title: Assessment of renal vasoconstriction in vivo after intra-arterial administration of the isosmotic contrast medium iodixanol compared to the low-osmotic contrast medium iopamidol.
abstract: BACKGROUND
  Low-osmotic contrast media (LOCM) such as iopamidol are known to increase the renal resistance index (RRI). The aim of our study was to evaluate in vivo the different effects of intra-arterial administration of LOCM in comparison to isosmotic contrast medium (IOCM) such as iodixanol on the human RRI.
  
  
  METHODS
  Twenty patients (16 males, 4 females; 66 years on average) with normal renal function (mean creatinine 1.0 mg/dl) had digital subtraction angiography (DSA) of the abdominal and lower-limb arteries. Ten patients received LOCM, and 10 patients IOCM (150 ml on average, 20 ml/s). The RRI was assessed by an experienced nephrologist with duplex ultrasound from 15 min before until 30 min after the first injection with delays of 1-5 min. The basic value of the RRI and differential RRI were calculated.
  
  
  RESULTS
  The basic value of the RRI was 0.69 in the LOCM group and 0.71 in the IOCM group. After LOCM a significant increase of the RRI to 0.73 on average (P < or = 0.001) 2 min after the first injection was found, whereas IOCM did not result in a significant change of the RRI (RRI remained 0.71 on average, P > or = 0.1). In the LOCM group, the RRI returned to the basic value after 30 min (+/-2.3 min).
  
  
  CONCLUSIONS
  Intra-arterial administration of IOCM had no influence on renal vascular resistance as expressed by the RRI, unlike LOCM, which induced a highly significant increase of the RRI for up to 30 min.
authors.affiliation: Department for Clinical Radiology, Clinical Center of the Ludwig-Maximilians-University of Munich, Pettenkoferstr. 8a, 80336 Munich, Germany. marcus.treitl@med.uni-muenchen.de
authors.forename: Marcus
authors.initials: M
authors.lastname: Treitl
authors.forename: Harald
authors.initials: H
authors.lastname: Rupprecht
authors.forename: Stefan
authors.initials: S
authors.lastname: Wirth
authors.forename: Markus
authors.initials: M
authors.lastname: Korner
authors.forename: Maximilian
authors.initials: M
authors.lastname: Reiser
authors.forename: Johannes
authors.initials: J
authors.lastname: Rieger
mesh_terms: D000368:Aged; D015901:Angiography, Digital Subtraction; D003287:Contrast Media / Q000494:pharmacology*; D003404:Creatinine / Q000097:blood; D005260:Female; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007479:Iopamidol / Q000493:pharmacokinetics / Q000494:pharmacology*; D007668:Kidney / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D009995:Osmosis; D011446:Prospective Studies; D012039:Regional Blood Flow / Q000502:physiology*; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000502:physiology; D012189:Retrospective Studies; D014283:Triiodobenzoic Acids / Q000493:pharmacokinetics / Q000494:pharmacology*; D018616:Ultrasonography, Doppler, Duplex; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology; D014661:Vasoconstriction / Q000187:drug effects* / Q000502:physiology*
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; D003404:Creatinine; C044834:iodixanol; D007479:Iopamidol