Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Mild enlargement of cardiac silhouette is present . The mediastinal and hilar contours are normal . The pulmonary vasculature is normal . There is minimal patchy opacity in the retrocardiac region which likely reflects atelectasis . No pleural effusion or pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
Mild retrocardiac atelectasis . No pneumothorax . Mild cardiomegaly .