Abstract
In spite of many previous research efforts, B-mode echoencephalography is not used clinically for adults because of the poor quality of the images obtained with current, techniques. The intervening presence of the skull results in low sensitivity, reverberations, distortions in the range and lateral dimension, and, most importantly, poor lateral resolution (White, 1970). Lateral resolution, which can be described by the system point spread function (PSF), is a function of the relative phase variation introduced across the transducer aperture by the presence of the skull. A technique has been described (Phillips, et al., this volume) whereby this phase aberration can be measured by a secondary transducer and compensated for in a phased array imaging system, thus restoring the PSF to its unaberrated condition. An alternate technique will be described here which requires no such a priori knowledge of the skull phase variation. This is accompushed by optimizing the transducer frequency and size, and by signal processing the returning echoes. It has been shown (Phillips, et al., this volume) that if one accurately measures the relative phase variation across the transducer due to the skull, the point spread function can be calculated to a close approximation. A simple but accurate model of the skull predicts that the phase variation, \( \Delta \phi \), is a linear function of skull thickness, y, and ultrasound frequency, f.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
References
Fried, D.L. (1965), Statistics of a Geometric Representation of a Deformed Wavefront. J. Opt. Soc. of Amer., 55:1427.
Fried, D.L. (1966), Optical Resolution Through a Randomly Inhomogeneous Medium for Very Long and Very Short Exposures. J. Opt. Soc. Amer., 56:1372.
Goodman, J.W., Huntley, W.H., Jr., Jackson, D.W., and Lehman, M. (1966), Wavefront-Reconstruction Imaging Through Random Media. App. Phys. Lett., 8:311.
Phillips, D.J., Smith, S.W., von Ramm, O.T., Thurstone, F.L., (1974), A Phase Compensation Technique for B-mode Echoencephalography. Proc. 19th Annual Meeting, A.I.U.M, D.N. White, Editor, Plenum Press.
Rhodes, W.T., and Goodman, J.W. (1973), Interferometric Techniques for Recording and Restoring Images Degraded by Unknown Aberrations. J. Opt. Soc. Amer., 63:647.
Somer, J.C. (1968), Electronic Sector Scanning for Ultrasonic Diagnosis. Ultrasonics, 6:153.
Thurstone, F.L., von Ramm, O.T. (1974), Electronic Beam Scanning for Ultrasonic Imaging, Proc. II World Congress on Ultrasonic Diagnostics in Medicine, Rotterdam, the Netherlands, 1973. Excerpta Medica, Amsterdam, 43.
White, D.N. (1970), Ultrasonic Encephalography, Medical Ultrasonic Laboratory, Kingston, Ontario, 119.
White, D.N., and Curry, G.R. (1974), Absorption of Ultrasonic Energy by the Skull. Proc. 19th Annual Meeting of A.I.U.M., D.N. White, Editor, Plenum Press.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1975 American Institute of Ultrasound in Medicine and Plenum Press, New York
About this chapter
Cite this chapter
Smith, S.W., Miller, E.B., von Ramm, O.T., Thurstone, F.L. (1975). Signal Processing Techniques for Improving B-Mode Echoencephalography. In: White, D. (eds) Ultrasound in Medicine. Springer, Boston, MA. https://doi.org/10.1007/978-1-4613-4443-8_122
Download citation
DOI: https://doi.org/10.1007/978-1-4613-4443-8_122
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4613-4445-2
Online ISBN: 978-1-4613-4443-8
eBook Packages: Springer Book Archive