Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Previously seen left pneumothorax has markedly improved , but small pneumothorax remains . There is no focal consolidation or effusion . The cardiomediastinal silhouette is normal . Imaged osseous structures are intact . No free air below the right hemidiaphragm is seen . A small left pleural catheter is in place . There is mild left chest wall subcutaneous emphysema
    OUTPUT:
    
Left pneumothorax has markedly improved , but small pneumothorax remains .