HIFU scattering by the ribs: constrained optimisation with a complex surface impedance boundary condition
HIFU scattering by the ribs: constrained optimisation with a complex surface impedance boundary condition
复制标题
肋骨的 HIFU 散射：复杂表面阻抗边界条件的约束优化
DOI：
10.1088/1742-6596/498/1/012004
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Gélat P
中科院分区：
文献类型：
--
作者：
Gélat P
高强度聚焦超声(HIFU)可以实现高度局部、非侵入性的组织消融，其疗效已在一系列癌症的治疗中得到证明，包括肾癌、前列腺癌和乳腺癌。HIFU提供了局部治疗深层肿瘤的能力，与切除、化疗和电离辐射等更成熟的治疗方式相比，HIFU可能产生的副作用更少。然而，目前仍有许多重大挑战阻碍了其在临床上的广泛应用。其中一个挑战是需要通过胸腔传输足够的能量来消融所需病灶处的组织，同时最大限度地减少副叶的形成，并保留健康组织。肋骨对超声波有很强的吸收和反射。这有时会导致治疗过程中骨骼和覆盖组织过热，导致皮肤烧伤。因此，成功治疗上腹部肿瘤患者需要对声能和热能的沉积方式有透彻的了解。以前，基于Burton-Miller公式的广义最小残差(GMRES)实现的边界元(BE)方法被用来预测散布在人体肋骨上的多单元HIFU阵列的场，其拓扑结构是从CT扫描数据获得的[1]。此后实现了传播介质内部的耗散机制，以及肋骨表面的复杂表面阻抗条件。将边界元方程重新表示为约束优化问题，以确定多单元HIFU阵列的复杂表面速度，该阵列产生的声压场在最小二乘意义上最符合所需的声压分布。这是在确保肋骨表面的声剂量率参数保持在指定阈值以下的情况下完成的。该方法是在存在解剖肋骨的球形多元阵列上以1 MHz的激励频率进行测试的。
High intensity focused ultrasound (HIFU) enables highly localised, non-invasive tissue ablation and its efficacy has been demonstrated in the treatment of a range of cancers, including those of the kidney, prostate and breast. HIFU offers the ability to treat deep-seated tumours locally, and potentially bears fewer side effects than more established treatment modalities such as resection, chemotherapy and ionising radiation. There remains however a number of significant challenges which currently hinder its widespread clinical application. One of these challenges is the need to transmit sufficient energy through the ribcage to ablate tissue at the required foci whilst minimising the formation of side lobes and sparing healthy tissue. Ribs both absorb and reflect ultrasound strongly. This sometimes results in overheating of bone and overlying tissue during treatment, leading to skin burns. Successful treatment of a patient with tumours in the upper abdomen therefore requires a thorough understanding of the way acoustic and thermal energy is deposited. Previously, a boundary element (BE) approach based on a Generalised Minimal Residual (GMRES) implementation of the Burton-Miller formulation was developed to predict the field of a multi-element HIFU array scattered by human ribs, the topology of which was obtained from CT scan data [1]. Dissipative mechanisms inside the propagating medium have since been implemented, together with a complex surface impedance condition at the surface of the ribs. A reformulation of the boundary element equations as a constrained optimisation problem was carried out to determine the complex surface velocities of a multi-element HIFU array which generated the acoustic pressure field that best fitted a required acoustic pressure distribution in a least-squares sense. This was done whilst ensuring that an acoustic dose rate parameter at the surface of the ribs was kept below a specified threshold. The methodology was tested at an excitation frequency of 1 MHz on a spherical multi-element array in the presence of anatomical ribs.
第12届英法物理声学会议(AFPAC2013)
DOI：
10.1088/1742-6596/498/1/011001
发表时间：
2014
期刊：
Journal of Physics: Conference Series
影响因子：
--
作者：
B. Quesson;M. Merle;M. Köhler;C. Mougenot;S. Roujol;B. D. de Senneville;C. Moonen
通讯作者：
C. Moonen
影响因子：
3.8
作者：
Liu, Hao-Li;Chang, Hsu;Lin, Win-Li
通讯作者：
Lin, Win-Li
影响因子：
3.5
作者：
Marquet, F.;Aubry, J. F.;Tanter, M.
通讯作者：
Tanter, M.