Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Again demonstrated is a large left pleural effusion which is loculated laterally , slightly decreased in size when compared to the prior study . Small right pleural effusion appears slightly increased compared to the prior exam . There is continued leftward shift of mediastinal structures . Left basilar lung opacification likely reflects atelectasis , similar when compared to the prior study . No areas of focal consolidation are demonstrated in the right lung . There is no pneumothorax . Mild multilevel degenerative changes are noted in the thoracic spine .
    OUTPUT:
    
Loculated large left pleural effusion , perhaps minimally decreased in size compared to the prior study , and small right pleural effusion , slightly increased compared to the prior exam . Persistent left basilar atelectasis .