Assessment of renal hemodynamics and function in pigs with 64-section multidetector CT: Comparison with electron-beam CT

Purpose: To prospectively evaluate the feasibility of obtaining reliable measurements of renal hemodynamics and function by using 64-section multidetector CT. Materials and Methods: This study was approved by the Institutional Animal Care and Use Committee. Eight pigs ( two with induced unilateral renal artery stenosis) were studied with both electron-beam CT and 64-section multidetector CT at 1-week intervals in randomized order. Both kidneys were scanned repeatedly, without table movement, for about 3 minutes after intravenous ( IV) administration of a bolus of contrast medium and again during vasodilator challenge ( acetylcholine). Images were reconstructed on each CT console but were analyzed on the same independent workstation. Attenuation changes in the kidneys were plotted as function of time, and time-attenuation curves ( TACs) were subsequently analyzed to determine regional perfusion and volume, glomerular filtration rate ( GFR), and renal blood flow ( RBF). Statistical analysis utilized Student t test, analysis of variance ( ANOVA), linear regression, and Bland-Altman analysis. Results: TACs obtained with multidetector CT were qualitatively similar to those obtained with electron-beam CT, as were the quantitative values of renal perfusion and function. RBF correlated significantly between the two techniques ( RBFMD = 0.96 (.) RBFEB mL/min; R = 0.77, P <.01). GFR(MD) was also similar to GFR(EB) ( 77.6 +/- 8.3 vs 79.8 +/- 8.8 mL/min, p >.05). Bland-Altman plots showed good agreement between the two techniques. Both techniques similarly detected the differences between stenotic and contralateral kidneys. Conclusion: The clinical multidetector CT scanner provides reliable measurements of single-kidney hemodynamics and function, which are similar to those obtained with previously validated electron-beam CT. (c) RSNA, 2007.