Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is normal . Mediastinal and hilar contours are unremarkable . The pulmonary vasculature is normal . Subsegmental atelectasis is noted in the lung bases . No focal consolidation , pleural effusion or pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
Mild subsegmental atelectasis at the lung bases . No acute cardiopulmonary abnormality otherwise demonstrated .