Refractive Index by Reconstruction: Use to Improve Compound B-Scan Resolution

  • J. F. Greenleaf
  • S. A. Johnson
  • W. F. Samayoa
  • C. R. Hansen

Abstract

Reconstructions of two-dimensional distributions of acoustic speed were utilized to correct digitized compound B-scan images for aberrations caused by inhomogeneous refractive index. Profiles of propagation’delays of acoustic pulses obtained during compound transmission scanning at 60 angles of view separated by 6° were used to reconstruct the distribution of acoustic speeds within a 64 × 64 element grid in the scan plane within which 8 to 16 digitized B-scans were obtained for views separated by 22.5° or less. Each B-scan contained 1000 to 1300 pulses, digitized at 10 or 20 megasamples/s. Values of calculated acoustic speed within those elements of the reconstruction grid which were intersected by the locus of each pulse trajectory were utilized to map the temporal sequence of echoes within each echo signal into the correct spatial sequence of echoes within the B-scan image. Straight line approximations to the loci of the acoustic beams were used. The set of corrected B-scans were summed to obtain high resolution compound B-scans of 128 × 128 or 256 × 256 picture elements. This method seems particularly suited to breast imaging although enhance. ment of abdominal scans may be possible as well.

Keywords

Arrival Time Refraction Index Acoustic Velocity Point Reflector Acoustic Speed 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    Kossoff, G., W. J. Garrett, and G. Ranavanovich: Grey scale ecography in obstetrics and gynecology. Australasian Radiology 28(1) March, 1974, pp 63–111.Google Scholar
  2. 2.
    Keating, P. N., R. F. Koppelrnann, T. Sawatari, and R. F. Steinberg: Holographic aperture synthesis via a transmitter array. Acoustical Holography, 6 (Ed: Newell Booth),, Plenum Press, New York, 1975, pp 485–506.Google Scholar
  3. 3.
    Johnson, S. A., J. F. Greenleaf, F. A. Duck, A. Chu, W. F. Samayoa, and B. K. Gilbert:Google Scholar
  4. Digital ‘computer simulation study of a real-time collection,. postprocessing synthetic focusing ultrasound cardiac camera. Acoustical Holography,, 6 (Ed: Newell Booth ), Plenum Press„ New York, 1975, pp 193–211.Google Scholar
  5. 4.
    Greenleaf, J. F., S. A. Johnson, W. F. Samayoa, and F. A. Duck:` Algebraic reconstruction of spatial distributions of acoustic velocities in tissue from their time of flight profiles. Acoustical Holography, 6(Ed: Newell Booth), Plenum Press, New York, 1975, pp 71–90.Google Scholar
  6. 5.
    Johnson, S. A.,’J.’F. Greenleaf, W. F. Samayoa, F. A. Duck, and J. D. Sjostrand: Reconstruction of three-dimensional velocity fields and other ‘parameters ’ by acoustic ray tracing: 1975 Ultrasonic Symposium Proceedings., IEEE Cat. #75,`CHP,994–4SU.Google Scholar
  7. 6.
    Lakshm.ina.rayanan,’ A. divergent ray data 1975, Department of versity of N. Y. at V.: Reconstruction from Technical Report #92, January, Computer Science, State Uni Buffalo.Google Scholar
  8. 7.
    Kak, A. C., L. R. Beaumont, and J. Woífley: Signal processing in the determination of acoustic impedance profiles. TREE 75–7, December, 1974, Department of Electrical Engineering, Purdue University, West Lafayette, Indiana.Google Scholar

Copyright information

© Springer Science+Business Media New York 1977

Authors and Affiliations

  • J. F. Greenleaf
    • 1
  • S. A. Johnson
    • 1
  • W. F. Samayoa
    • 1
  • C. R. Hansen
    • 1
  1. 1.Biophysical Sciences Unit, Department of Physiology and BiophysicsMayo FoundationRochesterUSA

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