On plain radiographs (Fig. 14A) and CT (Figs. 14B, C), pulmonary infarcts are typically multifocal, peripheral in location, contiguous with one or more pleural surfaces, and more commonly confined to the lower lungs.^3,47,48 The apex of these rounded or triangularly shaped opacities may point toward the hilum.³ The opacities resolve slowly over a period of several months, akin to “melting ice cubes,” and may leave a residual scar.³ The first documentation of the finding was made by Aubrey Otis Hampton, who was a practicing radiologist in the mid 1920s. He and his co-author Castleman first reported evidence of incomplete pulmonary infarction in the setting of PE in the 1940s.^47,48 Autopsy follow-up showed evidence of intra-alveolar hemorrhage without alveolar wall necrosis in the first 2 days of infarction. After 2 days, wall necrosis begins and eventually leads to pulmonary infarction and an organized scar.^47,48 Hampton also observed that there were differences in the healing of these incomplete infarcts depending on their premorbid cardiac history.^47,48 In patients without heart disease, the incomplete infarcts would generally heal without scarring, whereas patients with congestive failure were more likely to progress to infarction with a persisting pulmonary scar.^47,48 When pulmonary embolism results in infarction, airspace opacities typically develop within 12 to 24 hours.^3,48

References and Links

CXR Map