Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is at the upper limits of normal . The mediastinal and hilar contours are unremarkable . The left mid-lung demonstrates subtle , ill - defined opacity of uncertain clinical significance . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
No acute cardiopulmonary process ; ill - defined left mid-lung opacity which could be better defined by a nonemergent CT . Findings discussed with ___ at 7 : 50 am on ___ by ___ over the phone .