Nontraumatic orbital conditions: diagnosis with CT and MR imaging in the emergent setting.

Imaging provides crucial information regarding emergent orbital abnormalities, and the radiologist fulfills an important role in guiding patient care and contributing to favorable outcomes. Knowledge of the imaging features of nontraumatic orbital conditions commonly seen in the emergent setting-infections, inflammation, vascular abnormalities, and retinal and choroidal detachments-is necessary to achieve a prompt and accurate diagnosis, thereby avoiding permanent vision loss and other potentially devastating consequences. The ability to distinguish these entities from physiologic calcifications, posttherapeutic changes, and orbital devices allows optimal management without unnecessary further diagnostic work-up. For orbital imaging in the acute setting, computed tomography is the first-line modality, with magnetic resonance imaging playing an important secondary role. (c) RSNA, 2008.