The direct measurement of glomerular filtration rate from the continuous monitoring of DTPA clearance

Abstract

A method of measuring glomerular filtration rate is proposed, intended for use during gamma camera renography and involving the continuous monitoring of DTPA activity in blood, a single blood sample, and a urine collection. Data obtained from experiments using a CsI scintillation detector are presented and used to demonstrate the validity of the method. In a comparison with a direct measurement of renal clearance of DTPA the proposed method showed an average overestimate of 13% compared to an overestimate of 30% for an uncorrected single-compartment model calculation of filtration rate. Some limited data using a gamma camera to monitor the DTPA activity in blood are also presented.