Here, we provide a step-by-step acquisition and analysis protocol for the 3D volumetric assessment of the right ventricle, mainly focusing on the practical aspects that maximize the feasibility of this technique.
Traditionally, it was believed that the right side of the heart has a minor role in circulation; however, more and more data suggest that right ventricular (RV) function has strong diagnostic and prognostic power in various cardiovascular disorders. Due to its complex morphology and function, assessment of the RV by conventional two-dimensional echocardiography is limited: the everyday clinical practice usually relies on simple linear dimensions and functional measures. Three-dimensional (3D) echocardiography overcame these limitations by providing volumetric quantification of the RV free of geometrical assumptions. Here, we offer a step-by-step guide to obtain and analyze 3D echocardiographic data of the RV using the leading commercially available software. We will quantify 3D RV volumes and ejection fraction. Several technical aspects may help to improve the quality of RV acquisition and analysis as well, which we present in a practical manner. We review the current opportunities and the limiting factors of this method and also highlight the potential applications of 3D RV assessment in current clinical practice.
Echocardiography came a long way from its first clinical applications in the 1950s1. The first one-dimensional ultrasound probes were designed to provide simple linear diameters of the chamber walls and lumens; however, they undoubtedly represent a milestone in cardiovascular imaging. The development of two-dimensional (2D) ultrasound imaging was another major step by providing much more precise quantification of morphology and function and is still considered to be the standard method in everyday clinical practice. Nevertheless, 2D echocardiography-based assessment still carries a major limitation of the technique: imaging of a given chamber from a few tomographic planes does not adequately characterize the morphology and function of a three-dimensional (3D) structure. This problem is even more pronounced in the case of the right ventricle (RV): compared to the relatively simple bullet-shaped left ventricle (LV), the RV has a complex geometry2 that cannot be adequately quantified using linear diameters or areas3. Despite these widely known facts, RV morphology and function are usually measured by such simple parameters in the clinical practice.
For many decades, the RV was considered to have a much less important role in circulation compared to its left counterpart. Several landmark papers defeated this standpoint showing the strong prognostic role of RV geometry and function in a wide variety of diseases4,5,6,7. Numerous studies demonstrated the incremental value of RV measurement even by using relatively simple conventional parameters, which highlights the importance and need for more precise quantification of the chamber with potentially meaningful clinical value.
3D echocardiography overcomes several limitations of the 2D assessment of the cardiac chambers. While the measurement of volumes and also functional parameters free of geometrical assumptions may be of high interest in the case of the LV as well, it may gain particular importance in the assessment of the RV8. 3D-derived RV volumes and ejection fraction (EF) are shown to have significant prognostic value in various cardiovascular conditions9,10.
Nowadays, several vendors provide semi-automated solutions for 3D RV assessment with validated results against gold standard cardiac magnetic resonance (MR) measurements11,12. The technical requirements of 3D assessment are essential parts of a state-of-the-art cardiovascular imaging department nowadays, and it is expected that it will soon be part of the general equipment in every echocardiography lab. With proper expertise in 3D acquisition and post-processing, 3D RV analysis can be easily implemented into the standard examination protocol.
3D analysis of the RV represents an important step in everyday cardiology practice. In parallel with the growing interest of the morphology and function of the previously neglected cardiac chamber, these novel solutions provide clinically meaningful information about the right side of the heart. While 3D acquisition has several aspects that markedly differ from 2D echocardiographic imaging, by keeping special attention to the critical points and by using a thorough protocol, 3D RV analysis may progress from a scientific …
Project no. NVKP_16-1–2016-0017 (’National Heart Program’) has been implemented with the support provided from the National Research, Development and Innovation Fund of Hungary, financed under the NVKP_16 funding scheme. The research was financed by the Thematic Excellence Programme (2020-4.1.1.-TKP2020) of the Ministry for Innovation and Technology in Hungary, within the framework of the Therapeutic Development and Bioimaging thematic programmes of the Semmelweis University.
3V-D/4V-D/4Vc-D | General Electric | n.a. | ultrasound probe |
4D Auto RVQ | General Electric | n.a. | software for analysis |
E9/E95 | General Electric | n.a. | ultrasound machine |
EchoPac v203 | General Electric | n.a. | software for analysis |