Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient 's body habitus causes accentuated soft tissue densities particularly in the lower lobes . The lungs are clear . Cardiomediastinal silhouette and hilar contours are unremarkable . No pleural effusion or pneumothorax . Multilevel degenerative changes are again noted in the thoracic spine .
    OUTPUT:
    
No evidence of pneumothorax .