CT of inflation-fixed lungs: wedge-shaped density and vascular sign in the diagnosis of infarction.

To evaluate the role of high resolution CT (HRCT) in the diagnosis of pulmonary infarcts, we selected 83 postmortem lung specimens with subpleural densities from a collection of 180 lungs that had been prepared by a method which allows for a direct radiologic-pathologic correlation. Twelve of the lungs had pulmonary infarcts and 71 lungs had other disorders that had produced a subpleural shadow on HRCT. Lungs were evaluated for the presence of wedge-shaped pleural-based densities and for the presence of an associated vascular sign. There was no significant difference in the incidence of wedge-shaped densities on HRCT between lungs with pulmonary infarcts and lungs with pulmonary hemorrhage, pneumonia, tumor, or edema (p greater than 0.05). A vascular sign associated with a subpleural density was, however, more common (p less than 0.01) in lungs with pulmonary infarcts. We suggest that the vascular sign associated with a wedge-shaped density may be of importance in diagnosing pulmonary infarcts by HRCT.