Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are multiple rib fractures in the upper left chest cage . Displaced fractures of the fourth rib anteriorly and posteriorly are similar to prior exam . The anterior second rib fracture should not be mistaken for a lung lesion . Other minimally displaced fractures seen on CT are not seen on this examination . Heart size is normal . The mediastinal and hilar contours are normal . The pulmonary vasculature is normal . Moderate dependent left pleural effusion , some of which was probably present on ___ . No focal consolidation or pneumothorax is seen .
    OUTPUT:
    
1 . No pneumothorax . 2 . Moderate left pleural effusion and associated atelectasis . 3 . Previously seen multiple left rib fractures appear similar .