SIMULTANEOUS UROGRAPHY AND DETERMINATION OF GLOMERULAR-FILTRATION RATE - A COMPARISON OF TOTAL PLASMA CLEARANCES OF IOHEXOL AND CR-51-EDTA IN PLEGIC PATIENTS

The total plasma clearance of iohexol at urography and Cr-51-EDTA was compared in 31 patients with di- or tetraparesis. A reference Cr-51-ED TA clearance was also performed 24 hours prior to the urography. The G FR was calculated from one, 2 or 4 plasma samples collected 180, 210, 240 and 270 min after the injection. An X-ray fluorescence analyzer wa s used for the analysis of iohexol in plasma as well as the contrast m edium clearance calculations. It was shown that single or multiple sam ple clearance of iohexol and Cr-51-EDTA were equivalent methods for me asurement of the GFR. The GFR was not affected by iohexol in a dose ro utinely used for urography. It was concluded that the patient comfort is improved if Cr-51-EDTA clearance is replaced by contrast medium cle arance in association with urography.