Simultaneous Multiplane 2D-Echocardiography

Two-dimensional (2D) transthoracic echocardiography is one of the most frequently used techniques for diagnosis, management and follow-up of patients with any suspected or known cardiovascular disease. It is based on multiple single cardiac planes taken from standard positions on the chest wall. With the development of the matrix transducer, three-dimensional echocardiography (3D) can now be performed in the routine lab reducing the number of cross-sections needed for the information required. However, there are several challenges for the use of 3D echocardiography in daily clinical practice. The 3D transducer has a lower temporal resolution and the acquisition time is time-consuming often requiring offline analysis. Also as 3D echocardiography is a relatively new technique, it requires extra training and has a learning curve.
Recently, a new generation 2D/3D matrix transducer has become available, overcoming some of these drawbacks and even introducing a new image modality called “Simultaneous Multiplane Imaging” (SMPI). This new modality permits the use of a full electronic rotation of 360° of the 2D image (iRotate) and a simultaneously adjustable biplane 2D image (xPlane). This thesis investigates the potential contributions of this new imaging modality to cardiovascular imaging and patient care. Firstly it concentrates on how this new imaging modality can be utilized on day-to-day bases in the echo laboratory cutting down the scanning time and making cross-sectional scanning more robust. The following section on congenital and valvular heart disease reveals that this imaging technique makes the diagnose of a secundum atrial septal defect less operator dependent but most importantly a diagnostic transesophageal echocardiography (TEE) will not always be necessary. With 2D xPlane imaging the MV can be assessed in a systematic manner and we could correctly diagnose the site and extent of a mitral valve prolapse. Most patients may thus be operated on without the need for an outpatient pre-operative TEE. In transcatheter aortic valve implantation (TAVI) iRotate echocardiography may it possible to study the whole circumference of the TAVI prosthesis from an apical view. We also speculate on how this imaging technique could be of additional value in evaluating the tricuspid valve prior to a transcatheter tricuspid valve intervention.
Quantification of cardiac chambers and function is the cornerstone of cardiac imaging. Analyses of the RV has reached a new dimension with SMPI, similar to the LV we proposed a 13-segment RV model, recordable from one transducer position. We found that our model was highly feasible and we went on to publish normal recommendations for RV dimensions and function based on this model. Pilot study patients were included in this study to examine of this RV model was feasible. The results were encouraging and it is now important that large studies are carried out to evaluate the full potential of this technique.
Whether SMPI is here to stay will depend upon future developments in 3D echocardiography. I think, however, for the next ten years 3D will still be an “add on” imaging technique with SMPI playing a very important role in daily routine echocardiographic examinations.