[Pulmonary vessel calibre on in- and expiratory chest radiographs in young and old normal people (author's transl)].

Changes in pulmonary blood flow as see on chest radiographs have assumed considerable importance recently in the evaluation of left ventricular insufficiency. In order to study the results of poor radiographs on the evaluation of pulmonary haemodynamics, blood-flow patterns were studied in 39 individuals of various ages during normal inspiration, during the Valsalva manoeuvre and during expiration. All had normal lungs. The results indicate that changes in blood-flow patterns and loss of marginal definition of basal vessels are unreliable signs of left-sided insufficiency in old patients or in unco-operative patients, in the presence of a high diaphragm and in the supine position.