Abstract. In antero-posterior and lateral chest radiographs of patients with cystic fibrosis changes may be observed which reflect underlying lung abnormalities. Increases in lung volume can result in forward bowing of the sternum, diaphragmatic depression and spinal kyphosis. Parenchymal lung changes which are directly or indirectly a consequence of bronchiolar mucus plugging with infection, include mottled shadowing and ring shadowing. Prominence of bronchial line shadows is also commonly seen. Large shadows due to confluent consolidation or collapse may occur. --This paper gives a technique for the systematic evaluation of these changes which are then represented in numerical terms. The method gives repeatable results. The information recorded facilitates comparison of chest radiographs with each other and the comparison of radiological features with clinical and physiological assessments.

The persistent high mortality in infants with pulmonary artery "sling" (retrotracheal anomalous left pulmonary artery) is primarily due to the coexistence in such patients of long-segment tracheal stenosis due to complete cartilage rings. Five such patients are reported. Airway studies (by filtered high-kV radiography, bronchography, and/or CT) showed low carina, horizontal equal-length right and left mainstem bronchi, and long-segment tracheal stenosis. The length of the stenosis far exceeded the contact with the pulmonary sling. The suggested term "ring-sling complex" for such patients correctly places emphasis on detection of the tracheal malformation, which currently has no satisfactory surgical treatment.

Between 1968 and 1980, 51 children had an operation for various forms of vascular ring. Additional cardiac malformations were present in five patients, and six had noncardiac congenital anomalies. Although symptoms started within the first month of life in 39 infants, only 16 came to operation under three months of age, and a delay of more than six months occurred in 15. Stridor, often life-threatening, and recurrent infections were the most common symptoms, but dysphagia was also important. The reasons for delay in diagnosis are discussed. Barium swallow provided the diagnosis in 44 patients and suggested it in a further four patients. Innominate artery compression of the trachea was not diagnosed by barium swallow. Operations of various types were performed. Accuracy in diagnosis is important because not all patients could be treated through the classic left thoracotomy. Severe tracheomalacia was responsible for the only two deaths in the series; one of these had tracheostomy performed in the referring hospital, the second child also had Fallot's tetralogy. The large majority of the patients have done well, 76% being asymptomatic at follow-up. Minimal to moderate stridor persists among the remainder to the present time.