Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes are present . Heart size is normal . Mediastinal and hilar contours are unremarkable . There is crowding of the bronchovascular structures but no pulmonary edema is present . Lungs are clear . No pleural effusion or pneumothorax is present .
    OUTPUT:
    
No acute cardiopulmonary abnormality .