Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Predominantly peripheral and basilar regions of increased interstitial markings appear stable compared to the prior exam and are likely secondary to fibrotic changes and bronchiectasis . No new focal consolidations concerning for pneumonia are identified . There is no pleural effusion or pneumothorax . The heart size is normal . The hilar and mediastinal contours are normal . There is significant amount of pneumoperitoneum consistent with patient 's known perforated diverticulitis , better assessed on the recent CT abdomen pelvis performed on the same day .
    OUTPUT:
    
1 . Substantial amount of pneumoperitoneum , consistent with patient 's known perforated diverticulitis , and better assessed on the recent CT abdomen and pelvis performed the same day . 2 . No focal consolidations concerning for pneumonia identified .