Glomerular filtration rate estimated from a single plasma sample after contrast-enhanced radiological examinations

In twenty-six patients examined with radiographic procedures, including a single injection of meglumine metrizoate, blood samples were drawn 180, 200, 220 and 240 min after injection. Plasma was analysed for iodine concentration with X-ray fluorescence analysis and the total plasma clearance of metrizoate was calculated with the single sample method from each sample. The results were compared with the total plasma clearance of ⁵¹Cr-EDTA, calculated from multiple samples and determined no more than a few days apart from the X-ray examination. A good correlation, ranging from 0.91 and 0.94, was found. We therefore conclude that kidney function can be estimated from a single plasma sample after contrast-enhanced radiological examinations.