Detection and localization of nonmetallic intraocular foreign bodies by magnetic resonance imaging.

Computed tomography (CT) is useful in detecting metallic intraocular foreign bodies. Magnetic resonance imaging (MRI) is a technique that might allow the detection and localization of nonmetallic intraocular foreign bodies. We performed CT and MRI scans on ten freshly enucleated sheep eyes, eight of which contained nonmetallic intraocular foreign bodies of wood, glass, plastic, or rock. Computed tomography correctly detected seven of eight foreign bodies, while MRI detected all eight of the foreign bodies. Computed tomography is necessary to determine the presence of a metallic foreign body, but when the CT scan is negative, MRI may still detect small nonmetallic foreign bodies.