DYNAMIC CONTRAST BOLUS COMPUTED-TOMOGRAPHY FOR THE ASSESSMENT OF RENAL-FUNCTION

RATIONALE AND OBJECTIVES. We preliminarily investigated whether dynamic contrast bolus computed tomography (CT) could be used to measure glomerular filtration rate. METHOD. After bolus intravenous contrast injection, rapid sequence CT scans were performed at a fixed level through the kidneys and aorta in three patients with biochemically normal renal function who underwent routine CT examination. A mathematical technique developed initially for positron-emission tomography was adapted for analysis of the CT data for measurement of renal contrast clearance per unit renal volume and of the fraction of renal tissue occupied by blood volume. RESULTS. Renal blood volumes in the 3 patients were 0.28, 0.29, and 0.31 of total renal volume, respectively, and the corresponding contrast clearances were 0.44, 0.41, and 0.35 mL per min per mL of renal tissue. CONCLUSIONS. This preliminary study in normal patients demonstrates that dynamic contrast CT might be developed for clinical physiological renal studies. Further work to validate the accuracy and reliability of the method in comparison with established isotope methods is suggested.