MRI rules out appendicitis during pregnancy

NEW YORK (Reuters Health) - Pregnant women are prone to a number of conditions that can mimic appendicitis, so diagnosis of acute abdominal pain can be tricky in this situation. Now a team of physicians has shown that magnetic resonance imaging is accurate for excluding appendicitis in pregnant women.

Dr. Ivan Pedrosa and colleagues at Beth Israel Deaconess Medical Center in Boston note that while ultrasound is the preferred imaging method in pregnancy, it often fails to visualize the appendix.

Pedrosa's team took a look back at the diagnostic performance of MRI in 51 pregnant patients with suspected acute appendicitis who were seen between 1999 and 2004.

Ultimately, four patients had appendicitis and 47 did not.

According to the investigators' report in the journal Radiology, 48 patients underwent ultrasonography, which diagnosed appendicitis in two cases but failed to visualize the appendix in 46 cases.

MRI was positive for appendicitis in all four cases, while it was inconclusive in three instances. Among the 47 patients without appendicitis, MRI visualized the appendix in 39.

MRI didn't miss any cases of appendicitis, so it provides "an effective means for ruling out a surgical diagnosis in this patient population with a low prevalence of the disorder," Pedrosa's group concludes.

SOURCE: Radiology, March 2006.