Comparison of enhancement features of peripheral intrahepatic cholangiocarcinoma on contrast-enhanced ultrasound and dynamic enhanced MRI

Objective: To analyze and compare the imaging characteristics of contrast-enhanced ultrasound (CEUS) and dynamic enhanced magnetic resonance imaging (MRI) for diagnosis of peripheral intrahepatic cholangiocarcinoma, aiming to increase the accuracy of diagnostic imaging. Methods: The imaging characteristics of CEUS and dynamic enhanced MRI in 51 patients with peripheral intrahepatic cholangiocarcinoma confirmed by surgical pathology or fine needle aspiration biopsy were retrospectively analyzed and compared. Results: Fifty-five lesions in fifty-one cases were analyzed. On CEUS, the hyper-enhancement in arterial phase was seen in all 55 lesions, iso-echo in 8 lesions and hypo-echo in 47 lesions in portal phase, and hypo-echo in all 55 lesions in delayed phase. On enhanced MRI, all 55 lesions displayed the same characteristics as CEUS in arterial phase except 44 lesions continuously displaying hyper-intensity and 11 lesions displaying hypo-intensity in portal and delayed phases. On CEUS, 42 (76.4%) lesions displayed rim-like enhancement, and 13 (23.6%) lesions displayed gross enhancement. During the process of enhancement, the pattern of branch-like extending inwardly was observed in 40 (72.7%) lesions. On dynamic enhanced MRI, 40 (72.7%) lesions showed the pattern of rim-like enhancement, and other 15 (27.3%) lesions showed gross enhancement. The features of CEUS were rim-like enhancement in arterial phase with branch-like extending inwardly. A large proportion of the lesions displayed heterogeneous enhancement when reaching the peak intensity. The characteristics of dynamic enhanced MRI were similar to CEUS in arterial phase, but a continuous enhancement was seen in portal and delayed phases, indicating enhancement in late phase. The occurrence rate of characteristic manifestation on CEUS was 70.9% (39/55) according to the standard of “fast-in and fast-out” and “rim-like” and/or “branch-like” enhancement. The occurrence rate of characteristic manifestation on dynamic enhanced MRI was 69.1% (38/55) according to the standard of “rim-like enhancement” in arterial phase and “delayed enhancement” in late phase. There was no difference in the occurrence rate of characteristic manifestation between CEUS and dynamic enhanced MRI (P = 1.000). Conclusion: The characteristic manifestations on CEUS and dynamic enhanced MRI for the diagnosis of peripheral intrahepatic cholangiocarcinoma display a high diagnostic value. DOI:10.3781/j.issn.1000-7431.2014.33.459