Wilson Mark W, Fidelman Nicholas, Weber Oliver M, Martin Alastair J, Gordon Roy L, LaBerge Jeanne M, Kerlan Robert K, Wolanske Kristen A, Saeed Maythem
Department of Radiology, University of California, San Francisco, 505 Parnassus Avenue, Room M-361, San Francisco, CA 94143, USA.
J Vasc Interv Radiol. 2003 Sep;14(9 Pt 1):1169-75. doi: 10.1097/01.rvi.0000086539.44800.c5.
The purpose of this study was to use a combined x-ray angiography and MR imaging (XMR) system to manipulate intraarterial catheters and monitor the deposition of gadolinium (Gd)-impregnated embolic microspheres in vivo in a canine kidney model.
Seven anesthetized dogs (18-28 kg) were studied. The renal arteries were catheterized under fluoroscopic guidance. Renal blood flow rates were assessed with velocity-encoded cine MR imaging before and after renal artery embolization with Gd-impregnated microspheres (300-500 and 500-700 micro m in size). The particles were injected in vivo into 14 canine renal arteries under fast dynamic T1-weighted MR imaging guidance at one frame per second. Postembolic microsphere distributions were assessed with MR imaging and digital subtraction angiography (DSA).
Gd-impregnated microsphere injection into the renal arteries was successful in all animals. Renal enhancement due to the deposition of the particles persisted for at least 1 hour after the injection. The distribution of MR signal enhancement in the kidneys differed for the smaller versus the larger microspheres. The 300-500- micro m microspheres deposited preferentially in the outer cortical regions, whereas the 500-700- micro m microspheres preferentially deposited in the medulla and inner cortex. Renal blood flow was significantly reduced after the administration of both the 300-500- micro m microspheres (from 3.9 to 1.0 mL/min/g) and the 500-700- micro m microspheres (from 3.5 to 0.2 mL/min/g).
MR imaging permits real-time guidance of arterial embolization with Gd-impregnated microspheres.
本研究的目的是使用联合X射线血管造影和磁共振成像（XMR）系统在犬肾模型中体内操作动脉内导管并监测钆（Gd）浸渍栓塞微球的沉积情况。
对7只麻醉犬（18 - 28千克）进行研究。在荧光透视引导下对肾动脉进行插管。在用Gd浸渍微球（尺寸为300 - 500微米和500 - 700微米）进行肾动脉栓塞前后，用速度编码电影磁共振成像评估肾血流速率。在每秒一帧的快速动态T1加权磁共振成像引导下，将颗粒在体内注入14条犬肾动脉。用磁共振成像和数字减影血管造影（DSA）评估栓塞后微球分布。
向所有动物的肾动脉中注入Gd浸渍微球均成功。注射后，由于颗粒沉积导致的肾脏强化持续至少1小时。肾脏中磁共振信号增强的分布对于较小与较大微球有所不同。300 - 500微米的微球优先沉积在外皮质区域，而500 - 700微米的微球优先沉积在内髓质和内皮质。在给予300 - 500微米微球（从3.9降至1.0毫升/分钟/克）和500 - 700微米微球（从3.5降至0.2毫升/分钟/克）后，肾血流均显著降低。
磁共振成像可对Gd浸渍微球的动脉栓塞进行实时引导。
