Classic findings of perforated appendicitis, with a large area of perforation along the medial aspect evidenced by mucosal discontinuity, extraluminal fluid, and extraluminal air. This is particularly well seen on the coronal images. 

Sometimes the perforation is less obvious, and can be difficult to detect as the appendix often decompresses following perforation, and the mucosal defect can be rather subtle. In those cases, I recommend looking for extraluminal air and secondary signs of peritonitis of the adjacent structures (such as peritoneal or serosal thickening), which indicates irritation of the outer lining by enteric secretions. 

In this case, peritonitis is evidenced by thickening of the right paracolic gutter.