Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is mildly enlarged . The mediastinal and hilar contours are unremarkable . Pulmonary vasculature is not engorged . Retrocardiac streaky opacity likely reflects atelectasis . No focal consolidation , pleural effusion or pneumothorax is present . No acute osseous abnormality is detected .
    OUTPUT:
    
Retrocardiac streaky opacity , likely atelectasis .