A roentgen sign of pulmonary infarction

Abstract

<h2>Summary</h2> Dilatation of a descending pulmonary artery occurred in all of 23 consecutive instances of pulmonary infarction. In the right pulmonary infarcts, abnormal measurements of the right descending pulmonary artery, ranging from 17 mm. to 22 mm. were noted (normal upper limits for inspiratory measurement is 16 mm. for adult males and 15 mm. for adult females). A dilated left desending pulmonary artery, ranging from 17 mm. to 26 mm., is seen with left pulmonary infarction. This is a reliable and early roentgen sign. Measurement of the descending pulmonary artery on chest roentgenogram is most important in the diagnosis of the pulmonary infarction. This roentgen sign usually appears within 24 hours of the onset of chest pain and maximum dilatation of the descending pulmonary artery occurs in two to three days. In doubtful early cases, serial films taken at daily intervals for three days are helpful in making a differential and final diagnosis. In pneumonitis, and even with massive lobar pneumonia, this roentgen sign is absent. If available, comparison with previous chest roentgenograms is valuable since, if previous pulmonary hypertension was not present, a finding of increased descending pulmonary artery width is almost diagnostic of infarction when symptoms are present. This should re-emphasize the need for routine chest rotentgenograms on all hospitalized patients.