Time reversal operator decomposition with focused transmission and robustness to speckle noise: Application to microcalcification detection

The decomposition of the time reversal operator (DORT) is a detection and focusing technique using an array of transmit-receive transducers. In the absence of noise and under certain conditions, the eigenvectors of the time reversal operator contain the focal laws to focus ideally on well-resolved scatterers even in the presence of strong aberration. This paper describes a new algorithm, FDORT, which uses focused transmission schemes to acquire the operator. It can be performed from medical scanner data. A mathematical derivation of this algorithm is given and it is compared with the conventional algorithm, both theoretically and with numerical experiments. In the presence of strong speckle signals, the DORT method usually fails. The influence of the speckle noise is explained and a solution based on FDORT is presented, that enables detection of targets in complex media. Finally, an algorithm for microcalcification detection is proposed. In-vivo results show the potential of these techniques.

[1]  Gregg E. Trahey,et al.  Wavefront distortion measurements in the human breast , 1997, 1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118).

[2]  Arthur B. Baggeroer,et al.  An overview of matched field methods in ocean acoustics , 1993 .

[3]  R. Menis,et al.  Application of DORT to active sonar , 2004, Oceans '04 MTS/IEEE Techno-Ocean '04 (IEEE Cat. No.04CH37600).

[4]  M. Fink,et al.  The iterative time reversal mirror: A solution to self‐focusing in the pulse echo mode , 1991 .

[5]  W.D. O'Brien,et al.  Synthetic aperture techniques with a virtual source element , 1998, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[6]  Raoul Mallart,et al.  Adaptive focusing in scattering media through sound‐speed inhomogeneities: The van Cittert Zernike approach and focusing criterion , 1994 .

[7]  Mathias Fink,et al.  Decomposition of the time reversal operator: Detection and selective focusing on two scatterers , 1996 .

[8]  J. Jensen,et al.  Multielement synthetic transmit aperture imaging using temporal encoding , 2003, IEEE Transactions on Medical Imaging.

[9]  M. Fink,et al.  Time reversal of ultrasonic fields. I. Basic principles , 1992, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[10]  J. Devaney,et al.  1 Super-resolution Processing of Multi-static Data Using Time Reversal and MUSIC A , 2000 .

[11]  Mathias Fink,et al.  Characterization of extended objects with the D.O.R.T. method , 1996, 1996 IEEE Ultrasonics Symposium. Proceedings.

[12]  Liliana Borcea,et al.  Statistically stable ultrasonic imaging in random media. , 2002, The Journal of the Acoustical Society of America.

[13]  J. Cardoso,et al.  Diffraction Effects in Pulse-Echo Measurement , 1984, IEEE Transactions on Sonics and Ultrasonics.

[14]  M. O'Donnell,et al.  Phase-aberration correction using signals from point reflectors and diffuse scatterers: measurements , 1988, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[15]  D.-L. Donald Liu,et al.  A clinical study of adaptive beamforming using time-delay adjustments on a 1-D array , 2003, IEEE Symposium on Ultrasonics, 2003.

[16]  Mathias Fink,et al.  Eigenmodes of the time reversal operator: a solution to selective focusing in multiple-target media , 1994 .

[17]  D H Chambers,et al.  Time reversal for a single spherical scatterer. , 2001, The Journal of the Acoustical Society of America.

[18]  T. D. Mast,et al.  Focusing and imaging using eigenfunctions of the scattering operator. , 1997, The Journal of the Acoustical Society of America.

[19]  M Fink,et al.  Imaging in the presence of grain noise using the decomposition of the time reversal operator. , 2003, The Journal of the Acoustical Society of America.

[20]  Mathias Fink,et al.  Flaw detection in solid with the D.O.R.T. method , 1997, 1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118).

[21]  Gregg E. Trahey,et al.  Wavefront estimation in the human breast , 2001, SPIE Medical Imaging.

[22]  M. Fink,et al.  Time Reversal of Ultrasonic Fields-Part I : Basic Principles , 2000 .