S1044 Correlation and Assessment of Small Bowel Lesions Using Cross-Sectional Imaging Techniques vs Small Intestinal Contrast UltraSonography in Known Crohn’s Disease (CACTUS-CD Trial): A Paired, Validating Study (NCT06125678)
Bibliographic record
Abstract
Introduction: Magnetic resonance/computed tomography enterography (MRE/CTE) are established for assessing small bowel (SB) Crohn’s disease (CD) with superior accuracy compared to intestinal ultrasound (IUS). However, the role of small intestinal contrast ultrasound (SICUS) in monitoring CD activity needs further exploration. Methods: This study evaluated SICUS in comparison to CTE/MRE for monitoring known SB CD activity. Patients (age 18-75) with established SB CD underwent SICUS prior to CTE (n=75)/MRE (n=39). Accuracy of SICUS for detecting SB disease presence, extent, maximum bowel wall thickness (BWT), length of involvement, and complications (strictures, fistulas), and its impact on management were assessed against MRE/CTE. Results: A total of 111 patients (median age 35 years, 56% male) were included. SICUS showed sensitivity/specificity of 95.2%/100%, positive predictive value (PPV) of 100%, negative predictive value (NPV) of 58.3%, and accuracy of 95.5% for detecting SB disease. For disease extent, SICUS had sensitivity/specificity of 87.4%/87.5%, PPV 98.9%, NPV 35%, and accuracy 87.4%. Sensitivity/specificity for detecting strictures were 76.5% (58.8% with IUS alone)/98.3%, PPV 97.5%, NPV 83.1%, and accuracy 88.3%; for fistulas, 80%/99%, PPV 80%, NPV 99%, and accuracy 98.2%. SICUS correlated strongly with cross-sectional imaging for BWT (Spearman’s R=0.723, P < 0.001) and length of involvement (R=0.834, P < 0.001). Missed lesions were primarily in proximal and mid SB. Overall, management changed in 17% (n=19) after CTE/MRE. Conclusion: SICUS accurately identifies SB CD activity, extent, and complications, with limited impact on management decisions compared to cross-sectional imaging. It is particularly beneficial for detecting SB strictures. Cross-sectional imaging remains valuable for proximal and mid SB involvement. (Clinicaltrials.gov: NCT06125678) (see Figure 1, Table 1).Figure 1.: Correlation of cross sectional imaging (CTE-computed tomography enterography/MRE: magnetic resonance enterography) with intestinal ultrasound : maximum bowel wall thickness measurement (A) and correlation (B); length of involvement (C) and correlation (D). Table 1. - Baseline characteristics and key results of the study Baseline characteristics Total number of patients n=111 Male 62 (56%) Age (median/range, years) 35 (18-70) Disease location (Montreal classification), n(%) Terminal ileal disease (L1) 8 (7.2%) Ileo-colonic disease (L3) 20 (18.1%) Isolated SB disease (L4b) 38 (34.2%) Multiple segments involved 45 (40.5%) Disease behaviour (Montreal classification), n (%) B1 42 (37.8%) B2 59 (53.2%) B3 5 (4.5%) B2+B3 5 (4.5%) Perianal disease modifier 10 (9%) Previous small bowel resection, n (%) 14 (12.6%) Therapy, n (%) Azathioprine 73 (65.8%) Methotrexate 1 (0.9%) Steroid (prednisolone/budesonide) 39 (35.1%) 5 amino-salicylic acid (5-ASA) 12 (10.8%) Infliximab 12 (10.8%) Adalimumab 9 (8.1%) Vedolizumab 1 (0.9%) Ustekinumab 3 (2.7%) Results Change in management after cross-sectional imaging over IUS, n (%) 19 (17%) IUS guided management correlated with management after cross-sectional imaging 92 (83%) Accuracy of SICUS to identify active disease, n (%) Sensitivity: 95.2% Specificity: 100% PPV: 100% NPV: 58.3% Accuracy: 95.5% SICUS correctly identified extent of SB disease, n (%) Sensitivity: 87.4% Specificity: 87.5% PPV: 98.9% NPV: 35% Accuracy: 87.4% SICUS correlated with CTE/MRE for absence/presence of strictures, n (%) Sensitivity: 76.5% (58.8% IUS)Specificity: 98.3%PPV: 97.3%NPV: 79.7%Accuracy: 85.6% SICUS correctly identified extent of SB strictures, n (%) Sensitivity: 70.6% (51% IUS) Specificity: 98.3% PPV: 97.5% NPV: 83.1% Accuracy: 88.3% SICUS correlated with CTE/MRE for absence/presence of intra-abdominal fistula, n (%) Sensitivity: 80% Specificity: 99% PPV:80% NPV: 99% Accuracy: 98.2%
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.006 | 0.005 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.007 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".