Research in Acute appenDIcitis and mAgnetic resonaNCE imaging.

Acute appendicitis is the most common cause of acute abdominal pain requiring surgery in children, and typically occurs in older children and young adults. The main cause of appendicitis is obstruction of the appendiceal lumen that leads to diminished lymphatic and venous drainage, which in turn can result in bacterial infection of the appendiceal wall.
Appendicitis presents with periumbilical pain typically descending to the right lower quadrant, as well as nausea and vomiting in 50% of the patients. If presentation is less specific, it can be difficult to differentiate acute appendicitis from other sometimes non-surgical conditions that result in acute abdominal pain. In these cases, additional imaging is necessary to avoid delay of diagnosis or unnecessary surgical intervention. The main complication of a delayed diagnosis is perforation, which can lead to abscess formation, peritonitis, and even death. The prevalence of appendiceal perforation in various pediatric series ranges from 23% to 73%. Graded-compression US is the imaging method of choice, and high sensitivity and specificity can be achieved when employed by experienced examiners. However, the appendix is not always visible, especially if the appendix has a retrocoecal location or if the appendix is perforated. When further evaluation is necessary, other imaging modalities play an important role in diagnosis. CT examination in appendicitis has been validated and the number of CT scans performed in the presurgical diagnosis of appendicitis is increasing rapidly. However the lifetime risk of radiation-induced fatal cancer is estimated to be considerably higher for fetal, pediatric and adolescent exposure than for adult exposure. There are several publications describing good results with MR imaging of appendicitis in adults, mainly involving pregnant patients. However pediatric patients have a different constitution (in general less abdominal fat and the imaging characteristics of the appendix may be different (because of lymphoid tissue). As far as we know no prospective studies have been done in children, even though this population may benefit the most from this technique. One of the reasons for this may be that up to recently the examination time was long, resulting in motion artifacts. The introduction of ultra-fast sequences shortens the examination time, resulting in less motion artifacts, which is especially useful in children.

To determine the sensitivity and specificity and positive and negetive predictive value of MRI in a consecutive series of pediatric patients suspected for acute appendicitis.

1. The histopathologic findings if the patient is operated upon;

2. Diagnosis after a follow-up period of 3 months in all patients.


In patients who were treated conservatively (e.g. no appendicitis, or a different cause for the pain was detected) appendicitis will be ruled out, if in those 3 months no further operation upon the appendix was performed.



US and MRI findings will be compared to these study end points.

1. Ultra Sound (US);

2. Magnetic Resonance Imaging (MRI).