Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Linear opacities within the lung bases , left greater than right , likely represent areas of subsegmental atelectasis as seen on concurrent CT . The remainder of the lungs appear clear . There is no pneumothorax . Mild blunting of the bilateral costophrenic angles corresponds with small effusion seen on concurrent CT . Cardiomediastinal and hilar contours are within normal limits . There is a small hiatal hernia .
    OUTPUT:
    
1 . Bibasilar linear opacities most suggestive of subsegmental atelectasis . 2 . Small bilateral pleural effusions .