usefulness of lateral radiographs for detecting tuberculous lymphadenopathy in children – confirmation using sagittal ct reconstruction with multiplanar cross-referencing

Background. Diagnosis of pulmonary tuberculosis (PTB) in children remains difficult. Lateral chest radiographs are frequently used to facilitate diagnosis, but interpretation is variable. In this study, lateral chest radiographs (CXRs) are evaluated against sagittal CT reconstructions for the detection of mediastinal lymphadenopathy. Aim. To correlate suspected lymphadenopathy on lateral CXR with sagittal CT reconstructions and determine which anatomical group of lymph nodes contributes to each lateral CXR location. Methods and materials. Thirty TB-positive children’s lateral CXRs were retrospectively reviewed for presence of mediastinal lymphadenopathy in 3 pre-determined locations in relation to the carina: retrocarinal, subcarinal and precarinal. Findings of the CT sagittal reconstructions were then correlated with the CXRs for the presence of lymphadenopathy in the same 3 pre-determined areas across the width of the mediastinum. Axial and coronal CT crossreferencing confirmed the position of the lymphadenopathy. Results. The most frequent locations for lymphadenopathy were the subcarinal (28) and right hilar (25). Sensitivity and specificity values of the CXRs were moderate, with the precarinal region having the best sensitivity and specificity for presence of lymphadenopathy. Contribution to each zonal group on lateral CXR were from multiple anatomical lymph node sites. Conclusion. The precarinal zone on CXR had the best specificity and sensitivity, and represented mainly subcarinal and right hilar lymph node groups. Attention should be paid to this area on lateral CXRs for detecting lymphadenopathy in children with suspected PTB.