Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Opacities in the lower left lung base likely represent mild left basilar atelectasis . Otherwise , the lungs are grossly clear without evidence of focal consolidation , pulmonary edema , or pneumothorax . The cardiomediastinal silhouette and hilar contours are stable compared to multiple prior exams . Mild degenerative changes are seen in the thoracic spine .
    OUTPUT:
    
No acute cardiopulmonary process