Systematic Comparison of Left Ventricular Geometry Between 3D-Echocardiography and Cardiac Magnetic Resonance Imaging.

Debbie Zhao,Helene C Houle,Kathleen Gilbert,Jan D'Hooge,Peter N Ruygrok,Vicky Y Wang,João Pedrosa,Malcolm E Legget,Robert N Doughty,Martyn P Nash,Gina M Quill,Alistair A Young

doi:10.3389/fcvm.2021.728205

Abstract

Aims: Left ventricular (LV) volumes estimated using three-dimensional echocardiography (3D-echo) have been reported to be smaller than those measured using cardiac magnetic resonance (CMR) imaging, but the underlying causes are not well-understood. We investigated differences in regional LV anatomy derived from these modalities and related subsequent findings to image characteristics.Methods and Results: Seventy participants (18 patients and 52 healthy participants) were imaged with 3D-echo and CMR (<1 h apart). Three-dimensional left ventricular models were constructed at end-diastole (ED) and end-systole (ES) from both modalities using previously validated software, enabling the fusion of CMR with 3D-echo by rigid registration. Regional differences were evaluated as mean surface distances for each of the 17 American Heart Association segments, and by comparing contours superimposed on images from each modality. In comparison to CMR-derived models, 3D-echo models underestimated LV end-diastolic volume (EDV) by −16 ± 22, −1 ± 25, and −18 ± 24 ml across three independent analysis methods. Average surface distance errors were largest in the basal-anterolateral segment (11–15 mm) and smallest in the mid-inferoseptal segment (6 mm). Larger errors were associated with signal dropout in anterior regions and the appearance of trabeculae at the lateral wall.Conclusions: Fusion of CMR and 3D-echo provides insight into the causes of volume underestimation by 3D-echo. Systematic signal dropout and differences in appearances of trabeculae lead to discrepancies in the delineation of LV geometry at anterior and lateral regions. A better understanding of error sources across modalities may improve correlation of clinical indices between 3D-echo and CMR.

Highlights

Echocardiography is the most ubiquitous cardiovascular imaging modality, with applications both at bedside and during intervention
Significant differences in EDV and end-diastolic volume index (EDVI) were found between cardiac magnetic resonance (CMR) and 3D-echo for all three software tools, with 3D-echo EDV being smaller than the CMR EDV
Further significant differences were found between CMR and 3D-echo in terms of ejection fraction (EF)

Summary

Introduction

Echocardiography (echo) is the most ubiquitous cardiovascular imaging modality, with applications both at bedside and during intervention. Traditionally a two-dimensional (2D) modality, three-dimensional echocardiography (3D-echo) enables analyses of left ventricle (LV) structure and function without the need for geometric assumptions. 3D models of the LV can be used to precisely quantify remodeling [1] and calculate biophysical properties such as myocardial stiffness [2]. The traditional validation approach for 3D-echo-derived LV models has involved direct comparisons of volumetric indices against cardiac magnetic resonance (CMR)-derived reference values [3], which has been shown to provide a precise estimation of LV geometry [4]. 3D-echo is known to underestimate LV volume compared to CMR [5], the reasons for this discrepancy are not well understood. Existing studies are typically focused on global measurements and do not account for regional differences, with some exceptions [6,7,8]

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Results

Discussion

Conclusion