title: Comparison of non-breath-hold high resolution gadolinium-enhanced MRA with digital subtraction angiography in the evaluation on allograft renal artery stenosis.
abstract: OBJECTIVE
  The study objective was to compare the diagnostic accuracy of non-breath-hold high resolution gadolinium-enhanced magnetic resonance angiography (Gd-MRA) with intra-arterial digital subtraction angiography (DSA) in the evaluation of allograft renal artery stenosis (ARAS).
  
  
  METHODS
  We studied 17 renal transplant recipients (six men, 11 women, age 34-64 years) with a systolic bruit in the transplant region beyond the early post-operative period. Gadolinium-enhanced magnetic resonance angiography was performed by non-breath-hold high resolution 3D acquisition in the oblique coronal plane using a 256 x 512 matrix.Digital subtraction angiography was performed with AP and oblique views and ARAS was graded as < or =50% or >50% diameter stenosis on the view that displayed the maximal narrowing.
  
  
  RESULTS
  Digital subtraction angiography showed >50% stenosis in seven patients, all of whom were diagnosed correctly on Gd-MRA. Gadolinium-enhanced magnetic resonance angiography diagnosed two patients with >50% stenosis which were not confirmed on DSA. Eight patients had no or < or =50% stenosis on both Gd-MRA and DSA. The sensitivity and specificity of Gd-MRA in revealing >50% stenosis were 100% and 75%, respectively, using DSA as the gold standard.
  
  
  CONCLUSIONS
  High resolution Gd-MRA employing a non-breath-hold technique is highly sensitive in the diagnosis of ARAS greater than 50%. It is preferred as a non-invasive screening technique to DSA in suspected ARAS.
authors.affiliation: Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, Shatin, NT, Hong Kong. y1190chan@cuhk.edu.hk
authors.forename: Y L
authors.initials: YL
authors.lastname: Chan
authors.forename: C B
authors.initials: CB
authors.lastname: Leung
authors.forename: S C
authors.initials: SC
authors.lastname: Yu
authors.forename: D K
authors.initials: DK
authors.lastname: Yeung
authors.forename: P K
authors.initials: PK
authors.lastname: Li
mesh_terms: D000328:Adult; D015901:Angiography, Digital Subtraction; D003287:Contrast Media; D005260:Female; D005500:Follow-Up Studies; D019786:Gadolinium DTPA; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D016030:Kidney Transplantation; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D012078:Renal Artery Obstruction / Q000175:diagnosis* / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA