The value of radiological investigations in pre-endoscopic assessment of children with stridor.

The differential diagnosis of stridor in an infant depends on a careful history and examination, followed by radiological and endoscopic investigations. Currently a chest, lateral neck and antero-posterior, high kilovolt (Cincinnatti) view radiographs in association with a diagnostic barium swallow are performed prior to the definitive diagnostic procedure of microlaryngobronchoscopy. Our impression was that some of the routinely ordered radiological investigations were of limited value in the differential diagnosis. We undertook a retrospective audit study to determine the value of radiological investigations in the pre-endoscopic assessment of infants with stridor. The radiological and endoscopic information of 100 infants presenting over the three-year period 1991-1993 at Great Ormond Street Hospital, London (a tertiary referral centre) was collected. It was found that only five out of 65 barium swallow investigations performed had consistent positive findings at diagnostic microlaryngobronchoscopy. The lateral neck and Cincinnatti views identified many of the more gross pathologies of the larynx and trachea e.g. the space occupying lesions, which occur infrequently. The more common diseases e.g. laryngomalacia or subglottic stenosis are rarely identified radiologically. Our results confirmed that radiology had a limited screening role and that in a child presenting with stridor the initial radiological assessment should be a chest radiograph with further imaging and a barium swallow only if an abnormality is found at microlaryngobronchoscopy.