Principal strain vascular elastography using compounded plane wave imaging

Principal strain imaging could enhance the diagnostic performance of vascular elastography, but conventional ultrasound system cannot measure lateral displacements precisely, information needed to compute principal strain. The goal of this study is to investigate the feasibility of using compounded plane wave imaging to visualize principal strain within the carotid artery. To compare the quality of principal strain relative to radial and circumferential (polar) strain elastogram, we performed a simulation study. We synthesized radio-frequency (RF) echo frames of homogeneous and heterogeneous vessels. The simulated ultrasound scanner acquired plane wave images from transmission angles of -14 to 14 in steps of 2 using a linear transducer array operating at 5. The accuracy of principal and polar strains were comparable (both varied between 7 % to 12 %), but principal strain offered considerably higher elastographic contrast-to-noise ratio (4 - 14 dB). The results also revealed that the elastographic contrast-to-noise ratios of principal strain elastograms were significantly larger than those of polar (p < 0.05). The results suggest that compounding plane wave vascular elastography can produce useful principal strain elastograms.