Is airway diameter measured accurately on routine axial CT scans? Comparison with true axial diameter using MPR in children with airway compression owing to pulmonary TB

Abstract

Airway compression is a common complication of TB lymphadenopathy in children, and the diagnostic workup of patients with suspected tracheal or bronchial stenoses includes bronchoscopy and CT (computed tomography).2 This process affords the opportunity to study aspects of CT relating to airway stenosis. Axial CT scans produce excellent resolution in the horizontal plane, but the extent of airway disease may be underestimated if only axial images are obtained. An advantage of using multidetector CT (MDCT) is the use of multiplanar reconstruction (MPR) to align the image along the longitudinal axis of the airway. There is also uncertainty if window settings affect the measurement of the airway diameter. We wished to determine if there was a significant difference between the measurements of compressed airway diameter in the axial plane compared with measurements of diameter using MPR for determining longitudinal axis of the airway; and to evaluate how measurements on lung window settings compare with soft tissue window settings.

Keywords

• Axial CT
• Multiplanar Reconstruction
• Airway
• Tuberculosis
• Children