Robust strain estimation is important in elastography. However, a high signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) are sometimes attained by sacrificing resolution. We propose a least-squares-based smoothing-spline strain estimator that can produce elastograms with high SNR and CNR without significant loss of resolution. The proposed method improves strain-estimation quality by deemphasing displacements with lower correlation in computing strains. Results from finite-element simulation and phantom-experiment data demonstrate that the described strain estimator provides good SNR and CNR without degrading resolution.
WilsonLSRobinsonDEUltrasonic measurement of small displacements and deformations of tissueUltrasonic Imaging4, 71–82 (1982).
2.
KrouskopTADoughertyDRVinsonFSA pulsed Doppler ultrasonic system for making noninvasive measurements of the mechanical properties of soft tissueJ Rehabil Res Dev24, 1–8 (1987).
3.
LernerRMHuangSRParkerKJ“Sonoelasticity” images derived from ultrasound signals in mechanically vibrated tissuesUltrasound Med Biol16, 231–239 (1990).
4.
LernerRMParkerKJSono-elasticity in ultrasonic tissue characterization and echographic imaging, inProc 7th Eur Comm Workshop, ThijssenJM Ed. (Nijmegen, The Netherlands1987).
5.
YamakoshiY.SatoJ.SatoT.Ultrasonic imaging of internal vibration of soft tissue under forced vibrationIEEE Trans Ultrason Ferroel Freq Contr47, 45–53 (1990).
6.
AlamSKRichardsDWParkerKJDetection of Intraocular Pressure change in the eye using sonoelastic Doppler ultrasoundUltrasound Med Biol20, 751–758 (1994).
7.
RubensDJHadleyMAAlamSKSonoelasticity imaging of prostate cancer: In vitro resultsRadiology195, 379–383 (1995).
8.
OphirJ.CéspedesI.PonnekantiH.YazdiY.LiX.Elastography: A method for imaging the elasticity in biological tissuesUltrasonic Imaging13, 111–134 (1991).
9.
O'DonnellM.SkovorodaARShapoBMEmelianovSYInternal displacement and strain imaging using ultrasonic speckle trackingIEEE Trans Ultrason Ferroel Freq Contr41, 314–325 (1994).
10.
GarraBSCéspedesEIOphirJ.Elastography of breast lesions: Initial clinical resultsRadiology202, 79–86 (1997).
TalhamiHEWilsonLSNealeMLSpectral tissue strain: A new technique for imaging tissue strain using intravascular ultrasoundUltrasound Med Biol20, 759–772 (1994).
13.
GaoL.ParkerKJLernerRMLevinsonSFImaging of the elastic properties of tissue—A reviewUltrasound Med Biol22, 959–977 (1996).
14.
OphirJ.CéspedesI.GarraB.Elastography: ultrasonic imaging of tissue strain and elastic modulus in vivoEuro J Ultrasound3, 49–70 (1996).
15.
OphirJ.AlamSKGarraB.Elastography: ultrasonic estimation and imaging of the elastic properties of tissuesProc Inst Mech Engin, Part H: J Engin Med213, 203–233 (1999).
16.
OphirJ.AlamSKGarraB.Elastography: imaging the elastic properties of soft tissues with ultrasoundJapanese J Med Ultrason29, 155–171 (2002).
17.
KrouskopTAWheelerTMKallelF.GarraBSHallT.Elastic moduli of breast and prostate tissues under compressionUltrasonic Imaging20, 260–274 (1998).
18.
SarvazyanAPShear acoustic properties of soft biological tissues in medical diagnostics, inJ Acoust Soc Am Proc 125th meeting93, p. 2329 (1993).
19.
KallelF.OphirJ.A least-squares strain estimator for elastographyUltrasonic Imaging19, 195–208 (1997).
20.
AlamSKOphirJ.KonofagouEEAn adaptive strain estimator for ElastographyIEEE Trans Ultrason Ferroel Freq Contr45, 461–472 (1998).
21.
BrusseauE.PerreyC.DelachartreP.Axial strain imaging using a local estimation of the scaling factor from rf ultrasound signalsUltrasonic Imaging22, 95–107 (2000).
22.
CéspedesI.OphirJ.Reduction of image noise in elastographyUltrason Imag15, 89–102 (1993).
23.
AlamSKOphirJ.Reduction of signal decorrelation from mechanical compression of tissues by temporal stretching: approaches to elastographyUltrasound Med Biol23, 95–105 (1997).
24.
SchoenbergIJSpline functions and the problem of graduationProc Nat Acad Sc52, 947–950 (1964).
25.
ReinschC.Smoothing by spline functionsNumererisch Mathematik10, 177–183 (1967).
26.
RiceJARosenblattM.Smoothing-splines, regression, derivatives, and convolutionAnn Statistics11, 141–156 (1983).
27.
SilvermanBWSome aspects of the spline smoothing approach to non-parametric regression curve fittingJ Royal Stat Soc B47, 1–52 (1985).
28.
EubankRLNonparametric Regression and Spline Smoothing, 2nd Ed. (Marcel-Decker, New York1988).
29.
KhademA.SetarehdanSK Smoothing-spline-based strain estimation in ultrasound elastography, in Proc EEE Intern Conf Signal Proc Comm, pp. 680–683 (2007).
