Relationship of parenchymal and pleural abnormalities with acute pulmonary embolism: CT findings in patients with and without embolism.

PURPOSE To compare the frequency of pleural and parenchymal abnormalities detected on computed tomography (CT) in patients with and without acute pulmonary embolism (PE), and to investigate whether the pleuroparenchymal findings correlate with the severity of PE. MATERIALS AND METHODS We retrospectively reviewed contrast-enhanced CT scans acquired in 128 patients suspected of having acute PE. The presence of filling defects consistent with PE was recorded, and the clot burden was quantified. The presence and the severity of parenchymal abnormalities, and the presence, size, and location of pleural effusions were recorded. RESULTS Forty-nine patients (38%) had CT evidence of PE with a mean degree of obstruction of 27 +/- 21%. Parenchymal abnormalities were seen in 45 patients with PE (92%) and in 66 patients without PE (84%) (P = 0.28). Atelectasis, the most common finding, was present in 27 patients with PE (55%) and 42 patients without PE (53%) (P = 0.86). Wedge-shaped opacity was observed in 15 patients (31%) and consolidation was observed in 19 patients (39%) with PE (P = 0.001). Pleural effusions were present in 27 patients with PE (55%) and 42 patients without PE (53%) (P = 0.86). With regard to the severity of ancillary parenchymal findings, only the number of wedge shaped opacities showed mild correlation with the severity of PE (r = 0.34, P = 0.04). CONCLUSION The majority of patients with and without PE demonstrate parenchymal and pleural findings on CT. Wedge-shaped opacities and consolidation are significantly associated with PE. Other parenchymal and pleural findings on CT do not correlate with the presence and severity of PE.