Value of lateral neck radiography for ingested foreign bodies using the likelihood ratio.

OBJECTIVE

To determine the diagnostic accuracy of lateral neck radiography and its value in related radiographic findings in the detection of foreign bodies using the likelihood ratio.

PATIENTS AND

METHODS

This retrospective study comprised 114 patients who had neck radiography followed by rigid esophagoscopy. Interpretations of the radiographs were correlated with esophagoscopic findings and clinical follow-up for at least 1 month. Data were mainly assessed by likelihood ratio and detection rate.

RESULTS

Plain radiography had a positive likelihood ratio of 2.4 (95% confidence interval [CI] 1.8-3.1) and a negative likelihood ratio of 0.6 (95% CI 0.40-0.7). It had a sensitivity of 57.4% (95% CI 45.6-69.1) and a specificity of 76.1% (95% CI 63.8-88.4). Positive likelihood ratios for each radiographic finding (foreign body shadow, air, and soft tissue swelling) were 3.4 (95% CI 2.6-4.4), 1.5 (95% CI 0.9-2.6), and 4.1 (95% CI 1.9-8.7), respectively. Plain radiography had a high detection rate (72.5%) when foreign bodies were lodged in the hypopharynx and cervical esophagus. On the contrary, the detection rate was poor (0%) in the oropharynx.

CONCLUSIONS

A lateral neck radiograph is better taken after a negative finding in a thorough oral examination and fibre-optic laryngoscopy. Judging from the possible site of impacted foreign body and radiographic findings, we can better predict the presence of foreign bodies.