Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Calcified pleural plaques are again noted . Lower lung fibrosis accounts for the opacity in the lung bases bilaterally , however the retrocardiac and left lower lobe opacity has increased since prior examination worrisome for superimposed pneumonia . No large pleural effusion or pneumothorax . There is new mild widening of the mediastinum , measuring 7 .7 cm , likely accentuated due to supine positioning . Heart size , and hila are grossly unremarkable . Limited assessment upper abdomen is unremarkable . Visualized osseous structures are grossly unremarkable . No displaced rib fractures .
    OUTPUT:
    
1 . No displaced rib fractures . 2 . Lower lung fibrosis with superimposed left lower lobe pneumonia or aspiration pneumonia . Differential includes large pulmonary contusion or hemorrhage given history of trauma . 3 . Widened mediastinum is most likely accentuated due to patient positioning however findings can be seen with aortic dissection / aortic injury post trauma . Consider upright radiograph to allow for direct comparison . 4 . Calcified pleural plaques .