Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The aorta remains tortuous but unchanged . The mediastinal and hilar contours are unremarkable , and there is no pulmonary vascular congestion . Streaky left lower lobe opacity is nonspecific and may reflect atelectasis or infection . No pleural effusion or pneumothorax is identified . There are no acute osseous abnormalities . Multilevel degenerative changes are noted in the thoracic spine .
    OUTPUT:
    
Left lower lobe streaky opacity may reflect atelectasis or infection .