Radio-frequency ablation electrode displacement elastography: A phantom study
Radio-frequency ablation electrode displacement elastography: A phantom study
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DOI：
10.1118/1.2919763
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发表时间：
2008-06-01
期刊：
影响因子：
3.8
通讯作者：
Zagzebski, James A.
中科院分区：
文献类型：
--
作者：
Bharat, Shyam;Varghese, Tomy;Zagzebski, James A.
本文描述了一种新的组织位移方法的评估，该方法用于射频 (rf) 消融引起的病变的弹性成像可视化。该方法涉及使用射频消融电极作为位移装置，在感兴趣的区域提供局部压缩。这种位移机制具有易于体内实施的优点，因为这种方法减少了使用外部压缩时出现的过度横向和高度位移等问题。该方法在包含刚性连接到包涵体中心的射频消融电极的单包涵体组织模拟体模上进行了测试。在电极位移范围为 0.05 至 0.2 mm 之前和之后，从体模获取全帧射频回波信号。使用压缩前和压缩后信号之间的一维互相关分析来测量组织位移，并通过计算位移梯度来确定应变。根据所得应变图像估计应变对比度、对比度噪声比和信噪比。将弹性成像测量的尺寸与先验已知的单包含模型的尺寸进行比较。发现电极位移弹性成像稍微低估了夹杂物的尺寸。该方法还在第二个模拟组织模型和犬肝组织的体外射频消融病变上进行了测试。结果验证了之前的体内研究结果，即电极位移弹性成像是监测射频消融的有效方法。 (C) 2008 年美国医学物理学家协会。
This article describes the evaluation of a novel method of tissue displacement for use in the elastographic visualization of radio-frequency (rf) ablation-induced lesions. The method involves use of the radio-frequency ablation electrode as a displacement device, which provides localized compression in the region of interest. This displacement mechanism offers the advantage of easy in vivo implementation since problems such as excessive lateral and elevational displacements present when using external compression are reduced with this approach. The method was tested on a single-inclusion tissue-mimicking phantom containing a radio-frequency ablation electrode rigidly attached to the inclusion center. Full-frame rf echo signals were acquired from the phantom before and after electrode displacements ranging from 0.05 to 0.2 mm. One-dimensional crosscorrelation analysis between pre-and postcompression signals was used to measure tissue displacements, and strains were determined by computing the gradient of the displacement. The strain contrast, contrast-to-noise ratio, and signal-to-noise ratio were estimated from the resulting strain images. Comparisons are drawn between the elastographically measured dimensions and those known a priori for the single-inclusion phantom. Electrode displacement elastography was found to slightly underestimate the inclusion dimensions. The method was also tested on a second tissue-mimicking phantom and on in vitro rf-ablated lesions in canine liver tissue. The results validate previous in vivo findings that electrode displacement elastography is an effective method for monitoring rf ablation. (C) 2008 American Association of Physicists in Medicine.