The Value of CT and MRI in Diagnosis of Orbital Lymphomas

Objective To study the value of CT and MR in diagnosing orbital lymphomas. Methods There were totally 14 patients with primary orbital lymphoma including 9 males and 5 females,the age ranged from 1.5 to 65 years old (average age: 36). The course ofdiseases varied from 2 months to 16 years.All patients underwent CT scan,and 13 cases underwent contrast-enhanced CT scansimultaneously.Plain and contrast MR scans were performed in 5 patients. Results The diagnosis was confirmed pathologically in all cases. The lesions of 4 cases were bilateral and 10 cases were unilateral. Periorbital preseptal tissues were involved mainly in upper lateral quadrant of the orbit. Focal masses were showed in 5 patients. The lesions that infiltrated the lacrimal gland, adjacent extra ocular muscles, and intraorbital tissues along with extra ocular muscles were found in other patients,and appeared as either “casting sign” or “ring sign”. Theintrabulbar and bony structures were no abnormality. Isodensity soft-tissue masses with clear demarcation were found on plain CT film,and homogenous enhancement of tumors was observed on contrast-enhanced CT scan. The lesions displayed low to intermediate signal intensityon T_1WI MRI and slightly low or slightly high signal intensity on T_2WI. The lesions demonstrated homogenously marked enhancement oncontrast-enhanced MRI. Conclusion The examination of CT and MRI, especially MRI can demonstrate the location,configuration,inside structure and characteristic manifestations of the orbital lymphomas,the diagnosis can be made preoperatively.