Assessment of intraocular foreign bodies by helical-CT multiplanar imaging

The aim of this study was to examine the effectiveness of helical CT in the assessment of intraocular foreign bodies, evaluating two protocols with di fferent collimation. We performed helical-CT studies in 30 patients. Fiftee n patients were examined with 1.5-mm collimation and the other 15 patients with 3.0-mm collimation. All other imaging parameters were identical in bot h protocols. Multiplanar images were reconstructed. The examinations were r eviewed for presence, localization and size of intraocular foreign bodies. We compare our results with the surgical data. We estimate the required exa mination time. In the first group (collimation 1.5 mm) an intraorbital fore ign body was detected in 8 of 15 patients. In 3 of 8 patients an intraocula r foreign body (all were metallic) was detected. In the second group (colli mation 3.0 mm) an intraorbital foreign body was detected in 9 of 15 patient s. In 8 of 9 patients an intraocular foreign body (all were metallic) was d etected. Our results were confirmed by surgery in all cases. Examination ti me was 36 s in the first group and 18 s in the second group. Computed tomog raphy should be considered the imaging modality of choice in the assessment of metallic intraocular foreign bodies and 3.0-mm collimation is optional, because of reduced examination time and radiation exposure.