Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest show radiopacity in the left lung base that most likely represents atelectasis . Otherwise , lungs are clear , without focal opacity , pleural effusion or pneumothorax . The heart size is normal . Mitral annular calcifications again noted . The aorta is ectatic but relatively unchanged since ___ . There is no free air beneath the hemidiaphragms . There are degenerative changes in the thoracic spine including anterior osteophytes .
    OUTPUT:
    
No acute cardiopulmonary process .