Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Right internal jugular central venous catheter is in the upper SVC . Swan - Ganz catheter has been removed . Mediastinal and pleural drains remain in stable position . Lung volumes remain quite low . Left hilar and left retrocardiac opacity likely reflects atelectasis . There is no large pleural effusion or pneumothorax . There is no pulmonary edema . Mild cardiomegaly is unchanged . Postoperative widening of the mediastinum is improving .
    OUTPUT:
    
1 . Low lung volumes with left basilar atelectasis . No pulmonary edema . 2 . Improving postoperative mediastinal widening .