Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral radiographs of the chest demonstrate small left pleural effusion with left lower lobe opacity , which may reflect atelectasis , however pneumonia can not be excluded . There is a small right pleural effusion and mild interstitial pulmonary edema . Cardiomediastinal hilar contours are unchanged . No pneumothorax .
    OUTPUT:
    
Small left pleural effusion with left lower lobe opacity , which may reflect atelectasis , however pneumonia can not be excluded . Mild interstitial pulmonary edema .