Shear Wave and Strain Elastography in Crohn's Disease-A Systematic Review

Small Bowel Cancer in Crohn's Disease

Crohn's disease (CD) is a chronic inflammatory bowel disease (IBD) that frequently affects the small bowel. Individuals diagnosed with CD are at increased risk of developing bowel cancer compared to the general population. Small bowel cancer is a rare but significant CD complication. Adenocarcinoma represents the most prevalent of these neoplasms, followed by neuroendocrine tumors and sarcomas. The primary risk factors identified are being of the male sex, disease duration, previous surgical intervention, perianal disease, and chronic inflammation. The precise etiology remains unclear. Another crucial issue concerns the role of immunomodulators and advanced therapies. By inhibiting inflammation, these therapies can reduce the risk of cancer, which is often initiated by the inflammation-dysplasia-adenocarcinoma sequence. In accordance with the most recent guidelines, it is not necessary to conduct surveillance in patients with small bowel cancer among CD patients, as it is considered a rare disease. Nevertheless, it is of significant importance for gastroenterologists to be aware of this potential CD complication, as well as the patients who are most at risk of developing it. The purpose of this review is to provide a comprehensive overview of CD-SBC, focusing on epidemiology, etiopathogenesis, risk factors, diagnosis, and the role of advanced therapies in CD-SBC.

Multimodal dynamic ultrasound approach as predictor of response in patients with Crohn's disease treated with ustekinumab

Background

The approval of ustekinumab (UST) has opened new options for the treatment of Crohn's disease (CD), but potential markers predicting the efficacy of this interleukin-12/23 inhibitor are lacking. Contrast-enhanced ultrasound (CEUS) is non-invasive alternative to endoscopy, demonstrating early transmural changes after treatment induction.

Objectives

We conducted a prospective monocentric study aiming to explore the value of multimodal intestinal ultrasound (IUS) in predicting the response to UST in patients with active CD who have been previously exposed to anti-tumour necrosis factor α (TNFα).

Design and methods

Consecutive patients with moderate-to-severe CD involving the terminal ileum who were scheduled to begin UST therapy were enrolled between January 2020 and October 2021 in the inflammatory bowel diseases outpatient centre. A complete IUS evaluation, including B-mode, Doppler, dynamic CEUS and elastography, was performed at the time of induction (T0) and after 8 (T1), 16 (T2), 24 (T3) and 48 (T4) weeks of therapy. Each IUS parameter and their variations from baseline were correlated with endoscopic response and mucosal healing after 1 year.

Results

A total of 52 patients were included, 29 (55.8%) of which reached endoscopic response at T4. The univariate analysis revealed that, between T3 and T0, the percentage changes of bowel wall thickness, Limberg score, mean signal intensity, rise time, wash-in rate, C reactive protein and Harvey-Bradshaw Index were associated with long-term therapeutic outcome. Based on the above parameters, we developed an IUS score that showed a good performance in predicting 1 year-endoscopic response (area under the curve: 0.91).

Conclusion

Multimodal ultrasound could be helpful to predict long-term therapeutic outcome in patients with CD treated with UST.

Registration

NCT05987501.

The Reduction of Anastomosis-Related Morbidity Using the Kono-S Anastomosis in Patients with Crohn's Disease: A Meta-Analysis

(1) Background: we conducted this study to evaluate the effect of Kono-S anastomosis on postoperative morbidity after bowel resection for Crohn's disease. (2) Methods: This study adhered to the PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. The primary endpoint was the overall complications rate. Secondary outcomes included specific complications analyses, disease recurrence and efficiency endpoints. A systematic literature screening was performed in major electronic scholar databases (Medline, Scopus, Web of Science), from inception to 17 January 2024. Both Random (RE) and Fixed Effects (FE) models were estimated; the reported analysis was based on the Cochran Q test results. (3) Results: Overall, eight studies and 913 patients were included in this meta-analysis. Pooled analyses confirmed that Kono-S was not superior in terms of overall morbidity (OR: 0.69 [0.42, 1.15], p = 0.16). Kono-S displayed a reduced risk for anastomotic leakage (OR: 0.34 [0.16, 0.71], p = 0.004) and reoperation (OR: 0.12 [0.05, 0.27], p < 0.001), and a shortened length of hospital stay (WMD: -0.54 [-0.73, -0.34], p < 0.001). On the contrary, Kono-S results in higher rates of postoperative SSIs (OR: 1.85 [1.02, 3.35], p = 0.04). (4) Conclusions: This study confirms a comparable morbidity, but a lower risk of anastomotic leak and reoperation of Kono-S over conventional anastomoses. Further high quality studies are required to validate these findings.

Serial Changes in Intestinal Stenotic Stiffness in Patients with Crohn's Disease Treated with Biologics: A Pilot Study Using Ultrasound Shear Wave Elastography

BACKGROUND/AIMS

Intestinal strictures represent an important serious complication of Crohn's disease. Shear wave elastography is a promising noninvasive ultrasound technique for assessing tissue stiffness. This study aimed to evaluate stiffness in the areas of intestinal stricture in patients with Crohn's disease using shear wave elastography and the changes in stiffness after biologics.

MATERIALS AND METHODS

We enrolled 21 Crohn's disease patients having intestinal stricture. The patients consisted of 3 groups, which were the infliximab naïve (n = 6) group, the ustekinumab naïve (n = 8), and the bio-switch from infliximab to ustekinumab (n = 7) group. Bowell wall thickness was examined by ultrasound sonography, and the stiffness of Crohn's disease stricture lesions was evaluated using Shear wave speed before and 1 year after anti-tumor necrosis factor-alpha antibody infliximab, anti-interleukin 12/23 antibody ustekinumab, and bio-switch from infliximab to ustekinumab.

RESULTS

Bowell wall thickness was significantly improved after infliximab, ustekinumab, and the bio-switch. However, shear wave speed indices only in the ustekinumab group significantly decreased after treatment (P = .028), but not in the other group.

CONCLUSIONS

Shear wave elastography might be a useful method to evaluate stiffness in the areas of intestinal stricture in patients with Crohn's disease treated with biologics. However, a prospective randomized study evaluating the development of obstruction after biological treatment is needed to validate the study findings.

In vivo shear wave elasticity imaging for assessment of diaphragm function in muscular dystrophy

Duchenne muscular dystrophy (DMD) causes patients to suffer from ambulatory disability and cardiorespiratory failure, the latter of which leads to premature death. Due to its role in respiration, the diaphragm is an important muscle for study. A common method for evaluating diaphragm function is ex vivo force testing, which only allows for an end point measurement. In contrast, ultrasound shear wave elastography imaging (US-SWEI) can assess diaphragm function over time; however, US-SWEI studies in dystrophic patients to date have focused on the limbs without preclinical studies. In this work, we used US-SWEI to estimate the shear wave speed (SWS) in diaphragm muscles of healthy (WT) mice, mdx mice, and mdx mice haploinsufficient for utrophin (mdx-utr) at 6 and 12 months of age. Diaphragms were then subjected to ex vivo force testing and histological analysis at 12 months of age. Between 6 and 12 months, a 23.8% increase in SWS was observed in WT mice and a 27.8% increase in mdx mice, although no significant difference was found in mdx-utr mice. Specific force generated by mdx-utr diaphragms was lower than that of WT diaphragms following twitch stimulus. A strong correlation between SWS and collagen deposition was observed, as well as between SWS and muscle fiber size. Together, these data demonstrate the ability of US-SWEI to evaluate dystrophic diaphragm functionality over time and predict the biochemical and morphological make-up of the diaphragm. Additionally, our results highlight the advantage of US-SWEI over ex vivo testing by obtaining longitudinal measurements in the same subject. STATEMENT OF SIGNIFICANCE: In DMD patients, muscles experience cycles of regeneration and degeneration that contribute to chronic inflammation and muscle weakness. This pathology only worsens with time and leads to muscle wasting, including in respiratory and cardiac muscles. Because respiratory failure is a major contributor to premature death in DMD patients, the diaphragm muscle is an important muscle to evaluate and treat over time. Currently, diaphragm function is assessed using ex vivo force testing, a technique that only allows measurement at sacrifice. In contrast, ultrasonography, particularly shear wave elasticity imaging (USSWEI), is a promising tool for longitudinal assessment; however, most US-SWEI in DMD patients aimed for limb muscles only with the absence of preclinical studies. This work broadens the applications of US-SWE imaging by demonstrating its ability to track properties and function of dystrophic diaphragm muscles longitudinally in multiple dystrophic mouse models.

Acute Effects of Running on Shear Wave Elastography Measures of the Achilles Tendon and Calf Muscles in Professional Female Handball and Volleyball Players

Shear Wave Elastography (SWE) is currently used to detect tissue pathologies, i.e., tendinopathy. For preventive medicine, it is important to examine the sensitivity of SWE and to investigate how stiffness measures are affected by methodological variables. The aim of this study is to examine shear wave elastography (SWE) measures in order to compare the pre- and post-running values and to determine the correlation between the shear wave speed values (m/s). SWE examinations of the Achilles tendon (AT), soleus muscle (MS) and gastrocnemius muscle (MG)) were performed in 24 healthy professional female athletes. Measurements of the shear wave speed (m/s) were taken before and after incremental treadmill running until exhaustion. Correlations were investigated using the Pearson correlation coefficient and were examined for significance using the Student's t-test. The pre- and post-exercise shear wave speed did not differ. The pre-exercise and post-exercise stiffness for MS (r = 0.613), MG (r = 0.609) and AT (r = 0.583) correlated strongly. The pre-exercise values and changes in stiffness showed a significant correlation (p < 0.001). In professional athletes, acute exercise induces different tissue stiffness changes in AT, MS and MG for each individual. Thus, exercise activity immediately prior to the SWE measurement needs to be factored in when evaluating tissue stiffness.

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).

A single-center, retrospective, cross-sectional study comparing the number of non-diagnostic measurements ratio in the pSWE and SSI ultrasound elastography methods

The point shear wave elastography and supersonic shear imaging methods were compared regarding incorrect measurements during the liver examinations. A report-based, single-center, retrospective analysis of 425 liver elastography examinations was performed. A lower success ratio was observed for the point shear wave elastography method, as well as the older and obese patients pre-dominated in non-diagnostic studies. In our center experience, it is easier to obtain diagnostic data using the supersonic shear imaging method. However, further investigation of the subject is needed.

Quantitative Assessment of Breast-Tumor Stiffness Using Shear-Wave Elastography Histograms

Purpose: Shear-wave elastography (SWE) measures tissue elasticity using ultrasound waves. This study proposes a histogram-based SWE analysis to improve breast malignancy detection. Methods: N = 22/32 (patients/tumors) benign and n = 51/64 malignant breast tumors with histological ground truth. Colored SWE heatmaps were adjusted to a 0−180 kPa scale. Normalized, 250-binned RGB histograms were used as image descriptors based on skewness and area under curve (AUC). The histogram method was compared to conventional SWE metrics, such as (1) the qualitative 5-point scale classification and (2) average stiffness (SWEavg)/maximal tumor stiffness (SWEmax) within the tumor B-mode boundaries. Results: The SWEavg and SWEmax did not discriminate malignant lesions in this database, p > 0.05, rank sum test. RGB histograms, however, differed between malignant and benign tumors, p < 0.001, Kolmogorov−Smirnoff test. The AUC analysis of histograms revealed the reduction of soft-tissue components as a significant SWE biomarker (p = 0.03, rank sum). The diagnostic accuracy of the suggested method is still low (Se = 0.30 for Se = 0.90) and a subject for improvement in future studies. Conclusions: Histogram-based SWE quantitation improved the diagnostic accuracy for malignancy compared to conventional average SWE metrics. The sensitivity is a subject for improvement in future studies.

Intestinal Ultrasound for Differentiating Fibrotic or Inflammatory Stenosis in Crohn's Disease: A Systematic Review and Meta-analysis

BACKGROUND AND AIMS

Intestinal ultrasound [IUS] has been increasingly reported to distinguish inflammatory or fibrotic intestinal stenosis in Crohn's disease [CD] patients. However, the diagnostic value is unclear. This systematic review and meta-analysis aimed to assess the diagnostic role of different modes of IUS parameters.

METHODS

We searched PubMed, Embase, Web of Science, and Cochrane Library from inception to August 2021. Regarding effect sizes, weighted mean differences [WMDs] or standardised mean differences [SMDs] were used. We pooled data using a random-effects or fixed-effects model according to heterogeneity. The diagnostic accuracy of IUS for distinguishing fibrosis was pooled.

RESULTS

A total of 19 studies were retained for qualitative analysis, and 14 were included in the meta-analysis [with 511 total subjects and 635 bowel segments]. In patients with fibrotic stenosis, the pooled WMDs for bowel wall thickness were 1.30 mm (95% confidence interval [CI]: 0.69-1.91) thicker than in patients with inflammatory stenosis, and the pooled SMDs for strain value and strain ratio were 0.80 [95% CI: 0.41-1.20] and 1.08 [95% CI: 0.55-1.60] harder than in patients with inflammatory stenosis, respectively. The percentage of maximal enhancement of fibrotic stenosis was lower than that of inflammatory stenosis [WMD -10.03; 95% CI: -17.91- -2.16]. The diagnostic accuracy of IUS was not performed because only a few studies provided relevant diagnostic indicators, and these studies used different modes and parameters.

CONCLUSIONS

IUS currently is inaccurate to differentiate fibrotic or inflammatory stenosis in CD patients, and more studies assessing the significance of each parameter and its cut-off value in different modes of IUS are needed to be conducted in the future.

The knowledge and skills needed to perform intestinal ultrasound for inflammatory bowel diseases-an international Delphi consensus survey

BACKGROUND

Intestinal ultrasound (IUS) is a non-invasive modality for monitoring disease activity in inflammatory bowel diseases (IBD). IUS training currently lacks well-defined standards and international consensus on competency criteria.

AIM

To achieve international consensus on what competencies should be expected from a newly certified IUS practitioner.

METHODS

A three-round, iterative Delphi process was conducted among 54 IUS experts from 17 countries. Round 1 was a brainstorming phase with an open-ended question to identify the knowledge and skills that experts believe a newly certified IUS practitioner should possess. The experts' suggestions were then organised into statements by a Steering Committee. In round 2, the experts commented upon and rated the statements, which were revised accordingly. In round 3, the experts rated the revised statements. Statements meeting the pre-defined consensus criterion of at least 70% agreement were included in the final list of statements.

RESULTS

In total, 858 items were suggested by the experts in the first round. Based on these suggestions, 55 statements were organised into three categories: knowledge, technical skills and interpretation skills. After the second round, 53 revised statements remained. After the final round, a total of 41 statements had achieved consensus.

CONCLUSIONS

We established international, expert consensus on the knowledge and skills that should be expected from newly certified IUS practitioners. These consensus statements are the first step towards mastery learning for IUS training. Educators can utilise these statements to design training programmes and evaluate the competencies of trainees before they engage in independent practice.

Ultrasound Elastography in Inflammatory Bowel Diseases: A Systematic Review of Accuracy Compared with Histopathological Assessment

BACKGROUND AND AIMS

Ultrasound elastography [USE] is an innovative, non-invasive, promptly available, ancillary technique that has been proposed in the evaluation of intestinal fibrosis as a monitorable biomarker, in terms of stiffness. The non-invasive estimate of fibrosis by USE appears appealing for dedicated physicians, in order to optimise the treatments for inflammatory bowel disease [IBD] patients [surgical vs non-surgical]. We aimed to systematically review literature evidence on ultrasound elastography in IBD patients.

METHODS

For this qualitative systematic review, we searched PubMed, EMBASE, and Scopus to identify all studies, published until October 2021, investigating the application of USE in IBD patients compared with histopathological assessment.

RESULTS

Overall, 12 papers published between 2011 and 2019 were included. A total of 275 IBD patients were included: 272 Crohn's disease [CD] [98.9%] and three ulcerative colitis [UC] [1.1%]. Seven [58.3%] and four [41.6%] studies investigated strain elastography [SE] and shear wave elastography [SWE], respectively; in one study [0.1%] both techniques were addressed. The histological evaluation was largely conducted on surgical specimens and in two studies endoscopic biopsies were also included. The histological assessment was semi-quantitative in all the included studies, except for two where the fibrosis was evaluated only qualitatively. In 10/12 publications USE could accurately distinguish inflammation from fibrosis in the examined bowel tracts.

CONCLUSIONS

From the preliminary available data, an overall moderate-to-good accuracy of USE in detecting histological fibrosis [10/12 studies] was found. Point-shear wave elastography has been shown to perform superiorly. Further studies are needed to confirm these evidences.