DOI QR코드

DOI QR Code

Beamforming Technology in Medical Ultrasound System

초음파진단기의 빔포밍 기술

  • Bae, Moo-Ho (Department of Electronics Engineering, Hallym University)
  • 배무호 (한림대학교 전자공학과)
  • Received : 2012.08.29
  • Accepted : 2012.10.12
  • Published : 2012.10.30

Abstract

Medical ultrasound systems have been used since 1950s, and are now widely used in most hospitals as indispensable diagnostic imaging systems. Since array probe was introduced in 1970s, beamforming technology using electronic signal processing has been adopted to the medical ultrasound system, and has been improved. Beamforming is a important technology which defines the resolution of the ultrasound system. In this paper, the technologies are introduced from basic beamforming principles to current trend. They include principles of beamforming using array probe, basic theory, and practical implementation, and recent topics of synthetic aperture imaging, adaptive beamforming, 2-dimensional beamforming using 2-dimensional array are also introduced. These various technologies will improve system performances continuously by merging innovatively with various technologies in other fields.

초음파진단기는 1950년대부터 사용되기 시작했고 그 동안 꾸준한 기술 발전을 통해 현재 대부분의 병원에서 필수불가결한 영상진단장비로 널리 활용되고 있다. 1970년대 초음파진단기에 어레이 프로브가 사용되기 시작한 이래로 전자적 신호처리를 통한 빔포밍 기술이 초음파진단기에 적용되었고, 꾸준히 개선되어 왔다. 빔포밍 기술은 초음파진단기의 해상도를 결정짓는 중요한 신호처리 기술이다. 이 논문에서는 이 빔포밍 기술의 원리부터 최근 동향까지 간략히 소개하고자 한다. 여기에는 어레이 프로브(array probe)를 사용하는 빔포밍의 원리, 기본적 이론, 실제 구현 등이 포함되고, 또 최근 기술 중 합성구경영상(synthetic aperture imaging: SAI), 적응형 빔포밍(adaptive beamforming), 2차원 어레이 프로브를 사용하는 2차원 빔포밍 기술 등의 주제도 소개한다. 이런 다양한 빔포밍 기술들은 다양한 다른 분야의 기술들과 여러 가지 형태로 발전적으로 융합하면서 시스템의 성능을 지속적으로 향상시켜 갈 것이다.

Keywords

References

  1. J. A. Zagzebski, "Essentials of Ultrasound Physics," Mosby Inc., (1996)
  2. M.-H. Bae, "Evolution of signal processing technology for medical ultrasound B-mode imaging," Journal of Acoustical Society of Korea, Vol. 29, No. 4E, pp. 147-166 (2010)
  3. A. Macovski, "Ultrasonic imaging using arrays," Proc. IEEE, Vol. 67, No. 4, pp. 484-495, Apr. (1979) https://doi.org/10.1109/PROC.1979.11278
  4. M. H. Bae, "Resolution improvement by the synthetic focusing and a new focusing delay computation algorithm in the ultrasonic medical imaging system," Ph. D. Dissertation, Dept. Elect. Eng., Korea Advanced Institute of Science and Technology, Daejeon, Korea, (1992)
  5. T. K. Song and S. B. Park, "A closed-form field analysis of a broad-band annular array," IEEE. Trans. Ultrason., Ferroelect., Freq. Contr., Vol. 36, No. 6, pp. 661-671, Nov. (1989) https://doi.org/10.1109/58.39117
  6. J. A. Jensen, "A model for the propagation and scattering of ultrasound in tissue," J. Acoust. Soc. Am., Vol. 89, pp. 182-191 (1991) https://doi.org/10.1121/1.400497
  7. J. A. Jensen and N. B. Svendsen, "Calculation of pressure fields from arbitrarily shaped, apodized, and excited ultrasound transducers," IEEE Trans. Ultrason., Ferroelect., Freq. Contr., Vol. 39, pp. 262-267 (1992) https://doi.org/10.1109/58.139123
  8. J. A. Jensen, "Simulating arbitrary-geometry ultrasound transducers using triangles," Proc. IEEE Ultrason. Symp., Vol. 2, pp. 885-888 (1996)
  9. J. A. Jensen, "Ultrasound fields from triangular apertures," J. Acoust. Soc. Am., Vol. 100(4), pp. 2049-2056 (1996) https://doi.org/10.1121/1.417914
  10. J. A. Jensen, "Field: A program for simulating ultrasound systems," Medical & Biological Engineering & Computing, Vol. 4, No. Suppl. 1, part. 1, pp. 351-353 (1996)
  11. J. A. Jensen and P. Munk, "Computer phantoms for simulating ultrasound B-mode and cfm images," Acoustical Imaging, Vol. 23, pp. 75-80 (1997) https://doi.org/10.1007/978-1-4419-8588-0_12
  12. J. A. Jensen, "A new approach to calculating spatial impulse responses," Proc. IEEE Ultrason. Symp., pp. 1755-1759 (1997)
  13. J. H. Kim, T. K. Song and S. B. Park, "Pipelined sampled delay focusing in ultrasound imaging system," Ultrason. Imag., Vol. 9, No. 2, pp. 75-91 (1987) https://doi.org/10.1016/0161-7346(87)90007-1
  14. D. Lipschutz, "Delay interpolator for digital phased array ultrasound beamformers," US Patent 5,345,426 (1994)
  15. K. Jeon, M. H. Bae, S. B. Park and S. D. Kim, ""Anefficient real time focusing delay calculation in ultrasonic imaging systems," Ultrason. Imag., Vol. 16, No. 4, pp. 231-248 (1994) https://doi.org/10.1006/uimg.1994.1014
  16. M. H. Bae, "Focusing delay calculation method for real-time digital focusing and apparatus adopting the same," US. Patent 5,836,881 (1998)
  17. R. E. Daigle, "Ultrasound imaging system with pixel oriented processing," US patent application 20090112095, (2009)
  18. J. S. Hwang and T. K. Song, "A Study of the display pixel-based focusing method in ultrasound imaging," Ultrasonic Imaging, Vol. 23, No. 1, pp. 1-18 (2001) https://doi.org/10.1177/016173460102300101
  19. R. E. Williams, "Creating an acoustic synthetic aperture in the ocean," J. Acoust. Soc. Amer., Vol. 60, pp. 60-73 (1976) https://doi.org/10.1121/1.381049
  20. Y. Ozaki, H. Sumitani, T. Tomode and M. Tanaka, "A new system for real-time synthetic aperture ultrasonic imaging," IEEE. Trans. Ultrason., Ferroelect., Freq. Contr., Vol. 35, No. 6, pp. 828-838 (1988) https://doi.org/10.1109/58.9340
  21. M. Karaman, P. C. Li and Matthew O'Donnell, "Synthetic aperture imaging for small scale systems," IEEE. Trans. Ultrason., Ferroelect., Freq. Contr., Vol. 42, No. 3, pp. 196-207 (1995)
  22. J. R. Talman and S. S. Brunke, "Real-time 3-D ultrasound imaging using sparse synthetic aperture beamforming," IEEE Trans. Ultrason., Ferroelect., Freq. Contr., Vol. 45, pp. 980- 988 (1998) https://doi.org/10.1109/58.710573
  23. M. H. Bae and M. K. Jeong, "Bidirectional pixel based focusing in conventional B-mode ultrasound imaging," Electronics Letters, Vol. 34, No. 22, pp. 2105-2107 (1998) https://doi.org/10.1049/el:19981484
  24. M. H. Bae and M. K. Jeong, "A study of synthetic-aperture imaging with virtual source elements in B-mode ultrasound imaging systems," Trans. Ultrason., Ferroelect., Freq. Contr., Vol. 47, No. 6, pp. 1510-1519 (2000) https://doi.org/10.1109/58.883540
  25. M. K. Jeong, K. J. Lee, M. H. Bae, S. Y. Chang and S. B. Gye, "Beamforming using the synthetic sinc wave for ultrasonic imaging system," Proc. IEEE Ultrason. Symp., pp. 1539-1542 (2001)
  26. J. H. Chang, J. W. Park and T. K. Song, "A new synthetic aperture focusing method using nonspherical wave fronts," Proc. IEEE Ultrason. Symp, pp. 1525-1528 (2001)
  27. M.-H. Bae, S. B. Park, H. W. Lee, S. G Nam and M. K. Jeong, "A new extended range ultrasonic synthetic aperture tissue harmonic imaging system," Proc. IEEE Ultrason. Symp., pp. 401-404 (2011)
  28. C. H. Frazier and W. D. O'Brien, "Synthetic aperture techniques with a virtual source element," IEEE Trans. Ultrason., Ferroelect., Freq. Contr., Vol. 45, No. 1, pp. 196-207 (1998) https://doi.org/10.1109/58.646925
  29. J. Kortbek, J. A. Jensen and K. L. Gammelmark, "Synthetic aperture sequential beamforming," Proc. IEEE Int. Ultrason. Symp., pp. 966-969 (2008)
  30. H. Andresen, S. I. Nikolov and J. A. Jensen, "Precise time-of-flight calculation for 3-D synthetic aperture focusing," Ultrason. IEEE Trans. Ultrason., Ferroelect., Freq. Contr., Vol. 56, No. 9, pp. 1880-1887 (2009) https://doi.org/10.1109/TUFFC.2009.1264
  31. H. Andresen, S. I. Nikolov, M. M. Pedersen, D. Buckton and J. A. Jensen, "Threeimensional synthetic aperture focusing using a rocking convex array transducer," Trans. Ultrason., Ferroelect., Freq. Contr., Vol. 57, No. 5, pp. 1051-1063 (2010) https://doi.org/10.1109/TUFFC.2010.1517
  32. J. A. Jensen, M. Hansen, B. G. Tomov, S. I. Nikolov and H. H. Lund, "System architecture of an experimental synthetic aperture real-time ultrasound system," Proc. IEEE Ultrason. Symp., pp. 636-640 (2007)
  33. M. H. Bae, J. H. Ham, R. Y. Yoon, H. W. Lee and M. K. Jeong, "A new ASIC architecture for ultrasonic synthetic aperture imaging system," Proc. IEEE Ultrason. Symp., pp. 1346-1348 (2009)
  34. K. L. Gammelmark and J. A. Jensen, "Duplex synthetic aperture imaging with tissue motion compensation," Proc. IEEE Ultrason. Symp., pp. 1569-1573 (2003)
  35. M. H. Bae, B. S. Kim, M. K. Jeong, W. Y. Lee, J. H. Ham, D. Y. Kim and H. W. Lee, "A new motion estimation and compensation method for real-time ultrasonic synthetic aperture imaging," Proc. IEEE Ultrason. Symp., pp. 1511-1513 (2007)
  36. B. D. van Veen and K. M. Buckley, "Beamforming: A versatile approach to spatial filtering," IEEE ASSP Magazine, pp. 4-24 (1988)
  37. W. F. Gabriel, "Adaptive processing array systems," Proc. IEEE, Vol. 80, No. 1, pp. 152-162 (1992) https://doi.org/10.1109/5.119574
  38. S. Haykin, "Adaptive Filter Theory," 4th Ed., Prentice-Hall (2002)
  39. R. Bethel, B. Shapo and H. L. Van Trees, "Single snapshot spatial processing: Optimized and constrained," Sensor Array and Multichannel Signal Processing Workshop Proceedings, pp. 508-512 (2002)
  40. F. Viola, M. A. Ellis, and W. F. Walker, "Ultrasound imaging with beamforming adapted to target," Proc. IEEE Ultrason. Symp., pp. 128-131 (2006)
  41. M. A. Ellis and W. F. Walker, "Superresolution image reconstruction with reduced computational complexity," Proc. IEEE Ultrason. Symp, pp. 2351-2354 (2009)
  42. M. L. Li, "Adaptive imaging using principalcomponent- synthesized aperture data," Proc. IEEE Ultrason. Symp., pp. 1076-1079 (2008)
  43. J. Capon, "High-resolution frequency-wavenumber spectrum analysis," Proc. IEEE, Vol. 57, No. 8, pp. 1408-1418, Aug. (1969) https://doi.org/10.1109/PROC.1969.7278
  44. J. A. Mann and W. F. Walker, "A constrained adaptive beamformer for medical ultrasound: initial results," Proc. IEEE Ultrason. Symp, pp. 1763-1766 (2002)
  45. J. Synnevag, A. Austeng and S. Holm, "Adaptive beamforming applied to medical ultrasound imaging," IEEE Trans. Ultrason., Ferroelect., Freq. Contr., Vol. 54, No. 8, pp. 1606-1613 (2007) https://doi.org/10.1109/TUFFC.2007.431
  46. D. H. Brandwood, "A complex gradient operator and its application in adaptive array theory," IEE Proc., Vol. 130, Pts. Fand H, no. 1, pp. 11-16 1983) https://doi.org/10.1049/ip-f-1.1983.0003
  47. T.-J. Shan, M. Wax and T. Kailath, "On spatial smoothing for direction-of-arrival estimation of coherent signals," IEEE Trans. Acoust. Speech Signal Processing, Vol. 33, No. 4, pp. 806-811 1985) https://doi.org/10.1109/TASSP.1985.1164649
  48. J. Li, P. Stoica and Z. Wang, "On robust Capon beamforming and diagonal loading," IEEE Trans. Signal Processing, Vol. 51, No. 7, pp. 1702-1715 (2003) https://doi.org/10.1109/TSP.2003.812831
  49. B. M. Asl and A. Mahloojifar, "A lowcomplexity Adaptive beamformer for ultrasound imaging using structured covariance matrix," IEEE Trans. on Ultrason., Ferroelec., Freq. Contr., Vol. 59, No. 4, pp. 660-667 (2012) https://doi.org/10.1109/TUFFC.2012.2244
  50. C. Nilsen and I. Hafizovic, "Beamspace adaptive beamforming for ultrasound imaging," IEEE Trans. Ultrason. Ferroelectr. Freq. Control, Vol. 56, No. 10, pp. 2187-2197 (2009) https://doi.org/10.1109/TUFFC.2009.1301
  51. A. Austeng, T. Bjastad, J. F. Synnevaag, S. E. Masoy, H. Torp and S. Holm, "Sensitivity of minimum variance beamforming to tissue aberrations," Proc. IEEE Ultrason. Symp., pp. 1072-1075 (2008)
  52. J. F. Synnevag, A. Austeng and S. Holm, "Benefits of minimum-variance beamforming in medical ultrasound imaging," IEEE Trans. Ultrason., Ferroelect., Freq. Contr., Vol. 56, No. 9, pp. 1868-1879 (2009) https://doi.org/10.1109/TUFFC.2009.1263
  53. A. Austeng, A. C. Jensen, J. F. Synnevaag and S. Holm, "Image amplitude estimation with the minimum variance beamformer," Proc. IEEE Ultrason. Symp, pp. 2355-2358 (2009)
  54. F. G. Vignon and M. R. Burcher, "Preserving speckle statistics in minimum variance beamformed images: The effectiveness of spatial compounding," Proc. IEEE Ultrason. Symp., pp, 2332-2335 (2009)
  55. I. K. Holfort, A. Austeng, J. F. Synnevag, S. Holm, F. Gran and J. A. Jensen, "Adaptive receive and transmit apodization for synthetic aperture ultrasound imaging," Proc. IEEE Ultrason. Symp., pp, 337-340 (2009)
  56. B. M. Asl and A. Mahloojifar, "Minimum variance beamforming combined with adaptive coherence weighting applied to medical ultrasound imaging," IEEE Trans. Ultrason., Ferroelect., Freq. Contr, Vol. 56, No. 9, pp. 1923-1931 (2009) https://doi.org/10.1109/TUFFC.2009.1268
  57. B. M. Asl and A. Mahloojifar, "Contrast enhancement of adaptive ultrasound imaging using eigenspace-based minimum variance beamfoming," Proc. IEEE Ultrason. Symp., pp, 349-352 (2009)
  58. J. E. Powers, M. Averkiou, M. Bruce, D. M. Skyba, R. R. Entrekin, J. D. Fraser, C. R. Cooley, B. S. Robinson, D. N. Roundhill, G. A. Schwartz and P. R. Pesque, "Three dimensional ultrasonic diagnostic imaging with density hexagonal acquisition," US. Patent 6,471,650 B2 (2002)
  59. B. Savord, R. Solomon, "Fully sampled matrix transducer for real time 3D ultrasonic imaging," Proc. IEEE Ultrason. Symp., pp. 945-949 (2003)
  60. D. A. Petersen and J. C. Lazenby, "Interconnection from multidimensional transducer arrays to electronics," US Patent 7,304,415 (2007)