Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable single frontal chest radiograph was obtained . Lung volumes are very low with crowding of bronchovascular structures . There is no appreciable pneumothorax . The cardiomediastinal silhouette and hilar contours are unchanged . There is no pleural effusion .
    OUTPUT:
    
No radiographic evidence for acute cardiopulmonary process .