Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours are normal . Subsegmental atelectasis in the left lung base is present . Lungs are otherwise clear . No focal consolidation , pleural effusion or pneumothorax is present . Partially imaged is a left ureteral stent .
    OUTPUT:
    
Subsegmental atelectasis in the left lung base .