Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Linear opacities are visualized in the lung bases and may reflect areas of subsegmental atelectasis or overlying vasculature . No confluent opacity is identified to suggest pneumonia or aspiration . The lateral view is clear . No pneumothorax or pneumomediastinum . No vascular congestion , pulmonary edema or pleural effusions are identified . Calcifications of the aortic knob are noted . Cardiomediastinal and hilar contours are within normal limits . There are degenerative changes of the thoracic spine with dense anterior osteophytosis at multiple levels . No definite compression deformity is identified .
    OUTPUT:
    
Bibasilar linear opacities may be related to overlying vasculature or atelectasis . No confluent opacities to suggest pneumonia or aspiration . No pleural effusion .