Quantitative assessment of tissue perfusion using MDCT: Comparison of colorectal cancer and skeletal muscle measurement reproducibility

OBJECTIVE. The purposes of this study were to determine the reproducibility of quantitative colorectal cancer perfusion measurements using dynamic contrast-enhanced MDCT, and to compare this with measurements from skeletal muscle. SUBJECTS AND METHODS. Ten patients (mean age, 67 years; six men, four women) with histologically proven colorectal cancer were examined prospectively using 4-MDCT. Perfusion studies (cine mode; 4 x 5 turn collimation; 1 acquisition/s; 65 seconds total) were performed through the tumor epicenter after IV bolus contrast administration (iopamidol 340, 100 mL; 5 mL/s) and repeated within 48 hours. Quantitative values for blood volume, blood flow, mean transit time, and permeability were determined using commercial software. Two regions of interest were studied on the axial image: one within the tumor and another within the left gluteal muscle. Measurement reproducibility was assessed using Bland-Altman statistics. RESULTS. For the tumor, the mean difference (95% limits of agreement) was -0.04 mL/100 g tissue (-2.50, 2.42); 8.80 (-50.5, 68.0) mL/100 g tissue/min; -0.99 (-8.19, 6.20) seconds; and 1.20 (-5.42, 7.83) mL/100 g tissue/min for blood volume, blood flow, mean transit time, and permeability, respectively. For muscle, the mean difference (95% limits of agreement) was 0.02 (-1.40, 1.43), 6.60 (-11.2, 24.3), -3.76 (-16.87, 9.35), and 1.30 (-4.68, 7.28), respectively. CONCLUSION. Quantitative perfusion measurements are reproducible. Measurements from tumor are less variable than from skeletal muscle.