Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are low lung volumes . This accentuates the size of the cardiac silhouette which is likely mildly enlarged . The aorta is tortuous and demonstrates diffuse calcifications . Crowding of the bronchovascular structures is noted , though no overt pulmonary edema is visualized . Retrocardiac ill - defined opacity is present with small left pleural effusion . No pneumothorax is identified though evaluation of the lung apices is limited due to patient positioning and the patient 's chin obscuring the left lung apex .
    OUTPUT:
    
Low lung volumes . Ill - defined retrocardiac opacity which could reflect aspiration or infection with a small left pleural effusion .