A Comparison Between the Bowel Ultrasound Score and International Bowel Ultrasound Segmental Activity Score Based on Ileocolonoscopy in Patients with Crohn’s Disease

doi:10.21203/rs.3.rs-5320447/v1

Background and Aim

We aimed to compare two main existing scores, Bowel Ultrasound Score (BUSS) and International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) to predict simplified endoscopic activity score for CD (SES-CD).

Methods

A cross-sectional study was performed to evaluate the disease activity in CD patients with ileal involvement between November 2019 and February 2024. Remission for CD was accepted for SES-CD ≤2.

Results

Total 56 adult patients with CD (Male; 38, 67.9%, Median age; 40.5 years) were included in the study, the median duration of the disease was 8.4 years. The cut-off value for BUSS to determine endoscopic remission was 3.9, while the cut-off value for IBUS-SAS to establish endoscopic remission was 24.4. BUSS and SES-CD had a strong positive correlation (p<0.001), BUSS and IBUS-SAS had a high positive correlation (p<0.001), and BUSS and CRP had a slightly positive correlation (p<0.001).

Conclusion

In this study, we found that the most accurate cut-off value for BUSS was 3.9 and the most accurate cut-off value for IBUS-SAS was 24.4 in CD patients with endoscopic remission group. Furthermore, we have confirmed that both BUSS and IBUS-SAS significantly correlate with endoscopic activity in a real-world cohort.

Intestinal Ultrasound

Crohn’s Disease

Bowel Ultrasound Score

International Bowel Ultrasound Segmental Activity Score.

Crohn’s disease (CD) is characterized by chronic gastrointestinal inflammation with relapsing-remitting behavior and often requires endoscopic and various imaging assessment. Therefore, during follow-up of CD, monitoring of active bowel damage is crucial to identify any complications and assess the efficacy of medication (1). Intestinal ultrasound (IUS) has been used as valuable tool for accurately detecting intestinal damage and characterizing disease behavior in CD. IUS has a number of advantages over other cross-sectional imaging modalities, it is non-invasive, inexpensive and tolerable, and it permits repeated examinations, allows for the dynamic and real-time visualization of the mesenterium as well as the bowels (2). IUS has been recognized as one of the most reliable noninvasive methods for determining the degree of CD activity (3).

Of the 14 studies that have examined IUS scores for CD activity assessment to date, almost all of them had methodological deficiencies and have been rated as having at least one unclear or high risk of bias (4–6). Subsequently, four IUS scoring systems were created to identify inflammatory activity on CD using multivariable analysis (7–10). In particular, ileocolonoscopy was used in three out of the four studies, and the reference standard for a quantitative evaluation was the Simple Endoscopic score for CD (SES-CD) (8–10). The Bowel Ultrasound Score (BUSS) that uses ileocolonoscopy as the reference standard and have used parameters identified in multivariate analyses as independent predictors for detecting disease activity and severity, which detects endoscopic response with high accuracy (9). International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) used a global disease activity defined on a visual analogic scale which evaluate and identified vital parameters to assess disease activity through an expert consensus using the Delphi method (7), and recently, IBUS-SAS has been externally verified and clinically applied in the studies (6, 11).

The studies are needed to compare the characteristics and methods of these two existing scores (BUSS & IBUS-SAS), which have cut-off value, focusing on disease activity in patients with CD. In this study we aimed to compare these two scoring systems and to define a cut-off level of disease remission in patients with ileal CD using the SES-CD.

Study design and population

An observational cross-sectional study was performed to evaluate disease activity in consecutive adult CD patients with ileal involvement (Montreal classification: L1) attending our tertiary IBD clinic, between November 2019 and February 2024. Patients with severe comorbidity, pregnancy, isolated upper gastrointestinal tract disease, diagnosis less than 6 months and previous ileo-colonic surgery was excluded from the study. The interval between ileocolonoscopy and IUS was less than 1 week. Written consent was obtained from each patient to participate in this research. All baseline demographics characteristics of patients with CD were recorded. Clinical symptoms and laboratory tests were documented at the time of the ileocolonoscopy (during the bowel preparation for the current procedure), and clinical activity was defined as Crohn's disease activity index (CDAI) ≥ 150.

Ileocolonoscopy

Ileocolonoscopy was performed by a single, expert operator who was blind to the other examinations of the patients. Colonoscopies (Olympus; EVIS EXERA II Video System CV-180, Japan) were used after oral bowel cleansing. The endoscopic diagnosis of CD was made in accordance with the ECCO guidelines. The Simple Endoscopic Score for Crohn’s Disease (SES-CD) was used for evaluating the endoscopic disease activity in the terminal ileum. For SES-CD in the terminal ileum, four endoscopic variables were used: the presence and size of ulcers, extent of ulcerated surface, extent of affected surface and the presence of narrowing. Each of these variables was scored from 0 to 3, and segmental endoscopic activity can then be measured, 0–2 was defined as endoscopic remission for SES-CD.

Intestinal ultrasound

The IUS examination was performed by a gastroenterologist with expertise in IUS (12 years of experience); he was blind to the findings of the patient’s symptoms and other diagnostic procedures. There were no special patient preparations for IUS examination, such as the use of a contrast agent. IUS was performed after at least 6-hour fasting. The entire abdomen was investigated by using GE LOGIC S6 device (GE Healthcare, Chicago, United States) or Mindray DC-T6 (Mindray Bio-Medical Electronics, Shenzhen, P.R. China) starting from the left inguinal fossa initially employing a convex probe (3.5–5.5 MHz) and then a linear probe (7–12 MHz) for detailed examination. The time interval was lower than 10 days between ileocolonoscopy and IUS examination.

Bowel wall thickness of the terminal ileum (BWT) was measured in both transverse and longitudinal sections, from the interface between the mucosa and the lumen to the interface between the serosa and the muscle layer. A mean of two measurements for each section was calculated and a thickness up to 3 mm was accepted as normal value. Bowel wall stratification (BWS) [0–3], defined as 0 = normal, multi-layered, 1 = uncertain, 2 = predominantly hypoechogenic, focal [≤ 3 cm], 3 = lost, extensive [> 3 cm]. Colour Doppler signals (CDS) [0–3], defined as colour Doppler score; 0 = absent, 1 = short signals, 2 = long signals inside bowel, 3 = long signals inside and outside bowel. Mesenteric hypertrophy (i-fat) [0–2], defined as 0 = absent, 1 = uncertain, 2 = present (Figs. 1 and 2). The presence of other IUS parameters and complications was also investigated.

The BUSS was calculated according to the validated formula (BUSS = 0.75 × BWT + 1.65 × CDS; where CDS = 1 if present, or CDS = 0 if absent). Remission was defined as a BUSS score ≤ 3.52 by IUS. The IBUS − SAS was also calculated (IBUS-SAS = 4 × BWT + 15 × i- fat + 7 × CDS + 4 × BWS), colour Doppler signal was accepted, 0 = absent, 1 = short signals, 2 = long signals inside bowel, 3 = long signals inside and outside bowel for IBUS − SAS. Demonstrative score parameters of IUS showed in Figs. 1 and 2.

Ethics statement

The study was approved by the local Ethics Committee (Ethic number: 1-24-203).

Statistical analysis

Statistical analyses were done by using IBM SPSS version 25.0 (IBM Corp., Armonk, N.Y., USA). The Kolmogorov-Smirnov test was used to analyze the normality of the distribution of continuous variables. As all continuous variables were non-normally distributed, they were given as median (interquartile range (IQR)). Mann-Whitney U test was used for comparisons of continuous variables. Categorical variables were expressed as numbers (percentages) and using the Fisher’s exact test made comparisons. Receiver operating characteristic (ROC) curve analyses was performed for BUSS and IBUS-SAS to predict SES-CD ≤ 2 for Crohn's disease. The results were expressed as the area under the curve (AUC), 95% confidence interval (CI), cut-off value, sensitivity, specificity, and p-value. The cut-off value was determined as the maximum value of the Youden index (sensitivity + specificity − 1). The correlations of BUSS and IBUS-SAS between BUSS, IBUS-SAS, SES-CD, CDAI, CRP, hemoglobin, and albumin were analyzed by two-tailed Spearman correlation analyses. Correlation analysis results were expressed as correlation coefficient value (R) and P value. In the presence of a statistically significant P value, the R-value between 0 and 0.2 was considered a very weak correlation, the R-value between 0.2 and 0.4 was considered a weak correlation, the R-value between 0.4 and 0.6 was considered a moderate correlation, the R-value between 0.6 and 0.8 was considered a high correlation, and the R-value > 0.8 was considered a very high correlation. A two-tailed P value < 0.05 was considered statistically significant.

Study population

A total 132 patients with CD were underwent IUS and ileocolonoscopy, of whom 71 were excluded from the study because of colonic or ileo-colonic involvement, as well as 5 ileal CD underwent ileo-colonic resection and finally 56 adult patients with ileal CD were included in the study. The median age was 40.5 (IQR 26-46.75) years, 38 patients (67.9%) were male, and the median duration of the disease was 8.4 (IQR 4.93–10.29) years. Majority of the patients 50 (89.3%) had inflammatory behavior. 25 (44.6%) patients were naïve to immunomodulators and biologics, whereas 19 (33.9%) patients had received at least one biologic therapy. The median days between the examinations of IUS and ileocolonoscopy were 1.8 (IQR 0–10) days. All baseline demographics characteristics of patients with CD are summarized in Table 1.

BUSS and IBUS-SAS value to determine endoscopic active and inactive groups in 12 (21.4%) patients, the SES-CD was ≤ 2, while in 44 (78.6%) patients, the SES-CD was > 2.

In endoscopically remission (SES-CD ≤ 2) group; median BUSS was 2.63 (IQR 2.12–3.45) and median IBUS-SAS was 14 (IQR 11.3–18.4), while in endoscopically active (SES-CD > 2) group; median BUSS was 5.67 (IQR 3.47–7.76) and median IBUS-SAS was 49.7 (IQR 23.3-72.65). Both the median BUSS and the median IBUS-SAS in endoscopically remission group were significantly lower than in endoscopically remission group (p < 0.001, for both) (Table 2).

The cut-off value for BUSS to determine endoscopic remission (SES-CD ≤ 2) was 3.9 (AUC:0.839, 95% CI:0.737–0.941, sensitivity:92%, specificity:73%, p < 0.001), while the cut-off value for IBUS-SAS to establish endoscopic remission (SES-CD ≤ 2) was 24.4 (AUC:0.871, 95% CI:0.780–0.962, sensitivity:100%, specificity:73%, p < 0.001) (Table 3, Fig. 3–4).

Correlation between IUS scores and SES-CD

Table 4 shows the correlations between IUS scores and clinical activity index/laboratory variables. There was a positive very high correlation between BUSS and IBUS-SAS (r = 0.914, p < 0.001), a positive high correlation between BUSS and SES-CD (r = 0.659, p < 0.001), a positive moderate correlation between BUSS and CRP (r = 0.577, p < 0.001), and finally a positive weak correlation between BUSS and CDAI (r = 0.347, p = 0.009). In contrast to those hemoglobin and albumin were negatively weakly correlated with BUSS (r=-0.391, p = 0.003 and r=-0.289, p = 0.031). There was also a positive high correlation between IBUS-SAS and SES-CD and CRP (r = 0.728, p < 0.001 and r = 0.657, p < 0.001), a positive moderate correlation between IBUS-SAS and CDAI (r = 0.485, p < 0.001), in addition to that hemoglobin was negatively moderately and albumin was negatively weakly correlated with IBUS-SAS (r=-0.403, p = 0.002 and r=-0.274, p = 0.041).

Monitoring disease activity is one of the main goals of CD management, and ileocolonoscopy has been a common but challenging technique for detecting activity in CD. Patients frequently undergo multiple ileocolonoscopies; nevertheless, patient acceptance of this procedure remains limited and the assessment of merely mucosal inflammation by ileocolonoscopy may not be effective to assess disease activity because CD is a transmural inflammatory illnesses (3). Transmural healing has been a new and appropriate therapy target for patients with CD, and its use has increased notably in recent years. IUS is a non-invasive alternative method that is more favorable among patients and clinicians. Moreover, IUS offers real-time feasibility, which facilitates prompt clinical decision-making at the point of care.

Numerous IUS scoring systems have been proposed to assess disease activity in CD (7–10). The BUSS used ileocolonoscopy as the reference standard and has expended parameters identified in multivariate analyses as independent predictors for detecting disease activity and severity, which also reveals endoscopic response with high accuracy (9). The IBUS-SAS used a global disease activity defined on a visual analogic scale which evaluate and identified vital parameters to assess disease activity through an expert consensus using the Delphi method (7), and recently, IBUS-SAS has been externally studied and verified in the research (6, 11). However, validation studies are essential to substantiate IUS findings. The studies pointing IUS score can help identify additional cut-off values for BUSS, IBUS-SAS or other scores that may be more tailored to predicting severe endoscopic activity, complications, and the development of (6, 11). Further comparative analysis between IUS scores is needed to determine the optimal IUS score that predicts endoscopic activity using mural and mesenteric findings.

In the presented cross-sectional observational study, the BUSS and IBUS-SAS scores based on SES-CD in patients with ileal CD were compared, IUS parameters were individual evaluated for the terminal ileum, because of several biases, such as the deep pelvic placement of the rectum or anatomic variation and increased motility of the transvers colon. Research regarding segment-by-segment comparison between US findings and endoscopic and x-ray results in CD patients revealed that disease of the terminal ileum was the most easily detected site by US, with a sensitivity of 95%, which reduced to 82% for the transverse colon (12). Additionally, in cases where the multiple intestinal segments were affected, the authors measured the most affected segment with the highest scores (4, 6, 11). However, whereas ileocolonoscopy may detect identical endoscopic scores in the various ileocolonic segments, IUS may show a different activity score in the same ileo-colonoscopic representative area. Therefore, we believe that in patients with individual ileal CD (Montreal classification: L1), comparing BUSS and IBUS-SAS based on SES-CD yields more accurate results.

In our study, Both IUS scores (BUSS and IBUS-SAS) showed the strongest correlation with endoscopic activity. The BUSS demonstrated moderate correlation with CRP and a weak correlation with CDAI. However, the IBUS-SAS revealed high correlation with CRP and a moderate correlation with CDAI. Allocca M et al. presented that similar reliability to detect the presence of any endoscopic activity, both BUSS and IBUS-SAS have a good efficacy in stratifying the disease burden and in identifying disease activity, which is consistent with our activity score results (11). Our outcomes especially IBUS-SAS result, are strongly associated with recently published study by Dragoni G et al. that compared and externally validated four different IUS scores (6). They found that there was a strong correlation between endoscopy and clinical symptoms for all IUS scores. Nevertheless, IBUS-SAS outperformed the other IUS scores, which could be particularly useful in identifying various disease activity levels (6). We believe that IBUS-SAS might be the most reliable and appropriate score to be adopted in centers with well-informed expertise in IUS.

Increasing mesenteric fat around the circumference of the intestine is pathognomonic and may have an impact on CD (13). A recent study revealed a correlation between creeping fat and the need for corticosteroids and hospitalization (14). Mural and transmural edema can also be observed in active CD, which is seen as disturbed mural stratification on IUS. Furthermore, transmural edema is a response to active CD, which is associated with an anomaly of mesenteric fat (15). Imaging studies revealed that nearly all ultrasound parameters especially including BWT, BWS, mesenteric fat and CDS are significant correlation with CD activity (4, 6, 15, 16). Therefore, using the extended IUS parameters to detect CD activity might be more sensible approach to treat to target strategy.

Our analysis showed that the IUS cut-off value was 3.9 for BUSS and 24.4 for IBUS-SAS, which was comparable to the values reported for BUSS (3.52) and IBUS-SAS (22.8) in previous original studies (7, 9). Dragoni G et al. showed that four IUS scores was comparable reliability to detect the presence of endoscopic activity (6). In this study, IBUS-SAS for endoscopic activity had the highest accuracy, sensitivity and specificity for a cut-off value of 25.2, which is consistent with both our findings and those of the original report (6, 7). In view of these encouraging results, we endorse the use of these scores as useful instruments in routine clinical practice as well as clinical studies.

We believe the strengths of our study are the standardization of IUS scoring with the same cohort and same ileal region of patients by the constant specialist, and the close assessment IUS and ileocolonoscopy within a period of 7 days. As a limitation, our study was the single center research. Further research is needed to validate this tool in a prospective and multicenter study. Finally, the association between the endoscopic score and IUS scores may be limited by the endoscopic examination of the various anastomotic regions and non-passable stenosis in order to prevent over- or underestimating.

We found that the cut-off value for BUSS was 3.9 and IBUS-SAS was 24.4, respectively in CD patients with endoscopic remission. Furthermore, we have confirmed a significant correlation between endoscopic activity and both BUSS and IBUS-SAS. Future studies should investigate and compare IUS scores across various illness settings, including disease activity, location, and therapy response.

IUS; Intestinal Ultrasound, CD; Crohn’s Disease, BUSS; Bowel Ultrasound Score, IBUS-SAS; International Bowel Ultrasound Segmental Activity Score, BWT; Bowel Wall Thickness, BWS; Bowel Wall Stratification, CDS; Colour Doppler Signals, SES CD; Simple Endoscopic Score for Crohn’s Disease, CDAI; Crohn’s Disease Activity Index, CRP; C-Reactive Protein,

Acknowledgements:

None

Conflict of Interest:

Authors have no conflicts of interests to declare.

Financial Disclosure:

No financial support was received in our study.

Author contributions:

IY., YC., and MBD.: planned the conception and design of the study. AA., ME., OO, ETK., ABF., MMI., and ED.: performed the data collection. IY., and YC.: performed data analyses. IY and MBD.: interpreted the data. IY., YC., MBD., and ZMYK.: drafted the manuscript. All authors revised and approved the final version of the manuscript to be submitted.

Data Availability Statement:

The data underlying this article are available within the article. Any additional information will be shared on reasonable request to the corresponding author.

Panés J BR, Chaparro M, Gisbert JP, Martínez de Guereñu B, Mendoza JL. Systematic review: the use of ultrasonography, computed tomography and magnetic resonance imaging for the diagnosis, assessment of activity and abdominal complications of Crohn’s disease. Aliment Pharmacol Ther 2011. 2011.
Allocca M, Furfaro F, Fiorino G, Peyrin-Biroulet L, Danese S. Point-of-Care Ultrasound in Inflammatory Bowel Disease. Journal of Crohn's & colitis. 2021;15(1):143-51.
Rimola J, Torres J, Kumar S, Taylor SA, Kucharzik T. Recent advances in clinical practice: advances in cross-sectional imaging in inflammatory bowel disease. Gut. 2022;71(12):2587-97.
Goodsall TM, Nguyen TM, Parker CE, Ma C, Andrews JM, Jairath V, et al. Systematic Review: Gastrointestinal Ultrasound Scoring Indices for Inflammatory Bowel Disease. Journal of Crohn's & colitis. 2021;15(1):125-42.
Barchi A, D'Amico F, Zilli A, Furfaro F, Parigi TL, Fiorino G, et al. Recent advances in the use of ultrasound in Crohn's disease. Expert review of medical devices. 2023;20(12):1119-29.
Dragoni G, Gottin M, Innocenti T, Lynch EN, Bagnoli S, Macri G, et al. Correlation of Ultrasound Scores with Endoscopic Activity in Crohn's Disease: A Prospective Exploratory Study. Journal of Crohn's & colitis. 2023;17(9):1387-94.
Novak KL, Nylund K, Maaser C, Petersen F, Kucharzik T, Lu C, et al. Expert Consensus on Optimal Acquisition and Development of the International Bowel Ultrasound Segmental Activity Score [IBUS-SAS]: A Reliability and Inter-rater Variability Study on Intestinal Ultrasonography in Crohn's Disease. Journal of Crohn's & colitis. 2021;15(4):609-16.
Saevik F, Eriksen R, Eide GE, Gilja OH, Nylund K. Development and Validation of a Simple Ultrasound Activity Score for Crohn's Disease. Journal of Crohn's & colitis. 2021;15(1):115-24.
Allocca M, Craviotto V, Bonovas S, Furfaro F, Zilli A, Peyrin-Biroulet L, et al. Predictive Value of Bowel Ultrasound in Crohn's Disease: A 12-Month Prospective Study. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association. 2022;20(4):e723-e40.
Ripolles T, Poza J, Suarez Ferrer C, Martinez-Perez MJ, Martin-Algibez A, de Las Heras Paez B. Evaluation of Crohn's Disease Activity: Development of an Ultrasound Score in a Multicenter Study. Inflammatory bowel diseases. 2021;27(1):145-54.
Allocca M, Dell'Avalle C, Zilli A, Furfaro F, D'Amico F, Jairath V, et al. Ultrasound remission after biologic induction and long-term endoscopic remission in Crohn's disease: a prospective cohort study. EClinicalMedicine. 2024;71:102559.
Parente F, Greco S, Molteni M, Cucino C, Maconi G, Sampietro GM, et al. Role of early ultrasound in detecting inflammatory intestinal disorders and identifying their anatomical location within the bowel. Alimentary pharmacology & therapeutics. 2003;18(10):1009-16.
Coffey JC, O'Leary DP. The mesentery: structure, function, and role in disease. The lancet Gastroenterology & hepatology. 2016;1(3):238-47.
Fernandez-Clotet A, Ordas I, Masamunt MC, Caballol B, Rodriguez S, Gallego M, et al. Magnetic resonance enterography findings 46 weeks after initiation of biological therapy predict long-term adverse outcomes in Crohn's disease. Alimentary pharmacology & therapeutics. 2024;59(11):1435-45.
Kumar S, De Kock I, Blad W, Hare R, Pollok R, Taylor SA. Magnetic resonance enterography and intestinal ultrasound for the assessment and monitoring of Crohn's disease. Journal of Crohn's & colitis. 2024.
Kucharzik T, Wittig BM, Helwig U, Borner N, Rossler A, Rath S, et al. Use of Intestinal Ultrasound to Monitor Crohn's Disease Activity. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association. 2017;15(4):535-42 e2.

Table 1. Demographic characteristics of patients with ileal CD.

		Total n= 56
Age at onset of IBD, year, median (IQR)		40.5 (26-46.75)
Male, n (%)		38 (67.9)
Smokers (Current/Ex), n (%)		35 (62.5)
Family history of IBD, n (%)		4 (7.1)
Appendectomy, n (%)		7 (12.5)
BMI, kg/m², median (IQR)		24.34 (20.46-27.19)
Total disease duration, year, median (IQR)		8.4 (4.93-10.29)
Disease location, n (%)
Upper GI disease (L4)		13 (23.2)
Disease behavior, n (%)
Inflammatory disease (B1)		50 (89.3)
Stenosing (B2)		1 (1.8)
Penetrating (B3)		5 (8.9)
P (Perianal disease)		13 (23.2)
Extra-intestinal manifestations, n (%)		26 (46.4)
Conventional medication, n (%)
Thiopurine		22 (39.3)
Methotrexate		9 (16.1)
Steroids		15 (26.8)
Mesalazine		16 (28.6)
Sulphapyridine		5 (8.9)
Biologic medication, n (%)
Adalimumab		10 (17.9)
Infliximab		6 (10.7)
Vedolizumab		-
Ustekinumab		2 (3.6)
Sertolizumab		1 (1.8)
CRP, mg/L, median (IQR)		10.45 (4.59-38.95)
HB, g/dL, median (IQR)		13.55 (11.85-15.38)
Albumin, g/dL, median (IQR)		4.08 (3.83-4.57)
CDAI, median (IQR)		202 (83-310.25)
SES-CD, median (IQR)		6 (3-10)
BUSS, median (IQR)		4.54 (2.79-7.04)
IBUS-SAS, median (IQR)		31 (15.3-63.6)

CD: Crohn’s Disease, IBD: Inflammatory Bowel Disease. BMI: Body Mass Index. CRP: C - reactive Protein. HB: Hemoglobin. CDAI: Crohn’s Disease Activity Index. SES-CD: Simple Endoscopic Score for Crohn's Disease. BUSS: Bowel Ultrasound Score. IBUS-SAS: International Bowel Ultrasound Segmental Activity Score.

Data are presented as medians (interquartile range) or percentages when appropriate.

Table 2: Comparison of BUSS and IBUS-SAS regarding SES-CD endoscopic activity for terminal ileum.

SES-CD ≤2

n=12 (21.4%)

SES-CD > 2

n=44 (78.6%)

p value

BUSS, median (IQR)

2.63 (2.12-3.45)

5.67 (3.47-7.76)

<0.001

IBUS-SAS, median (IQR)

14 (11.3-18.4)

49.7 (23.3-72.65)

<0.001

BUSS: Bowel Ultrasound Score. IBUS-SAS: International Bowel Ultrasound Segmental Activity Score. SES-CD: Simple Endoscopic Score for Crohn's Disease

Table 3. ROC analysis results of BUSS and IBUS-SAS to predict SES-CD ≤2 for Crohn’s disease.

		95% CI	95% CI
	AUC	Lower	Upper	P value	Cut-off value	Sensitivity	Specificity
BUSS	0.839	0.737	0.941	<0.001	3.9	0.917	0.727
IBUS-SAS	0.871	0.780	0.962	<0.001	24.4	1	0.727

AUC: Area under curve, CI: Confidence interval, BUSS: Bowel Ultrasound Score, IBUS-SAS: International Bowel Ultrasound Segmental Activity Score, SES-CD: Simple Endoscopic Score for Crohn's Disease.

Table 4. Correlation of BUSS and IBUS-SAS to disease activity index and laboratory tests.

		BUSS	IBUS-SAS
BUSS	R	-	0.914
BUSS	P	-	<0.001
IBUS-SAS	R	0.914	-
IBUS-SAS	P	<0.001	-
SES-CD	R	0.659	0.728
SES-CD	P	<0.001	<0.001
CDAI	R	0.347	0.485
CDAI	P	0.009	<0.001
CRP	R	0.577	0.657
CRP	P	<0.001	<0.001
Hemoglobin	R	-0.391	-0.403
Hemoglobin	P	0.003	0.002
Albumin	R	-0.289	-0.274
Albumin	P	0.031	0.041

BUSS: Bowel Ultrasound Score, IBUS-SAS: International Bowel Ultrasound Segmental Activity Score, CRP: C-reactive protein, CDAI: Crohn’s Disease Activity Index, SES-CD: Simple Endoscopic Score for Crohn's Disease

No competing interests reported.

A Comparison Between the Bowel Ultrasound Score and International Bowel Ultrasound Segmental Activity Score Based on Ileocolonoscopy in Patients with Crohn’s Disease

Status:

Version 1

Abstract

Figures

Introduction

Methods

Study design and population

Ileocolonoscopy

Intestinal ultrasound

Ethics statement

Statistical analysis

Results

Study population

Correlation between IUS scores and SES-CD

Discussion

Conclusion

Abbreviations

Declarations

References

Tables

Additional Declarations

Status:

Version 1