Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: An endotracheal tube , left - approach central venous catheter and ___ ___-___ tube are in expected unchanged positions . Diffuse ground - glass opacities involving both lungs persist ; however , there is slight clearing of the lungs bilaterally suggesting improvement . No large pleural effusion is identified . There is no pneumothorax . Cardiomediastinal and hilar contours appear mildly enlarged , though are unchanged .
    OUTPUT:
    
Mild improvement in aeration of the bilateral lungs .