The Diagnostic and Prognostic Utility of Transabdominal Ultrasound in Crohn's Disease: A Clinical Study

In this retrospective study we aimed to assess the diagnostic, monitoring, and prognostic utility of transabdominal ultrasound (TBUS) in patients with Crohn's disease in China and evaluate the utility of 16-week bowel wall thickness (BWT) reduction as a predictor of long-term outcomes.

Patients with CD, either newly or previously diagnosed, who received biologic therapy for the first time and underwent baseline TBUS and endoscopy between June 2022 and September 2023 were included, with follow-up TBUS performed at Weeks 16 and 52 after the initiation of biologic therapy; clinical, ultrasound, laboratory, and disease activity data were collected.

Among the 60 patients, TBUS identified bowel wall thickening in 55 patients, with an average thickness of 7.36 ± 2.56 mm. The Limberg score of vascularization in the affected segments was ≥ 3 in 58.3% of the patients. Ascites, lymphadenopathy, and mesenteric fat hypertrophy were observed in 23.3%, 41.7%, and 41.7% of the patients, respectively. Significant correlations were found between baseline SES-CD or CDAI and BWT (r = 0.650 for SES-CD and 0.331 for CDAI) and the Limberg score (r = 0.538 for SES-CD and 0.387 for CDAI). The receiver operating characteristic (ROC) curve analysis revealed high diagnostic accuracy for BWT (area under the ROC curve [AUROC] 0.973) and the Limberg score (AUROC 0.927). Follow-up TBUS at Weeks 16 and 52 showed significant reductions in BWT and Limberg score. BWT reduction at Week 16 was significantly associated with CD clinical remission at Week 52 (p < 0.05).

TBUS, particularly BWT and Limberg score, may serve as a useful noninvasive tool for diagnosis, monitoring, and prognosis in CD.