Pelvic MRI Detects Subclinical Perianal Disease in Pediatric Crohn’s Disease
Routine pelvic MRI at the time of Crohn’s disease (CD) diagnosis may reveal subclinical perianal involvement in pediatric patients, according to new data from a prospective registry review at the Edmonton Pediatric Inflammatory Bowel Disease Clinic.
The findings suggest that early imaging can influence both the timing of biologic therapy and the need for perianal surgery—even in the absence of symptoms.
Among 139 newly diagnosed pediatric patients with CD (median age 13), 19% had asymptomatic perianal disease detected on pelvic MRI, despite a normal physical exam. In the subgroup of patients who were both asymptomatic and had a normal perianal exam, 20% still had MRI evidence of disease.
“These patients needed more and earlier perianal surgery and had higher biologic use despite their perianal disease being subclinical,” the authors reported.
Compared to asymptomatic patients without MRI findings, those with MRI-detected perianal disease were 40% more likely to initiate biologics within 6 months, and 32% more likely by 12 months. Surgical risk was also elevated. MRI-positive asymptomatic patients required perianal surgery sooner and more often than their MRI-negative counterparts (p = 0.02). Notably, the presence of a perianal side-branch fistula on MRI was a strong predictor of surgical intervention (OR 107.6; p < 0.0001).
The study highlights a diagnostic blind spot in pediatric CD management and supports adding baseline pelvic MRI to initial workup, even in the absence of perianal symptoms, the authors noted.
“1 in 5 newly diagnosed pediatric CD patients had subclinical perianal disease, even when having a normal perianal physical exam,” the authors concluded. Early imaging may help identify high-risk patients and guide timely intervention to potentially prevent disease complications.
Reference
Antaya M, Hudson AS, Lerner EP, et al. The impact of integrating pelvic MRI at diagnosis on early detection of perianal Crohn's disease in pediatrics. Am J Gastroenterol. Published online August 20, 2025. doi:10.14309/ajg.0000000000003733
