SPIRAL CT VERSUS CONVENTIONAL CT IN THE PREOPERATIVE ASSESSMENT OF METALLIC INTRAOCULAR FOREIGN-BODIES

Purpose: To compare the effectiveness of spiral CT versus conventional CT in the preoperative assessment of metallic intraocular foreign bod ies. Methods: Eighteen patients with penetrating eye injuries and susp ected metallic intraocular foreign bodies were assigned to undergo eit her spiral CT or conventional CT in the axial plane. The spiral and th e conventional CT data were transferred to a workstation, and reconstr uctions in the coronal and sagittal planes were performed. Additional direct coronal scanning was performed only when necessary for preopera tive assessment. The quality of the axial as well as the reconstructed coronal and sagittal images was assessed for each imaging modality. T he size of the foreign bodies was measured and compared to the actual diameter. Total examination time and radiation dose delivered to the l ens were measured for each imaging modality. Results: All foreign bodi es were detected by each scanning modality on the axial and on the rec onstructed planes. The quality of the axial images was similar for spi ral and conventional CT. The spiral technique provided high-quality re constructed images which allowed accurate localization of the foreign bodies in all cases. Reconstructions by conventional technique were in adequate for preoperative assessment. The examination time for the tot al orbital volume was 18 s for spiral CT and 52 s for conventional CT. Radiation dose delivered to the lens was 35 mGy for spiral CT and 56 mGy for conventional CT axial scanning. Conclusion: Spiral CT multipla nar imaging offers several significant advantages for the preoperative assessment of metallic intraocular foreign bodies compared to the con ventional CT technique in clinical practice, including short examinati on time, minimized motion artifacts, reduced radiation exposure, and a ccurate localization.