Analysis of CT and MRI signs of hepatic eosinophilic infiltration

Objective To study and analyze the CT and MRI findings of hepatic eosinophilic infiltration. Methods Twenty nine patients of hepatic eosinophilic infiltration who were confirmed by biopsy or clinical diagnosis were retrospectively analyzed. All the patients underwent CT and/or MRI scan. Twenty seven cases underwent upper abdominal CT plain scan and three phase enhanced scan, and 5 cases underwent upper abdominal MR plain scan and three phase enhanced scan, of which 3 cases underwent CT and MRI scan. Evaluations were made regarding to the numbers of lesion, distribution, size, shape, margin, density or signal characteristic, parttern and other special features. Pearson correlation analysis was used to analyze the correlation between the number of hepatic lesions and the number of eosinophils in peripheral blood. Results A total of 108 lesions of eosinophilic hepatic infiltration were observed in 29 cases, including 2 cases with single lesion and 27 cases with multiple lesions. Ninety five of the lesions were located in subcapsular parenchyma or surrounding the vein. Most subcapsular lesions were wedge-shaped (n=28). Lesions surrounding vein were round-shaped (n=32), while the hepatic parenchymal lesions were irregular or round-shaped (n=13). The mean size of lesion was 34 mm, ranging from 3 to 61 mm. The margin of all the lesions were obscure. The lesions showed slightly low density or isodensity on CT pre-contrast images. On MR pre-contrast images, lesions showed slightly low signal or isointense on T1WI, and hyperintense on T2WI. Branches of vein were found infilrated by all lesions. Tueleve cases showed stripe sign along the vein branches, 16 cases showed halo ring sign around the vein. Pearson analysis indicated a significant correlation between the number of eosinophilic hepatic infiltrated lesions and the increase of eosinophils in peripheral blood (r=0.783, P<0.05). Conclusion The imaging features of EHI had certain characteristics, especially in the three phase dynamic enhanced scanning, from which we can mainly find progressive enhancement , portal vein sign , stripe sign and halo ring sign . Key words: Eosinophilia; Tomography, X-ray computed; Magnetic resonance imaging; Hepatic infiltration