Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to the study obtained approximately 3 hr earlier , the retrocardiac patchy opacity appears worse , likely reflective of worsening atelectasis . Mild atelectasis in the right lung base is unchanged . No large pleural effusion or pneumothorax is present . The cardiac and mediastinal contours remain unchanged . Pulmonary vasculature is not engorged . Right - sided Port - A - Cath tip remains in the low SVC .
    OUTPUT:
    
Slight interval worsening of left basilar opacity likely reflective of worsening atelectasis . Coexistent infection is not excluded .