Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared the prior study , there is increase in opacity at the right mid to lower lung difficult to exclude small left pleural effusion . Pneumonia pneumothorax is seen . The cardiac and mediastinal silhouettes are stable . Chronic deformity of the posterior right fourth rib .
    OUTPUT:
    
Increase in opacity at the right mid to lower lung is nonspecific , could be due to infection and / or aspiration .