Department of Radiology, Duke University Medical Center, Durham, NC, USA
Transplantation. 2013 Jul 15;96(1):91-6. doi: 10.1097/TP.0b013e318295464c.
In renal allograft recipients presenting with graft dysfunction, it is critical to determine the patency of the transplant vasculature to guide clinical management. Conventional modalities such as Doppler ultrasound, contrast-enhanced computed tomography, magnetic resonance angiography (MRA), and noncontrast MRA are each of limited use because of technical factors and toxicity of standard contrast agents. The purpose of this study was to retrospectively review our institutional experience with renal transplant MRA using ferumoxytol (a nonnephrotoxic medication) as a contrast agent and evaluate its use in the assessment of allograft vascular patency in patients with graft dysfunction, either delayed or slow graft function within hours to days after kidney transplantation or acute kidney injury weeks to months after kidney transplantation.
Sixteen kidney transplant recipients were retrospectively identified who underwent ferumoxytol-enhanced MRA after a nondiagnostic ultrasound for kidney dysfunction after transplantation. Image evaluation was performed by two radiologists, and clinical follow-up data were collected.
In 1 of 16 subjects, MRA with ferumoxytol demonstrated complete arterial occlusion of an allograft. In 2 of 16 subjects, MRA detected moderate to severe anastomotic stenoses, which were confirmed at catheter angiography and successfully treated, resulting in the improvement of graft function. In 13 of 16 subjects, MRA demonstrated normal graft vasculature, and an alternative cause of allograft dysfunction was ultimately confirmed.
Our study suggests that ferumoxytol-enhanced MRA may be a novel, safe method to accurately detect graft artery abnormalities in renal transplant recipients without the risk of nephrotoxicity, when transplant ultrasound is nondiagnostic.
在出现移植物功能障碍的肾移植受者中，确定移植血管的通畅性对于指导临床管理至关重要。由于技术因素和标准造影剂的毒性，传统的模态，如多普勒超声、对比增强 CT、磁共振血管造影（MRA）和非对比 MRA，各有其局限性。本研究的目的是回顾性分析我们机构使用铁氧体（一种非肾毒性药物）作为造影剂进行肾移植 MRA 的经验，并评估其在评估移植物血管通畅性中的应用，这些患者的移植物功能障碍包括移植后数小时至数天出现延迟或缓慢移植物功能或数周至数月后出现急性肾损伤。
回顾性分析了 16 例因移植后肾功能障碍而进行非诊断性超声检查后接受铁氧体增强 MRA 的肾移植受者。由两名放射科医生进行图像评估，并收集临床随访数据。
在 16 例患者中，铁氧体 MRA 显示 1 例移植物完全动脉闭塞。在 16 例患者中，2 例 MRA 检测到中度至重度吻合口狭窄，在导管血管造影中得到证实，并成功治疗，改善了移植物功能。在 16 例患者中，MRA 显示正常的移植物血管，最终证实了移植物功能障碍的其他原因。
我们的研究表明，铁氧体增强 MRA 可能是一种新颖的、安全的方法，可以在移植超声无诊断的情况下，准确检测肾移植受者的移植物动脉异常，而无肾毒性风险。
