Chronic Nonbacterial Osteomyelitis Evidenced by Concomitant [18F]FDG PET/CT and MRI in 2 Phases of the Disease

Chronic nonbacterial osteomyelitis is a rare disease that mainly affects children and adolescents. This disease is characterized by chronic inflammation of the bones, alternating between periods of remission and relapse. Currently, MRI is the most commonly used imaging method to diagnose the disease, but several studies have shown that [ 18 F]fluorodeoxyglucose ([ 18 F]FDG) positron emission tomography combined with computed tomography (PET/CT) is also useful for evaluating disease activity. We report a rare case of a 53-year-old woman in whom the disease was illustrated in 2 distinct phases by concomitant MRI and [ 18 F]FDG PET/CT, highlighting the variable nature of this pathology.