The "Survived Lung:" An Ultrasound Sign of "Bubbly Consolidation" Pulmonary Infarction

Since the presence of "bubbly consolidation" (central lucencies) on a multi-slice computed tomography pulmonary angiography (MCTPA) is one of the highly specific imaging appearances of infarct secondary to pulmonary embolism, we investigated the ultrasound characteristics of these infarctions. In this study, 118 patients with MCTPA diagnosis of acute pulmonary embolism were enrolled. Pulmonary infarctions were detected in 21 patients (17.7%), of which 10 (47.6%) showed the typical appearance of bubbly consolidation on MCTPA. Lung ultrasound (LUS) was performed to evaluate the characteristics of the infarcts highlighted by MCTPA. The bubbly consolidations showed a very peculiar echographic aspect represented by a triangular hypoechoic consolidation with sharp margins, the absence of air bronchograms and a mostly central roundish hyperechoic area. Air lucencies within a pulmonary infarct is hypothesized to represent the coexistence of aerated non-infarcted lung with the infarcted lung in the same lobule. The ultrasound appearance confirms this hypothesis, so we named the roundish hyperechoic area the "survived lung." This picture was found in all patients with a diagnosis of bubbly consolidation on MCTPA (100%). Χ² between MCTPA and LUS regarding the bubbly consolidation diagnosis is 17.18 (df = 1; p value = 0.00003). Bubbly consolidations show a very typical appearance on LUS. Their detection suggests further investigations (MCTPA or point-of-care multi-organ ultrasonography).