Advertisement

High-frequency Pulse-compression Ultrasound Imaging with an Annular Array

  • J. Mamou
  • J.A. Ketterling
  • R.H. Silverman
Part of the Acoustical Imaging book series (ACIM, volume 29)

Abstract

High-frequency ultrasound (HFU) allows fine-resolution imaging at the expense of limited depth-of-field (DOF) and shallow acoustic penetration depth. Coded-excitation imaging permits a significant increase in the signal-to-noise ratio (SNR) and therefore, the acoustic penetration depth. A 17-MHz, five-element annular array with a focal length of 31 mm and a total aperture of 10 mm was fabricated using a 25-μm thick piezopolymer membrane. An optimized 8-μs linear chirp spanning 6.5–32 MHz was used to excite the transducer. After data acquisition, the received signals were linearly filtered by a compression filter and synthetically focused. To compare the chirp-array imaging method with conventional impulse imaging in terms of resolution, a 25-μm wire was scanned and the -6-dB axial and lateral resolutions were computed at depths ranging from 20.5 to 40.5 mm. A tissue-mimicking phantom containing 10-μm glass beads was scanned, and backscattered signals were analyzed to evaluate SNR and penetration depth. Finally, ex-vivo ophthalmic images were formed and chirp-coded images showed features that were not visible in conventional impulse images.

Key words

Ultrasound Chirp High-frequency Pulse-compression 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    J. A. Ketterling, O. Aristizábal, D. H. Turnbull, and F. L. Lizzi, “Design and fabrication of a 40-mhz annular array transducer,” IEEE Trans. Ultrason. Ferroelect. Freq. Contr., vol. 52, pp. 672–681, 2005.CrossRefGoogle Scholar
  2. 2.
    J. A. Ketterling, S. Ramachandran, and O. Aristizábal, “Operational verification of a 40-mhz annular array transducer,” IEEE Trans. Ultrason. Ferroelect. Freq. Contr., vol. 53, pp. 623–630, 2006.CrossRefGoogle Scholar
  3. 3.
    T. Misaridis and J. A. Jensen, “Use of modulated excitation signals in medical ultrasound. part II: Design and performance for medical imaging applications,” IEEE Trans Ultrason Ferroelectr Freq Control, vol. 52, pp. 192–207, 2005.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • J. Mamou
    • 1
  • J.A. Ketterling
    • 1
  • R.H. Silverman
    • 1
  1. 1.F. L. Lizzi Center for Biomedical EngineeringRiverside Research InstituteNew YorkUSA

Personalised recommendations