Bolus contrast medium enhancement for distinguishing pleural from parenchymal lung disease: CT features

Various morphologic criteria have been proposed to distinguish pleural from pulmonary parenchymal processes using CT. Although these criteria are helpful in most instances, they are not infallible. In a retrospective review of chest CT over a 1 1/2 year period, previously described signs were not sufficient to distinguish pleural from parenchymal disease in five patients who underwent routine contrast-enhanced CT. This was true in cases of large, localized areas of air-space disease and in cases of combined pleural and parenchymal disease. In these patients bolus intravenous contrast medium administration at the plane of major abnormality proved extremely useful for diagnosis by directly demonstrating pulmonary blood vessels and/or contrast enhancement in parenchymal processes.