Case Report: Multimodality imaging features and serial metabolic changes on 18 F-FDG PET/CT in a dog with granulomatous hepatitis.

Granulomatous hepatitis is an uncommon inflammatory liver disease that can mimic hepatic malignancy on diagnostic imaging. A 12-year-old spayed female Cocker Spaniel presented with multiple target-like hepatic and splenic lesions showing peripheral enhancement on triple-phase CT and markedly increased 18F-FDG uptake on PET/CT (SUVmax 11.2), raising strong suspicion for malignancy. However, histopathology confirmed granulomatous hepatitis. Serial PET-CT performed 4 months later demonstrated decreased metabolic activity, supporting a chronic inflammatory process. This case highlights the potential role of serial PET-CT beyond malignancy assessment, demonstrating its utility for evaluating metabolic activity and monitoring therapeutic response over time in inflammatory hepatic disease such as active granulomatous hepatitis.