Abstract: PET image analysis mainly includes the visual assessment and quantitative or semiquantitative approaches, and the quantitative or semiquantitative parameters include SUV, metabolic tumor volume and total lesion glycolysis. PET/CT provides both metabolic and morphologic information, and becomes the most important imaging armamentarium in lymphoma. This article reviews major metabolic activity parameters of ¹⁸F-FDG PET/CT and their application in lymphoma.