Correlation Between Dual-energy and Perfusion CT in Patients with Focal Liver Lesions Using Third-generation...

Objective To compare measurements of dual-energy CT iodine map parameters and liver perfusion CT parameters in patients with focal liver lesions using a third-generation dual-source CT scanner. Methods Between November 2015 and August 2016,33 patients with non-cystic focal lesions of liver were enrolled in this study. CT examinations were performed with a third-generation dual-source CT. The study CT protocol included a perfusion CT and dual-energy arterial and portal venous scans,with a time interval of 15 minutes. Iodine attenuation was measured at five region of interests including areas of high,medium,and low density within the lesion,as well as right and left liver parenchyma from the iodine map,while arterial liver perfusion (ALP),portal venous liver perfusion (PVP),and hepatic perfusion index (HPI) at the same location were measured from perfusion CT. The Pearson product-moment correlation coefficient was used to evaluate the relationship between iodine attenuation and perfusion parameters. Results The iodine attenuation at arterial phase showed significant intra-individual correlation with ALP (r=0.812,95% CI=0.728-0.885,P<0.001)and PVP (r=-0.209,95% CI=-0.323--0.073,P=0.007),but not significantly correlated with HPI (r=0.058,95% CI=0.046-0.498,P=0.461). The iodine attenuation at portal venous phase showed significant correlation with PVP (r=0.214,95% CI=0.072-0.361,P=0.005) but not with HPI(r=0.036,95% CI=-0.002-0.242,P=0.649). The mean effective dose of arterial phase and portal venous phase of dual-energy CT together [(3.53±1.17)mSv] was significantly lower than that of the perfusion CT [(14.53±0.45)mSv](t=25.212,P<0.001). Conclusion Iodine attenuation from arterial phase of dual energy CT demonstrates significant correlation with ALP and PVP,and iodine attenuation from portal venous phase demonstrates significant correlation with PVP.