III. Pulmonary Fibrosis and the Collagen Diseases: Radiological Aspects

The radiological changes in the chests of patients suffering from the commoner collagen diseases are discussed in this paper. All may show a linear or reticular pattern which in many cases appears to be of vascular origin. It is not possible to say which of the lung vascular systems is involved though it appears to be the pulmonary arterial system rather than the bronchial. In all the conditions discussed lung changes demonstrable radiologically are uncommon. The changes in polyarteritis nodosa are mottling, small consolidations, increased vascular markings, pneumatoceles and occasional pleural effusions. They are often transitory, their appearance may be linked with eosinophilia and they disappear more rapidly after cortisone treatment. In the terminal stages, especially when there is also renal involvement, cardiac enlargement and the “batswing” type of pulmonary oedema may be found. In acute lupus erythematosus there may be seen pleural or pericardial effusions (usually small), subpleural consolidations, lobar consolidations of low density and rarely a “vascular” pattern. The lesions are uninfluenced by cortisone. Scleroderma may reveal an interstitial infiltration or a sclero-cystic appearance. Radiographs of rheumatoid patients may demonstrate a basal reticulation which in older people is steadily progressive and which may be modified by co-existent conditions, such as pneumoconiosis, to produce smooth round shadows with a peculiar distribution in the periphery of the lung and in the middle and lower zones.