99mTc-DTPA--a useful clinical tool for the measurement of glomerular filtration rate.

The single injection 99mTc-DTPA clearance was compared with the inulin clearance performed with the constant infusion technique in 22 subjects. There was a good correlation between these two methods (r = 0.968, p less than 0.001). Although the single injection technique calculated by one compartment model is not accurate enough for research purposes, it seems to work well in routine clinical practice for the measurement of glomerular filtration rate using 99mTc-DTPA as a tracer substance. The performance is simple, it needs only a few blood samples, nor does it need any urine collection, the radiation dose is low and it seems to be more accurate than the endogenous creatinine clearance.