Until now, in cases where appendicitis is strongly suspected and ultrasound is inconclusive, computed tomography (CT) has been the method physicians rely on for further investigation. However, this technique involves the use of ionising radiation, which is less desirable during pregnancy because of potential harm to the foetus.

"MRI can potentially spare thousands of women and their developing foetuses from exposure to radiation by minimizing the need for CT to rule out appendicitis," said Dr. Ivan Pedrosa, M.D., lead author of the study from Beth Israel Deaconess Medical Center and assistant professor of radiology at Harvard Medical School in Boston.

Dr. Pedrosa's study constitutes the largest series of pregnant women with abdominal pain evaluated with MRI to date. Abdominal pain is a common complaint during pregnancy, and physicians are challenged with recognizing situations where emergency surgical intervention is necessary. Appendicitis is the most common cause of belly pain requiring emergency surgical treatment in pregnant women.

Typically, ultrasound is the preferred method for imaging the appendix in pregnant women, but the enlarged uterus and other physiologic changes – particularly during the third trimester – may prevent ultrasound from effectively visualizing the appendix, rendering the exam inconclusive.

In Dr. Pedrosa's study, 51 pregnant women underwent MRI after complaints of abdominal pain. Forty-eight of the women had a prior ultrasound exam. MRI yielded four diagnoses of acute appendicitis. Two of these four cases were not detected with ultrasound.

"Our study clearly demonstrates the capability of MRI when evaluating pregnant patients suspected of having appendicitis," said Dr. Pedrosa. "Additionally, MRI can reveal other conditions that may masquerade as appendicitis clinically, without unnecessary radiation exposure."

MEDICA.de; Source: Radiological Society of North America