Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable supine radiograph of the chest . Lung volumes are low causing a crowding of the pulmonary vasculature . The lungs are clear . The cardiomediastinal and hilar contours are normal . There is no pneumothorax or pleural effusion . Pulmonary vascularity is normal .
    OUTPUT:
    
Low lung volumes . No acute cardiopulmonary process .