Iohexol clearance for the determination of glomerular filtration rate in clinical practice: evidence for a new gold standard

J Urol. 1991 Sep;146(3):675-9. doi: 10.1016/s0022-5347(17)37891-6.


X-ray fluorescence analysis provides a simple method of measuring glomerular filtration rate from the clearance of ordinary unlabeled radiographic contrast media. To measure the accuracy of iohexol clearance using a clinically simple 2-sample single injection technique, a comparison was made in 30 patients with classical continuous infusion techniques for plasma (y = 1.03x - 0.015, r = 0.981) and renal (y = 0.950x + 7.26, r = 0.964) iohexol clearance. A comparison was made with classical inulin clearance. The renal clearance of iohexol and inulin was virtually identical (y = 0.998x + 2.31, r = 0.986). Single injection iohexol clearance agreed closely with the renal inulin clearance (y = 0.947x + 4.92, r = 0.983) as did clearance based on a single 3-hour sample (y = 0.875x + 12.63, r = 0.962). Iohexol clearance using x-ray fluorescence is a simple, rapid and accurate alternative to inulin clearance for clinical and research purposes.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Glomerular Filtration Rate*
  • Humans
  • Inulin
  • Iohexol* / pharmacokinetics
  • Male
  • Middle Aged
  • Spectrometry, X-Ray Emission


  • Iohexol
  • Inulin