Tissue thermal conductivity by magnetic resonance thermometry and focused ultrasound heating
Tissue thermal conductivity by magnetic resonance thermometry and focused ultrasound heating
复制标题
DOI：
10.1002/jmri.10199
复制
发表时间：
2002-11-01
影响因子：
4.4
通讯作者：
Plewes, DB
中科院分区：
文献类型：
--
作者：
Cheng, HLM;Plewes, DB
目的：探讨磁共振（MR）温度成像与聚焦超声（FUS）联合应用于无创组织热特性测定的方法。材料和方法：简单地说，使用工作频率为1.68 MHz的球形气背传感器在组织中产生温度升高的空间脉冲，并在1.5特斯拉临床扫描仪中使用磁共振温度成像进行测量。一种基于热冲洗的新技术应用于分析获得的MR温度图像，以估计组织热导率和灌注。结果：体外和体内的数值模拟和实验表明，在1.5特斯拉的温度下，MR测温可以测量到导热系数在真实值的10%以内。然而，由于温度精度可达到1.5特斯拉，稳健的灌注估计仅在高度灌注的器官或肿瘤中可行。结论：本研究已经开发出一种方法来确定患者和器官在感兴趣部位的组织热特性，并允许重复应用。这种能力与使用磁共振引导的FUS系统进行肿瘤消融的热治疗计划有关。
Purpose: To investigate the combined use of magnetic resonance (MR) temperature imaging and focused ultrasound (FUS) for the noninvasive determination of tissue thermal properties.Materials and Methods: Brief, spatial impulses of temperature elevation were created in tissue using a spherical, air-backed transducer operating at 1.68 MHz and measured using MR temperature imaging in a 1.5-Tesla clinical scanner. A novel technique based on thermal washout is applied in an analysis of the acquired MR temperature images to estimate tissue thermal conductivity and perfusion.Results: Numerical simulations and experiments in vitro and in vivo demonstrate that thermal conductivity can be measured to within 10% of the true value with MR thermometry at 1.5 Tesla. With the temperature precision available at 1.5 Tesla, however, robust perfusion estimation is feasible only in highly perfused organs or tumors.Conclusion: This study has developed a method for determining tissue thermal properties specific to the patient and organ at the site of interest, and allows repeated application. This capability is relevant in thermal therapy planning of tumor ablation using MR-guided FUS systems.