[Quantification of renal function with 99mTc-MAG3--quantification of tubular extraction rate using Bubeck's method].

99mTc-mercaptoacetyltriglycine (MAG3) is a new agent for dynamic renal scintigraphy. It provides not only superior quality of imaging to conventional agents such as 131I-orthoiodohippurate or 99mTc-demethylenetriaminepantaacetic acid but also quantification of renal function as do the latter agents. The aim of the present study was to evaluate the value of the tubular extraction rate (TER) using 99mTc-MAG3 calculated by Bubeck's method, a simple technique for quantifying renal function. In 31 patients with renal disorders, we compared the TER thus obtained with laboratory data, plasma paraaminohippurate clearance, effective renal plasma flow calculated by Tauxe's method, and plasma 99mTc-MAG3 clearance calculated according to the two-compartment model. TER was easily applicable in clinical settings, and showed close parallels with the other indexes of renal function. We believe, therefore, that it can serve as a useful parameter of renal function.