Journal of radiological science and technology (대한방사선기술학회지:방사선기술과학)

Korean Society of Radiological Science (대한방사선과학회)
권호 표지

Influence to the Doppler Images by the Defects of Piezoelectric Elements of the Probe of Medical Ultrasonic Scanners (Focusing on the Impact of an Increase in the Defects of Piezoelectric Elements)

초음파 프로브 소자 결함이 도플러 영상에 미치는 영향 (소자 결함 증가에 따른 영향을 중심으로)

  • 이경성 (제주한라대학교 방사선과)
  • Received : 2014.04.21
  • Accepted : 2014.06.16
  • Published : 2014.06.30
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Abstract

This study has investigated the effects of the defects in the probe elements influence Doppler images in the medical ultrasonic scanners. This work was implemented that the quality of Doppler images depended on the extent and location of the probe element defected. The probe performance was rated in terms of the number of piezoelectric elements lost and this was studied in the experiment by electrical disconnection to the elements. The results showed that Doppler velocity became rapidly reduced as the defected elements encountered with the element group activated at the Doppler mode, not as the flow velocity. The effect of the probe defect is decreased when the defects occurred at the element group activated for Doppler mode, as was increased the number of the elements. It was observed that the higher the flow velocity of Doppler flow phantom is, the wider the spectrum of Doppler is. And the Doppler velocity soared up and the dispersion of image brightness is increased when the defected elements got out of the elements activated at Doppler mode. The result showed that TADVP(time-average-Doppler-velocity-profile) is decreased with the increase of the probe element defect, especilly in the region of high frequency. It is expected that the research of various defects of probe elements are needed, and this study can be practical tools for probe based ultrasonic QA in the future.

본 연구는 초음파 진단 장치에서 초음파 프로브 소자의 결함이 도플러 영상에 미치는 영향을 평가한 것이다. 초음파 프로브 소자결함의 여러 유형 중에서 동일한 방식으로 단선된 초음파 프로브 소자 수를 변화하면서, 도플러 모드 영상에 미치는 영향을 실험으로 살펴보았다. 실험 결과는 첫째, 소자 결함에 따른 도플러 속도는 도플러 소자군 부분에서 급격히 변화하고 있으며, 혈류 속도에는 크게 영향을 받지 않는 것으로 나타났다. 둘째, 도플러 소자군 주변에서 결함 있을 때 소자의 번호가 높은 쪽 소자의 결함에 의한 효과가 작은 것을 알 수 있었다. 셋째, 팬텀의 혈류 속도가 높을수록 도플러 속도 스펙트럼의 폭은 커지지만 크기는 감소하고 있다. 그리고 결함이 증가할수록 도플러 속도와 영상의 밝기의 분산이 더 커지는 것으로 나타났다. 이는 프로브 소자의 결함이 증가하면 전체적으로 시간 평균 도플러 속도 프로파일(TADVP)의 크기가 감소하며 고주파수 영역에서 더 빨리 떨어지는 것으로 알 수 있다.

Keywords

References

  1. Moore G W, Gessert J and Schafer M : Perspectives On Image Performance Assessment II : The Impact of Compromised Elements Within An Ultrasound Transducer On Image and Doppler Quality. American Association of Physicists in Medicine (AAPM) 45th Annual Meeting, San Diego, California, USA, 10-14 Aug 2003
  2. Price R : Routine Quality Assurance of Ultrasound Imaging Systems, The Institute of Physical Sciences in Medicine (IPSM), Report No.71: York, UK, 1995
  3. Kang G S, Choi M J, Park S S, Paeng D G, Gibson N M and Coleman A J : Deterioration of the quality of ultrasonic images caused by probe defects. Proc. Acoust. Soc. Kor. Conference 2005, 24, 165-168, 2005
  4. Choi M J, Kang K S, Lee K S, Yang J H, Paeng D G , Kim C C, Rhim S, Gibson N and Coleman A : Low Contrast Sensitivity of B-mode Images against Ultrasonic Probe Defects, The World Federation for Ultrasound in Medicine & Biology, KOEX, Seoul, Korea, 28 May-1 June 2006
  5. 서대철, 권태원 역 : 최신 혈관초음파검사, 고려의학, 2007
  6. Burns P N : The physical principles of Doppler and spectral analysis. J. Clinical Ultrasound, 15, 567-590, 1987 https://doi.org/10.1002/jcu.1870150903
  7. Chivers R C and Parry R J : Ultrasonic velocity and attenuation in mammalian tissue. J Acoust Soc Am, 63, 940-953, 1978 https://doi.org/10.1121/1.381774
  8. Hoskins P R, Sherriff S B and Evans J A (ed) : Testing of Doppler Ultrasound Equipment, The Institute of Physical Sciences in Medicine (IPSM), Report No.70: York, UK, 1994
  9. Merritt C R B : Physics of Ultrasound: In Diagnostic Ultrasound. 3rd ed. Mosby: St. Louis, 3-34, 2005
  10. Taylor K J and Holland S : Doppler US. Part I. Basic principles, instrumentation and pitfalls. Radiology, 174, 297-307, 1990 https://doi.org/10.1148/radiology.174.2.2404309
  11. Fish P : Physics and instrumentation of diagnostic medical ultrasound. John Wiley & Suns, 17-19, 57-64 and 172, 1990
  12. Alkinson P and Woodcock J P : Doppler ultrasound and its use in clinical measurement, Academic Press: New York, 1982
  13. Boote E J : Doppler US Techniques: Concepts of Blood Flow Detection and Flow Dynamics. Radiographics, 23, 1315-1327, 2003 https://doi.org/10.1148/rg.235035080
  14. Browne J E, Watson A J, Gibson N M, Dudley N J and Elliott A T : Objective measurements of image quality. Ultrasound in Med. & Biol., 30, 229-237, 2004 https://doi.org/10.1016/j.ultrasmedbio.2003.10.002
  15. Dudley N J, Griffith K, Houldsworth G, Holloway M and Dunn M A : A review of two alternative ultrasound quality assurance programmes. European Journal of Ultrasound, 12, 233-245, 2001 https://doi.org/10.1016/S0929-8266(00)00119-1