Experience in the application of ultrasound indices for assessing the activity of inflammatory bowel diseases

Aim. To evaluate the diagnostic value of ultrasound (US) parameters and indices for assessing the active inflammatory bowel diseases (IBD). Materials and methods. The study included 115 patients with IBD, 41 (36%) patients were with ulcerative colitis (UC) and 74 (64%) – with Crohn's disease (CD). Transabdominal US examination of the intestine was performed on Sonoscape S2N, with a bowel wall thickness (BWT) of 3 mm considered the norm. To assess activity in UC, the Milan Ultrasound Criteria (MUC) score was used, and in CD – International Bowel Ultrasound Segmental Activity Score (IBUS-SAS). Results. In active UC BWT (5.91 [4.87; 6.95] mm) was greater than in remission (2.9 [2.6; 3.1] mm; p = 0.003). For active UC diagnosis BWT greater than 3 mm had sensitivity (Se) of 90.5% and specificity (Sp) of 70.6%. The MUC in exacerbation (9 [7.88; 11.8]) was higher than in remission (4.2 [3.64; 4.9]; p 0.001). In 31 (89%) patients in exacerbation, the MUC was higher than 6.2 (Se 88.9%, Sp 87.5%), and in 34 (97%) at a threshold of 5.18 (Se 96.3%, Sp 87.5%). In active CD, BWT (4.9 [3.8; 6.6] mm) was greater than in remission (3.18 [2.6; 3.5]; p = 0.0001), with Se 87.0%, Sp 71.4%. The IBUS-SAS in active CD (46.8 [27; 71.5]) was higher than the remission (12.6 [11.2; 30.2]; p = 0.001). At a threshold of 37.5, the IBUS-SAS had Se 92.6%, Sp 61.5%, and at 45.2, Se 92.6%, Sp 87.2%. Conclusion. US imaging is a useful and effective tool for assessing IBD activity; a threshold value of the MUC score of 5.18 and IBUS-SAS of 45.2 suggests better diagnostic value for differentiating between exacerbation and remission.