Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest . No prior . Relatively low lung volumes are seen . The lungs , however , are clear . There is no effusion or pneumothorax . The cardiomediastinal silhouette is within normal limits . Descending thoracic aorta is slightly tortuous . No acute osseous abnormality is detected . Degenerative changes are seen at the left acromioclavicular joint .
    OUTPUT:
    
No acute cardiopulmonary process .