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.