Role of Computed Tomography in the Assessment of Intraorbital Foreign Bodies Antonio Pinto, MD, PhD,* Luca Brunese, MD, † Stefania Daniele, MD,* Angela Faggian, MD, ‡ Gianluigi Guarnieri, MD, § Mario Muto, MD, § and Luigia Romano, MD* Intraorbital foreign bodies (IOFBs) are a common occurrence worldwide and happen at a frequency of once in every 6 cases of orbital trauma. An orbital foreign body may produce a variety of signs and symptoms related to its size, composition, and ballistics. Retained foreign bodies may give rise to cellulitis, abscess, fistulas, and impaired vision and motility. Prompt detection and accurate localization of IOFBs are essential for the optimum man- agement of patients, to enable the surgeon to plan the most atraumatic method of removing the IOFB. Computed tomography (CT) is very useful in determining the size of foreign bodies and localizing them as intraocular, extraocular, or retro-ocular. CT is generally considered the gold standard in the evaluation of IOFBs because it is safe to use with metallic IOFBs, excludes orbitocranial extension, and is also able to diagnose orbital wall fractures and orbital sepsis with high accuracy. Other potential complications excludible by CT are abscess formation in the orbit, bone, and brain. Magnetic resonance imaging is generally not recommended for the evaluation of the foreign bodies because of risks associated with magnetic metal. Semin Ultrasound CT MRI 33:392-395 © 2012 Elsevier Inc. All rights reserved. I ntraorbital foreign bodies (IOFBs) are a common occur- rence worldwide and happen at a frequency of once in every 6 cases of orbital trauma. 1 IOFB is a relatively common entity in emergency depart- ments, present in 10.2% of ocular injuries. 2 IOFB injuries occasionally have a dramatic presentation, but typically they are subtle, potentially escaping detection unless one main- tains high index of suspicion. IOFBs are a well-known risk factor for posttraumatic endophthalmitis and a wide range of other complications, including hyphema, cataract, vitreous hemorrhage, and retinal tears and detachment. 3-5 Clinical management of foreign bodies is dependent on the composition and site. Intraocular foreign bodies are usually removed surgically to prevent complications from chemical reactions (eg, siderosis from iron) or infection. Extraocular foreign bodies are managed conservatively, and therefore, it is important to accurately differentiate between intraocular and extraocular locations. Among the diagnostic procedures used in the assessment of IOFBs, computed tomography (CT) is considered as the most sensitive method for the detection of IOFBs, because it is accurate at detecting and localizing intraorbital metallic, glass, and stone foreign bodies. This article highlights the role of CT in the assessment of IOFBs. Anatomy The orbits are pyramid-shaped spaces located between the cranial cavity and remainder of the face. The spaces are lined by the orbital plates of 7 bones: the frontal bone superiorly, the zygomatic bone laterally, the maxillary and palatine bones inferiorly, the lacrimal and ethmoid bones medially, and the sphenoid bone posteriorly. There are 6 extraocular muscles that move the eyeball: the superior, inferior, lateral, and medial rectus muscles, and the superior and inferior oblique muscles. The levator palpebrae superioris muscle is an additional important anatomic struc- ture located in the superior aspect of the orbit. 6 The orbital contents are surrounded by adipose tissue, or orbital fat, that extends from the orbital apex to the orbital septum anteriorly. The lacrimal gland resides in the lacrimal gland fossa located superolaterally, along the orbital aspect of the zygomatic process of frontal bone. *Department of Radiology, Cardarelli Hospital, Naples, Italy. †Department of Health Science, University of Molise, Campobasso, Italy. ‡Section of Radiology, Department “Magrassi-Lanzara,” Second University of Naples, Naples, Italy. §Neuroradiology Service, “A. Cardarelli” Hospital, Naples, Italy. Address reprint requests to Antonio Pinto, MD, PhD, Department of Radi- ology, Cardarelli Hospital, Via Posillipo 168/D, I-80123 Naples, Italy. E-mail: antopin1968@libero.it 392 0887-2171/$-see front matter © 2012 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1053/j.sult.2012.06.004