Abstract
High-intensity focused ultrasound (HIFU) techniques are promising modalities for the non-invasive treatment of cancer. For HIFU therapies of, e.g., liver cancer, one of the main challenges is the accurate focusing of the acoustic field inside a ribcage. Computational methods can play an important role in the patient-specific planning of these transcostal HIFU treatments. This requires the accurate modeling of acoustic scattering at ribcages. The use of a boundary element method (BEM) is an effective approach for this purpose because only the boundaries of the ribs have to be discretized instead of the standard approach to model the entire volume around the ribcage. This paper combines fast algorithms that improve the efficiency of BEM specifically for the high-frequency range necessary for transcostal HIFU applications. That is, a Galerkin discretized Burton-Miller formulation is used in combination with preconditioning and matrix compression techniques. In particular, quick convergence is achieved with the operator preconditioner that has been designed with on-surface radiation conditions for the high-frequency approximation of the Neumann-to-Dirichlet map. Realistic computations of acoustic scattering at 1 MHz on a human ribcage model demonstrate the effectiveness of this dedicated BEM algorithm for HIFU scattering analysis.
Highlights
The patient-specific planning of transcostal High-intensity focused ultrasound (HIFU) treatment is likely to rely on numerical simulations to optimize the configuration of the multielement ultrasound transducer array
An innovative fast boundary element method (BEM) has been developed in this paper for application to HIFU simulations
Scattering analysis of a human ribcage at 1 MHz confirms the improvement of convergence and the effectiveness of matrix compression with the dedicated fast BEM algorithm
Summary
The liver is a common site of occurrence for tumors, and the incidence of liver cancer is on the rise in Europe. Hepatocellular carcinoma, the most common form of liver cancer, is a growing global health problem as it is the third most common cause of cancer related death with increased incidence rates worldwide.. As a result of the large domain dimensions at the MHz frequencies required for transcostal HIFU, many models have relied on simplified shadowing techniques.15,16,20,21 Whilst these algorithms, such as ray tracing, may replicate features of wave propagation during transcostal HIFU treatments, they do not accurately address the actual scattering mechanisms involved in complex 3D structures and are likely to be of limited use in clinical treatment planning applications. Owing to the large grid sizes resulting from the discretization of the entire region around the ribcage, these studies have been confined to 2D models Efficient approaches, such as k-space pseudospectral methods have shown promise for modeling acoustic fields in heterogeneous media.. The experimental results in this paper demonstrate the convergence improvement of the preconditioner, the compression rates of the matrices, and its feasibility for the simulation of transcostal HIFU techniques
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
