Roentgenographic Diagnosis of Glass Foreign Bodies

Abstract

lass fragments are not uncommonly encountered in trauma wound. Most physicians are not sure whether they are visible on radiography or not because of controversy in literature. This study was designed to answer: (1) Is the glass visible on standard roentgenogram? (2) Is there any difference in different kinds of glass? and (3) What's the effect of overlying bone on glass fragment? Four chemically elementary classes of glass, clear, tinted, reflective and mirror glass were used for this study. Nine glass samples were broken into pieces and then driven into the subcutaneous tissue of cadaveric pig. Standard radiography film was taken on different kinds of glass first. Then, computed tomography was undertaken to determine their individual Hounsfield value. Finally, different size of plain glass (clear glass) which has the lowest Hounsfield value were used to assess the limitation of standard roentgenogram and the effect of obscuration by overlying bone. Different kinds of glass did not have the visibility difference on standard roentgenogram, though the metal compounds used in the tinted, reflective, and mirror glass had made their Hounsfield values higher than plain glass. Thin glass fragment as small as 1mm can be easily visible roentgenographically if it is not obscured by bone. Different views of standard roentgenogram should provide a good diagnostic aids for glass foreign bodies in trauma wound.