Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Assessment is limited by lordotic positioning . Low lung volumes are present . This accentuates the size of the cardiac silhouette which appears mildly enlarged . The mediastinal and hilar contours are unremarkable . Pulmonary vasculature is not engorged . Patchy retrocardiac opacity may reflect atelectasis . No pleural effusion or pneumothorax is clearly identified . Known rib fractures are not clearly visualized on the current radiograph .
    OUTPUT:
    
Known rib fractures are not well visualized on the current radiograph . Low lung volumes with patchy retrocardiac opacity , likely atelectasis .