Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is normal . The hilar and mediastinal contours are within normal limits . Bibasilar densities are present , corresponding to rounded atelectasis within the right lower lobe and linear atelectasis within the left lower lobe , as seen on the CT examination performed on the same day . There is no pneumothorax or pleural effusion . Linear bibasilar densities reflect atelectasis , better visualized on the CT examination performed today .
    OUTPUT:
    
Bibasilar opacites , seen as rounded atelectasis at the right base and linear atelectasis at the left base on the CT performed earlier this evening .