Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Upright portable radiograph of the chest demonstrates persistent elevation of the left hemidiaphragm , with low lung volumes bilaterally . There is unchanged displacement of the trachea towards the right secondary to a very tortuous intrathoracic aorta . The heart is borderline enlarged in size , unchanged since the prior study . There is no evidence of pulmonary edema . There is no evidence of subdiaphragmatic free air . No pneumothorax is present .
    OUTPUT:
    
No acute cardiopulmonary process . No evidence of subdiaphragmatic free air .