Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are clear without consolidation , effusion , or edema . There is likely external material mimicking a pleural reflection at the left lung apex however in combination with lucency below the left hilum , repeat exam in expiratory phase is suggested . The cardiomediastinal silhouette is within normal limits . No acute osseous abnormalities .
    OUTPUT:
    
No acute cardiopulmonary process . Likely external structure mimicking pleural reflection line at the left lung apex for which repeat exam in expiration is suggested to exclude pneumothorax .