[Radionuclide determination of renal clearance equivalent to physiological clearance measurements].

The concept of renal clearance in nuclear medicine describes the tubular secretion and glomerular filtration of a substance being removed from the blood plasma. The concept of clearance as used physiologically is rather wider and includes consideration of the outflow of the substances remained back in the kidneys. The present paper discusses clearance measurements as seen from a thermo-dynamic point of view, in which isotope clearances become equivalent with the physiological concept of clearance. In addition, it is possible to quantify each single step of the excretory function of each kidney separately.