Hyperthermia by MR-guided focused ultrasound: Accurate temperature control based on fast MRI and a physical model of local energy deposition and heat conduction
Hyperthermia by MR-guided focused ultrasound: Accurate temperature control based on fast MRI and a physical model of local energy deposition and heat conduction
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DOI：
10.1002/(sici)1522-2594(200003)43:3
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发表时间：
2000-03-01
影响因子：
3.3
通讯作者：
Moonen, CTW
中科院分区：
文献类型：
--
作者：
Salomir, R;Vimeux, FC;Moonen, CTW
MR引导聚焦超声中的温度调节需要快速MR温度映射和超声输出的自动反馈控制。在这里，提出了一种基于局部能量沉积和热传导的物理模型的调节方法。根据温度图实时评估局部温度梯度是控制系统的重要组成部分。每次获得新图像时，实时调整超声功率，以获得焦点温度的所需演变。在体外和体内的性能表明，快速和准确的温度控制和超声波吸收和热传导的初始估计误差的大容忍度。当使用模型的物理参数的正确估计时，焦点温度被控制在测量噪声限制内。吸收和扩散参数的初始误差以用户定义的响应时间进行指数补偿，建议响应时间为10秒。(C)2000 Wiley-Liss，Inc.
Temperature regulation in MR-guided focused ultrasound requires rapid MR temperature mapping and automatic feedback control of the ultrasound output. Here, a regulation method is proposed based on a physical model of local energy deposition and heat conduction. The real-time evaluation of local temperature gradients from temperature maps is an essential element of the control system. Each time a new image is available, ultrasound power is adjusted on-the-fly in order to obtain the desired evolution of the focal point temperature. In vitro and in vivo performance indicated fast and accurate control of temperature and a large tolerance of errors in initial estimates of ultrasound absorption and heat conduction. When using correct estimates for the physical parameters of the model, focal point temperature was controlled within the measurement noise limit. Initial errors in absorption and diffusion parameters are compensated for exponentially with a user-defined response time, which is suggested to be on the order of 10 sec. (C) 2000 Wiley-Liss, Inc.