[Imaging of orbital masses].

A wide spectrum of tumors and pseudotumors may involve the orbit. Their clinical presentation is often nonspecific, consisting of exophthalmos, diplopia, visual loss, orbital pain or signs of orbital inflammation. Imaging plays a major role in the etiological diagnosis, providing a precise analysis of the location of the lesion, its components, and its effects on adjacent and nearby structures. It studies tumor extension and often provides a good evaluation of its composition. Imaging is mainly performed with MRI. CT is needed when the lesion affects the orbital walls. Ultrasound is proposed in case of anterior location of the mass or vascular lesion. This paper presents a brief summary of the technical aspects of imaging and of the normal anatomy of the orbit and its components. It presents the best sequences needed to depict specific pathologies and the aspects of the most common diseases encountered.