MRI effective for pediatric appendicitis, even when read by adult-focused radiologists

Ultrasound (US) and CT are typically viewed as the most appropriate imaging modalities for diagnosing pediatric appendicitis, but what about MRI? According to new research published in the American Journal of Roentgenology, unenhanced MRI for suspected pediatric appendicitis is “clinically effective,” even when performed by healthcare providers who typically treat adult patients.

“Numerous studies performed at children's hospitals by pediatric fellowship–trained radiologists have shown that MRI is a viable alternative to CT for the evaluation of appendicitis,” wrote author James D. Covelli, MD, of the department of radiology at San Antonio Military Medical Center at Fort Sam Houston in San Antonio, Texas, and colleagues. “To our knowledge, however, there have been no studies to date in which non–pediatric-trained radiologists interpret all of the examinations.”

The authors noted that US and CT both present physicians with certain challenges when diagnosing pediatric patients, making MRI an especially intriguing option. Their research included more than 500 pediatric patients—all of them younger than 18 years old—who underwent MRI after US yielded indefinite results from 2012 to 2016. No IV contrast material or sedative was administered to the patients. The MRI protocol involved three sequences and took 11 minutes.

Overall, more than 10 percent of patients had surgically or pathologically proven appendicitis. Sensitivity of MRI for appendicitis was 96.4 percent, and specificity was 98.9 percent. An appendix that turned out to be normal, or issues unrelated to the appendix, were revealed in more than 21 percent of patients.

“Our results show sensitivity and specificity values comparable to those reported in the recent literature and show that MRI can be accurate in nonpediatric hospital settings with nonpediatric radiologists interpreting examinations,” the authors wrote.

Covelli and colleagues did note that the radiologists were not completely comfortable interpreting body MRI scans of pediatric patients. This is because, unless they are trained specifically in body imaging, many radiologists do not have exposure to body MRI—especially with young patients. In addition, the facility’s radiologists typically have all nonpregnant adult patients undergo CT for suspected appendicitis, not MRI.

“To overcome these challenges, an image-rich, evidence-based campaign was developed and implemented by our pediatric radiology section to educate ED providers, general and pediatric surgeons, pediatricians, nonpediatric radiologists, and parents,” the authors wrote. “In addition to educational posters and pamphlets, this campaign involved multiple grand rounds and other departmental, interdepartmental, and multidisciplinary conferences with educational and how-to lectures and opportunities for input and questions from clinicians and nonpediatric radiologists. Over time, this educational campaign, direct interpretive feedback, and coaching by pediatric radiology, along with key collaborative modifications to decrease imaging algorithm time, proved successful and opposition progressively subsided while confidence and trust in MRI interpretation increased.”