Estimation of relative bilateral renal function of potential voluntary kidney donors using various computerized tomography methods

OBJECTIVE: To investigate four computed tomographic (CT) based methods of split renal function and to compare results Tc 99 DTPA scintigraphy. 1. Semi-automated volume method, 2. Attenuation capacity method, 3. Modified ellipsoid method, 4. Parenchymal area method. METHODS: Sixty two potential renal donors with both CT and nuclear renography were prospectively evaluated for estimated split function using 4 CT methods to determine accuracy. For the CT methods, correlation, ease in image post-processing, and the ability of CT-derived methods to determine the dominant kidney before renal transplantation were evaluated using a nuclear renography reference standard. RESULTS: Three of the 4 CT methods (split renal volume, modified ellipsoid method and attenuation capacity) showed similar strong Pearson’s correlation (r = 0.74 to 0.79). Bland-Altman analysis revealed similar performance in differences (SDs G3.0%) between these CT measures and reference standard. The parenchymal area method showed the least correlation (r= 0.54). Each CT-based method showed excellent agreement ( 98.4%) with renography regarding the determination of dominant kidney. CONCLUSION: Excellent correlation with nuclear split renal function supports the use of CT alone for the imaging assessment for many potential renal donors, including the decision of which kidney to harvest. Among the CT-based methods, the modified ellipsoid method can be performed rapidly with high accuracy and reproducibility