Evaluation of intraocular foreign bodies by spiral computed tomography and multiplanar reconstruction

Abstract

This study aimed to evaluate the ability of spiral computed tomography (CT) and multiplanar reconstruction in the assessment of intraocular foreign bodies. The study design was experimental. Three foreign bodies (metal, glass, and plastic) implanted into the globe of a cadaveric head were studied. Spiral CT in the axial plane was used. Beam collimation and table increment were both 3 mm, whereby overlapping axial slices were reconstructed at 1-mm intervals. The data were transferred to a workstation, and reconstructions in the coronal and sagittal plane were performed. The ability to detect and evaluate localization, shape, and size of the foreign bodies in all three imaging planes was assessed. All foreign bodies were detected in the axial and in both reconstructed planes. The metal foreign body caused imaging artifacts in the axial plane. In the reconstructed planes. imaging artifacts were less severe, and evaluation of localization and shape was improved. Glass and plastic foreign bodies were well seen in all planes, and shape and localization were well demonstrated. Appropriate window settings improved determination of size of the different foreign bodies. Spiral CT of the orbit and multiplanar reconstruction offers a promising tool for evaluation of intraocular foreign bodies. Advantages of spiral CT compared to conventional CT are data acquisition in only one axial plane; shortened examination time; reduced radiation exposure; reduced imaging artifacts from metallic foreign bodies in the reconstructed planes; and demonstration of localization, shape, and size of the foreign body in three imaging planes.