Background: 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.
Methods: 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.
Results: 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.
Conclusions: 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.
1 Department of Radiology, Duke University Medical Center, Durham, NC.
2 Department of Surgery, Duke University Medical Center, Durham, NC.
3 Department of Pediatrics, Duke University Medical Center, Durham, NC.
4 Department of Medicine, Duke University Medical Center, Durham, NC.
5 Address correspondence to: Mustafa R. Bashir, M.D., Department of Radiology, Duke University Medical Center, 3808 Durham, NC.
The authors declare no funding or conflicts of interest.
M. R. B. and M. J. E. participated in making the research design, performing the research, analyzing the data, and writing the paper. T. A. J. participated in performing the research, analyzing the data, and writing the paper. T. V. B. and U. D. P. participated in analyzing the data and writing the paper.
Received 7 March 2013. Revision requested 19 March 2013.
Accepted 2 April 2013.