Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes cause bronchovascular crowding and bibasilar atelectasis . Mild pulmonary vascular congestion without pulmonary edema . The cardiomediastinal silhouette , including mild cardiomegaly , and tortuous aorta is stable . There is no pleural effusion , pneumothorax . Left lower lobe atelectasis has improved .
    OUTPUT:
    
Mild cardiomegaly and mild pulmonary vascular congestion . Left lower lobe atelectasis has improved . .