Differentiating normal from abnormal inferior thoracic paravertebral soft tissues on chest radiography in children

OBJECTIVE: The purposes of this investigation were to define the normal appearances, define factors that have the potential to influence appearance, and establish defined criteria to differentiate normal from abnormal appearances of posteroinferior paravertebral soft tissues on chest radiography in children. SUBJECTS AND METHODS: Paravertebral soft tissues were evaluated on frontal chest radiographs in 23 children with documented abnormalities and 275 children without abnormalities in the region. The frequency of visualization, course, width, and factors (patient positioning, age, and sex) potentially influencing the appearance of paravertebral soft tissues were determined. Inferolateral course and width greater than that of the adjacent pedicle were evaluated as criteria for abnormality. RESULTS: Only 28% of the children without abnormalities had paravertebral soft tissues visualized, and the frequency of visualization directly increased with age (p = 0.001). For identification of abnormal cases on the left side, width greater than the adjacent pedicle had a sensitivity of 100% and a specificity of 98%, and inferolateral course had a sensitivity of 86% and a specificity of 95%. Visualization on the right side (n = 5) was always abnormal. Six normal cases had a width greater than that of the adjacent pedicle on the left side on initial radiographs obtained with supine positioning and met normal criteria on repeated radiographs with upright positioning. CONCLUSION: Width greater than the adjacent pedicle is the best radiographic criterion for differentiation of abnormal from normal left-sided paravertebral soft tissues, particularly on radiographs obtained with upright positioning. Identifiable right-sided paravertebral soft tissue is always abnormal. These criteria are useful aids in determining the need for additional imaging, such as CT.