Imaging features in patients with SAPHO/CRMO: a pictorial review

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome and chronic recurrent multifocal osteomyelitis (CRMO) have been described as disorders of chronic osteoarthritic inflammation frequently associated with skin manifestations, and SAPHO and CRMO (SAPHO/CRMO) are rare autoinflammatory disorders of unknown etiology. SAPHO tends to occur in adults and CRMO predominantly occurs in children and adolescents. SAPHO/CRMO can affect any skeletal region (e.g., anterior chest wall, spine, or long bones). As SAPHO/CRMO are diagnoses of exclusion, the diagnoses might be difficult if skin manifestations are not clearly evident. However, knowledge of the imaging findings of skeletal disorders is helpful for correcting the diagnosis and avoiding unnecessary invasive procedures, as well as in facilitating early diagnosis and adequate treatment. This pictorial review describes the appearance of increased skeletal uptake for SAPHO/CRMO on bone scintigraphy along with findings from radiography, computed tomography, and magnetic resonance imaging.