Nonenhanced MRI comparable to ultrasound for pediatric appendicitis diagnosis

Nonenhanced MRI has demonstrated high diagnostic performance that is similar to that of ultrasound for suspected pediatric appendicitis, according to a study published online March 17 by Radiology.

Though ultrasonography is often utilized when imaging pediatric patients with suspected acute appendicitis, the imaging modality does not come without its challenges. Many facilities lack the ability to perform ultrasonography in the pediatric demographic, so CT is often used instead. However, “Magnetic resonance imaging has been proposed as an alternative to CT for imaging suspected appendicitis,” wrote lead author Robert C. Orth, MD, PhD, of Texas Children’s Hospital in Houston, and colleagues. “Unlike ultrasonography, it is readily available at many adult facilities due to the need for 24-hour-a-day stroke imaging and is less operator dependent.”

The researchers prospectively compared the diagnostic performance of nonenhanced MRI to an ultrasound for susptected appendicitis in pediatric patients by enrolling 81 patients in their prospective study. Each patient underwent right lower quadrant ultrasonography and nonenhanced, nonsedated abdominopelvic MRI exams. Two pediatric radiologists were then blinded to the ultrasonography results and reviewed the MRI images.

Of the study’s 81 patients, 37 percent had pathologically demonstrated acute appendicitis. When equivocal interpretations were deemed positive, sensitivity and specificity were respectively 93.3 percent and 98 percent for MRI and 90 percent and 86.3 percent for ultrasonography. When equivocal interpretations were deemed negative, the sensitivity and specificity were unchanged for MRI. The specificity and sensitivity of ultrasonography were 86.7 percent and 100 percent, respectively.

“Our study findings showed MR imaging to be highly efficacious for the diagnosis of pediatric appendicitis,” wrote Orth and colleagues. They recommend future studies to determine the general feasibility and cost-effectiveness in using MRI for acute appendicitis diagnosis in pediatric patients.