Use of plain radiography and computed tomography to identify fish bone foreign bodies.

Abstract

Fish bones are the most common aerodigestive foreign bodies in adults. Radiographic studies, often ordered for diagnosis, have questionable utility. With a laryngoscope, bones from 10 fish species were placed in a variety of positions in a human head and neck cadaver specimen. Plain films and CT scans were obtained and evaluated by blinded readers. Plain radiography exhibited a sensitivity and specificity of 39% and 72%. Cooking did not grossly change radio-opacity. The species of fish affected visibility in soft tissue, without correlation to the characteristic optical density of each species. Bones placed orthogonal to the film in the vallecula were most readily identified. CT scanning correctly identified 9 of 10 bones. Plain radiography poorly visualizes fish bone foreign bodies in soft tissue; visibility varied with fish species, location, and orientation. CT is the test of choice to radiographically diagnose fish bone impactions.