Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: No obvious pneumothorax identified on the current film . Interval improvement in previously seen subcutaneous emphysema in the lower neck / upper chest . Changes at the right and left lung bases , likely a combination of a small amount of pleural fluid and atelectasis , are similar to the prior study . No new infiltrate is identified . No overt CHF . Cardiomediastinal silhouette is grossly unchanged .
    OUTPUT:
    
No obvious pneumothorax identified .