Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A small right apical pneumothorax has decreased in size compared to the prior examination measuring approximately 1 cm in maximum distance from the chest wall , previously 2 .5 cm . Cardiomediastinal silhouette is stable . Lungs are clear . There is no pleural effusion .
    OUTPUT:
    
Decreased size of right pneumothorax .