Abstract
A combined in vitro-in vivo renal function procedure has proved to be an important clinical tool in the nuclear medicine laboratory. This noninvasive test is relatively simple from the patient’s standpoint. For the technologist, however, it involves scintigraphic imaging as well as a complex series of calculations including effective renal plasma flow, excretion rates, bladder retention, etc., all derived from a single injection of 131I-orthoiodohippurate.