Comparison of lateral neck X-ray to neck CT in patients with suspicious bone impaction: “Old habits die hard”

Objective: Bone impaction (BI) is a common cause for emergency room visits. Among foreign bodies, fish bone is considered the most common. The sensitivity of symptoms in predicting BI is relatively low, making imaging a central tool to aid diagnosis. Current imaging practices include both neck plain film radiography and none-contrast CT scans of the neck. We evaluated the accuracy of neck plain film radiography and CT scans of the neck for the diagnosis of BI. Methods: Retrospective review of all patients who presented to the emergency room between 2009 and 2016 with a suspicious history of BI whom underwent plain film neck radiography or CT. All Images were reviewed by two neuro-radiologist blinded to the clinical symptoms and findings. Symptoms, clinical findings and images results were compared to the final diagnosis. Results: 89 patients (30.7%), out of 290 patients who presented with complaints of BI, were diagnosed with BI. Mean age was 44.7 years old. Plain film neck radiography failed to predict BI (sen. 14.4%, spe 89.8% accuracy 63.2%), neck CT has an improved accuracy and sensitivity in locating BI (sen. 83.3%, spe. 94.1% accuracy 92.5%). Interobserver agreement between the two neuro-radiologists was moderate (0.46) and substantial (0.77) in neck radiography and CT images, respectively. Neck radiography missed 60 (out of 61) oropharyngeal BI's. Conclusion: Neck radiography has high inter-observer variability and low sensitivity for the diagnosis of BI. Neck CT should be the first imaging modality in patients with suspicious complaints for BI and negative physical exam.