Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette size is normal . The mediastinal and hilar contours are unremarkable . Pulmonary vasculature is not engorged . Patchy opacity is noted within the left lung base , likely atelectasis . Right lung is clear . No pleural effusion or pneumothorax is present . No acute osseous abnormality is detected .
    OUTPUT:
    
Patchy left basilar opacity , likely atelectasis . No acute osseous abnormalities detected . Please note that if there is continued concern for a rib fracture , consider a dedicated rib series .