Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Neither pneumonia nor pleural effusion present on the 2 prior examinations is present today . Lungs are fully expanded and clear . Normal cardiomediastinal and hilar silhouettes and pleural surfaces . The only possible abnormality is hyperinflation of the chest which could be due to small airways disease or sulcal emphysema .
    OUTPUT:
    
No explanation for weight loss . No evidence of malignancy or infection . Possible small airway obstruction or emphysema .