Fluoro-deoxy-glucose positron emission tomography/computed tomography in lymphoma: A pictorial essay

F-18 fluoro-deoxy-glucose (FDG) positron emission tomography/computed tomography (PET/CT) has emerged as a powerful imaging modality in the field of oncology. F-18 FDG PET/CT is now an established tool in the management of lymphoma. This has been shown to be useful in staging, detection of bone marrow involvement (BMI), early response assessment and end of therapy response assessment in lymphoma. Interpretation of F-18 FDG PET/CT in lymphoma is carried out by various qualitative response assessment criteria. London criteria are used for interpretation of interim PET/CT and International Harmonization Project (IHP) criteria are used to interpret PET/CT done after the end of chemotherapy. Quantitative analysis is also found to be useful in assessment of response early after two cycles of chemotherapy in patients with diffuse large B cell lymphoma (DLBCL). This pictorial essay provides few images describing the FDG avidity of lymphoma, patterns of bone marrow uptake and their relevance in predicting BMI, role of staging PET/CT, quantitative analysis in response assessment, example images of response according to London criteria and IHP criteria. Few pitfalls in imaging of lymphoma with PET/CT are also discussed in the images legend.