Bowel elastography - a pilot study for developing an elastographic scoring system to evaluate disease activity in pediatric Crohn's disease

The usefulness of transabdominal ultrasound elastography in Helicobacter pylori gastritis in children

Background

Helicobacter pylori can colonize the submucosal layer as well as the mucosa in the stomach. Inflammation and erosions cause both mucosal and submucosal thickening in patients with Helicobacter pylori gastritis. Elastography is a method for measuring the elasticity and hardness of tissues by visualization of their response to the applied force. Hard tissues respond to applied compression differently compared to soft tissues. Hard tissues displace as a whole without deforming as opposed to soft tissues. In this study, we investigated the diagnostic performance of transabdominal ultrasound elastography in detecting Helicobacter pylori gastritis in children.

Methods

Nineteen children (group 1) with Helicobacter pylori gastritis, 33 children (group 2) with Helicobacter pylori (-) gastritis and 37 healthy children (group 3) were included the study. These groups were compared in terms of their strain index values. Ultrasonographic examinations were performed with a single transducer at 1.8-6.2 MHz frequency range.

Results

Both group 1 and 2 had significantly higher strain index values compared to the control group (2.7, 2.2 and 1.4 respectively). Additionally, the mean strain index value was significantly higher in group 1 compared to group 2.

Conclusion

Transabdominal ultrasound elastography has diagnostic value in differentiating Helicobacter pylori (+) gastritis from Helicobacter pylori (-) gastritis as well as in the diagnosis of gastritis in children.

Ultrasound elastography in children - nice to have for scientific studies or arrived in clinical routine?

Ultrasound elastography (USE) is a modality that in addition to fundamental B-mode, Doppler, and contrast-enhanced sonography is suitable to make qualitative and quantitative statements about the stiffness of tissues. Introduced more than 20 years ago in adults, USE becomes now a diagnostic tool also in children. The aim of this paper is to describe current available techniques for USE in children. The significance for routine use in children is shown, and further interesting applications are reported.

Ultrasound Elastography in the Assessment of the Intestinal Changes in Inflammatory Bowel Disease-Systematic Review

Inflammatory bowel disease (IBD) is a chronic condition affecting primarily the gastrointestinal tract and characterized by growing incidence worldwide. Complex diagnostic process of IBD as well as evaluation of disease activity and intestinal complications that are crucial for the therapeutic decisions, require repetitive, invasive, expensive, time-consuming and poorly tolerated tests. In contrast to endoscopy and computed tomography, ultrasound elastography (UE) is non-invasive, non-radiating and non-contrasting dependent tool which might be utilized in IBD patients for the assessment of the intestinal changes. Therefore, we performed the systematic review to evaluate the possible application of the ultrasound elastography for assessment of the intestinal changes in IBD. After the search of three databases: PubMed, World of Knowledge and Scopus, we identified 12 papers which were included in the final analysis. The majority of the studies were focused on the evaluation of the symptomatic ileal/ileocolonic strictures in Crohn's disease patients that required surgical resection. Only one study concerned ulcerative colitis. The authors evaluated different UE techniques: strain elastography (SE), acoustic radiation force impulse (ARFI) and shear wave elastography (SWE). Results were expressed with semi-quantitative color mapping and strain measurement. Histological scores of inflammation and fibrosis in Crohn's disease were used as a reference test in the majority of studies. Ultrasound elastography seems to be a promising novel imaging technique supporting evaluation of the intestinal strictures in Crohn's disease patients in respect to fibrosis detection as well as differentiation between fibrosis and inflammation. However, further research is needed to establish the position of ultrasound elastography in IBD management.

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

One modern imaging technique used in the diagnosis of Crohn’s disease (CD) is sonoelastrography of the intestine. Guidelines regarding the use of bowel sonoelastography in CD have still not been specified. The aim of our research was to conduct a systematic review of the use of sonoelastography in the diagnosis, assessment, and monitoring of strictures in the course of CD. A systematic review was conducted according to the PRISMA guidelines statement. The following databases were searched in January 2021: MEDINE via PubMed, Embase and Scopus. The search utilised the following MeSH tags: ‘Ultrasound Shear Wave’, ‘Elastography’, ‘elastogram’, ‘elastographies’ AND ‘Crohn disease’. The inclusion criteria were as follows: from 2010 or later, articles with abstracts, articles in English, human-based studies and original articles. Articles were assessed independently by two reviewers. Out of 181 articles, only 15 met the criteria and were included in the review. Due to a small number of studies and significant methodological differences, the feasibility of using sonoelastography for Crohn’s disease must be proven through further research and analysis. In the future, standardised assessment criteria and cut-off points should be established for both strain elastography (SE) and shear wave elastography (SWE).

Use of Contrast-Enhanced Ultrasonography and Shear-Wave Elastography in the Diagnosis of Granulomatous Colitis in a French Bulldog

An 11-month-old male intact French Bulldog was referred for chronic intermittent diarrhea lasting three months. Ultrasonographic (US) examination revealed severe thickening of the wall of the colon and caecum; contrast-enhanced US (CEUS) and elastography showed increased, heterogeneous vascularization and non-uniform stiffness of the colonic wall. The mucosa was thickened, fragile, and ulcerated as revealed by endoscopy, and histological examination confirmed the suspicion of granulomatous colitis.

The establishment of a regression model from four modes of ultrasound to predict the activity of Crohn's disease

To establish a multi-parametric regression model from four modes of ultrasound to predict the activity of Crohn's disease (CD) noninvasively. Score of 150 of the Crohn’s Disease Activity Index (CDAI) was taken as the cut-off value to divide the involved bowel segments of 51 patients into the active and inactive group. Eleven parameters from four modes of ultrasound (B-mode ultrasonography, color Doppler flow imaging, contrast-enhanced ultrasonography and shear wave elastography) were compared between the two groups to investigate the relationship between multimodal ultrasonic features and CD activity. P < 0.05 was considered statistically significant. Parameters with AUC larger than 0.5 was selected to establish the prediction model of CDAI. Totally seven ultrasound parameters (bowel wall thickness, mesenteric fat thickness, peristalsis, texture of enhancement, Limberg grade, bowel wall perforation and bowel wall stratification) were significantly different between active and inactive group. A regression model was established based on the seven parameters as followed: CDAI = 211.325 + 3.186BWT − 53.003BWS + 6.280BWP + 0.392MFT + 22.239PS + 79.012LG + 72.793TE. (R² = 0.72, P = 0.037). The multimodal ultrasound parametric regression model was designed to predict CDAI score invasively. The model has the potential to provide an alternative method for quantifying the CD activity.

Multiparametric ultrasound in the diagnosis and monitoring of ischemic colitis: description of a case of ischemic colitis of the right colon and revision of the literature

The aim of this paper is to describe the usefulness of multiparametric US in the diagnosis and subsequent follow-up of a case of right-side ischemic colitis and to present a review of the data reported in the literature. Ischemic colitis is frequently diagnosed in the field of gastroenterology. Diagnosis is usually based on the outcome of endoscopy and histological examination, and in case of right-side ischemic colitis also on the results of contrast-enhanced CT. In the described case, multiparametric US indicated the diagnosis including a prognostic judgment, and during follow-up US-monitored patency of the stents positioned under angiographic guidance. One of the available US techniques, CEUS, seems to have a special role in the detection of residual vascularization of the gastrointestinal tract affected by ischemia. However, before introducing this method into daily clinical practice, further studies are required to confirm its diagnostic accuracy.

Contrast-Enhanced Ultrasound and Shear Wave Elastography Evaluation of Crohn's Disease Activity in Three Adolescent Patients

Characterizing inflammation and fibrosis in Crohn's disease (CD) is necessary to guide clinical management, but distinguishing the two remains challenging. Novel ultrasound (US) techniques: contrast-enhanced US (CEUS) and shear wave elastography (SWE) offer great potential in evaluating disease activity in pediatric patients. Three patients ages 16 to 20 with known CD underwent CEUS and SWE to characterize bowel wall inflammation and fibrosis. Magnetic resonance enterography, endoscopy, or surgical pathology findings are also described when available. The patients' disease activity included acute inflammation, chronic inflammation with stricture formation, and a fibrotic surgical anastomosis without inflammation. CEUS was useful in determining the degree of inflammation, and SWE identified bowel wall fibrosis. Used together these techniques allow for better characterization of the degree of fibrosis and inflammation in bowel strictures. With further validation CEUS and SWE may allow for improved characterization of bowel strictures and disease flares in pediatric patients suffering from CD.

Strain elastography in Crohn's disease: the role of visual observation and semiquantitative parameters

Strain elastography is a recently developed ultrasound method that seems to contribute to the diagnosis and monitoring of inflammatory bowel diseases. This pictorial essay aims to present the feasibility of strain elastography in clinical practice by comparing visual observation and semiquantitative parameters with endoscopic or radiological images in some common cases of Crohn's disease. In our opinion, strain elastography with visual observation is easily performed in connection with B-mode ultrasound and color Doppler imaging and may provide relevant information. Strain elastography with the elaboration of semiquantitative parameters is not as immediate as the visual observation method, but it seems to provide more objective data and seems more appropriate for monitoring the evolution of the disease. However, for the elastographic method to extensively contribute in inflammatory bowel diseases, standardization and further studies are required to confirm the promising results already reported in the literature.

Ultrasonography in Gastroenterology: The Need for Training

The use of ultrasonography (US) as an imaging modality in medicine has spread across almost every clinical specialty. This diffusion is based on the simplicity, accessibility, portability and affordability of the technique producing real-time high-resolution images using non-ionising radiation. On the other hand, this trend also extended the technique to settings other than healthcare, such as public facilities, private houses or remote sites. This tendency can be observed worldwide, from developing countries to prestigious medical schools and tertiary referral hospitals. Furthermore, point-of-care US (POCUS), i.e., US executed at the patient's bedside to obtain real-time objective information with diagnostic and clinical monitoring purposes or to guide invasive procedures, has been incorporated in many specialties. In gastroenterology, despite the essential role of endoscopy, clinical practice is highly dependent on non-endoscopic imaging techniques. However, as in other specialties, the indications of US in gastroenterology have been increasing steadily, covering a broad range of conditions. In response to the generalised employment of US by non-radiologists, institutions such as the European Federation of Societies for Ultrasound in Medicine and Biology and the Royal College of Radiologists issued recommendations to ensure high-quality practice. These theoretical and practical requisites include performing a certain number of examinations and mandatory skills in order to achieve certification to execute unsupervised US. Therefore, there is a need for modern gastroenterology to include US as a basic skill in its clinical practice. To ensure the provision of high-quality US, adequate instruction of future specialists should be guaranteed by the gastroenterology departments and required in the residency training programme.

Real-time elastography in Crohn's disease: feasibility in daily clinical practice

Ultrasound (US) is the first-line investigation in patients with abdominal symptoms and it has a role in the diagnosis and monitoring of inflammatory bowel diseases. Strain elastography (SE) is a US method for estimating tissue elasticity. This method is still not routinely used in clinical practice, although it is suggested by the EFSUMB Guidelines for the characterization of intestinal stenosis in Crohn's disease. The purpose of this Pictorial Essay is to confirm the feasibility of elastography in Crohn's disease in clinical practice by comparing elastography images with corresponding endoscopic or radiological images. At present, diagnostic accuracy of SE is reported in the literature only in connection with detection of bowel wall fibrosis in advanced cases of Crohn's disease. However, in our opinion, SE can add useful diagnostic information to grayscale and color Doppler US by providing a more accurate characterization of the bowel wall in the various manifestations of Crohn's disease.

Light and sound - emerging imaging techniques for inflammatory bowel disease

Patients with inflammatory bowel disease are known to have a high demand of recurrent evaluation for therapy and disease activity. Further, the risk of developing cancer during the disease progression is increasing from year to year. New, mostly non-radiant, quick to perform and quantitative methods are challenging, conventional endoscopy with biopsy as gold standard. Especially, new physical imaging approaches utilizing light and sound waves have facilitated the development of advanced functional and molecular modalities. Besides these advantages they hold the promise to predict personalized therapeutic responses and to spare frequent invasive procedures. Within this article we highlight their potential for initial diagnosis, assessment of disease activity and surveillance of cancer development in established techniques and recent advances such as wide-view full-spectrum endoscopy, chromoendoscopy, autofluorescence endoscopy, endocytoscopy, confocal laser endoscopy, multiphoton endoscopy, molecular imaging endoscopy, B-mode and Doppler ultrasound, contrast-enhanced ultrasound, ultrasound molecular imaging, and elastography.

Feasibility of CEUS and strain elastography in one case of ileum Crohn stricture and literature review

Contrast-enhanced ultrasonography (CEUS) and strain elastography (SE) are diagnostic imaging methods, which are still not routinely used in the clinical management of inflammatory bowel diseases. However, there are studies in the literature reporting on the use of both CEUS and SE in patients with bowel obstruction due to Crohn's disease, documenting the usefulness of these two methods in the differentiation between inflammation and fibrosis affecting the bowel wall. The aim of this case report is to evaluate the usefulness of CEUS and SE performed in a patient with Crohn's disease, who was admitted to hospital with bowel obstruction due to terminal ileal stricture and submitted to ileocecal resection. CEUS and SE identified and to some extent also characterized the inflammatory and fibrotic processes affecting the bowel wall. Macroscopic and microscopic examinations of the surgical specimen confirmed the presence of inflammatory phenomena (exudates, ulcers, and fistulas) and fibrosis as suggested by ultrasound (US) imaging methods.