Transcostal imaging with large coherent apertures: Ex vivo studies

In order to implement and evaluate a basic blocked-element detection and compensation algorithm on large arrays we acquired large synthetic 2-D aperture data sets on canine ribs ex vivo. Elements that were blocked by the ribs exhibited significantly lower values for the signal amplitude and nearest-neighbor cross-correlation than the remaining elements on the aperture. Turning off these elements retroactively in transmit and receive synthetic apertures significantly reduced clutter magnitude in the resulting B-mode images. Measured point spread functions showed now significant difference after blocked-element compensation was applied.