LESION DEVELOPMENT IN FOCUSED ULTRASOUND SURGERY - A GENERAL-MODEL
LESION DEVELOPMENT IN FOCUSED ULTRASOUND SURGERY - A GENERAL-MODEL
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DOI：
10.1016/0301-5629(94)90066-3
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发表时间：
1994-01-01
影响因子：
2.9
通讯作者：
TERHAAR, GR
中科院分区：
文献类型：
--
作者：
HILL, CR;RIVENS, I;TERHAAR, GR
由于暴露于强、高聚焦的超声波束（如可用于微创手术），已经建立了组织中热损伤形成过程的分析模型。该模型对焦点区域的光束形状采用高斯近似，并考虑到热扩散和血液灌注的影响，对任何这样的焦点光束在横向和轴向上预测病变开始的时间延迟以及病变随后的生长时间过程。考虑了模型的必要近似和假设。将预测结果与实验测量的猪肝切除数据进行比较，结果一致。我们还将这一理论与先前发表的关于损伤阈值强度的暴露时间依赖性的数据进行了比较。在现有的超声聚焦手术声学暴露测量和报告实践中发现了不足之处，因此，从计量学和生物物理相关性的角度来看，提出了一个更令人满意的量，即在线性条件下确定的焦平面中半压力最大轮廓所包围区域的空间平均强度，暂时表示为I（SAL）。
An analytical model has been constructed for the process of formation of thermal lesions in tissue, resulting from exposure to intense, highly focused ultrasound beams such as may be used in minimally invasive surgery. The model assumes a Gaussian approximation to beam shape in the focal region and predicts, for any such focal beam, the time delay to initiation of a lesion and the subsequent time course of growth of that lesion in lateral and axial dimensions, taking into account the effects of thermal diffusion and blood perfusion. The necessary approximations and assumptions of the model are considered. Comparison of predictions with experimentally measured data on excised pig liver indicate generally good agreement. Comparisons are also made of this theory with previously published data on exposure-time dependence of lesioning threshold intensity. Deficiencies are identified in existing practice for measuring and reporting acoustic exposures for focused ultrasound surgery, and the proposal is therefore made that a quantity that would be more satisfactory, from the viewpoints both of metrology and biophysical relevance, is the intensity spatially averaged over the area enclosed by the half-pressure-maximum contour in the focal plane, as determined under linear conditions, provisionally denoted as I(SAL)