title: Comparison of intraarterial and IV gadolinium-enhanced MR angiography with digital subtraction angiography for the detection of renal artery stenosis in pigs.
abstract: OBJECTIVE
  Catheter-based intraarterial injections of gadolinium are useful during MR imaging-guided endovascular procedures to generate rapid vascular road maps. Using an animal model of renal artery stenosis, we tested the hypothesis that intraarterial gadolinium-enhanced MR angiography is as accurate as IV gadolinium-enhanced MR angiography and digital subtraction angiography (DSA). We also tested the hypothesis that intraarterial MR angiography uses less gadolinium than IV MR angiography.
  
  
  METHODS
  We induced bilateral renal artery stenosis in five pigs. All pigs underwent comparative imaging with DSA, IV MR angiography, and aortic catheter-directed intraarterial MR angiography. For IV and intraarterial MR angiography, we used the same three-dimensional acquisition. We assessed differences in quantitative stenosis measurements among DSA, IV MR angiography, and intraarterial MR angiography using the Wilcoxon's signed rank test.
  
  
  RESULTS
  Mean stenosis measurements (+/-SD) were as follows: DSA, 58% +/- 12%; IV MR angiography, 63% +/- 9.3%; and intraarterial MR angiography, 64% +/- 11%. There were no statistically significant differences in accuracy between DSA and IV MR angiography (p = 0.06), DSA and intraarterial MR angiography (p = 0.16), or IV and intraarterial MR angiography (p = 0.70). Intraarterial MR angiography used a mean gadolinium dose of 5.6 mL, compared with 9 mL for IV MR angiography.
  
  
  CONCLUSIONS
  In swine, IV and intraarterial MR angiography have a similar accuracy for detecting renal artery stenosis. Intraarterial MR angiography uses smaller doses of injected gadolinium.
authors.affiliation: Department of Radiology, Northwestern University Medical School, 676 N. St. Claire St., Ste. 800, Chicago, IL 60611, USA.
authors.forename: Reed A
authors.initials: RA
authors.lastname: Omary
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Henseler
authors.forename: Orhan
authors.initials: O
authors.lastname: Unal
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Maciolek
authors.forename: J Paul
authors.initials: JP
authors.lastname: Finn
authors.forename: Debiao
authors.initials: D
authors.lastname: Li
authors.forename: Albert A
authors.initials: AA
authors.lastname: Nemcek
authors.forename: Robert L
authors.initials: RL
authors.lastname: Vogelzang
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Grist
mesh_terms: D015901:Angiography, Digital Subtraction; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D019786:Gadolinium DTPA / Q000008:administration & dosage; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007261:Infusions, Intra-Arterial; D007262:Infusions, Intravenous; D007472:Iohexol / Q000008:administration & dosage; D018810:Magnetic Resonance Angiography; D012078:Renal Artery Obstruction / Q000175:diagnosis*; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D007472:Iohexol; C064925:gadodiamide; D019786:Gadolinium DTPA