OBJECTIVE: To determine the relative radio-opacity on plain x-ray of bones of fish species commonly consumed in South East Queensland. DESIGN: A cadaveric sheep model was used to mimic the soft tissues of a human neck. Bones of 10 fish species were placed in the paratracheal tissues and adjacent to the larynx. X-rays were taken and the images (including four control images with no bones) were incorporated into a Microsoft PowerPoint presentation to be interpreted by emergency specialists and registrars. Observers were blinded to which specimens contained fishbones and which did not. MAIN OUTCOME MEASURES: Sensitivity and specificity of plain x-rays for detecting impacted fishbones. RESULTS: Significant interobserver variability was identified. Despite this, the overall specificity of plain x-rays was 90%. The sensitivity of the technique was 79% overall, but varied significantly between fish species. CONCLUSION: Lateral soft tissue neck x-ray is an appropriate screening tool in cases of a suspected impacted fishbone. If a fishbone is identified on x-ray, the patient should be referred for endoscopy without further imaging. X-ray may be of limited value in cases of Dory or Spanish mackerel bone ingestion. In such cases, a computed tomography scan should be the first-line investigation.
OBJECTIVE: To determine the relative radio-opacity on plain x-ray of bones of fish species commonly consumed in South East Queensland. DESIGN: A cadaveric sheep model was used to mimic the soft tissues of a human neck. Bones of 10 fish species were placed in the paratracheal tissues and adjacent to the larynx. X-rays were taken and the images (including four control images with no bones) were incorporated into a Microsoft PowerPoint presentation to be interpreted by emergency specialists and registrars. Observers were blinded to which specimens contained fishbones and which did not. MAIN OUTCOME MEASURES: Sensitivity and specificity of plain x-rays for detecting impacted fishbones. RESULTS: Significant interobserver variability was identified. Despite this, the overall specificity of plain x-rays was 90%. The sensitivity of the technique was 79% overall, but varied significantly between fish species. CONCLUSION: Lateral soft tissue neck x-ray is an appropriate screening tool in cases of a suspected impacted fishbone. If a fishbone is identified on x-ray, the patient should be referred for endoscopy without further imaging. X-ray may be of limited value in cases of Dory or Spanish mackerel bone ingestion. In such cases, a computed tomography scan should be the first-line investigation.