Figure 11a. Thymic rebound in a 25-year-old woman with a history of Hodgkin disease who was referred for posttherapy evaluation. Axial PET scan (b) demonstrates findings that are consistent with posttherapy thymic rebound (arrows). (a, c) Axial CT (a) and PET-CT fusion (c) images reveal a symmetric hypermetabolic focus (arrows) that corresponds to the thymus and appears as a bilobed structure with convex lateral borders in the anterosuperior mediastinum at CT.