Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are decreased lung volumes compared to the prior study . The heart size is normal with a mild left ventricular predominance . The aorta is mildly unfolded . The mediastinal and hilar contours otherwise are unremarkable . The pulmonary vascularity is normal . There is mild crowding of the bronchovascular structures , with minimal streaky opacity in the lung bases compatible with atelectasis . No focal consolidation , pleural effusion or pneumothorax is present . No acute osseous abnormalities are seen .
    OUTPUT:
    
Low lung volumes with mild bibasilar atelectasis .