title: Renal transplant imaging using magnetic resonance angiography with a nonnephrotoxic contrast agent.
abstract: 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.
authors.affiliation: Department of Radiology, Duke University Medical Center, Durham, NC, USA mustafa.bashir@duke.edu
authors.forename: Mustafa R
authors.initials: MR
authors.lastname: Bashir
authors.forename: Tracy A
authors.initials: TA
authors.lastname: Jaffe
authors.forename: Todd V
authors.initials: TV
authors.lastname: Brennan
authors.forename: Uptal D
authors.initials: UD
authors.lastname: Patel
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Ellis
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D052203:Ferrosoferric Oxide / Q000008:administration & dosage; D005500:Follow-Up Studies; D006801:Humans; D007275:Injections, Intravenous; D007668:Kidney / Q000098:blood supply* / Q000473:pathology; D016030:Kidney Transplantation; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000473:pathology; D055031:Primary Graft Dysfunction / Q000473:pathology*; D012189:Retrospective Studies; D014654:Vascular Patency
chemical_list: D003287:Contrast Media; D052203:Ferrosoferric Oxide