Objective To analyze MRI and CT features of struma ovarii (SO).Methods CT and MRI findings of 14 patients with pathologically confirmed single SO were retrospectively analyzed.The morphology,size,density/signal intensity and enhancement pattern of lesions were analyzed.Results All the tumors appeared as well-defined cystic-solid masses,11 were multilobulated and 3 were round-like.Thirteen lesions were multicystic,and 1 was unilocular.The solid components appeared as thickness septa or wall in 11 and as nodule in 3 lesions.The maximum diameter of the tumors were 3-34 cm,with an average size of (11.34±2.24)cm.MRI showed extremely low signal intensity regions in cyst portion of 7 masses on T2WI without enhancement,while obvious enhancement in solid potion.CT showed high attenuation in cyst portion of 7 masses without enhancement,CT value were 57-90 HU,whereas the solid potion obviously enhanced,and CT values were 145-270 HU.Plaque-like calcification on the walls or nodules were observed in 4 patients.Conclusion CT and MRI findings of SO have certain characteristics,which are helpful for diagnosis and differential diagnosis.