THE RENOGRAM AND ITS QUANTITATION

SUMMARY The interpretation of the renogram is not straightforward. This is due to the complexity of the kidney and not to any complexity in the technique of renography. The commonly used empirical method of interpretation is discussed. The technique of Computer Assisted Blood Background Subtraction (C.A.B.B.S.) renography is described and a theory of the renogram is presented which leads to a rigorous method of quantitation. The ratio between the efficiencies with which the kidneys take up Hippuran can be obtained. This is equivalent to the ratio of the effective renal plasma flows. It is hoped to quantitate aspects of the mechanism of transport of Hippuran through the kidney in order to assess renal autoregulation and other aspects of nephron function.