PET/MR of pediatric bone tumors. What the radiologist needs to know

Integrated 2-deoxy-2-[fluorine-18]fluoro-d-glucose (${}^{18}$F-FDG) positron emission tomography (PET)/magnetic resonance (MR) imaging can provide "one stop" local tumor and whole-body staging in one session, thereby streamlining imaging evaluations and avoiding duplicate anesthesia in young children. ${}^{18}$F-FDG PET/MR scans have the benefit of lower radiation, superior soft tissue contrast, and increased patient convenience compared to ${}^{18}$F-FDG PET/computerized tomography scans. This article reviews the ${}^{18}$F-FDG PET/MR imaging technique, reporting requirements, and imaging characteristics of the most common pediatric bone tumors, including osteosarcoma, Ewing sarcoma, primary bone lymphoma, bone and bone marrow metastases, and Langerhans cell histiocytosis.