Measurement of glomerular filtration rate with a portable cadmium telluride detector.

The plasma clearance rate constant of 99Tcm-DTPA was measured with a portable cadmium telluride detector over anterior chest wall and lateral leg sites to obtain an empirical estimate of glomerular filtration rate (GFR). Thirteen patients with a range of renal dysfunction were studied to compare the accuracy of the estimates over various time periods compared to GFR estimated from plasma sampling. The chest site was more accurate for GFR assessment over all time periods assessed up to 4 h following injection. The clearance rate constants obtained up to 1 h after injection from the chest site were not significantly less accurate then those from later time periods.