Contrast-Enhanced Imaging in the Management of Intrahepatic Cholangiocarcinoma: State of Art and Future Perspectives

Abstract

Intrahepatic cholangiocarcinoma (iCCA) represents the second most common liver cancer after hepatocellular carcinoma, accounting for 15% of primary liver neoplasms. Its incidence and mortality rate have been rising during the last years, and total new cases are expected to increase up to 10-fold during the next two or three decades. Considering iCCA's poor prognosis and rapid spread, early diagnosis is still a crucial issue and can be very challenging due to the heterogeneity of tumor presentation at imaging exams and the need to assess a correct differential diagnosis with other liver lesions. Abdominal contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) plays an irreplaceable role in the evaluation of liver masses. iCCA's most typical imaging patterns are well-described, but atypical features are not uncommon at both CT and MRI; on the other hand, contrast-enhanced ultrasound (CEUS) has shown a great diagnostic value, with the interesting advantage of lower costs and no renal toxicity, but there is still no agreement regarding the most accurate contrastographic patterns for iCCA detection. Besides diagnostic accuracy, all these imaging techniques play a pivotal role in the choice of the therapeutic approach and eligibility for surgery, and there is an increasing interest in the specific imaging features which can predict tumor behavior or histologic subtypes. Further prognostic information may also be provided by the extraction of quantitative data through radiomic analysis, creating prognostic multi-parametric models, including clinical and serological parameters. In this review, we aim to summarize the role of contrast-enhanced imaging in the diagnosis and management of iCCA, from the actual issues in the differential diagnosis of liver masses to the newest prognostic implications.

Keywords: contrast-enhanced computed tomography; contrast-enhanced ultrasound; intrahepatic cholangiocarcinoma; magnetic resonance imaging.

Figure 1

(A,B) Computed tomography imaging of intrahepatic cholangiocarcinoma (12 cm × 11 cm) of the right liver lobe: dishomogeneous enhancement in the arterial phase with hypodense areas of intralesional necrosis. (C) Dilatation of the peripheral intrahepatic biliary ducts.

Figure 2

(A,B) Computed tomography imaging of an intrahepatic cholangiocarcinoma of approximately 8 cm in the left hepatic lobe, with capsular retraction, central hypodensity, and inhomogeneous enhancement due to necrotic-colliquative phenomena. Peripheral rim enhancement in the arterial phase (A) with progressive contrast filling in the subsequent phases (B). (C) Locoregional lymph nodes (white arrow).

Figure 3

Magnetic resonance imaging of a 3 cm intrahepatic cholangiocarcinoma in segment III: (A,B) Moderately hyperintense lesion in T2 weighted sequences with weak restriction in diffusion-weighted imaging; (C,D) Peripheral contrast enhancement with perfusional alterations.

Figure 4

(A–E) Magnetic resonance imaging of an intrahepatic cholangiocarcinoma of 11 cm × 7 cm in the left liver lobe: weak hyperdensity in T2 weighted sequences; restriction at diffusion-weighted imaging (DWI); peripheral wash-in with late central retention. (F) Lymphadenopathies in celiac, hepatic, and left paraaortic area. (G,H) Positron emission tomography with 18-fluoro-2-deoxy-d-glucose (18FDG-PET) of the same lesion: increased uptake of the metabolic agent in the hepatic hypodense lesion, with markedly inhomogeneous distribution of the radiopharmaceutical. (I) Weak uptake of the metabolic tracer in the locoregional lymph nodes.

Figure 5

Contrast-enhanced imaging features a lesion of 5.5 cm intrahepatic cholangiocarcinoma of segment IV. (A) CT imaging: peripheral hyperenhancement in the arterial phase; (B) Hypoechoic aspect in B-mode ultrasound. (C,D) Contrast-enhanced ultrasound: peripheral hyperenhancement in the arterial phase and subsequently marked early washout.