Influence on the Radiorenogram of Variations in Renal Clearance, Renal Pelvic Volume and Urinary Flow Rate an Experimental Model Study

Abstract

A model was constructed to study the influence on the [¹³¹I] Hippuran renogram of variations in renal clearance, renal pelvic volume, and urinary flow rate. Renograms were simulated under conditions equivalent to normal and clinically relevantly impaired renal states. From the renograms, time to the peak and to its half-value were shown to be applicable parameters for estimating renal excretion. This is dependent on both renal pelvic volume and urinary flow rate and is expressed by the quotient between the two. The influence of renal clearance on the time-parameters must be considered. Renal excretion can also be estimated by ‘minimum renal transit time’, which was shown to be independent of renal clearance. Statistical analysis with respect to the relations mentioned provided very good fit to linear regressions.

Key Words:

• minimum renal transit time
• radio-isotope renography
• renal clearance
• renal pelvic volume
• renographic time parameters
• urinary flow rate