Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A moderate - sized right pleural effusion is slighlty increased in size since ___ . Bibasilar opacity most likely represents atelectasis and is also unchanged . There is new increased opacity in the left lung base which may represent a combination of atelectasis and pneumonia . No pneumothorax is seen . The aortic knob is calcified . The cardiac silhouette is moderately enlarged . There are degenerative changes in the thoracic spine .
    OUTPUT:
    
Slight increase size of moderate right pleural effusion . New left lower lobe opacities could represent atelectasis ; however , in the correct clinical setting pneumonia or aspiration is possible .