Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a moderate to large right - sided pneumothorax identified . Lung hyper expansion of the right hemi thorax with leftward mediastinal shift is noted . The left lung is clear . The cardiomediastinal silhouette is otherwise within normal limits . Atherosclerotic calcifications noted at the aortic arch . No acute osseous abnormalities .
    OUTPUT:
    
Moderate to large right pneumothorax with leftward mediastinal shift .