Beam Coding with Orthogonal Complementary Golay Codes for Signal to Noise Ratio Improvement in Ultrasound Mammography

Authors: Y. Kumru, K. Enhos, H. Köymen

Abstract:

In this paper, we report the experimental results on using complementary Golay coded signals at 7.5 MHz to detect breast microcalcifications of 50 µm size. Simulations using complementary Golay coded signals show perfect consistence with the experimental results, confirming the improved signal to noise ratio for complementary Golay coded signals. For improving the success on detecting the microcalcifications, orthogonal complementary Golay sequences having cross-correlation for minimum interference are used as coded signals and compared to tone burst pulse of equal energy in terms of resolution under weak signal conditions. The measurements are conducted using an experimental ultrasound research scanner, Digital Phased Array System (DiPhAS) having 256 channels, a phased array transducer with 7.5 MHz center frequency and the results obtained through experiments are validated by Field-II simulation software. In addition, to investigate the superiority of coded signals in terms of resolution, multipurpose tissue equivalent phantom containing series of monofilament nylon targets, 240 µm in diameter, and cyst-like objects with attenuation of 0.5 dB/[MHz x cm] is used in the experiments. We obtained ultrasound images of monofilament nylon targets for the evaluation of resolution. Simulation and experimental results show that it is possible to differentiate closely positioned small targets with increased success by using coded excitation in very weak signal conditions.

Keywords: Coded excitation, complementary Golay codes, DiPhAS, medical ultrasound.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1474809

References:

[1] Yasin KUMRU, “Using Spread Spectrum Coded Pings in Active Sonar Technology”, Bilkent University, M.Sc. Thesis, July 2014.
[2] M.O.Güleryüz, “Low Power Range Estimation with DSSS technique In Underwater Acoustics”, Bilkent University, M.Sc. Thesis, August 2013.
[3] Pearson, Medical Imaging Signals and Systems, Prince & Links, 2/2014.
[4] U.Madhow, Fundamentals of Digital Communication, Cambridge Universtiy Press 2008.
[5] C.A.Balanis, Antenna Theory, Wiles Interscience, Third Edition,2005.
[6] D.T.Blackstock, Fundamentals of Physical Acoustics.
[7] W.S.Burdic, Underwater Acoustic System Analysis.Prentice Hall,1984.
[8] R.J.Urick, Principles of Underwater Sound. Peninsula Publishing 3rd edition,1983.
[9] M.J.E.Golay, “Complementary Series”, IRE Transactions on Information Theory, vol IT-7, pp 82-87, 1961.
[10] D.Z.Dokovic,”Equivalence Classes and Representatives of Golay Sequences” Discrete Mathematics 189 (1998) 79-93.
[11] Elena Kalashnikov, “An Introduction to Golay Complementary Sequences”, Department of Mathematics, University of Alberta, 2004.
[12] S.Kounias, C.Koukouvinos and K.Sotirakoglou“OnGolay Sequences” Discrete Mathematics 92 (1991) 177-185,1988.
[13] I.Trots, A.Nowicki, W.Secomski, J.Litniewski “Golay Sequences-Side Lobe-Canceling Codes For Ultrasonography”, Archives of Acoustics, 2004.
[14] J.A.Jensen, “Field: A Program for simulating ultrasound systems”.
[15] T.X.Misaridis and J.A JENSEN, “Use of Modulated Excitation Signals in Medical Ultrasound. Part I: Basic concepts and Expected Results”, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, Vol.52, No.2, February 2005.
[16] T.X.Misaridis and J.A JENSEN, “Use of Modulated Excitation Signals in Medical Ultrasound. Part II: Design and Performance for Medical Imaging Applications”, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, Vol.52, No.2, February 2005.
[17] T.X.Misaridis and J.A JENSEN, “Use of Modulated Excitation Signals in Medical Ultrasound. Part III: High Frame Rate Imaging”, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, Vol.52, No.2, February 2005.
[18] R.Y.Chiao and X.Hao, “Coded Excitation for Diagnostic Ultrasound: A System Developer’s Perspective”, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, Vol.52, No.2, February 2005.
[19] I.Trots, Y.Tasinkevych, A.Nowicki, M.Lewandowski, “Coded Transmission in Synthetic Transmit Aperture Ultrasound Imaging Method”,WASET,2012.
[20] J.f.Synnevag, S.Holm, “Adaptive Beamforming Applied to Medical Ultrasound Imaging”, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, August 2007.
[21] L.Huang, Y.Labyed, F.Simonetti, M.Williamson, R.Rosenberg,P.Heintz, D.Sandoval, “High-resolution imaging with a real-time synthetic aperture ultrasound system:A phantom study”, 2011 SPIE Medical Imaging Meeting.
[22] M.Lewandowski, A.Nowicki, “Universal Coded Ultrasound Imaging System with Software Processing”, Archives of Acoustics, 32, 4 (Supplement), 81-86 (2007).
[23] B.Haider, P.A.Lewin, K.E.Thomenius, “Pulse Elongation and deconvolution filtering for medical ultrasound imaging”, IEEE Transactions on UFFC, Volume:45, Issue:1, Jan.1998.