Khairul Najmi Muhammad Nawawi.1,3, Kuan Yee Lim1 , Faizah Mohd Zaki2, Juliana Fairuz Maktar2, Zhiqin Wong1,3, Raja Affendi Raja Ali1,3
1Gastroenterology Unit, Department of Medicine, Faculty of Medicine, The National University of Malaysia, Cheras, Kuala Lumpur, Malaysia, 2Department of Radiology, Faculty of Medicine, The National University of Malaysia, Cheras, Kuala Lumpur, Malaysia, 3GUT Research Group, Faculty of Medicine, The National University of Malaysia, Cheras, Kuala Lumpur, Malaysia
Background/Aims: Intestinal ultrasound (IUS) is an emerging test in the management of IBD. We aim to determine the performance of IUS as compared to ileocolonoscopy and other diagnostic modalities to assess the disease activity.
Methods: IUS parameters include intestinal wall thickness, loss of wall stratification, mesenteric fibrofatty proliferation, and increased vascularity. Endoscopic and clinical activity indices used include SES-CD (CD), UCEIS (UC), HBI (CD) and Partial Mayo score (UC).
Results: This is a prospective, cross-sectional study involving 25 patients that comprised of 47.6% male, with overall mean age of 40 years. Fifty-two percent had underlying ulcerative colitis with the mean IBD duration of 7.6 years. Against ileocolonoscopy, IUS had a sensitivity of 62.5% [26,90] for detecting endoscopically active disease. It had high specificity of 92% [62,99] with positive and negative predictive values of 80%. Against clinical activity index, IUS had a similar performance with sensitivity 62.5% [26,90] and specificity 92% [62,99] for detecting moderate to severe disease.As compared to the disease biomarkers such as C-reactive protein (CRP) and faecal calprotectin, IUS had a sensitivity of 44.4% [15,77] and 33.3% [9,69] respectively and a specificity of 83.3% [51,97] and 85.7% [42,99] respectively. Against radiological examinations, IUS had a better performance with sensitivity 66.7% [24,94] and specificity 75% [22,99].Among individual IUS parameters, presence of bowel wall thickening (>3cm) had the highest sensitivity for detecting endoscopically active disease – 62.5% [26,90], followed by loss of wall stratification – 37.5% [10,74]. For per-bowel segment analysis, IUS (bowel wall thickening) able to achieve 100% sensitivity and specificity when examining the transverse colon.
Conclusion: IUS has moderate sensitivity with excellent specificity in detecting active disease. IUS is mostly sensitive in detecting a diseased colon at transverse. IUS can be employed as an adjunct in the assessment of IBD.
Keywords: Intestinal Ultrasound, Inflammatory Bowel Disease, Sensitivity, Specificity