Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post left lower lobectomy with clips noted in the left juxtahilar region . Leftward shift of mediastinal structures is re - demonstrated . Opacity within the left lung base likely reflects a combination of small pleural fluid as well as likely atelectasis though infection can not be completely excluded . No pulmonary edema is present , in the right lung is clear . No pneumothorax is clearly evident . Subcutaneous gas within the left chest wall extending into the neck has decreased in the interval . Rounded opacity posteriorly overlying the mid thoracic spine is re - demonstrated , which again may reflect loculated pleural fluid . Mild degenerative changes are seen within the thoracic spine .
    OUTPUT:
    
Persistent opacity within the left lung base , likely reflecting a combination of small pleural effusion and atelectasis , though infection is not excluded .