Purpose or Case Report: Suspected airway compression in symptomatic children with Lymphobronchial Tuberculosis (LBTB) can be diagnosed using modern computed tomography (CT) assisted by coronal minimum intensity projection (MinIP) reconstructions. The accuracy of plain radiographs in detecting airway compression in children with TB has not been evaluated against an imaging gold standard in a dedicated manner.

We aimed to compare frontal CXR against thick-slab angled coronal CT MinIP in identifying airway stenosis at ten specific sites and to determine the agreement between the modalities regarding the degree of stenosis.
Methods & Materials: Retrospective cross-sectional study comparing CXR with standardized angled coronal CT MinIP in children with symptomatic LBTB at 10 predetermined airway locations. CXRs were evaluated by one paediatric radiologist (> 20 years’ experience), and CT MinIP reconstructions were evaluated by consensus of three general radiologists. Sensitivity and specificity were calculated using the CT MinIP as the gold standard test. Stenosis was graded as 1 for mild (1-50%), 2 for moderate (51-75%), 3a for severe (76-99%), and 3b for total (100%). Agreement regarding severity of stenosis was calculated using kappa score between the two modalities per site affected.
Results: A total of 37 subjects were included in the study. The median age of the patients was 14.3 months (IQR 8.0-23.2), and 370 individual bronchi (10 x 37 subjects) were evaluated for stenosis. CXR showed that 31 [84%] out of 37 patients had stenosis at least in one of 10 evaluated sites in this study and it was confirmed via CT MinIP modality. The gold standard which was CT MinIP demonstrated stenosis in at least one of 10 sites in all 37 patients [100%].
Kappa agreement between CXR and CT for grade of stenosis for each site showed substantial agreement (Kappa 0.67) for the LMB and moderate agreement (kappa 0.58) for the BI. Severe stenosis was found on CT in 78 bronchi compared to CXR found in 32 bronchi (9 and 23).
Conclusions: CXR has been demonstrated to be accurate in detecting airway stenosis and in identifying severe stenosis at the LMB and BI in the paediatric population, where the incidence and severity of airway stenosis from LBTB is high. The most common bronchi affected by stenosis were the LMB and BI, and CXR showed greatest sensitivity and specificity at these locations. The LMB and BI should be the focus of CXR interpretation and can be used for both diagnosis and classification of patients for treatment.