A composite imaging technique for high frame-rate and full-view cardiovascular ultrasound and elasticity imaging

Abstract

The frame-rate of ultrasound radio-frequency (RF) data acquisition is critical for imaging of the pulse wave and electromechanical wave propagation in cardiovascular tissues as well as improving the strain estimation. Therefore, an automated method had been developed to overcome the frame-rate limitations on standard systems by retrospective multi-sector signal acquisition through an electrocardiogram (ECG) gating technique. The method achieved a frame rate of 481 Hz at a 100% field of view, 64 line densities and an imaging depth of 11cm. The composite full-view images were reconstructed by retrospectively combining seven small-sector RF frames using the ECG-gating technique. The axial displacements of both long-axis and short-axis views of a human left ventricle and a long-axis view of the abdominal aorta were calculated using an RF based speckle-tracking technique comprising ID cross-correlation methods in a 2D search (window size of 6.9 mm and overlap of 80%). Several sequences of electromechanical waves propagating in a left ventricular long-axis and short-axis view, and long-axis view of abdominal aorta were imaged at high frame rates. Currently, the method was implemented on an Ultrasonix RP system (Ultrasonix Medical Corp. Richmond, Canada) and could be potentially implemented on other clinical systems. © 2007 IEEE.