title: Time domain reconstruction of sound speed and attenuation in ultrasound computed tomography using full wave inversion.
abstract: Ultrasound computed tomography (USCT) is a non-invasive imaging technique that provides information about the acoustic properties of soft tissues in the body, such as the speed of sound (SS) and acoustic attenuation (AA). Knowledge of these properties can improve the discrimination between benign and malignant masses, especially in breast cancer studies. Full wave inversion (FWI) methods for image reconstruction in USCT provide the best image quality compared to more approximate methods. Using FWI, the SS is usually recovered in the time domain, and the AA is usually recovered in the frequency domain. Nevertheless, as both properties can be obtained from the same data, it is desirable to have a common framework to reconstruct both distributions. In this work, an algorithm is proposed to reconstruct both the SS and AA distributions using a time domain FWI methodology based on the fractional Laplacian wave equation, an adjoint field formulation, and a gradient-descent method. The optimization code employs a Compute Unified Device Architecture version of the software k-Wave, which provides high computational efficiency. The performance of the method was evaluated using simulated noisy data from numerical breast phantoms. Errors were less than 0.5% in the recovered SS and 10% in the AA.
authors.affiliation: Grupo de Física Nuclear, Dpto. de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, Campus de Excelencia Internacional Moncloa, Avenue Complutense S/N, Facultad de Ciencias Físicas, Madrid 28040, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Pérez-Liva
authors.affiliation: Grupo de Física Nuclear, Dpto. de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, Campus de Excelencia Internacional Moncloa, Avenue Complutense S/N, Facultad de Ciencias Físicas, Madrid 28040, Spain.
authors.forename: J L
authors.initials: JL
authors.lastname: Herraiz
authors.affiliation: Grupo de Física Nuclear, Dpto. de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, Campus de Excelencia Internacional Moncloa, Avenue Complutense S/N, Facultad de Ciencias Físicas, Madrid 28040, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Udías
authors.affiliation: Department of Electrical and Computer Engineering, Tufts University, 161 College Avenue, Medford, Massachusetts 02155, USA.
authors.forename: E
authors.initials: E
authors.lastname: Miller
authors.affiliation: Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, United Kingdom.
authors.forename: B T
authors.initials: BT
authors.lastname: Cox
authors.affiliation: Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, United Kingdom.
authors.forename: B E
authors.initials: BE
authors.lastname: Treeby