Merkle E M, Shonk J R, Duerk J L, Jacobs G H, Lewin J S
Department of Radiology/Division of MRI, University Hospitals of Cleveland, Case Western Reserve University, OH 44106-5056, USA.
AJR Am J Roentgenol. 1999 Sep;173(3):645-51. doi: 10.2214/ajr.173.3.10470895.
The purpose of the study was to evaluate the ability of MR imaging to reveal RF interstitial thermotherapy in the porcine kidney, as a model for future human trials, and to provide guidance for RF probe insertion.
Ten MR-guided RF ablations were performed in the kidneys of three pigs. A 17-gauge monopolar RF probe electrode was inserted into the renal cortex using MR guidance, and RF was applied for 10 min. After postprocedure imaging (T2-weighted, turbo short inversion time inversion recovery [STIR], and T1-weighted sequences), the kidneys were harvested for pathologic examination.
Successful RF probe placement was accomplished in all cases; the interventional procedure time for probe insertion ranged from 4 to 15 min. The thermal lesion size varied from 7 to 14 mm perpendicular to the probe track and was best seen on turbo STIR images. Turbo STIR had the highest renal cortex-to-RF thermal lesion contrast-to-noise ratio with an average of 4.4 +/- 3.5. Turbo STIR imaging never overestimated pathologic lesion diameter with a mean difference of 1.5 +/- 1.4 mm. Three subcapsular hematomas occurred. which could be detected immediately on postprocedure imaging.
MR-guided RF thermal ablation in the porcine kidney was found to be feasible, but minor complications occurred. Induced thermal lesion size was best monitored using turbo STIR images. In the future, RF ablation may offer an alternative treatment option for renal cancer.
本研究旨在评估磁共振成像（MR）显示猪肾射频间质热疗的能力，以此作为未来人体试验的模型，并为射频探头插入提供指导。
对三头猪的肾脏进行了10次MR引导下的射频消融。在MR引导下，将一根17号单极射频探头电极插入肾皮质，并施加射频10分钟。术后成像（T2加权、快速短反转时间反转恢复序列[STIR]和T1加权序列）后，取出肾脏进行病理检查。
所有病例均成功放置射频探头；探头插入的介入操作时间为4至15分钟。热损伤灶大小在垂直于探头轨迹方向上为7至14毫米，在快速STIR图像上显示最佳。快速STIR的肾皮质与射频热损伤灶的对比噪声比最高，平均为4.4±3.5。快速STIR成像从未高估病理损伤直径，平均差异为1.5±1.4毫米。发生了3例包膜下血肿，术后成像可立即检测到。
发现MR引导下猪肾射频热消融是可行的，但出现了轻微并发症。使用快速STIR图像可最佳监测诱导的热损伤灶大小。未来，射频消融可能为肾癌提供一种替代治疗选择。
