Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Redemonstrated are multiple right - sided rib fractures , some of which are segmental and consistent with a flail chest . There is a stable right - sided apical pneumothorax , as well as multiple stable appearing hydropneumothoraces within the right lower to mid hemi thorax . There are several right - sided perihilar / basilar opacities noted , improving and more fully characterized as atelectasis on the recent chest CT . A small , left - sided pleural effusion is noted , similar in size as compared to the prior examination . The heart size is normal . Mediastinal contours are normal .
    OUTPUT:
    
1 . Multiple contiguous right - sided rib fractures , suggestive of flail chest . 2 . Stable appearance of a right - sided apical pneumothorax , and multiple loculated , right - sided hydropneumothoraces . 3 . Improving right perihilar / basilar atelectasis . 4 . Stable , small left - sided pleural effusion .