Abstract:Objective To explore CT and MR imaging features of head and neck rhabdomyosarcoma in children.Methods Twenty-nine pediatric patients with head and neck rhabdomyosarcoma were retrospectively analyzed. Twenty-three of these cases underwent MRI examination and 18 received CT scanning.Results Among the 29 cases,tumors originated in the paranasopharynx(n=10), nasal cavity and paranasal sinuses(n=4),nose(n=5), cheek(n=3), ear(n=7), and left fossae infratemporalis(n=1). The tumors were irregular and inhomogeneous in density, without any calcification. On MRI images, the tumors were isointense to muscle or slightly hypointense to muscle on T1WI, and hyperintense to muscle on T2WI. Post-contrast MR showed intense inhomogeneous enhancement. The tumors grew infiltratively and eroded the adjacent bone. The lesions invaded the orbit,nasal cavity, paranasal sinuses, mastoid, petrous bone, and skull base in 8, 13, 14, 15, 21, and 14 cases respectively. The lesions invaded the adjacent brain in 4 cases. Cerebrospinal fluid metastasis was proved in 2 cases.Conclusions Head and neck rhabdomyosarcoma in children occurs mostly in the parameningeal region.CT can provide a clear view of bone destruction while MRI can demonstrate optimally the extent of lesion invasion. Combined imaging commodities can provide more detailed information for diagnosis and therapy of rhabdomyosarcoma.