Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Mild flattening of the hemidiaphragms may reflect mild hyperexpansion . The lungs are clear . Heart size is normal . The mediastinal and hilar contours are normal . There is no large pleural effusion or pneumothorax .
    OUTPUT:
    
Flattening of the hemidiaphragms suggests mild hyperexpansion . No acute intrathoracic process .