Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours appear unchanged , including mild unfolding of the descending thoracic aorta . There is a patchy linear opacification in the left lower lung most suggestive of minor atelectasis , but otherwise , the lungs appear clear . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
Patchy left basilar opacity suggesting minor atelectasis ; otherwise unremarkable .