title: Persistent renal enhancement after intra-arterial versus intravenous iodixanol administration.
abstract: OBJECTIVE
  To examine the clinical significance of persistent renal enhancement after iodixanol administration.
  
  
  METHODS
  We retrospectively studied 166 consecutive patients who underwent non-enhanced abdominopelvic CT within 7 days after receiving intra-arterial (n=99) or intravenous (n=67) iodixanol. Renal attenuation was measured for each non-enhanced CT scan. Persistent renal enhancement was defined as CT attenuation>55 Hounsfield units (HU). Contrast-induced nephropathy (CIN) was defined as a rise in serum creatinine>0.5 mg/dL within 5 days after contrast administration.
  
  
  RESULTS
  While the intensity and frequency of persistent renal enhancement was higher after intra-arterial (mean CT attenuation of 73.7 HU, seen in 54 of 99 patients, or 55%) than intravenous contrast material administration (51.8 HU, seen in 21 of 67, or 31%, p<0.005), a multivariate regression model showed that the independent predictors of persistent renal enhancement were a shorter time interval until the subsequent non-enhanced CT (p<0.001); higher contrast dose (p<0.001); higher baseline serum creatinine (p<0.01); and older age (p<0.05). The route of contrast administration was not a predictor of persistent renal enhancement in this model. Contrast-induced nephropathy was noted in 9 patients who received intra-arterial (9%) versus 3 who received intravenous iodixanol (4%), and was more common in patients with persistent renal enhancement (p<0.01).
  
  
  CONCLUSIONS
  Persistent renal enhancement at follow-up non-contrast CT suggests a greater risk for contrast-induced nephropathy, but the increased frequency of striking renal enhancement in patients who received intra-arterial rather than intravenous contrast material also reflects the larger doses of contrast and shorter time to subsequent follow-up CT scanning for such patients.
authors.affiliation: Department of Radiology, University of California San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143-0628, United States.
authors.forename: Shinn-Huey
authors.initials: SH
authors.lastname: Chou
authors.forename: Zhen J
authors.initials: ZJ
authors.lastname: Wang
authors.forename: Jonathan
authors.initials: J
authors.lastname: Kuo
authors.forename: Miguel
authors.initials: M
authors.lastname: Cabarrus
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Fu
authors.forename: Rizwan
authors.initials: R
authors.lastname: Aslam
authors.forename: Judy
authors.initials: J
authors.lastname: Yee
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Zimmet
authors.forename: Kendrick
authors.initials: K
authors.lastname: Shunk
authors.forename: Brett
authors.initials: B
authors.lastname: Elicker
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Yeh
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000008:administration & dosage*; D003404:Creatinine / Q000097:blood; D005260:Female; D006801:Humans; D007269:Injections, Intra-Arterial; D007275:Injections, Intravenous; D007668:Kidney / Q000000981:diagnostic imaging*; D007674:Kidney Diseases / Q000139:chemically induced* / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014283:Triiodobenzoic Acids / Q000008:administration & dosage*
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; D003404:Creatinine; C044834:iodixanol