Characterization of orbital lesions by surface coil MR imaging

Surface coil MR imaging is an effective technique for evaluating orbital pathology. T1 and T2 weighting provides information not obtainable by CT and results in better characterization of some lesions. MR appears to be most useful for characterizing ocular pathology, specifically for differentiating retinoblastoma from benign diseases (Coat's disease and PHPV). MR can also be used to separate ocular tumors from associated subretinal fluid. With MR imaging, the signal intensities of lymphoma differ from those of benign inflammatory or infiltrative conditions such as pseudotumor or thyroid ophthalmopathy. Mucoceles, too, have a specific signal intensity pattern with T1 and T2 weighting. CT appears to be superior to MR for demonstrating densely calcified lesions or lesions of bone.