MRI Versus CT Scans to Spot Appendicitis

Appendicitis diagnosis in children equally determined with MRI as with CT scans

(RxWiki News) It seems natural to use the "best" tool for a job. But what if that tool involves extra risks? And what if the risk is to children?

That's exactly what researchers investigated in a recent study involving different methods of diagnosing appendicitis.

The researchers found that using ultrasounds and magnetic resonance imaging (MRI) was just as effective and accurate to diagnose appendicitis as using computed tomography (CT) scans.

However, the ultrasounds and MRI, which uses a giant magnet to create an image, do not expose children to radiation as the CT scan does.

"See your doctor immediately if you experience severe abdominal pain."

This study, led by Gudrun Aspelund, MD, of the Division of Pediatric Surgery at Columbia University Medical Center in New York, looked at the effectiveness of using ultrasounds and MRIs instead of CT scans for diagnosing appendicitis.

CT scans have traditionally been considered the best diagnostic tool for appendicitis because of their accuracy and consistency. However, CT scans also expose children to higher levels of radiation than other diagnostic tests, which may increase the children's risk of cancer over time.

Ultrasounds and MRI scans do not expose children to any radiation, so the researchers wanted to find out whether using these methods led to similar outcomes for children.

These researchers compared two groups of children with suspected appendicitis, both seen at Morgan Stanley Children's Hospital in New York.

One group of 265 children was assessed between November 2008 and October 2010, when the main method of diagnosis involved CT scans for most children.

The other group, with 397 children, was assessed between November 2010 and October 2012, after the hospital began using primarily ultrasound and MRI scans for appendicitis diagnosis instead.

The researchers compared the results, including "false positives" or "false negatives," across these two groups.

Appendicitis was identified in 51 percent of the children in the first group and 41 percent of the children in the second group.

Even though these findings were different, the accuracy of CT scans versus ultrasounds with follow-up MRI scans (when needed) were similar.

None of the children in either group received a false-negative. Only 2.5 percent of the first group and 1.4 percent of the second group had false-negatives, in which a child was treated for appendicitis without actually having it.

Similarly, the time it took for the children to receive treatment, whether an operation or antibiotics, and the time the children spent in the hospital was similar across both groups.

Hence, the researchers concluded that using ultrasounds along with MRI scans to diagnose appendicitis was just as effective and accurate as using CT scans — but without the extra radiation exposure.

According to Chris Galloway, MD, a dailyRx expert who specializes in emergency medicine, practitioners are becoming more and more conscientious about minimizing unnecessary radiation exposure for all patients – especially children – since radiation accumulates over a lifetime.

"This paper demonstrates a diagnostic pathway for ruling in or out appendicitis that can reach the same accuracy of a CT scan without exposing our pediatric patients to damaging radiation," he said.

Yet, "it should be mentioned that this approach with ultrasound followed by MRI means the patient leaves the emergency department for multiple tests that can be lengthy" and that ultrasound skill is often dependent on the operator, he said.

"Additionally, not all ERs have MRI availability, and these tests require considerable patient cooperation or else accuracy is compromised," he said. "There are evolving decision rules for clinician evaluation incorporating bedside blood tests and algorithms that will hopefully show high levels of sensitivity and specificity negating need for imaging in the future."

This study was published March 3 in the journal Pediatrics. The research used no external funding, and the authors reported no conflicts of interest.

Review Date: 
March 5, 2014