Imagerie des exophtalmies

Exophthalmos is the bulging forward of one or both eyes. The most common cause of exophthalmos is thyroid disease (Graves'disease). CT scan without enhancement should be performed as the initial imaging modality. Diagnosis is most difficult in case of unilateral or asymmetric exophthalmos. The precise location of the lesion (which can be the intra-conal space, the extra-conal space, or between the orbit and other structures) and the features of the lesion (density, signal, enhancement) are useful for the differential diagnosis. Imaging is also useful to select the appropriate surgical approach and to control the post-therapeutic evolution.