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An assessment of the DORT method on simple scatterers using boundary element modelling
P Gélat1, G Ter Haar, N Saffari
1Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK.
Physics in Medicine and Biology
|April 18, 2015
Summary
High-intensity focused ultrasound can now treat liver tumors by focusing through ribs using the DORT method. This technique selectively targets tumors while minimizing ultrasonic dose to surrounding bone, overcoming a key limitation in HIFU therapy.
Area of Science:
- Acoustics
- Medical Physics
- Biomedical Engineering
Background:
- High-intensity focused ultrasound (HIFU) is limited by rib interference in liver tumor treatment.
- Ribs strongly absorb and reflect ultrasound, posing a challenge for therapeutic applications.
- Accurate measurement of ultrasonic dose on ribs is difficult due to experimental challenges.
Purpose of the Study:
- To theoretically assess the efficacy of the DORT (décomposition de l'opérateur de retournement temporel) method for focusing ultrasound through scatterers.
- To evaluate the DORT method's ability to selectively focus on liver tumors while minimizing dose to ribs.
- To compare the DORT method's focusing performance against other techniques using a validated theoretical model.
Main Methods:
- Implemented the DORT method theoretically using the boundary element method (BEM) on spherical scatterers.
- Assessed focusing capability by comparing specific absorption rate (SAR) at the scatterer surface and focal region.
- Utilized a singular value decomposition of inter-element transfer functions for DORT implementation.
Main Results:
- The boundary element method (BEM) provided a validated theoretical model for assessing the DORT method.
- The DORT method demonstrated the ability to focus through scatterers without prior knowledge of their geometry.
- Theoretical assessment showed the DORT method's potential for selective focusing in the presence of scatterers like ribs.
Conclusions:
- The boundary element method (BEM) is well-suited for theoretically assessing acoustic focusing methods like DORT.
- The DORT method shows promise for overcoming the limitations of HIFU in treating liver tumors by enabling focusing through ribs.
- Theoretical validation is crucial for evaluating complex acoustic focusing techniques and ensuring safety in medical applications.
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