Estimation of renal function using kidney dynamic contrast material-enhanced CT perfusion: accuracy and feasibility.

Abstract

To measure glomerular filtration rates (GFRs) using kidney dynamic contrast material-enhanced (DCE)-CT perfusion scans and correlate them with estimated GFRs (eGFRs). Split-bolus CT urography, including pre-contrast and nephrographic-excretory phase imaging, was performed with a kidney DCE-CT perfusion scan protocol. We analysed 55 patients with suspected renal disease. All CT acquisitions were obtained on a 256-slice CT scanner for 3.5 min continuously with shallow breathing. Renal volume, perfusion and permeability values were calculated using a dedicated prototype software. Based on Patlak plots, split and total renal GFR values were determined. Paired t-tests, Pearson's correlation analysis and Bland-Altman plots were used for comparisons between kidney DCE-CT perfusion scan-derived GFR (CT-GFR) and the corresponding eGFR value. The p values < 0.05 were considered statistically significant. The mean CT-GFR was 91.19 ± 20.71 mL/min/1.73 m2. The eGFR values based on the CKD-EPI and MDRD equations were 89.64 ± 19.74 mL/min/1.73 m2 and 89.50 ± 24.89 mL/min/1.73 m2, respectively. No statistically significant differences were found between CT-GFR and eGFRs (p > 0.05). Excellent correlation and agreement between CT-GFR and eGFRs (correlation coefficient r = 0.91 for CKD-EPI and 0.84 for MDRD equations, respectively) were confirmed. Kidney DCE-CT perfusion is an accurate and feasible technique to assess renal function.