Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Bilateral lower lobe opacities are new since ___ , likely reflecting atelectasis or mild aspiration . There is no pneumothorax or pleural effusion . The heart size is top normal . The hilar and mediastinal contours are within normal limits .
    OUTPUT:
    
Bilateral lower lobe infiltrates , possibly representing mild aspiration superimposed on atelectasis .