Comparison of Renal Scintigraphy and Computed Tomographic Renal Volumetry for Determining Split Renal Function and Estimating Post-Transplant Renal Function

Background. In living donor kidney transplantation, the decision regarding which donor kidney to transplant is based on characteristics such as vascular anatomy and split renal function (SRF). Computed tomography (CT) was used to assess vascular anatomy and renal scintigraphy was used to evaluate SRF. The ability of split renal volume (SRV) calculated from volumetric examination of CT scans and that of SRF of renal scintigrams derived from Tc-99m mercaptoacetyltriglycine-3 (MAG3) renography to predict donor residual single kidney function after donor nephrectomy were compared. Material and Methods. CT images and renal scintigrams from 35 live kidney donors who had at least 1 year post-donation renal function follow-up were analyzed. Results. Predonation GFR was 99.1 +/- 17.2 mL/min/1.73 m(2). The average right and left kidney volumes were 138.8 +/- 29.4 mL and 136.1 +/- 29.2 mL, respectively. SRV was strongly and significantly correlated with SRF-MAG3 (r = 0.714). The residual renal functions predicted from calculating SRV and SRF-MAG3 were 46.2 +/- 8.3 mL/min/1.73 m(2) and 46.0 +/- 9.2 mL/min/1.73 m(2), respectively. Both SRV (r = 0.708) and SRF-MAG3 (r = 0.634) showed significant linear correlations with residual renal function after 1 year, with SRV showing a stronger correlation. Conclusion. Calculating SRV from predonation CT examination is a valid method to estimate postdonation renal function after 1 year. CT volumetry may become a standard method in the near future.