Renal perfusional cortex volume for arterial input function measured by semiautomatic segmentation technique using MDCT angiographic data with 0.5-mm collimation.

OBJECTIVE. The purpose of this study was to evaluate the usefulness of renal perfusional cortex volume for arterial input function. MATERIALS AND METHODS. This retrospective study included 45 potential kidney donors-33 patients with aortic dissection and 12 patients with renovascular hypertension- who underwent both MDCT angiography with 0.5-mm collimation and renal Tc-99m-diethylenetriamine pentaacetic acid (DTPA) scanning using the modified Gates method. Each perfusional cortex volume for the arterial input function and parenchymal volume was measured by semiautomatic segmentation using the region-growing technique. Linear regression analysis and correlation coefficients were used to assess the impact of the cortical volume, parenchymal volume, and renal scanning glomerular filtration rate (GFR) on estimated GFR (eGFR) using a modified Modification of Diet in Renal Disease (MDRD) equation. RESULTS. The correlation coefficient was higher for the total renal DTPA GFR adjusted for body surface area, weight-adjusted perfusion cortex volume, and adjusted total parenchyma volume in rank (r = 0.712, 0.642, 0.510, respectively, p < 0.0001 for each). The coefficient of the right renal perfusional cortex volume percent with a mean value of 52.1% +/- 10.1% was 0.826 (p < 0.0001) for the right renal DTPA GFR percent with a mean value of 51.0% +/- 12.1% (range, 22.0-89.5%), although the value for the right renal parenchymal volume percent with a mean value of 49.5% +/- 5.5% was 0.764 (p < 0.0001). CONCLUSION. Weight-adjusted perfusional cortex volume for arterial input function can be measured clinically and may replace renal DTPA scanning using the modified Gates method.