RESUMO
Objective To explore the imaging characteristics of intrathoracic extramedullary hematopoiesis(EMH).Methods Clinical and imaging findings of 6 cases with EMH were retrospectively analyzed,and the imaging characteristics,diagnosis and differential diagnosis were discussed.Results Among 6 the cases of EMH,3 lesions were located in mediastinum,and the other 3 lesions in mediastinum and adjacent chest wall.Five cases appeared as globular shadows which protruded toward the lung fields on X-ray films,on plain CT scan,all the 6 lesions appeared of smooth margin and homogeneous soft-tissue density,and the CT values ranged from 38 to 45 HU.Two lesions showed slight homogeneous enhancement on postcontrast CT scan using the common CT scanner,and the CT values ranged from 61 to 65 HU.Four lesions showed significant homogeneous enhancement on postcontrast CT images using the 16-slices CT,and the CT values ranged from 72 to 83 HU.On MRI images,4 lesions showed the same signal intensity as compared to adjacent muscles on T_1WI and T_2WI,and there was slight enhancement of the lesions after intravenous contrast administration.Conclusion EMH has specific imaging findings,and accurate diagnosis can be made by combining X-ray,CT and MR imaging findings with clinical history.