18F-FDG PET/CT findings of a right subphrenic foreign-body granuloma.

We report a case of an 85-year-old woman with a foreign-body granuloma which accumulated 18F-fluorodeoxyglucose (FDG). Unenhanced computed tomography showed a hyperdense mass with a hypodense rim in the right subphrenic space. FDG PET/CT images showed intense FDG uptake in the hypodense rim and little FDG uptake in the center of the mass, showing a ring-shaped appearance. The fusion imaging of FDG PET/CT represented the metabolic features of the foreign-body granuloma. When a ring-shaped FDG uptake is noted in the abdomen of a patient with a history of abdominal surgery, a foreign-body granuloma should be included in the differential diagnosis.