Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Chest PA and lateral radiograph demonstrates unremarkable mediastinal , hilar and cardiac contours . Bilateral low lung volumes evident with minimally increased retrocardiac opacification , likely atelectasis . No pneumothorax or pleural effusion evident .
    OUTPUT:
    
Bibasilar opacities likely reflect atelectasis .