Vigen Karl K, Jarrard Jerry, Rieke Viola, Frisoli Joan, Daniel Bruce L, Butts Pauly Kim
Department of Radiology, Stanford University, Stanford, California, USA.
J Magn Reson Imaging. 2006 Apr;23(4):578-84. doi: 10.1002/jmri.20528.
To demonstrate in vivo MR-guided temperature mapping during radiofrequency (RF) ablation of the liver with a commercially available RF generator modified to allow simultaneous RF treatment and MRI.
A commercial RF generator was modified using passive filtering to allow the continuous application of the treatment current during MRI studies. A total of six ablations were performed with the device in vivo in three porcine livers, and imaging was concurrently performed using one of two different temperature mapping strategies.
MR images acquired during RF ablation demonstrated no noticeable interference from the RF ablation device, which was operated at clinically relevant power levels. Temperature maps showed areas of heating that were consistent with the dimensions of the RF ablation probe, with some asymmetry (likely depending on the orientation of the probe and heat propagation effects), and some differences in heating-spot area stability depending on the specific temperature mapping strategy used. Lesions were visualized on post-ablation imaging and sectioning.
The feasibility of performing RF ablation with a modified commercial RF generator simultaneously with MRI was demonstrated. Interference-free MR temperature maps were produced with both variable respiratory motion and mechanical ventilation, and showed the extent of heating as the ablation progressed.
使用经过改装以允许同时进行射频治疗和磁共振成像（MRI）的市售射频发生器，在肝脏射频（RF）消融过程中进行体内MR引导的温度测绘。
使用无源滤波对市售射频发生器进行改装，以便在MRI研究期间持续施加治疗电流。使用该设备在三只猪的肝脏中进行了总共六次体内消融，并使用两种不同温度测绘策略之一同时进行成像。
在RF消融过程中采集的MR图像显示，在临床相关功率水平下运行的RF消融设备没有明显干扰。温度图显示加热区域与RF消融探针的尺寸一致，存在一些不对称性（可能取决于探针的方向和热传播效应），并且根据所使用的特定温度测绘策略，加热点区域稳定性存在一些差异。消融后成像和切片显示了病变。
证明了使用改装后的市售射频发生器与MRI同时进行RF消融手术的可行性。在呼吸运动可变和机械通气的情况下均产生了无干扰的MR温度图，并显示了消融过程中加热的程度。
