Lillaney Prasheel V, Yang Jeffrey K, Losey Aaron D, Martin Alastair J, Cooke Daniel L, Thorne Bradford R H, Barry David C, Chu Andrew, Stillson Carol, Do Loi, Arenson Ronald L, Saeed Maythem, Wilson Mark W, Hetts Steven W
From the Department of Radiology and Biomedical Imaging, University of California, San Francisco, 185 Berry St, Suite 350, Room 320, San Francisco, CA 94107-5705 (P.V.L., J.K.Y., A.D.L., A.J.M., D.L.C., B.R.H.T., C.S., L.D., R.L.A., M.S., M.W.W., S.W.H.); and Penumbra, Alameda, Calif (D.C.B., A.C.).
Radiology. 2016 Oct;281(1):219-28. doi: 10.1148/radiol.2016152036. Epub 2016 Mar 28.
Purpose To assess the feasibility of a magnetically assisted remote-controlled (MARC) catheter system under magnetic resonance (MR) imaging guidance for performing a simple endovascular procedure (ie, renal artery embolization) in vivo and to compare with x-ray guidance to determine the value of MR imaging guidance and the specific areas where the MARC system can be improved. Materials and Methods In concordance with the Institutional Animal Care and Use Committee protocol, in vivo renal artery navigation and embolization were tested in three farm pigs (mean weight 43 kg ± 2 [standard deviation]) under real-time MR imaging at 1.5 T. The MARC catheter device was constructed by using an intramural copper-braided catheter connected to a laser-lithographed saddle coil at the distal tip. Interventionalists controlled an in-room cart that delivered electrical current to deflect the catheter in the MR imager. Contralateral kidneys were similarly embolized under x-ray guidance by using standard clinical catheters and guidewires. Changes in renal artery flow and perfusion were measured before and after embolization by using velocity-encoded and perfusion MR imaging. Catheter navigation times, renal parenchymal perfusion, and renal artery flow rates were measured for MR-guided and x-ray-guided embolization procedures and are presented as means ± standard deviation in this pilot study. Results Embolization was successful in all six kidneys under both x-ray and MR imaging guidance. Mean catheterization time with MR guidance was 93 seconds ± 56, compared with 60 seconds ± 22 for x-ray guidance. Mean changes in perfusion rates were 4.9 au/sec ± 0.8 versus 4.6 au/sec ± 0.6, and mean changes in renal flow rate were 2.1 mL/min/g ± 0.2 versus 1.9 mL/min/g ± 0.2 with MR imaging and x-ray guidance, respectively. Conclusion The MARC catheter system is feasible for renal artery catheterization and embolization under real-time MR imaging in vivo, and quantitative physiologic measures under MR imaging guidance were similar to those measured under x-ray guidance, suggesting that the MARC catheter system could be used for endovascular procedures with interventional MR imaging. (©) RSNA, 2016.
目的 评估在磁共振（MR）成像引导下，磁辅助遥控（MARC）导管系统用于体内简单血管内操作（即肾动脉栓塞）的可行性，并与X线引导进行比较，以确定MR成像引导的价值以及MARC系统可改进的具体领域。材料与方法 根据机构动物护理和使用委员会的方案，在1.5 T实时MR成像下，对3头农场猪（平均体重43 kg±2[标准差]）进行体内肾动脉导航和栓塞测试。MARC导管装置由壁内铜编织导管构成，其远端连接到激光光刻鞍形线圈。介入医师控制室内推车，通过向其输送电流来使MR成像仪中的导管偏转。使用标准临床导管和导丝在X线引导下对侧肾脏进行类似的栓塞。在栓塞前后，使用速度编码和灌注MR成像测量肾动脉血流和灌注的变化。测量MR引导和X线引导的栓塞操作的导管导航时间、肾实质灌注和肾动脉血流速度，并在本初步研究中以平均值±标准差表示。结果 在X线和MR成像引导下，所有6个肾脏的栓塞均成功。MR引导下的平均插管时间为93秒±56，而X线引导下为60秒±22。MR成像和X线引导下，灌注率的平均变化分别为4.9 au/秒±0.8和4.6 au/秒±0.6，肾血流速度的平均变化分别为2.1 mL/分钟/克±0.2和1.9 mL/分钟/克±0.2。结论 MARC导管系统在体内实时MR成像下用于肾动脉插管和栓塞是可行的，并且MR成像引导下的定量生理测量与X线引导下测量的结果相似，表明MARC导管系统可用于介入性MR成像的血管内操作。（©）RSNA，2016年。
