Diagnosing patients who experience right, lower-quadrant abdominal pain has evolved significantly over the years, according to a recent study published by the Journal of the American College of Radiology. A patient’s personal history and a physical examination were once a physician’s primary tools for diagnosing appendicitis, but imaging plays a much larger role in the emergency departments of today.

Michael D. Repplinger, MD, PhD, University of Wisconsin-Madison, and colleagues studied data for more than 2,100 emergency department patients from between 1992 and 2014, looking for trends in how imaging utilization has been used in the diagnosis of appendicitis. These are three of the team’s biggest discoveries:

1. CT use has increased significantly

The most noteworthy finding of the entire study was that the use of CT for diagnosing appendicitis has increased significantly in the last 22 years. More than two percent of patients with appendicitis were diagnosed by CT alone in 1992, and that number skyrocketed to more than 83 percent in 2014.

Changes in ultrasound, MRI, and a combination of CT and ultrasound, however, were “not statistically significant.”

According to Repplinger et al., there is one potential issue with this increase.

“Increased use of CT has an associated increase in exposure to ionizing radiation, which is a risk factor for developing cancer,” the authors wrote. “This risk is of particular importance for pediatric patients, who are more radiosensitive and likely have a longer time in which cancer can develop.”

The American College of Radiology’s Appropriateness Criteria specifically addresses this issue by recommending the use of ultrasound when diagnosing younger patients, and the authors noted that CT use has actually decreased in some children’s hospitals.

2. MR use is rare

The use of MRI for diagnosing appendicitis was just 1.7 percent in 2014.

However, the authors wrote, recent studies praising the accuracy of MRI use could potentially sway this data in the near future. In addition, the number may be so low because of specific circumstances at the facility being analyzed.

“Our medical center does not have a labor and delivery service; pregnant patients are directed to another local hospital affiliated with our center,”  the authors wrote. “Given that the strongest recommendations regarding MR use to diagnose appendicitis are for the pregnant population, the low level of MR utilization for appendicitis is partially explained by this operational issue.”

3. Diagnosing appendicitis without the use of any imaging is way down

The number of patients diagnosed with no imaging—no CT, no MRI, nothing—dropped from more than 91 percent in 1992 all the way to more than 2 percent in 2014.

“It seems that referring physicians, almost universally, are incorporating medical imaging into the routine evaluation of patients suspected of having appendicitis,” the authors wrote.

The researchers noted that their study did have numerous limitations. For instance, only “a subset of years” within the 22-year time period were broken down and studied. Large variations may have occurred, they said, but the likelihood that that happened is “highly unlikely.” Also, low-dose CT protocols were implemented at their facility. Had those protocols not been put in place, the authors concluded, ultrasound may have increased much more than the data shows.