Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are low lung volumes . This causes crowding of the bronchovascular structures . Heart size is borderline enlarged , and the mediastinal and hilar contours are grossly unremarkable . No overt pulmonary edema is noted . Focal opacity within the retrocardiac region may reflect an area of pneumonia or aspiration . No pleural effusion or pneumothorax is seen . ___ rod and spinal fusion hardware is noted within the imaged thoracolumbar spine . There are no acute osseous abnormalities .
    OUTPUT:
    
Limited exam with low lung volumes causing crowding of the bronchovascular structures . Retrocardiac opacity could reflect aspiration or pneumonia .