In-Vivo Comparison of Multiline Transmission and Diverging Wave Imaging for High Frame Rate Speckle Tracking Echocardiography.

High frame rate (HFR) speckle tracking echocardiography (STE) assesses myocardial function by quantifying motion and deformation at high temporal resolution. Among the proposed HFR techniques, Multi-Line Transmission (MLT) and Diverging Wave (DW) imaging have been used in this context both being characterized by specific advantages and disadvantages. Therefore, in this paper, we directly contrast both approaches in an in-vivo setting while operating at the same frame rate. First, images were recorded at baseline (resting condition) from healthy volunteers and patients. Next, additional acquisitions during stress echocardiography were performed on volunteers. Each scan was contoured and processed by a previously proposed 2D HFR STE algorithm based on cross-correlation. Then, strain curves and their end-systolic (ES) values were extracted for all myocardial segments for further statistical analysis. The baseline acquisitions did not reveal differences in estimated strain between the acquisition modes (p>0.35); myocardial segments (p>0.3) nor an interaction between imaging mode and depth (p>0.87). Similarly, during stress testing, no difference (p=0.7) was observed for the two scan sequences, stress levels nor an interaction sequence-stress level (p=0.94). Overall, our findings show that MLT and DW compounding give comparable HFR STE strain values and that the choice for using one method or the other may thus rather be based on other factors, e.g. system requirements or computational cost.