Prone CT for diagnosis of silicone oil intraventricular migration after intraocular tamponade

Abstract

Silicone oil tamponade is a frequent treatment for retinal detachment. Intraventricular migration of this agent is rare, but was described previously in patients with chronic glaucoma and atrophy of the optic disc. We describe a patient with prior silicone oil tamponade in the left eye with a noncontrast computed tomography demonstrating hyperattenuating material along the course of the left optic nerve and in the frontal horns of the lateral ventricles, and emphasize the use of prone noncontrast computed tomography as an important diagnostic tool in order to confirm the low specific gravity of the oil agent.

Keywords: CSF, cerebrospinal fluid; MRI, magnetic resonance imaging; NCCT, non-contrast computed tomography; Prone CT; Silicone oil intraventricular migration; Silicone oil tamponade; T1WI, T1 weighted images; T2WI, T2 weighted images.

Fig. 1

Head NCCT demonstrates hyperattenuating materials in the anterior portion of the left globe, along the course of ipsilateral optic nerve (A) and in the frontal horns of the lateral ventricles (B).

Fig. 2

Brain MRI demonstrates identical signal of the substance in the left eye vitreous space and anterior horns of lateral ventricles, with hyperintensity on T1WI (A, B) and hypointensity on T2WI (C, D). Both T1WI and T2WI depicted crescent-shaped bands in the silicone oil-aqueous interface representing a chemical shift artifact, more evident on gradient-recalled echo sequence (E, F).

Fig. 3

Prone head NCCT shows the hyperattenuating substance located in the occipital horns of the lateral ventricles (A) and in the posterior aspect of the left eye vitreous space (B), demonstrating the material moved from a gravity nondependent location to another gravity nondependent location, which confirms the relative lower specific gravity of the hyperattenuating substance, consistent with silicone oil.