Howling S J, Evans T W, Hansell D M
Department of Radiology, Royal Brompton Hospital, London, UK.
Clin Radiol. 1998 Feb;53(2):105-9. doi: 10.1016/s0009-9260(98)80055-x.
Irreversible bronchial dilatation on computed tomography (CT) is seen in patients with interstitial pulmonary fibrosis whereas reversible dilatation of the bronchi is a feature of many conditions. The aim of this study was to determine whether airways dilatation, which is a frequent finding in adult respiratory distress syndrome (ARDS), is reversible and to establish whether persistent airways dilatation is accompanied by other CT signs of established interstitial fibrosis.
Thin section CT scans of 16 patients with ARDS were analysed at a lobar level in the acute phase of the disease and at follow-up (median interval 6.3 months) for the presence and extent of a ground-glass pattern, reticular or linear opacities and the presence or absence of bronchial dilatation.
95 out of 96 (99%) lobes on the initial CT scan showed ground-glass pattern. Airway dilatation was present in 65 of 95 (68%) of these lobes. On follow-up CT the airways remained dilated in 60 of 65 (92%) lobes and, in the majority of these, 53 of 60 (88%), a reticular and linear pattern with associated distortion had developed. A coexisting ground-glass pattern was present in 12 of 60 (20%) lobes on follow-up CT, but was the sole residual abnormality in only one lobe.
In patients with ARDS, dilatation of the airways within areas of ground-glass pattern is a frequent observation in the acute phase of the condition and tends to persist at follow-up, usually accompanied by the CT features of supervening pulmonary fibrosis.
