Soft tissue Absorption Tomography with Correction for Scattering Aberrations

Abstract

Among the many factors involved in ultrasound attenuation phenomena, scattering effects play a major role, even in the unexpected case of soft tissues. It is proposed in this study to quantitatively evaluate the scattering affecting the measurements before reconstructing the absorption parameter alone.

The reconstruction procedure involves three steps: (1) Estimating the sound speed map using a transmission tomography algorithm. This estimation procedure provides a numerical phantom of the organ probed, cleared of all dissipative components. This absorption free phantom mimics the (viscoacoustic) tissues imaged except for the density and absorption characteristics: the density a priori equals 1000 kg/m³ and the absorption is not taken into account. The impedance fluctuations in the object are therefore approximated on the basis of the sound speed contrast. (2) Synthesing the field scattered by the absorption free phantom; the attenuation observed here results solely from the scattering phenomenon. The synthesis is carried out using a finite-element time domain code simulating the ultrasonic propagation through the phantom. It provides the scattering distortion reference introduced into the log spectral absorption estimator. (3) Reducing the scattering distortions affecting the integrated absorption measured along the ray paths using a log spectral procedure.

The corrected integrated absorption is then processed using a tomographic reconstruction procedure that provides an estimate of the absorption distribution. Simple numerical simulations show the improvement obtained in the absorption estimates with this approach.

Keywords

Absorption tomography scattering viscoacoustic propagation model ultrasound

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References

McDaniel

Ultrasonic attenuation measurements on excised breast carcinoma at frequencies from 6 to 10 MHz, in Proc IEEE Ultrasonics Symp, pp. 234–23 (IEEE Cat. no. 77CH1264-ISU, 1977).

Fry

Sanghi

Fry

Gallager

Frequency dependent attenuation of malignant breast tumors studied by the fast Fourier transform technique, in Ultrasound Tissue Characterization II, Linzer

, Ed., pp. 85–92, NBS Special Publication 525 (US Government Printing Office, 1979).

Kuc

Clinical application of an ultrasound attenuation coefficient estimation technique for liver pathology characterization, IEEE Trans Biomed Eng 27 312–319 (1980).

Maklad

Ophir

Balsara

Attenuation of ultrasound in normal liver and diffuse liver disease in vivo, Ultrasonic Imaging 6, 117–125 (1984).

Landini

Sarnelli

Squantini

Frequency-dependent attenuation in breast tissue characterization, Ultrasound Med Biol 11, 599–603 (1985).

Flax

Pelc

Glover

Gutmann

McLachlan

Spectral characterization and attenuation measurements in ultrasound, Ultrasonic Imaging 5, 95–116 (1983).

Claesson

Salomonsson

Estimation of varying ultrasonic attenuation, Ultrasound Med Biol 11, 131–145 (1985).

Greenleaf

. Application of stochastic analysis to ultrasonic echoes — Estimation of attenuation and tissue heterogeneity from peaks of echo envelope, J Acoust Soc Am 79, 526–534 (1986).

Jiang

Song

Park

. Ultrasound attenuation estimation in soft tissue using the entropy difference of pulsed echoes between two adjacent envelope segments, Ultrasonic Imaging 10, 248–264 (1988).

10.

Kuc

Schwartz

Estimating the acoustic attenuation coefficient slope for liver from reflected ultrasound signals, IEEE Trans Sonics Ultrasonics SU-26, 353–362 (1979).

11.

Meyer

. An iterative, parametric spectral estimation technique for high-resolution pulse-echo ultrasound, IEEE Trans Biomed Eng 26, 207–212 (1979).

12.

Dines

Kak

. Ultrasonic attenuation tomography of soft tissues, Ultrasonic Imaging 1, 16–33 (1979).

13.

Narayana

Ophir

Spectral shifts of ultrasonic propagation: A study of theorotical and experimental models, Ultrasonic Imaging 5, 22–29 (1983).

14.

Fink

Hottier

Cardoso

. Ultrasonic signal processing for in vivo attenuation measurement: short time fourier analysis, Ultrasonic Imaging 5, 117–135 (1983).

15.

Ophir

Shawker

Maklad

Attenuation estimation in reflection: progress and prospects, Ultrasonic Imaging 6, 349–395 (1984).

16.

Pan

Liu

. Tomographic reconstruction of ultrasonic attenuation with correction for refractive errors, IBM J Res Develop 25, 71–82 (1981).

17.

Cloostermans

Thijssen

. A beam corrected estimation of the frequency dependent attenuation of biological tissues from backscattered ultrasound, Ultrasonic Imaging 5, 136–147 (1983).

18.

Insana

Zagzebski

Madsen

Improvements in the spectral difference method for measuring ultrasonic attenuation, Ultrasonic Imaging 5, 331–345 (1983).

19.

O'Donnell

Effects of diffraction on measurements of the frequency dependent ultrasonic attenuation, IEEE Trans Biom Engin 30, 320–326 (1983).

20.

Laugier

Berger

Fink

Perrin

Diffraction correction for focused transducers in attenuation measurements in vivo, Ultrasonic Imaging 9, 258–259 (1987).

21.

Kaufman

. Diffraction correction methods for insertion ultrasound attenuation estimation, IEEE Trans Biom Eng 40, 563–570 (1993).

22.

Sehgal

Greenleaf

. Scattering of ultrasound by tissues, Ultrasonic Imaging 6, 60–80 (1984).

23.

Laugier

Berger

Fink

Perrin

Specular reflector noise: effect and correction for in vivo attenuation estimation, Ultrasonic Imaging 7, 277–292 (1985).

24.

Morfey

. Dictionary of Acoustics (Academic Press, pp. 110, 2001).

25.

Greenleaf

Johnson

Lee

Herman

Wood

. Algebraic reconstruction of spatial distributions of acoustic absorption within tissue from their two dimensional acoustic projections, in Acoustical Holography 5, pp. 591–603 (Plenum Press, New York, 1974).

26.

Johnson

Greenleaf

Samayoa

Duck

Sjosstrand

. Reconstruction of three-dimensional velocity fields and others parameters by acoustic ray tracing, in Proc IEEE Ultrasonics Symp pp. 46–51 (1975).

27.

Norton

Linzer

Correcting for ray refraction in velocity and attenuation tomography: a perturbation approach, Ultrasonic imaging 4, 201–233 (1982).

28.

Sehgal

Greenleaf

. Ultrasonic absorption and dispersion in biological media: a postulated model, J Acoust Soc Am 72, 1711–1718 (1982).

29.

Groby

Tsogka

A time domain method for modeling wave propagation phenomena in viscoacoustic media, in Proc 6th Inter Conf on Maths Num Aspects Wave Propag. pp. 911–915 (2003).

30.

Groby

Tsogka

A time domain method for modeling viscoacoustic wave propagation, J Comput Acoust (in press, 2005).

31.

Ferriere

Mensah

Weakly inhomogeneous media tomography, Ultrasonic Imaging 25, 122–133 (2003).

32.

Mensah

Ferriere

Diffraction tomography: a geometrical distortion free procedure, Ultrasonics 42, 677–682 (2004).

33.

Kak

Slaney

Principles of computerized Tomographic Imaging, pp. 77–86 (IEEE Press, New York, 1988).

34.

Kjartansson

Constant Q wave propagation and attenuation, J Geophys Roy 84, 4737–4748 (1979).

35.

Emmerich

Korn

Incorporation of attenuation into time-domain computations of sismic wave fields, Geophysics 52, 1252–1264 (1987).

36.

Day

Minster

. Numerical simulation of attenuated wavefield using a Padé approximant method, Geophys J Roy Astr Soc 78, 105–118 (1984).

37.

Robertson

JAO

Blanch

Symes

. Modeling of a Q constant: methodology and algorithm for an efficient and optimally inexpensive viscoelastic technique, Geophysics 60, 178–184 (1995).

38.

Bécache

Joly

Tsogka

An analysis of new mixed finite elements for the approximation of wave propagation problems, SIAM J Numer Anal 37, 1053–1085 (2000).

39.

Collino

Tsogka

Application of the pml absorbing layer model to the linear elastodynamic problem in anisotropic heteregeous media, Geophysics 66, 294–305 (2001).