Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: No previous studies for comparison . Cardiac silhouette and mediastinum is within normal limits . Lungs are grossly clear . No calcifications or lucencies over the liver are seen . There are some mild degenerative changes of the AC joint . Thoracic spine is preserved .
    OUTPUT:
    
No signs for acute cardiopulmonary process .