Final answer:
Peritonitis is an injury that commonly follows blunt abdominal trauma but can be missed on initial abdominal CT. It is the inflammation of the peritoneum, the lining of the abdominal cavity.
Step-by-step explanation:
One injury that commonly follows blunt abdominal trauma, but can be missed on initial abdominal CT, is peritonitis. Peritonitis is the inflammation of the peritoneum, which is the lining of the abdominal cavity. It can occur when the wall of the alimentary canal is breached, allowing the contents of the lumen to enter the peritoneal cavity. While a CT scan can detect some signs of peritonitis, such as the presence of fluid or abscess, it may not always reveal the underlying inflammation.