Hand-Held Sound-Speed Imaging Based on Ultrasound Reflector Delineation
A novel hand-held speed-of-sound (SoS) imaging method is proposed, which requires only minor hardware extensions to conventional ultrasound (US) B-mode systems. A hand-held reflector is used as a timing reference for US signals. A robust reflector-detection algorithm, based on dynamic programming (DP), achieves unambiguous timing even with 10 dB signal-to-noise ratio in real tissues, successfully detecting delays <100 ns introduced by SoS heterogeneities. An Anisotropically-Weighted Total-Variation (AWTV) regularization based on L1-norm smoothness reconstruction is shown to achieve significant improvements in the delineation of focal lesions. The Contrast-to-noise-ratio (CNR) is improved from 15 dB to 37 dB, and the axial resolution loss from >300 % to <15 %. Experiments with breast-mimicking phantoms and ex-vivo liver samples showed, for hard hypoechogenic inclusions not visible in B-mode US, a high SoS contrast (2.6 %) with respect to cystic inclusions (0.9 %) and the background SoS noise (0.6 %). We also tested our method on a healthy volunteer in a preliminary in-vivo test. The proposed technique demonstrates potential for low-cost and non-ionizing screening, as well as for diagnostics in daily clinical routine.
KeywordsStreak Artifact Cystic Inclusion Hard Inclusion Daily Clinical Routine Real Tissue
This work was funded by the Swiss National Science Foundation.
- 1.Crimi, A., Makhinya, M., Baumann, U., Thalhammer, C., et al.: Automatic measurement of venous pressure using B-mode ultrasound. IEEE TMI 63, 288–299 (2016)Google Scholar
- 2.Duric, N., Littrup, P., Li, C., Roy, O., Schmidt, S., et al.: Breast imaging with softVue: initial clinical examination. In: SPIE Medical Imaging, pp. 90400V (2014)Google Scholar
- 4.Foroughi, P., Boctor, E., et al.: Ultrasound bone segmentation using dynamic programming. In: IEEE Ultras Symposium, New York, NY, USA, pp. 2523–2526 (2007)Google Scholar
- 9.Krueger, M., Burow, V., et al.: Limited-angle us transmission tomography of the compressed female breast. In: IEEE Ultrasonics Symposium, Miyagi, Japan, pp. 1345–1348 (1998)Google Scholar
- 10.Nebeker, J., Nelson, T.R.: Imaging of sound speed using reflection ultrasound tomography. J. Ultrasound Med. 31, 1389–1404 (2012)Google Scholar
- 11.Radovan, J., Peterlik, I., et al.: Sound-speed image reconstruction in sparse-aperture 3-D us transmission tomography. IEEE Trans. Ultrason. Ferroelectr., Freq. Control 59, 254–264 (2012)Google Scholar