Figure 25. Residual fibrosis in a 39-year-old man with large B-cell lymphoma. FDG PET-CT was performed for restaging after chemotherapy and radiation therapy. Axial fused FDG PET-CT image obtained at the level of the main pulmonary artery shows numerous prevascular lymph nodes—which are considered enlarged according to size criteria—with surrounding abnormal soft tissue without metabolic activity (arrow), findings indicative of residual fibrosis.