Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral radiographs were acquired . Moderate cardiomegaly is not significantly changed , allowing for slightly low lung volumes on today 's study . Subtle interstitial opacities with a perihilar predominance are compatible with mild interstitial pulmonary edema . There is minimal bibasilar atelectasis . A trace left pleural effusion is possible . There is no pneumothorax . The mediastinal contours are normal .
    OUTPUT:
    
1 . Mild interstitial pulmonary edema . 2 . Unchanged moderate cardiomegaly . 3 . Possible trace left pleural effusion .