Using ultrasonography and magnetic resonance imaging instead of computed tomography to diagnose children’s acute appendicitis resulted in similar clinical outcomes, a study found.
The retrospective study found no differences in the time to receive antibiotics or an appendectomy, the negative appendectomy rate, the perforation rate, or the length of stay among children undergoing either diagnostic method, reported Dr. Gudrun Aspelund and her colleagues at Columbia University Medical Center, New York (Pediatrics 2014;133:1-8).
Dr. Gudrun Aspelund
CT scans have historically been used to diagnose appendicitis because of their high sensitivity and specificity, but they expose children to radiation, raising concerns about cumulative exposure and later cancer risk. Ultrasonography requires more operator expertise (with a sensitivity range of 44%-100%), but it involves no radiation and has been used with MRI to effectively diagnose appendicitis in adults.
Among 662 patients under age 18 with suspected appendicitis at Morgan Stanley Children’s Hospital, New York, 265 (group A) were assessed between November 2008 and October 2010, including 224 (84.5%) with CT, 40 with ultrasonography, and 1 with MRI. After the hospital prioritized ultrasonography/MRI for diagnostic imaging for appendicitis, 397 (group B) were assessed between November 2010 and October 2012, including 365 receiving ultrasounds, 142 receiving MRI, and 35 receiving CT scans (including those receiving multiple imaging).
Among group A patients (primarily CT scans), 51% had positive imaging for appendicitis; group B included 41% with positive imaging (P = .007). Patients with appendicitis were treated with an appendectomy, percutaneous drainage, or antibiotics. While the 291 patients with negative studies were confirmed true negatives, 74 others (11%) were lost to follow-up but believed to be true negatives.
Despite the significantly higher positive imaging rate in group A than in group B, no false negative imaging was identified in either group, and negative appendectomy rates were similar: 2.5% in group A and 1.4% in group B (P = .7). "Sensitivity, specificity, and positive and negative predictive value of the imaging pathways for the diagnosis of appendicitis were similar between study periods," the researchers reported.
Appendectomy rates were 45% in group A and 37% in group B (P = .0003). The researchers reported that perforation rates were not significantly different between the groups, but they did not provide numbers for the rates.
Similarly, there was no difference in time to antibiotics (8.7 hours in group A and 8.2 hours in group B) or time to appendectomy (13.2 and 13.9 hours, respectively). Overall length of stay did not differ between the groups (52.2 and 43.3 hours), nor did length of stay for image-positive appendicitis (82.2 and 76.6 hours).
"Use of ultrasonography and MRI is possible and effective for diagnosis in most cases of pediatric appendicitis," Dr. Aspelund and her associates reported. "These data support the notion that use of CT could be limited."
The study was internally funded, and the authors reported no disclosures.