title: Intrahepatic mass-forming cholangiocarcinoma and solitary hypovascular liver metastases: is the differential diagnosis using diffusion-weighted MRI possible?
abstract: Background Intrahepatic mass-forming cholangiocellular carcinoma (IMC) is the second most common primary liver tumor. The differentiation between IMC and solitary hypovascular liver metastases (SHLM) represents a diagnostic challenge due to many overlapping magnetic resonance imaging (MRI) features. Purpose To determine the value of diffusion-weighted imaging (DWI) in addition to conventional MRI for the distinction between intrahepatic mass-forming cholangiocarcinoma and solitary hypovascular liver metastases. Material and Methods Fifty-three patients with pathologically proven IMC (n = 31) and SHLM (n = 22) who had undergone MRI and DWI before surgery or percutaneous biopsy were enrolled in this study. The following MRI features were analyzed: the size and shape of the lesion, presence of capsular retraction and segmental biliary dilatation, T2-weighted (T2W) signal intensity, the presence of target sign on DWI and enhancement pattern. Apparent diffusion coefficient (ADC) values were calculated for each lesion ( b = 800 s/mm2). Univariate and multivariate logistic regression analyses were used to identify significant differentiating features between IMCs and SHLMs. Results Univariate analysis revealed that following parameters favor diagnosis of IMCs over SHLMs: lobulating shape, heterogeneous T2W signal intensity, capsular retraction, segmental biliary dilatation, target sign on DWI and rim-like enhancement on arterial phase followed by progressive enhancement in delayed phases. ADC values measured in the periphery of the lesion were significantly lower in IMCs in comparison to SHLMs. Multivariate analysis revealed that target sign on DWI was the most significant predictor of IMCs. Conclusion Qualitative DWI analysis with target sign significantly improves diagnostic accuracy for differentiation among IMC and SHLM lesions.
authors.affiliation: 1 Center for Radiology and Magnetic Resonance Imaging, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Jelena Djokić
authors.initials: JD
authors.lastname: Kovač
authors.affiliation: 2 First Surgical Clinic, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Danijel
authors.initials: D
authors.lastname: Galun
authors.affiliation: 1 Center for Radiology and Magnetic Resonance Imaging, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Đurić-Stefanović
authors.affiliation: 1 Center for Radiology and Magnetic Resonance Imaging, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Gordana
authors.initials: G
authors.lastname: Lilić
authors.affiliation: 1 Center for Radiology and Magnetic Resonance Imaging, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Dragan
authors.initials: D
authors.lastname: Vasin
authors.affiliation: 1 Center for Radiology and Magnetic Resonance Imaging, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Ljubica
authors.initials: L
authors.lastname: Lazić
authors.affiliation: 1 Center for Radiology and Magnetic Resonance Imaging, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Dragan
authors.initials: D
authors.lastname: Mašulović
authors.affiliation: 1 Center for Radiology and Magnetic Resonance Imaging, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Đorđije
authors.initials: Đ
authors.lastname: Šaranović
mesh_terms: D001650:Bile Duct Neoplasms / Q000000981:diagnostic imaging*; D018281:Cholangiocarcinoma / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies
keywords: Intrahepatic mass-forming cholangiocarcinoma; diffusion weighted imaging; magnetic resonance imaging (MRI); solitary hypovascular liver lesions