Use of arterial to equilibrium enhancement washout to predict viability in liver cancers treated with transcatheter arterial chemoembolization

Abstract

Liver cancers are very common in Korea and Computed Tomography (CT) imaging is commonly used to diagnose them. This study improves the diagnosis of liver cancer by using a novel parametric image combining various phases of dynamic CT imaging. The objective of this study is to investigate the diagnostic value of arterial to equilibrium enhancement washout (AEEW) obtained by image registration and dynamic subtraction in predicting tumor viability in a hepatocellular carcinoma (HCC) treated with transcatheter arterial chemoembolization (TACE). Forty patients who had forty-seven iodized-oil defect areas (IODAs) in HCCs treated with TACE were included. These patients were divided into two groups, one group with viable tumors (n = 27) and the other group with non-viable tumors (n = 20) in the IODAs. All the patients underwent triple-phase CT before and after TACE. The attenuation differences of the IODAs between the arterial and the equilibrium phases were measured and compared between two groups. Quantitative AEEW color maps of the whole liver were created from the triple-phase CT image by using prototype research software. Two radiologists independently analyzed following two sets of image: one with standard tri-phase CT images and the other with tri-phase CT images and quantitative AEEW color map images. The diagnostic performances in terms of mean sensitivity, specificity, and accuracy for identifying viable or non-viable tumors by using quantitative AEEW color map images in addition to tri-phase CT was larger than the performance obtained using tri-phase CT only. In conclusion, quantitative AEEW color map images improve the diagnostic performances of multiphasic CT for determining the viability of the IODA in a HCC treated with TACE.