Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Right PICC terminates in lower SVC . Tracheostomy tube is in unchanged position . Lung volume is low . Left lung base opacity and leftward mediastinal shift are persistent . Right lung base atelectasis is improved . There is probable left pleural effusion . Cardiomediastinal silhouette is stable
    OUTPUT:
    
Improved right lung base atelectasis . Persistent left lower lobe collapse .