Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable chest radiograph demonstrates unremarkable mediastinal , hilar and cardiac contours . Stable right basilar atelectasis . Minimally increased retrocardiac opacity likely represent atelectasis . No pleural effusion or pneumothorax evident .
    OUTPUT:
    
Minimally increased retrocardiac opacity , likely atelectasis exagerrated by low lung volumes .