Volume matters: CT-based renal cortex volume measurement in the evaluation of living kidney donors

Abstract

SummaryCurrently, no international standard for the pre-transplant evaluation of living donor renal function exists. Following a standardized questionnaire on current practice in all Eurotransplant (ET) centers, we compared a new CT-based technique to measure renal cortex volume with our standard of DTPA-clearance combined with MAG3-scintigraphy (DTPA 9 MAG3) and with creatinine-based methods in 167 consecutive living kidney donors. Most ET centers use creatinineclearance (64%) to measure total renal function and radioistopic methods (82%) to assess split renal function. Before transplantation, CT-measured total cortex volume (r = 0.67; P < 0.001) and estimated GFR using the Cockcroft-Gault formula [eGFR(CG)] (r = 0.55; P < 0.001) showed the strongest correlation with DTPA-clearance. In contrast, the correlation between DTPA-clearance and creatinine clearance was weak (r = 0.21; P = 0.02). A strong correlation was observed between CT-measured split cortex volume and MAG3-measured split renal function (r = 0.93; P < 0.001). A strong correlation was also found between pretransplant split renal function assessed by eGFR(CG) together with cortex volume measurement and post-transplant eGFR(CG) of both, the donor (r = 0.83; P < 0.001) and the recipient (r = 0.75; P < 0.001). In conclusion CT-based assessment of renal cortex volume bears the potential to substitute existing methods to assess pre-transplant living donor split renal function.

Live Donor Renal Anatomic Asymmetry and Posttransplant Renal Function

“…16,25–27 Halleck et al reported a strong correlation (r=0.93, p-value<0.001) between MAG3-based radioisotopic split function estimates and CT-based split renal volume measurements in their center specific cohort of 144 consecutive living donors. 24 They also reported that moderate correlation existed between percentage of both split function estimates (MAG3-based split function: r=0.45, p<0.001; CT-measured split cortex volume: r=0.43, p-value<0.001) and the post-transplant eGFR (calculated by using Cockcroft-Gault equation) in the recipient. In our study, we showed that volume and split function ratios between two donor kidneys (r=0.79, p-value<0.001) were strongly correlated.…”

“…23 Halleck et al conducted a survey among all Eurotransplant centers (7 countries and 61 centers) in 2012. 24 They found that majority of the centers use creatinine clearance (64%) in estimating GFR and radioisotopic techniques (82%) in assessing SFD. All German transplant centers (39) measured split function with radioisotopic methods, whereas all Dutch centers (7) utilized CT-based volumetric methods.…”

Does size matter? Kidney transplant donor size determines kidney function among living donors

“…Others have reported a pre-operative measure of GFR <82 mL/min/1.72 m 2 as a predictor of donor CKD [33], and rate of renal recovery among transplant donors has been mostly explored generally [22, 23, 28, 37] but not according to kidney size. Although preserved kidney volume has been identified as a predictor of donor eGFR 6 months [36] and 1 year after donation [38] by multivariate logistic regression analysis, no study to our knowledge has examined how kidney size determines rate of renal recovery and the risk of non-recovery to an eGFR ≥60 mL/min/1.73 m 2 post-nephrectomy.…”

CT volumetry is superior to nuclear renography for prediction of residual kidney function in living donors

“…Other studies have calculated split kidney function using algorithms that quantify and compare kidney enhancement as a function of time after intravenous contrast injection . CT‐based studies have shown a high level of concordance with nuclear renography for determining split kidney function and suggest the feasibility of performing a comprehensive evaluation of live donor candidates using solely CT …”