Studying the Correlation Between Ultrasound Features and Crohn's Disease Severity in Pediatric Patients Referred to Imam Hossein Hospital in Isfahan, Iran, Between 2019 and 2021

Purpose: Crohn's disease is a type of Inflammatory Bowel Disease which can lead to abdominal pain, severe diarrhea, malnutrition, weight loss and fatigue. Ultrasound (US) is safer than CT, which has a high radiation exposure, and it is gaining popularity for diagnosing Crohn's disease in children. This study aimed to assess the correlation between US features and Crohn's disease severity in pediatric patients.

Methods/Materials: This is a cross-sectional study performed from March 2019 to April 2021 at Imam Hosein hospital, affiliated with Isfahan University of medical science, Isfahan, Iran. We used convenience sampling to study 22 pediatrics and assessed their Crohn's disease severity with the pediatric Crohn's disease activity index (PCDAI). We examined and documented US imaging data, including the thickness of ascending colon loop, number of lymph nodes, short axis diameter of lymph nodes, the thickness of the ileal loop, spleen span, free fluid, fistula, liver echogenicity, vascularity around the loops, lumen narrowing, terminal ileum compression, mesenteric fat hypertrophy, intestinal wall and mesenteric fat echogenicity and superior and inferior Mesenteric indices.

Results: Comparing mild with the severe forms of Crohn's disease, intestinal wall echogenicity, fat echogenicity, mesenteric fat hypertrophy, hypervascularity, and lumen narrowing changed significantly (p < 0.05). In addition, the mean ileal loop thickness increased significantly (p=0.005 < 0.05) from mild (2.12 ± 0.58 mm) to severe (4.49 ± 1.43 mm). The changes in mean ascending colon loop thickness, number of lymph nodes, short axis diameter of lymph nodes, spleen span, and mesenteric artery indices were not statically significant (p>0.05).

Conclusions: This study shows that US features change with the severity of Crohn's disease. This can lead physicians to do the US on pediatric patients with Crohn's disease as the first diagnostic workup. They can also potentially do follow-ups by tracing changes in the US features such as intestinal wall echogenicity, fat echogenicity, mesenteric fat hypertrophy, hypervascularity, lumen narrowing, and mean ileal loop thickness.