The role of diffusion-weighted imaging in differentiation of hepatic alveolar echinococcosis and intrahepatic cholangiocarcinoma

Abstract

ObjectiveA technique is proposed for evaluating the utility of apparent diffusion coefficient (ADC) measurements in the differentiation of type 4 hepatic alveolar echinococcosis (HAE) from the mass-forming type of intrahepatic cholangiocarcinoma (IHCC), using diffusion-weighted magnetic resonance imaging (DW-MRI). MethodsThis study, conducted from November 2013 to January 2015, was approved by the ethics committee of First Affiliated Hospital of Xinjiang Medical University. All patients were given written informed consent. A total of 11 patients underwent T1WI, T2 fat-saturation, and a respiratory triggered DWI sequence by a 1.5T MR imaging system. An experienced radiologist measured the ADC in both alveolar echinococcosis and cholangiocarcinoma lesions. DWI was performed with a b-value gradient of 0 and 600. The mean ADC values of type 4 hepatic alveolar echinococcosis were compared with those of mass-forming type cholangiocarcinoma, in order to determine variations between the two. Differences in ADC between lesion types were determined by using an independent samples t-test and a statistically significant (P < 0.05) difference was observed. ResultsMean ADC values for IHCC were 1.24 ± 0.23 × 10−3 mm2/s, which was significantly lower than the 1.71 ± 0.23 × 10−3 mm2/s observed for HAE. These results supported the use of this technique as a mechanism for lesion differentiation. ConclusionsLower ADC in DW-MRI represents restricted diffusion. Due to multicellularity being higher in IHCC than HAE, the mean ADC values for IHCC were lower than for HAE.