18F-FDG-avid sites mimicking active disease in pediatric Hodgkin's.

About 1,700 children in the United States are diagnosed yearly with lymphomas; Hodgkin's disease accounts for approximately half of these cases, or 6% of all childhood cancers. Contemporary therapy allows for the achievement of remission in the majority of cases. The fusion of positron emission tomography (PET) with CT provides the most accurate imaging method for disease characterization and treatment response. However, experience with 18F-FDG PET-CT is limited in pediatric Hodgkin's disease. Numerous non-oncologic processes can mimic recurrent or residual tumor. This pictorial addresses mimickers of disease such as uptake in normal structures, infections, transforming germinal canters and effects of therapy on normal tissues. It is essential for radiologists to be familiar with these findings in order to stage disease activity and therapeutic response accurately.