Tri-Plane Cardiac Imaging Using Multi-Line Transmission on a Spiral Array: A Feasibility Study

The assessment of regional cardiac function requires imaging all segments of the left ventricle. Since full 3D echocardiography remains limited in space-time resolution, triplane imaging has been proposed as an intermediate solution to alleviate such problem. Although its time resolution was further improved by a multi-line transmission (MLT)scheme, its implementation resulted impractical since it requires a fully wired 32⨯32 array. The aim of this study was therefore to test the feasibility of MLT-based tri-plane imaging using a 2D array with low element count. A spiral array (SA)was designed based on a 32⨯32 full array (FA); both SA and FA were simulated in Field II and their performance compared in terms of 3D one-way pressure fields when used in tri-plane imaging modality. Both probes performed similarly in terms of lateral resolution (2.4 mm)and depth of field (>37 mm)but, as expected, the SA presented lower sensitivity (−13.7dB)and worse grating-lobe level (+5.6dB); correspondingly, SA reduces the image contrast ratio (−9.2dB)and contrast-to-noise ratio (−20 % ). On the other hand, the SA slightly improved the speckle signal-to-noise ratio (+7%) thus increasing the homogeneity of the background region. In conclusion, despite an unavoidable loss in image quality, triplane imaging using MLT using a SA seems feasible.