Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Upright frontal and lateral views of the chest . Linear bibasilar opacities most likely represent atelectasis ; otherwise , the lungs are clear without focal opacities , pulmonary edema , pleural effusion or pneumothorax . The aorta is ectatic , and the heart is top normal in size . There is no free air beneath the right hemidiaphragm . Degenerative changes within the thoracic spine appear unchanged since ___ .
    OUTPUT:
    
No acute cardiopulmonary process .