3D ultrafast elastography imaging of the carotid artery using sparse arrays

Non-invasive Vascular Elastography (NIVE) using sparse arrays is a novel method for ultrafast elastography imaging of the carotid artery. Sparse array imaging retains the advantages of fully synthetic aperture imaging i.e. high lateral sensitivity, while overcoming its limitations of poor frame rate and high data volumes. In this study, we investigated the performance of a sparse array system comprising of only seven transmit elements in a dynamic motion regime. It was demonstrated, through simulation and experimental studies, that this technique can produce high quality axial and lateral displacement elastograms that can be used to compute accurate radial and circumferential strain elastograms. In this study, we compare the performance of elastograms obtained using a sparse array to those obtained with plane wave imaging. It was found that while plane wave imaging has a relatively higher frame rate and sonographic SNR, sparse array imaging provides better lateral displacement estimates resulting in superior strain elastograms.