Metastasis versus focal eosinophilic infiltration of the liver in patients with extrahepatic abdominal cancer: an evaluation with gadobenate dimeglumine-enhanced magnetic resonance imaging

Abstract

PURPOSE: To determine the performance of gadobenate dimeglumine (Gd-BOPTA)-enhanced magnetic resonance imaging (MRI) to differentiate focal eosinophilic infiltration (FEI) from metastasis.

MATERIALS AND METHODS: Gadobenate dimeglumine-enhanced MRI conducted in 38 patients (lesions of 43 metastases and 33 FEIs) with extrahepatic abdominal carcinoma were reviewed retrospectively. Images were divided into 2 sets. Set 1 was composed of precontrast MRI with dynamic phase images. Set 2 included hepatobiliary phase images in addition to the images of set 1. Two blinded radiologists independently categorized each set of images into 5 grades to differentiate metastases from FEI. The area under the receiver operating characteristic curve (Az) was calculated for each set of images. The observers evaluated the shape, signal intensity (SI), and enhancement pattern of the lesions in consensus.

RESULTS: The Az values for set 2 images (reader 1: 0.976, and reader 2: 0.743) were greater than those of set 1 (0.961 and 0.709), without statistical significance (P = 0.470 and 0.223). Target appearance was seen in 27 of 43 (63%) metastases on hepatobiliary phase imaging, but none on the FEI. Twenty-five (76%) of the 33 FEIs showed intermingled hypo-SI and iso-SI on hepatobiliary phase images with changing size and shape compared to the T2-weighted images, whereas none of the metastases did.

CONCLUSION: Gadobenate dimeglumine-enhanced MRI may assist in the differentiation of FEI from metastasis by highlighting the distinctive features between them, even without hepatobiliary phase imaging.