Figure 1

Assessment of total stroke volume (SV_tot) by 2D Doppler echocardiography (A – measurement of the left ventricular outflow tract diameter (D_LVOT) in the parasternal long axis view; B – Doppler spectrum of the velocity time integral of the LVOT (VTI_LVOT) obtained by pulsed-wave Doppler in the apical long axis view) and by 2D left ventricular biplane planimetry in the apical 2 (C) – and 4 (D)-chamber view using the modified Simpson’s rule.

Figure 2

Assessment of the effective stroke volume (SV_eff) by 2D Doppler echocardiography using the diameter of the pulmonary valve (D_PV) at the level of the pulmonary ring in the parasternal short-axis view at the level of the aortic valve (A – transthoracic; B – transesophageal). The Doppler spectrum of the VTI of the pulmonary valve obtained by pulsed-wave Doppler in the parasternal short-axis view is shown in (C).

Figure 3

Assessment of SV_tot, SV_eff, the regurgitant volume (RVol) and the regurgitant fraction (RF) by cardiac magnet resonance imaging (cMRI) (A), by 2D biplane planimetry in the apical 2-and 4-chamber view (B) and 2D Doppler echocardiography (D) and by left and right ventricular volume analyses by 3D echocardiography (TomTec) (C).

Figure 4

Comparison of total stroke volume (SV_tot) assessed by 2D left ventricular (LV) planimetry and 2D Doppler echocardiography (A), 2D (planimetry) and 3D echocardiography (B), 2D echocardiography and cMRI (C) and 3D echocardiography and cMRI (D).

Figure 5

Comparison of regurgitant volume (RVol) assessed by 2D and 3D echocardiography (A), 2D echocardiography and cMRI (B) and 3D echocardiography and cMRI (C).

Figure 6

Comparison of regurgitant fraction (RF) assessed by 2D and 3D echocardiography (A), 2D echocardiography and cMRI (B) and 3D echocardiography and cMRI (C).