Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A patchy area of opacity in the right infrahilar region has slightly improved compared to the previous study and is localized to the posterior basilar segment on the lateral view . More peripherally , a linear area of atelectasis has increased from the prior exam . Remainder of lungs are clear . Minimal posterior blunting of lateral costophrenic angles on lateral view could potentially represent small effusions .
    OUTPUT:
    
Slight improvement in right lower lobe opacity , which may be due to aspiration , pneumonia or atelectasis .