Infliximab response associates with radiologic findings in bio-naïve Crohn's disease

OBJECTIVES

Since a reliable model for predicting infliximab (IFX) benefits in bio-naïve Crohn's disease (CD) is still lacking, we constructed a magnetic resonance enterography (MRE)-based model to predict the risk of loss of response to IFX in bio-naïve patients with CD.

METHODS

This retrospective multicenter study enrolled 188 bio-naïve patients with CD who underwent MRE before IFX therapy. Therapeutic outcomes were determined based on clinical symptoms and endoscopic findings within 52 weeks. The areas of bowel wall segmentation were decided by two experienced radiologists in consensus. Texture features were extracted using the least absolute shrinkage and selection operator, and a radiomic model was built using multivariate logistic regression. The model performance was validated by receiver operating characteristic, calibration curve, and decision curve analysis.

RESULTS

The area under the curve of radiomic model was 0.88 (95% confidence interval: 0.82-0.95), and the model provided clinical net benefit in identifying the loss of response to IFX and exhibited remarkable robustness among centers, scanners, and disease characteristics. The high-risk patients defined by the radiomic model were more likely to develop IFX nonresponse than low-risk patients (all p < 0.05).

CONCLUSIONS

This novel pretreatment MRE-based model could act as an effective tool for the early estimation of loss of response to IFX in bio-naïve patients with CD.

KEY POINTS

• Magnetic resonance enterography model guides infliximab therapy in Crohn's disease. • The model presented significant discrimination and provided net clinical benefit. • Model divided patients into low- and high-risk groups for infliximab failure.

Application of multi-spectral CT imaging in Crohn's disease: a systematic review

BACKGROUND

No quantitative computed tomography (CT) biomarker is actually sufficiently accurate to assess Crohn's disease (CD) lesion activity, with adequate precision to guide clinical decisions.

PURPOSE

To assess the available literature on the use of iodine concentration (IC), from multi-spectral CT acquisition, as a quantitative parameter able to distinguish healthy from affected bowel and assess CD bowel activity and heterogeneity of activity along the involved segments.

MATERIAL AND METHODS

A literature search was conducted to identify original research studies published up to February 2022. The inclusion criteria were original research papers (>10 human participants), English language publications, focus on dual-energy CT (DECT) of CD with iodine quantification (IQ) as an outcome measure. The exclusion criteria were animal-only studies, languages other than English, review articles, case reports, correspondence, and study populations <10 patients.

RESULTS

Nine studies were included in this review; all of which showed a strong correlation between IC measurements and CD activity markers, such as CD activity index (CDAI), endoscopy findings and simple endoscopic score for Crohn's disease (SES-CD), and routine CT enterography (CTE) signs and histopathologic score. Statistically significant differences in IC were reported between affected bowel segments and healthy ones (higher P value was P < 0.001), normal segments and those with active inflammation (P < 0.0001) as well as between patients with active disease and those in remission (P < 0.001).

CONCLUSION

The mean normalized IC at DECTE could be a reliable tool in assisting radiologists in the diagnosis, classification and grading of CD activity.

Jejunal Inflammation in Crohn's Disease: Comparison between Diffusion Weighted Magnetic Resonance Imaging and Video Capsule Endoscopy

BACKGROUND

Jejunal disease is associated with worse prognosis in Crohn's disease. The added value of diffusion weighted imaging for evaluating jejunal inflammation related to Crohn's Disease is scarce.

OBJECTIVES

To compare diffusion weighted imaging, video capsule endoscopy, and inflammatory biomarkers in the assessment of Crohn's disease involving the jejunum.

METHODS

Crohn's disease patients in clinical remission were prospectively recruited and underwent magnetic resonance (MR)-enterography and video capsule endoscopy. C-reactive protein and fecal-calprotectin levels were obtained. MR-enterography images were evaluated for restricted diffusion, and apparent diffusion coefficient values were measured. The video capsule endoscopy-based Lewis score was calculated. Associations between diffusion weighted imaging, apparent diffusion coefficient, Lewis score, and inflammatory biomarkers were evaluated.

RESULTS

The study included 51 patients, and 27/51 (52.9%) with video capsule endoscopies showed jejunal mucosal inflammation. Sensitivity and specificity of restricted diffusion for video capsule endoscopy mucosal inflammation were 59.3% and 37.5% for the first reader, and 66.7% and 37.5% for the second reader, respectively. Diffusion weighted imaging was not statistically associated with jejunal video capsule endoscopy inflammation (P = 0.813).

CONCLUSIONS

Diffusion weighted imaging was not an effective test for evaluation of jejunal inflammation as seen by video capsule endoscopy in patients with quiescent Crohn's disease.

Sarcopenia and Myosteatosis Assessed by Magnetic Resonance Enterography May Predict Negative Outcomes in Patients with Crohn's Disease

BACKGROUND

Limited research has examined the clinical consequences of sarcopenia and myosteatosis in Crohn's disease. This study aimed to determine the prevalence, risk factors, and effects of sarcopenia and myosteatosis on prognostic outcomes in Crohn's disease patients who underwent magnetic resonance enterography.

MATERIALS AND METHODS

This retrospective observational study included 116 Crohn's disease patients who underwent magnetic resonance enterography between January 2015 and August 2021. Skeletal muscle index was the ratio of the cross-sectional area of skeletal muscles at the L3 vertebral level to the square of the neck in cross-sectional imaging. Sarcopenia was defined as skeletal muscle index <38.5 cm2/m2 in women and <52.4 cm2/m2 in men. Myosteatosis was considered positive if the ratio of the mean signal intensity of the psoas muscle to the mean signal intensity of the cerebrospinal fluid was above 0.107.

RESULTS

Among the negative results in the post-procedure follow-up of the patients, a significant increase was observed in the sarcopenia group regarding abscess and the need for surgery (P < .05). Anti-tumor necrosis factor initiation was found to be significantly higher in the follow-up than in patients without myosteatosis (P = .029). In the multivariate model established with these variables, the presence of sarcopenia in the surgical follow-up was odds ratio = 5.34 (CI: 1.02-28.03, P = .047) and was found to be significantly associated with the increased risk.

CONCLUSIONS

The presence of myosteatosis and sarcopenia detected in magnetic resonance enterography may be a harbinger of negative outcomes in Crohn's disease patients. Nutritional support should be provided to these patients with the potential to alter the course of the disease.

Radiomics could predict surgery at 10 years in Crohn's disease

BACKGROUND

Predicting clinical outcomes represents a major challenge in Crohn's disease (CD). Radiomics provides a method to extract quantitative features from medical images and may successfully predict clinical course.

AIMS

The aim of this pilot study is to evaluate the use of radiomics to predict 10-year surgery for CD patients.

METHODS

We selected a cohort of CD patients with CT scan enterographies and a 10-year follow up. The R library Moddicom was used to extract radiomic features from each lesion of CD, segmented in the CT scans. A logistic regression model based on selected radiomic features was developed to predict 10-year surgery. The model was evaluated by computing the area under the curve (AUC) of the receiver operating characteristic curve, sensitivity, specificity, positive and negative predictive values (PPV, NPV).

RESULTS

We enroled 30 patients, with 44 CT scans and 93 lesions. We extracted 217 radiomic features from each lesion. The developed model was based on two radiomic features and presented an AUC (95% CI) of 0.83 (0.73-0.91) in predicting 10-year surgery. Sensitivity, specificity, PPV, NPV of the radiomic model were equal to 0.72, 0.90, 0.79, 0.86, respectively.

CONCLUSION

Radiomics could be a helpful tool to identify patients with high risk for surgery and needing a stricter monitoring.

Evaluation of symptomatic small bowel stricture in Crohn's disease by double-balloon endoscopy

PURPOSE

To assess the efficacy of double-balloon endoscopy (DBE) for the detection of small-bowel strictures in Crohn's disease (CD).

METHODS

This tertiary-referral hospital cohort study was conducted between January 2018 and May 2022. CD patients with symptoms of small-bowel stricture were enrolled sequentially. All of the patients were subjected to both computed tomography enterography (CTE) and DBE, and their symptoms of stricture were assessed using the Crohn's Disease Obstructive Score (CDOS). The diagnostic yield of DBE was compared to that of CTE, and the relationship between the DBE findings and CDOS was investigated. The factors influencing the DBE diagnosis were examined using Cox regression analysis.

RESULTS

This study included 165 CD patients. The CDOS scores were higher in 95 patients and lower in 70 patients. DBE detected 92.7% (153/165) and CTE detected 85.5% (141/165) of the strictures. The DBE diagnostic yields were 94.7% (90/95) in the high CDOS patients and 91.4% (64/70) in the low CDOS patients (P = 0.13). Patients with a history of abdominal surgery and abscess had a lower diagnosis rate in the multivariate analysis.

CONCLUSION

DBE has been demonstrated to be an efficient diagnostic method for detecting small bowel strictures in CD patients. Additionally, there was no difference in the diagnostic yields between patients with low and high obstructive scores.

Crohn's disease phenotype analysis with iodine density from dual-energy CT enterography

PURPOSE

To compare dual-source dual-energy CT enterography (dsDECTE) obtained iodine density (I) (mg/mL) and I normalized to the aorta (I%) with Crohn's disease (CD) phenotypes defined by the SAR-AGA small bowel CD consensus statement.

METHODS

Fifty CD patients (31 male, 19 female; mean [SD] age: 50.4 [15.2] years) who underwent dsDECTE were retrospectively identified. Two abdominal radiologists assigned CD phenotypes: no active inflammation (group-2), active inflammation without (group-3) or with luminal narrowing (group-4), stricture with active inflammation (group-5), stricture without active inflammation (group-1), and penetrating disease (group-6). Semiautomatic prototype software was used to determine the median I and I% of CD-affected small bowel mucosa for each patient. The means of the I and I% medians were compared among 4 groups ("1 + 2", "3 + 4", "5", "6") using one-way ANOVA (significance level 0.05 for each outcome) for each outcome individually followed by Tukey's range test for pairwise comparisons with adjusted p-values (overall alpha = 0.05).

RESULTS

Mean [SD] I was 2.14 [1.07] mg/mL for groups 1 + 2 (n = 16), 3.54 [1.71] mg/mL for groups 3 + 4 (n = 15), 5.5 [3.27] mg/mL for group- "5" (n = 9), and 3.36 [1.43] mg/mL for group-"6" (n = 10) (ANOVA p = .001; group "1 + 2" versus "5" adj-p = .0005). Mean [SD] I% was 21.2 [6.13]% for groups 1 + 2, 39.47 [9.71]% for groups 3 + 4, 40.98 [11.76]% for group-5, and 35.01 [7.58]% for group-6 (ANOVA p < .0001; groups "1 + 2" versus "3 + 4" adj-p < .0001, group "1 + 2" versus "5" adj-p < .0001, and groups "1 + 2" versus "6" adj-p = .002).

CONCLUSION

Iodine density obtained from dsDECTE significantly differed among CD phenotypes defined by SAR-AGA, with I (mg/mL) increasing with phenotype severity and decreasing for penetrating disease. I and I% can be used to phenotype CD.

Diagnosis of ulcerative colitis and Crohn's disease using transabdominal ultrasonography

The following are some common features of ulcerative colitis (UC) and Crohn's disease (CD) on transabdominal ultrasonography (TUS). UC, which consists primarily of mucosal inflammation, is seen on TUS as wall thickening with preserved layer structure continuing from the rectum in the active phase of UC. Inflammation confined to the mucosa is seen as thickening of the mucosal/submucosal layers. When the inflammation becomes severe, the echogenicity of the submucosal layer decreases and the layer structure becomes indistinct. CD, which consists primarily of discontinuous transmural inflammation, shows more pronounced hypoechoic wall thickening than UC at the transmural inflammation. On TUS, the layer structure becomes indistinct and gradually disappears due to the depth of the myriad inflammation during the active phase of CD. It is important to evaluate the changes in wall thickening and layer structure when diagnosing UC and CD with TUS. In addition, diagnostic techniques such as color Doppler and contrast-enhanced ultrasonography, which can be used to assess blood flow, and elastography, which can be used to evaluate stiffness, are also used. Thus, TUS is a noninvasive and convenient modality that shows promise as a useful examination for diagnosis of UC and CD.

Recent advances in the use of ultrasound in Crohn's disease

INTRODUCTION

A clear consensus exists on the role of IUS for the assessment and monitoring of Crohn's disease (CD) in the 'treat-to-target' strategy.

AREAS COVERED

IUS is an accurate tool for the management of CD. It is noninvasive and well tolerated. IUS has good-to-optimal inter-operator reliability either for assessing disease activity or for evaluating treatment response, especially combining Bowel Wall Thickness (BWT) and Color Doppler Signals (CDS). IUS is able to evaluate transmural remission (TR), the ultimate goal of the 'treat-to-target' strategy. Several studies confirmed its accuracy in the assessment of the post-operative recurrence (POR). Thanks to recent advances in trans-perineal ultrasound technique (TPUS), it allows to characterize peri-anal disease and its complications. Small intestine contrast ultrasound (SICUS) and contrast-enhancement ultrasound (CEUS) may improve IUS performance, particularly in stricturing or penetrating CD. Ultrasound elastography (USE) is raising interest for its accuracy in differentiating CD phenotypes (fibrotic versus inflamed).

EXPERT OPINION

IUS is a pivotal step in the management of CD, in early assessment as in therapeutic monitoring, with advantages of evaluating transmural response. Development and validation of novel ultrasound biomarkers of activity and fibrosis, especially those linked to advanced ultrasound techniques, are expected in the coming years.

Description of a new ultrasound sign to distinguish Crohn's anal fistula from cryptoglandular fistula: The rosary sign

AIM

Endoanal and endorectal ultrasound are essential diagnostic tools for perianal fistula. Recent studies have examined ultrasound signs that help differentiate cryptoglandular anal fistula from perianal fistulizing Crohn's disease. The main aim of this work was to describe a new ultrasound sign for perianal fistula and to evaluate its ability to differentiate Crohn's disease from cryptoglandular anal fistula.

METHOD

This study included 363 patients (113 women; mean age 46.5 ± 14.3 years). Overall, 287 (79.1%) patients had a cryptoglandular perianal fistula and 76 (20.9%) had fistulizing Crohn's disease. All patients underwent three-dimensional anal endosonography for perianal fistula. The reading was carried out by two observers.

RESULTS

Observer 1, who was an experienced sonographer and colorectal surgeon, observed the ultrasound sign in 120 patients (33.1%), while observer 2, who was inexperienced, observed it in 129 patients (35.5%). The overall interobserver agreement was 67.22%. The Kappa coefficient measuring interobserver agreement was 0.273 (0.17-0.38). Among those patients with Crohn's disease, 48.68% had the sign and 16% did not (p = 0.001). A logistic regression study showed that the sign was a predictor of Crohn's disease (p = 0.001), with an odds ratio of 2.33 (1.39-3.91). Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 38.68%, 71.08%, 30.83%, 83.95% and 66.39%, respectively.

CONCLUSION

This study provides a new ultrasound sign for perianal fistula (the rosary sign) in patients with Crohn's disease. The sign can be used to differentiate Crohn's disease from other types of fistula. This is useful in the management of patients with anal fistula.

Small bowel imaging in inflammatory bowel disease: updates for 2023

INTRODUCTION

Cross-sectional imaging techniques including MR and CT enterography and ultrasound are integral to Crohn's disease management, accurate, responsive, and well tolerated. They assess the full thickness of the bowel wall, perienteric environment, and distant complications. As we strive toward tighter disease control, imaging's role will expand further with transmural healing becoming an increasingly important therapeutic target.

AREAS COVERED

MEDLINE and Web of Science were searched from 2012 to 2023 inclusive. We review the evidence for cross-sectional imaging in assessing disease activity, phenotyping, and therapeutic response assessment. Emerging novel imaging applications such as quantifying enteric motility and fibrosis, prognostication, and potential utility of artificial intelligence will be covered. Recent international consensus statements highlight the need for standardized imaging reporting and definitions of transmural healing and remission. We will discuss how recent advances may be best integrated into patient care and highlight key outstanding research questions.

EXPERT OPINION

Cross-sectional imaging is established in Crohn's disease management. Research emphasis should be placed on optimal integration of imaging modalities in clinical care pathways, workforce training, definitions, and evidence for use of imaging based therapeutic targets such as transmural healing, better phenotyping of stricturing disease, and developing novel techniques, including integration of artificial intelligence.

Motility Mapping Quantification Using the Classical Optical Flow Algorithm for Small Bowel Crohn's Disease: Comparison with Balloon-assisted Enteroscopy Findings

PURPOSE

To quantify bowel motility shown on cine MRI using the classical optical flow algorithm and compare it with balloon-assisted enteroscopy (BAE) findings in patients with Crohn's disease (CD).

METHODS

This retrospective study included 29 consecutive patients with CD who had undergone MR enterocolonography (MREC) and BAE between March and May 2017. We developed computer software to present motion vector magnitudes between consecutive cine MR images as bowel motility maps via a classical optical flow algorithm using the Horn-Schunck method. Cine MR images were acquired with a balanced steady-state free precession sequence in the coronal direction to capture small bowel motility. The small bowels were divided into three segments. In total, 63 bowel segments were assessed via BAE and MREC. Motility scores on the maps, simplified MR index of activity (sMaRIA), and MREC score derived from a 5-point MR classification were assessed independently by two radiologists and compared with the CD endoscopic index of severity (CDEIS). Correlations were assessed using Spearman's rank coefficient. The areas under the receiver-operating characteristic curve (AUCs) of motility score for differentiating CDEIS was calculated; a P value < 0.05 was considered statistically significant.

RESULTS

Motility score was negatively correlated with CDEIS (r = -0.59 [P < 0.001] and -0.54 [P < 0.001]), and the AUCs of motility scores for detecting CDEIS ≥ 3 were 88.2% and 78.6% for observers 1 and 2, respectively. There were no significant differences in the AUC for detecting CDEIS ≥ 3 and CDEIS ≥ 12 between motility and sMaRIA or MREC score.

CONCLUSION

The motility map was feasible for locally quantifying the bowel motility. In addition, the motility score on the map reflected the endoscopic inflammatory activity of each small bowel segment in patients with CD; hence, it could be used as a tool in objectively interpreting cine MREC to predict inflammatory activity in CD.

Intestinal ultrasound in patients with suspected Crohn's disease - results of a prospective evaluation by trainees

BACKGROUND AND AIMS

Intestinal ultrasound (IUS) performed by experts is a valuable tool for the diagnostic work-up and monitoring of Crohn's disease (CD). However, concern about insufficient training and perceived high inter-observer variability limit the adoption of IUS in CD. We examined the diagnostic accuracy of trainee-performed IUS in patients with suspected CD.

METHOD

Patients recruited to a prospective trial investigating the diagnostic accuracy of magnetic resonance enterocolonography (MREC) in patients with clinically suspected CD underwent IUS performed by trainees. The primary end-point was IUS per-patient sensitivity and specificity for ileocolonic CD determined by ileocolonoscopy.

RESULTS

129 patients with clinically suspected CD and a complete IC and IUS were included in the analysis. IUS detected signs of CD in 49 cases (small bowel 31, colon 15, small bowel, and colon 3). The sensitivity and specificity for detection of ileocolonic CD by trainee performed IUS improved during the first to the second half of the study period from 57.1% (CI 34.0-78.2) to 73.1% (CI 52.2-88.4) and 76.5% (CI 58.8-89.3) to 89.7% (CI 72.6-97.8). The overall sensitivity and specificity of diagnosing CD with IUS were 65.4% (CI 50.9-78.0) and 80.5% (CI 69.9-88.7). There was no difference in diagnostic performance between IUS and MREC for the detection of CD.

CONCLUSION

Trainees improved during the study, and IUS performance in disease detection corresponded to expert-evaluated MREC.Registered at ClinicalTrials.gov (NCT03134586).

Endoscopic imaging in inflammatory bowel disease

In inflammatory bowel disease, including Crohn's disease and ulcerative colitis, an excessive immune response due primarily to T-cell lymphocytes causes inflammation in the gastrointestinal tract. Lesions in Crohn's disease can occur anywhere in the gastrointestinal tract, i.e., from the oral cavity to the anus. Endoscopically, aphthoid lesions/ulcers believed to be initial lesions progress to discrete ulcers, which coalesce to form a longitudinal array and progress to longitudinal ulcers with a cobblestone appearance, which is a typical endoscopic finding. Before long, complications such as strictures, fistulas, and abscesses form. Lesions in ulcerative colitis generally extend continuously from the rectum and diffusely from a portion of the colon to the entire colon. Endoscopically, lack of vascular pattern, fine granular mucosa, erythema, aphthae, and small yellowish spots are seen in mild cases; coarse mucosa, erosions, small ulcers, bleeding (contact bleeding), and adhesion of mucous, bloody, and purulent discharge in moderate cases; and widespread ulcers and marked spontaneous bleeding in severe cases.

Prognostic role of intestinal ultrasound in Crohn’s disease

The majority of patients affected by Crohn’s disease (CD) develop a chronic condition with persistent inflammation and relapses that may cause progressive and irreversible damage to the bowel, resulting in stricturing or penetrating complications in around 50% of patients during the natural history of the disease. Surgery is frequently needed to treat complicated disease when pharmacological therapy failes, with a high risk of repeated operations in time. Intestinal ultrasound (IUS), a non-invasive, cost-effective, radiation free and reproducible method for the diagnosis and follow-up of CD, in expert hands, allow a precise assessment of all the disease manifestations: Bowel characteristics, retrodilation, wrapping fat, fistulas and abscesses. Moreover, IUS is able to assess bowel wall thickness, bowel wall stratification (echo-pattern), vascularization and elasticity, as well as mesenteric hypertrophy, lymph-nodes and mesenteric blood flow. Its role in the disease evaluation and behaviour description is well assessed in literature, but less is known about the potential space of IUS as predictor of prognostic factors suggesting response to a medical treatment or postoperative recurrence. The availability of a low cost exam as IUS, able to recognize which patients are more likely to respond to a specific therapy and which patients are at high risk of surgery or complications, could be a very useful instrument in the hands of IBD physician. The aim of this review is to present current evidence about the prognostic role that IUS can show in predicting response to treatment, disease progression, risk of surgery and risk of post-surgical recurrence in CD.

LAVA HyperSense and deep-learning reconstruction for near-isotropic (3D) enhanced magnetic resonance enterography in patients with Crohn's disease: utility in noise reduction and image quality improvement

PURPOSE

This study aimed to compare near-isotropic contrast-enhanced T1-weighted (CE-T1W) magnetic resonance enterography (MRE) images reconstructed with vendor-supplied deep-learning reconstruction (DLR) with those reconstructed conventionally in terms of image quality.

METHODS

A total of 35 patients who underwent MRE for Crohn's disease between August 2021 and February 2022 were included in this retrospective study. The enteric phase CE-T1W MRE images of each patient were reconstructed with conventional reconstruction and no image filter (original), with conventional reconstruction and image filter (filtered), and with a prototype version of AIRTM Recon DL 3D (DLR), which were then reformatted into the axial plane to generate six image sets per patient. Two radiologists independently assessed the images for overall image quality, contrast, sharpness, presence of motion artifacts, blurring, and synthetic appearance for qualitative analysis, and the signal-to-noise ratio (SNR) was measured for quantitative analysis.

RESULTS

The mean scores of the DLR image set with respect to overall image quality, contrast, sharpness, motion artifacts, and blurring in the coronal and axial images were significantly superior to those of both the filtered and original images (P < 0.001). However, the DLR images showed a significantly more synthetic appearance than the other two images (P < 0.05). There was no statistically significant difference in all scores between the original and filtered images (P > 0.05). In the quantitative analysis, the SNR was significantly increased in the order of original, filtered, and DLR images (P < 0.001).

CONCLUSION

Using DLR for near-isotropic CE-T1W MRE improved the image quality and increased the SNR.

Intestinal ultrasound as a non-invasive tool to monitor inflammatory bowel disease activity and guide clinical decision making

Intestinal ultrasound (IUS) is a non-invasive, real-time, cross-sectional imaging tool that can be used at the point-of-care to assess disease activity in patients with Crohn’s disease or ulcerative colitis. IUS promotes quick and impactful treatment decisions that can modify disease progression and enhance patient compliance. This review will summarize the technical aspects of IUS, the evidence to support the use of IUS in disease activity monitoring, the comparison of IUS to current standard of care monitoring modalities such as colonoscopy and calprotectin, and the optimal positioning of IUS in a tight-control monitoring strategy.

Clinical and MRI evolution after local injection of bone marrow-derived mesenchymal stem cells in perianal fistulae in Crohn's disease: results from a prospective monocentric study

INTRODUCTION

Local injection of adipose tissue-derived mesenchymal stem cells (MSC) is effective in fistulizing perianal Crohn's disease (CD). Less is known about bone marrow-derived MSC and little is known about predictive factors of response and MRI evolution of the fistulae after MSC injection. Our aims were to evaluate the safety and clinical outcome of bone marrow-derived MSC injection for perianal fistulizing CD, to evaluate the MRI evolution of the fistulae and to identify factors associated with fistula closure.

PATIENTS AND METHODS

All CD patients with perianal fistula and appropriate drainage with a seton without abscess at MRI were eligible. Clinical examination, biomarkers and pelvic MRI were performed at weeks 0, 12 and 48. The clinical outcome was assessed by closure of the treated external openings at clinical examination and MRI exploration.

RESULTS

Sixteen patients with a median age of 49 years old and a median duration of perianal CD of 8 months were included. No unexpected safety event occurred. At week 12 and 48, 9/16 and 8/16 patients had complete fistula(e) closure, respectively, whereas 11/16 patients had at least partial closure. At MRI, the degree of fibrosis significantly increased after MSC injection. Eighty-six % of patients with >80% of fibrosis of the fistula tract at week 48 had fistula closure. Fistula closure at week 12 was predictive of fistula closure at week 48. The MAGNIFI-CD did not change significantly overtime.

CONCLUSION

Open-label injection of bone marrow-derived mesenchymal stem cells was safe and was effective in half of the patients in fistulizing perianal CD and induced significant MRI changes associated with favorable clinical outcome.

Usefulness of Intestinal Ultrasound to Detect Small Intestinal Stenosis in Patients With Crohn's Disease

OBJECTIVES

Double balloon enteroscopy (DBE) with retrograde contrast is useful as a monitoring tool for small intestinal lesions in Crohn's disease (CD), but these are burdensome for patients. Intestinal ultrasound (IUS) can be used with ease in daily clinical practice, but there is less evidence regarding the accuracy of detection of small intestinal stenosis in CD. This study aimed to examine the diagnostic power of IUS for small intestinal stenosis in patients with CD.

METHODS

The findings of DBE and IUS in 86 patients with CD with small intestinal lesions were evaluated. Using DBE as the reference standard, we examined the detection rate of IUS for small intestinal stenosis. We evaluated three parameters: luminal narrowing, prestenotic dilation, and to-and-fro movement for determining stenosis using IUS. In addition, we compared the characteristics between the stenosis-detectable and stenosis-undetectable groups by IUS.

RESULTS

Of the 86 patients, 30 had small intestinal stenosis. In IUS findings, when lesions that met two or more of the three parameters were judged as stenosis, the detection rate was 70.0% for sensitivity, 98.2% for specificity, and 88.4% for accuracy. Moreover, there were patients with a younger age at diagnosis (P < 0.05) and more ileocolonic disease location (P < 0.05) in the stenosis-detectable group by IUS. The stenoses detected by IUS were significantly longer than those undetected by IUS (14.1 mm versus 5.2 mm, P < 0.05).

CONCLUSIONS

IUS delivered reliable results for clinically important small intestinal stenosis of CD with high diagnostic accuracy.

Length of the healthy and pathological small intestine in patients with Crohn's disease: calculations using computed tomography and magnetic resonance enterography

Many patients with Crohn's disease (CD) require surgical intervention during their lifetime. A correct preoperative assessment of the intestinal length is necessary to predict and quickly treat postoperative nutritional disorders. The aim of this paper is to explain the method used in our hospital to measure intestinal length in patients with CD and its usefulness for making the correct therapeutic decision. Vessel analysis software is used to measure small bowel length through computed tomography enterography (CTE) or magnetic resonance enterography (MRE). The method permits two-dimensional and three-dimensional curved multiplanar reconstructions and allows each loop to be stretched using a point-by-point identification of the intestinal lumen. Subsequently, the software allows the creation of a virtual image, on which the intestinal length is measured linearly. This methodology was tested on three patients; patients 1 and 3 were examined using CTE, and patient 2 was examined using MRE. The outcomes were discussed at a multidisciplinary team meeting (MDT). As a result, surgical ileocolic resection was recommended for patient 1 and medical therapy for patients 2 and 3. Intestinal length measurements have proved vital during MDTs for making appropriate therapeutic decisions.

The Simplified MR Index of Activity Score in Pediatric Small-Bowel Crohn Disease: An Interreader Agreement and Responsiveness Study

BACKGROUND. The simplified MR index of activity (MaRIA) score is used to assess the severity of small-bowel inflammation without use of IV contrast material. OBJECTIVE. The purposes of this study were to assess interreader agreement on the use of simplified MaRIA scores for evaluation of the inflammatory activity of terminal ileal Crohn disease in children and young adults and to assess whether simplified MaRIA scores change after biologic medical therapy. METHODS. This analysis was ancillary to a previously reported primary prospective research investigation. The study included 20 children and young adults with newly diagnosed ileal Crohn disease and 15 healthy control participants who underwent research small-bowel MRI examinations between December 2018 and October 2021. The participants with Crohn disease underwent baseline MRI and MRI 6 weeks and 6 months after beginning anti-tumor necrosis factor α-treatment as well as weighted pediatric Crohn disease activity index (wPCDAI) and C-reactive protein (CRP) assessment on the day of each examination. Control participants underwent one MRI examination. Four pediatric radiologists independently assigned simplified MaRIA scores using axial and coronal T2-weighted SSFSE images. Median simplified MaRIA score among readers was computed. Interreader agreement was assessed with Fleiss kappa coefficients and intra-class correlation coefficient (ICC). Analysis included the Mann-Whitney U test, Friedman test, and Spearman rank correlation. RESULTS. Simplified MaRIA scores (across time points and study groups) had substantial interreader agreement (κ = 0.65 [95% CI, 0.56-0.74]; ICC, 0.71 [95% CI, 0.63-0.78]). Median scores were higher in participants with Crohn disease at baseline than in healthy control participants (3.5 [IQR, 2.5-4.9] vs 0.5 [IQR, 0-2.0]; p < .001). Scores decreased after medical treatment in participants with Crohn disease (p = .005). The median score was 3.5 (IQR, 2.5-4.9) at baseline, 2.3 (IQR, 1.6-3.9) at 6 weeks, and 2.0 (IQR, 0.5-2.5) at 6 months. In participants with Crohn disease, median scores had significant correlations with wPCDAI (ρ = 0.46 [95% CI, 0.18-0.64]; p < .001) and CRP level (ρ = 0.48 [95% CI, 0.27-0.65]; p < .001). CONCLUSION. Radiologists had substantial agreement in use of simplified MaRIA scores to assess intestinal inflammation in ileal Crohn disease. Scores changed over time after medical therapy. CLINICAL IMPACT. The results support the simplified MaRIA score as an objective MRI-based clinical measure of intestinal inflammation in children and young adults with Crohn disease.

DWI ratios: New indexes for Crohn's disease activity at magnetic resonance enterography?

BACKGROUND

The aim of the study was to provide radiologists and clinicians a rapid tool for assessment of intestinal inflammation in Crohn's disease (CD) patients through quantification of diffusion-weighted imaging (DWI) signal intensity while performing magnetic resonance enterography (MRE).

MATERIALS AND METHODS

A monocentric retrospective study was conducted between September 2018 and July 2021 on CD patients who underwent MRE. Two radiologists measured signal intensity on DWI scans at the highest b-value (800 s/mm²) within pathologic intestinal walls, lymph nodes, spleen and psoas muscle and calculated the relative ratios. Spearman, Mann-Whitney and Jonckheere-Terpstra tests were applied for estimating correlation among ratios, significant differences between the two patient groups and determining the trend in relation to endoscopic classes. Wilcoxon's and Cronbach's alpha tests were employed for comparison of DWI measurements and ratios between the two observers.

RESULTS

Fifty-nine patients were enrolled in the study. In the non-surgical group, correlation has been found among Simple Endoscopic Score for Crohn's Disease (SES-CD) classes and the different ratios: bowel/spleen (p = 0.034), bowel/psoas (p = 0.008) and bowel/lymph node (p = 0.010). Within the surgical group, positive correlation was found only between bowel/lymph node ratio and bowel/psoas ratio (p = 0.014). The J-T test demonstrated an increasing monotonic trend for bowel/psoas ratio and bowel/lymph node ratio and SES-CD classes. Inter-reader evaluation demonstrated no statistical differences for DWI measurements and high degree of concordance for the final ratios.

CONCLUSION

DWI ratios correlate with endoscopic classes in non-surgical patients and have inter-observer reproducibility.

Ultrasound shear wave elastography in pediatric stricturing small bowel Crohn disease: correlation with histology and second harmonic imaging microscopy

BACKGROUND

Preclinical animal as well as small exploratory ex vivo and in vivo human studies have suggested that bowel wall shear wave speed (SWS) measurements may be a noninvasive biomarker of intestinal damage.

OBJECTIVE

To evaluate the relationships between bowel wall stiffness, measured using ultrasound shear wave elastography (SWE), and intestinal fibrosis and smooth muscle hypertrophy as determined by (1) histology and (2) second harmonic imaging microscopy (SHIM) in surgically resected ileal strictures from pediatric Crohn disease patients.

MATERIALS AND METHODS

Nineteen pediatric Crohn disease patients with symptomatic ileal strictures underwent research ultrasound examinations before surgical resection between December 2017 and September 2020. Two-dimensional SWE was performed through the area of the most severe stenosis, with measurements obtained from the bowel wall at the 9:00, 12:00 and 3:00 o'clock locations with 0%, 10% and 20% abdominal strain. Overall right lower quadrant stiffness also was documented. Median bowel wall and overall right lower quadrant SWS measurements were correlated with bowel wall histological scores of inflammation, fibrosis and smooth muscle proliferation as well as SHIM collagen signal.

RESULTS

Diagnostic ultrasound SWE imaging was obtained from 18 participants. The median age was 16.8 years. There were negative correlations between histological mucosal active inflammation and both bowel wall SWS with 10% abdominal strain (r=-0.50, P = 0.04) and overall right lower quadrant SWS with 20% abdominal strain (r=-0.69, P = 0.002). There were positive correlations between histological muscularis propria inner layer smooth muscle hypertrophy and both median bowel wall SWS with 10% abdominal strain (r = 0.72, P = 0.002) and overall right lower quadrant SWS with 20% abdominal strain (r = 0.71, P = 0.002). There were no associations between ultrasound stiffness metrics and bowel wall SHIM collagen measurements.

CONCLUSION

Bowel wall and overall right lower quadrant ultrasound stiffness measurements correlate with mucosal active inflammation and muscularis propria smooth muscle hypertrophy in pediatric stricturing ileal Crohn disease, but not with intestinal fibrosis.

Development of a multimodal machine-learning fusion model to non-invasively assess ileal Crohn's disease endoscopic activity

BACKGROUND AND OBJECTIVE

Recurrent attentive non-invasive observation of intestinal inflammation is essential for the proper management of Crohn's disease (CD). The goal of this study was to develop and evaluate a multi-modal machine-learning (ML) model to assess ileal CD endoscopic activity by integrating information from Magnetic Resonance Enterography (MRE) and biochemical biomarkers.

METHODS

We obtained MRE, biochemical and ileocolonoscopy data from the multi-center ImageKids study database. We developed an optimized multimodal fusion ML model to non-invasively assess terminal ileum (TI) endoscopic disease activity in CD from MRE data. We determined the most informative features for model development using a permutation feature importance technique. We assessed model performance in comparison to the clinically recommended linear-regression MRE model in an experimental setup that consisted of stratified 2-fold validation, repeated 50 times, with the ileocolonoscopy-based Simple Endoscopic Score for CD at the TI (TI SES-CD) as a reference. We used the predictions' mean-squared-error (MSE) and the receiver operation characteristics (ROC) area under curve (AUC) for active disease classification (TI SEC-CD≥3) as performance metrics.

RESULTS

121 subjects out of the 240 subjects in the ImageKids study cohort had all required information (Non-active CD: 62 [51%], active CD: 59 [49%]). Length of disease segment and normalized biochemical biomarkers were the most informative features. The optimized fusion model performed better than the clinically recommended model determined by both a better median test MSE distribution (7.73 vs. 8.8, Wilcoxon test, p<1e-5) and a better aggregated AUC over the folds (0.84 vs. 0.8, DeLong's test, p<1e-9).

CONCLUSIONS

Optimized ML models for ileal CD endoscopic activity assessment have the potential to enable accurate and non-invasive attentive observation of intestinal inflammation in CD patients. The presented model is available at https://tcml-bme.github.io/ML_SESCD.html.