Abstract
The imaging performance of echographic equipment is greatly depenlent on the characteristics of the ultrasound transducer. The paper is confined to single element focussed transducers which are still widely employed in modern equipment. Extrapolation of the results to array transducers maybe made to a certain extent. The performance is specified by the 2 dimensional point spread function (PSF) in the focal zone of the transmitted sound field. This PS? is fixed by the bandwidth of the transducer when the axial (depth) direction is considered, and by the central frequency and the relative aperture in the lateral direction. The PSF concept applies to the imaging of specular reflections and the PSF is estimated by scanning a single reflector. In case of scattering by small inhomogeneities within parenchymal tissues the concept of “speckle” formation has to be introduced. The speckle is due to interference phenomena at reception. It can be shown that the average speckle size in the focus is proportional to the PSF above defined for specular reflections. The dependencies of the speckle size on the distance of the tissue to the transducer (beam diffraction effects) and on the density of the scatterers were explored. It is concluded that with the necessary corrections tissue characterization by statistical analysis of the image texture can be meaningful.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Abbott, J.G. and Thurstone, F.L. (1979). Acoustic speckle: theory and experimental analysis, Ultrasonic Imag. 1,pp. 303–324.
Bamber, J.C. and Dickinson R.J. (1980). Ultrasonic B-scanning: a computer simulation: Phys. Med. Biol., 25, pp. 463–479.
Burckhardt, C.B. (1978). Speckle in ultrasound B-mode scans, IEEE Trans. SU-25, pp. 1–6.
Cosgrove, D.O. (1980). Ultrasonic tissue characterization in the liver. In: Ultrasonic Tissue Characterization, J.M. Thijssen (ed.), Stafleu, Alphen a/d Rijn, pp. 84–90.
Flax, S.W., Glover, G.H. and Pelc, N.J. (1981). Textural variations in B-mode ultrasonography: a stochastic model, Ultrasonic Imag. 3, pp. 235–257.
Goodman, J.W. (1975). Statistical properties of laser speckle patterns. In: Laser Speckle and Related Phenomena, J.C. Dainty (ed.), Springer, Berlin, pp. 9–75.
Insana, M.F., Wagner R.F., Garra, B.S., Brown, D.G. and Shawker, T.H. (1985). Analysis of ultrasound image texture via generalized rician statistics. In: Proc. Soc. Photo-Opt. Instr. Engrs (SPIE) 56, pp. 153–159.
Kossoff, G., Garrett, W.J., Carpenter, D.A., Jellins, J. and Dadd, M.J. (1976). Principles and classification of soft tissues by gray scale echography, Ultrasound Med. 2, pp. 89–105.
Kossoff, G. (1979). Analysis of the focussing action of spherically curved transducers: Ultrasound Med. 5, pp. 359–365.
Nicholas, D. (1982). Evaluation of backscattering coefficients for excised human tissues: results, interpretation and associated results: Ultrasound Med. 8, pp. 17–28.
Oosterveld, B.J., Thijssen, J.M. and Verhoef, W.A. (1985). Texture of B-mode echograms: 3-D simulations and experiments of the effects of diffraction and scatterer density, Ultrasonic Imag. 7, pp. 142–160.
Papoulis, A. (1965). Probability, Random Variables and Stochastic Processes, McGraw Hill, New York.
Thijssen, J.M. and Oosterveld, B.J. (1985). Texture in B-mode echograms: a simulation study of the effects of diffraction and of scatterer density on gray scale statistics. In: Acoustical Imaging, Vol. 14. A.J. Berkhout, J. Ridder, and L.F. van der Wal (eds.), Plenum, New York, pp. 481–485.
Thijssen, J.M. and Oosterveld, B.J. (1986). Texture of echographic B-mode images. In: Proceedings SIDUO XI Congress, Capri, in press.
Verhoef, W.A., Cloostermans, M.J. and Thijssen, J.M. (1984). The impulse response of a focussed source with an arbitrary axisymmetric surface velocity distribution, J. Acoust. Soc. Amer. 75, pp. 1716–1721.
Wagner, R.F., Smith, S.W., Sandrik, J.M. and Lopez, H. (1983). Statistics of speckle in ultrasound B-scans, IEEE Trans. SU-30, pp. 156–163.
Wagner, R.F., Insana, M.F. and Brown, D.G. (1985). Unified approach to the detection and classification of speckle texture in diagnostic ultrasound. In: Proc. Soc. Photo-opt. Instr. Engrs (SPIE) 556, pp. 146–152.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1988 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Thijssen, J.M., Oosterveld, B.J. (1988). Performance of Echographic Equipment and Potentials for Tissue Characterization. In: Viergever, M.A., Todd-Pokropek, A. (eds) Mathematics and Computer Science in Medical Imaging. NATO ASI Series, vol 39. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-83306-9_24
Download citation
DOI: https://doi.org/10.1007/978-3-642-83306-9_24
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-83308-3
Online ISBN: 978-3-642-83306-9
eBook Packages: Springer Book Archive