Fluorine-18-FDG PET findings of focal eosinophilic liver disease: correlation with CT and/or MRI, laboratory, and pathologic findings

To review the 2-deoxy-2-fluoro-[F-18]-d-glucose (FDG) positron emission tomography (PET) findings of focal eosinophilic liver disease (FELD) and to correlate them with radiologic and pathologic findings. Fourteen patients, who were clinically or pathologically diagnosed as FELD and underwent CT and/or MR and PET, were enrolled. Two radiologists analyzed CT and MRI regarding size, shape, margin, attenuation, signal intensity (SI), and enhancement patterns of the lesion, both qualitatively and quantitatively. One pathologist determined whether the lesion is eosinophilic abscess (EA) or infiltration. One nuclear medicine physician reviewed the PET images and calculated the peak standardized uptake value (SUV) of the lesion. PET findings were then correlated with CT or MRI, and pathologic findings. Eighty-five lesions were detected on CT (n = 85) and MRI (n = 10). Only four of the lesions showed FDG uptake and their mean SUV was 4.0. The size of the lesions with FDG uptake (26.5 mm) was significantly larger than those without uptake (11.8 mm). Mean attenuation and SI differences between the lesion and adjacent liver on CT and T2-weighted MRI tended to be larger in the uptake group (64.3 and 124.5) than the group without uptake (28.5 and 43.5). Among the four histologically confirmed lesions, two EAs and one of the two EIs showed FDG uptake. Most FELD do not show FDG uptake on PET. However, larger nodules with greater attenuation or SI differences from the background liver on CT or T2-weighted MRI or those with EA on pathology tend to show FDG uptake on PET.