Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Spinal stimulator device is redemonstrated in unchanged position . The heart size is normal . The mediastinal and hilar contours are unremarkable . The pulmonary vascularity is within normal limits . There is minimal atelectasis in the left lung base . No focal consolidation , pleural effusion or pneumothorax is visualized .
    OUTPUT:
    
Minimal atelectasis in the left lung base .