TY - JOUR

T1 - Acoustic interface contrast imaging

AU - Van Der Neut, Joost

AU - Van Den Berg, Peter M.

AU - Fokkema, Jacob T.

AU - Van Dongen, Koen W.A.

PY - 2018

Y1 - 2018

N2 - In acoustic reflectivity imaging, we infer the internal reflectivity of an unknown object from reflected waveforms. A common assumption is that the mass density is constant and that the recorded pressure field is related to a volume contrast in the wave speed by a nonlinear volume-integral representation. This representation is typically linearized under the Born approximation and solved for the volume contrast by iterative inversion. We propose an alternative methodology, which we refer to as interface contrast imaging. In our derivation, we assume a medium with constant wave speed, which contains discontinuities of the acoustic impedance at a collection of interfaces between piecewise-homogeneous subdomains. A linear relationship is established between the recorded data and the gradient of the acoustic impedance at the interfaces, which we refer to as an interface contrast. This contrast can be solved for by iterative inversion. With this procedure, acoustic interfaces can be delineated with superior resolution compared to volume contrast imaging. Since the convergence speed is relatively fast and a reasonable image can already be obtained after a single iteration, real-time applications seem feasible. If necessary, the acoustic impedance can also be imaged by integrating the retrieved reflectivity contrast over space.

AB - In acoustic reflectivity imaging, we infer the internal reflectivity of an unknown object from reflected waveforms. A common assumption is that the mass density is constant and that the recorded pressure field is related to a volume contrast in the wave speed by a nonlinear volume-integral representation. This representation is typically linearized under the Born approximation and solved for the volume contrast by iterative inversion. We propose an alternative methodology, which we refer to as interface contrast imaging. In our derivation, we assume a medium with constant wave speed, which contains discontinuities of the acoustic impedance at a collection of interfaces between piecewise-homogeneous subdomains. A linear relationship is established between the recorded data and the gradient of the acoustic impedance at the interfaces, which we refer to as an interface contrast. This contrast can be solved for by iterative inversion. With this procedure, acoustic interfaces can be delineated with superior resolution compared to volume contrast imaging. Since the convergence speed is relatively fast and a reasonable image can already be obtained after a single iteration, real-time applications seem feasible. If necessary, the acoustic impedance can also be imaged by integrating the retrieved reflectivity contrast over space.

KW - acoustic reflectivity imaging

KW - acoustic representation theorem

KW - ultrasound diffraction tomography

UR - http://www.scopus.com/inward/record.url?scp=85054639780&partnerID=8YFLogxK

U2 - 10.1088/1361-6420/aad92c

DO - 10.1088/1361-6420/aad92c

M3 - Article

AN - SCOPUS:85054639780

VL - 34

JO - Inverse Problems: inverse problems, inverse methods and computerized inversion of data

JF - Inverse Problems: inverse problems, inverse methods and computerized inversion of data

SN - 0266-5611

IS - 11

M1 - 115006

ER -