Early appendicitis on CT may be a subtle finding that requires a skilled radiologist to diagnose. The appendix is a worm like structure at the base of the cecum, or the start of the colon. Appendicitis on CT classically demonstrates a dilated fluid filled appendix which has thickened walls, is fluid filled, and has surrounding inflammatory change or dirty fat.
Early appendicitis on CT does not always look like a classic appendicitis. There may be one of the findings seen like a fluid filled appendix and inflammatory changes of surrounding fat can be absent. Even the way the patient presents to the clinical doctor may be confusing or not clear.
Diagnosing early appendicitis is important to achieve a good outcome. A missed appendicitis can burst and be life threatening. Therefore, it is crucial to make the diagnosis in a timely manner. An acute or sudden abdominal pain will often prompt an order for a CT scan.
The CT scan can often show appendicitis and many other diagnosis responsible for the abdominal pain. Early appendicitis can be a challenge to diagnose and requires a skilled radiologist who knows about the clinical suspicion for appendicitis. In some cases, the diagnosis is proposed but not confirmed. Often the radiologist raises early appendicitis as a possibility and leaves it up to the clinical judgement of the clinical doctor.
In these cases, a surgeon will often be consulted who will manage the care. If the clinical findings are concerning for acute appendicitis, then the surgeon may observe the patient or go directly to surgery for appendectomy. Sometimes, the emergency or primary care physician will order additional imaging with oral and intravenous contrast agents.
Once the radiologist proposes that early appendicitis is a possibility, then the possibility of a bad outcome goes down significantly. It is better to be more careful in these cases and have occasional cases that turn out to not be appendicitis and something more benign. The diagnosis of appendicitis can be challenging at times and requires a coordinated effort from multiple specialists and tests. Imaging can not be definitive in every case.