Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . Heart size appears to be mildly enlarged , unchanged . Mediastinal and hilar contours are grossly unremarkable . There is mild crowding of bronchovascular structures with slight upper zone vascular redistribution suggestive of mild pulmonary vascular congestion . Streaky opacities in the lung bases likely reflect atelectasis . No pleural effusion , focal consolidation or pneumothorax is demonstrated . There are no acute osseous abnormalities .
    OUTPUT:
    
Mild pulmonary vascular congestion and bibasilar atelectasis in the setting of low lung volumes .