Measuring Split Renal Function in Renal Donors: Can Computed Tomography Replace Renography?

Purpose: To develop and evaluate a method of calculating split renal function from computed tomography (CT) images based on the assumption that the accumulation of contrast medium is proportional to the renal function, and to compare the results with the renogram. Material and Methods: The study comprised a retrospective analysis of CT images and renograms from previous donors. Twenty-seven potential renal donors were studied using a technique for measuring the area and mean attenuation of the separate CT slices, and for calculating the volume and total attenuation of the whole kidney. Results: Correlation between CT and renography was moderate (r=0.43), but the range of results was narrow. The ratio between the two kidneys was more even with CT (50±2.1%) than with the renogram (48±2.9%) (right kidney), and the mean difference between the two methods was 3±2.3 percentage points. Conclusion: The renogram can be replaced using calculations from the CT examination in estimating split renal function in potential renal donors