US of gastrointestinal tract disease

Prediction of mechanical ventilation outcome by early abdominal-visceral-blood-flow-and-function score in critically ill patients after cardiopulmonary bypass in the ICU: A prospective observational study

Background

Abdominal organs are important organs that sense and respond to ischemia and hypoxia, but there are few evaluation methods.We use ultrasonography to evaluate abdominal organ function and blood flow in patients with mechanical ventilation (MV) after cardiopulmonary bypass and to obtain a semiquantitative score for abdominal organ function and blood flow.

Methods

Patients with cardiopulmonary bypass in the Critical Care Department of Peking Union Medical College Hospital in China from March to July 2021 were enrolled in this prospective observational study. The correlation of the abdominal-visceral-blood-flow-and-function score (AVBFS) with the duration of MV, number of days spent in the intensive care unit (ICU), acute physiology and chronic health evaluation II (APACHE-II), sequential organ failure assessment (SOFA), lactate, epinephrine, and norepinephrine use was analyzed, and the results were used to assess the predictive value of the receiver operating characteristic curve (ROC) regression analysis score for the duration of MV.

Results

Of the 92 patients who underwent cardiopulmonary bypass, 41 were finally included. The AVBFS were significantly correlated with the duration of MV, number of days spent in the ICU, APACHE-II score, SOFA score, and norepinephrine use time. The AVBFS in a group of patients using ventilators ≥36 h were significantly higher than those obtained for a group of patients using ventilators <36 h (P <0.05). The evaluation results for the AVBFS at 0-12 h after ICU admission were as follows: area under the ROC curve (AUC)=0.876 (95% confidence interval [CI]: 0.767 to 0.984), cut-off value=2.5, specificity=0.842, and sensitivity=0.773.

Conclusions

Abdominal visceral organ function and blood perfusion can be used to evaluate gastrointestinal function. It is related to early and late extubation after cardiac surgery.

Value of intestinal ultrasound in pediatric magnet ingestion: a case report

Ingestion of magnetic foreign bodies in pediatric settings has become more common in the last years due to the marketing of various toys containing small magnetic parts. Most magnets, especially if a single element is ingested, usually pass through the gastrointestinal tract without complications. However, ingestion of multiple magnets or magnets and small metallic components may require a prompt intervention due to the risk of attraction across bowel layers, leading to pressure necrosis, perforation, and even death. Routinely, serial radiological evaluations are needed to follow the progression of magnets through the intestine, while the role of small bowel ultrasound is regarded as marginal. Here we report a case of a 5-years old boy who ingested 8 magnets and in which small bowel ultrasound was pivotal for the correct assessment of magnets location to correct address the surgical approach.

Spectrum of bowel wall thickening on ultrasound with pathological correlation in children

Applications for bowel US in children have been well described; however, less focus has been placed on patterns of bowel wall architectural change in specific disease states. This pictorial essay reviews normal bowel wall architecture and covers a variety of inflammatory, infectious, vascular and neoplastic disorders outside the neonatal period as seen on US, with illustrative pathological correlation. A thorough understanding of normal and abnormal bowel wall architecture can enrich sonographic interpretation and provide a valuable adjunct to appropriate clinical investigation.

Imaging Approaches to Monitor Inflammasome Activation

Inflammasomes are a critical component of innate immune response which plays an important role in the pathogenesis of various chronic and acute inflammatory disease conditions. An inflammasome complex consists of a multimeric protein assembly triggered by any form of pathogenic or sterile insult, resulting in caspase-1 activation. This active enzyme is further known to activate downstream pro-inflammatory cytokines along with a pore-forming protein, eventually leading to a lytic cell death called pyroptosis. Understanding the spatiotemporal kinetics of essential inflammasome components provides a better interpretation of the complex signaling underlying inflammation during several disease pathologies. This can be attained via in-vitro and in-vivo imaging platforms, which not only provide a basic understanding of molecular signaling but are also crucial to develop and screen targeted therapeutics. To date, numerous studies have reported platforms to image different signaling components participating in inflammasome activation. Here, we review several elements of inflammasome signaling, a common molecular mechanism combining these elements and their respective imaging tools. We anticipate that future needs will include developing new inflammasome imaging systems that can be utilized as clinical tools for diagnostics and monitoring treatment responses.

Ileal duplication cyst with giant polypoidal gastric heterotropia

Enteric duplication cysts (EDCs) are congenital malformations of the gastrointestinal tract. EDCs can present as tubular or spherical cystic lesions of the abdomen. The tubular variant of EDC arises as an outpouching from the bowel wall, whereas the spherical variant rarely shows bowel communication. EDCs are known to harbour heterotopic pancreatic parenchyma or gastric mucosa. We present a case of EDC of the ileum (tubular type) with heterotopic gastric mucosa in a 7-year-old child who came with malena and abdominal discomfort. CT revealed focal abnormal dilatation of the ileal loop with polypoidal mucosal thickening. Differential diagnosis of lymphoma, bowel polyps and Meckel's diverticula with gastric heterotopia (GH) were considered. Subsequent surgery followed by histopathology revealed it to be EDC with GH. We discuss this case to familiarise radiologists with the atypical imaging features of EDC, to prevent misdiagnosis and initiate prompt treatment in appropriate clinical settings.

Ultrasonography in infectious and neoplastic diseases of the bowel and peritoneum

Ultrasonography is not the most cited imaging technique for the evaluation of infectious and neoplastic diseases of the gastrointestinal tract and the peritoneum, but it is often the initial technique used in the initial workup for nonspecific clinical syndromes. Despite its limitations, ultrasonography's strengths enable it to provide meaningful diagnostic information. To discuss the most important ultrasonographic, clinical, and epidemiological findings for infectious disease, we follow a topographical approach: stomach (Anisakis), proximal small bowel (Giardia lamblia, Strongyloides stercoralis, Mycobacterium avium-intracellulare complex, and Cryptosporidium), distal small bowel (Yersinia, Salmonella, and Campylobacter), terminal ileum and cecum (tuberculosis), right colon (Entamoeba histolytica), left colon (Shigella), sigmoid colon and rectum, pancolitis (Clostridium difficile, Cytomegalovirus, and Escherichia coli), and peritoneum. To discuss the ultrasonographic and clinical findings of the most common neoplastic diseases, we follow a nosological approach: polyploid lesions as precursors of tumors, carcinomas, neuroendocrine tumors, hematological tumors, mesenchymal tumors, and metastases. We briefly discuss tumors of the peritoneum and the use of ultrasonography to guide percutaneous biopsy procedures.

Implementation of bowel ultrasound practice for the diagnosis and management of necrotising enterocolitis

Necrotising enterocolitis (NEC) is a serious inflammatory bowel disease of prematurity with potentially devastating complications and remains a leading cause of morbidity and mortality among premature infants. In recent years, there has been accumulating data regarding benefits of using bowel ultrasound (BUS) in the diagnosis and management of NEC. Despite this, adoption of robust BUS programmes into clinical practice has been slow. As BUS is a relatively new technique, many barriers to implementation exist, namely lack of education and training for sonographers and radiologists, low case volume and unfamiliarity by clinicians regarding how to use the information provided. The aim of this manuscript is to provide a framework and a roadmap for units to implement BUS in day-to-day practice for NEC diagnosis and management.

Intussusception due to intramural jejunal splenosis

Splenosis is defined as the growth of ectopic splenic tissue, due to its direct seeding, usually seen after traumatic or surgical procedures to the spleen. It often occurs on highly vascularized surfaces such as the omentum or the mesentery, and grows in sessile form, supplied by adjacent vessels. Intestinal splenosis with endoluminal extension is extremely rare. We present a case of intestinal splenosis with endoluminal growth in a 14-year-old boy that provoked a small bowel intussusception requiring surgical resolution.

Ultrasound findings of Crohn's disease: correlation with MR enterography

Crohn's disease is a chronic inflammatory bowel disease characterized by periods of relative inactivity alternating with acute flare-ups. Imaging techniques play a fundamental role in the diagnosis and follow-up of Crohn's disease, providing information on the extent of disease, disease activity, and the presence of extramural complications. Because of the frequent re-evaluation required by the relapsing nature of Crohn's disease and the relative young age at which most patients are diagnosed, techniques that use ionizing radiation are best avoided in monitoring this population. Thus, magnetic resonance enterography (MRE) and ultrasonography (US) are the preferable techniques. Various studies have demonstrated that US is accurate in assessing the gut. Despite some clear advantages over MRE, US has long been underused in the evaluation of intestinal disease. This review presents an overview of the main imaging findings in Crohn's disease, correlating representative US images with MRE and surgical pathology specimens. We conclude that US reliably depicts both bowel-related and mesenteric features of Crohn's disease and US findings correlate strongly with MRE findings.

Recommendations of the Spanish Working Group on Crohn's Disease and Ulcerative Colitis (GETECCU) on the use of abdominal ultrasound in inflammatory bowel disease

Ultrasound has an excellent diagnostic performance when Crohn's disease is suspected, when performing an activity assessment, or determining the extension and location of Crohn's disease, very similar to other examinations such as MRI or CT. It has a good correlation with endoscopic lesions and allows the detection of complications such as strictures, fistulas or abscesses. It complements colonoscopy in the diagnosis and, given its tolerance, cost and immediacy, it can be considered as a good tool for disease monitoring. In ulcerative colitis, its role is less relevant, being limited to assessing the extent and activity when it is not possible with other diagnostic techniques or if there are doubts with these. Despite its advantages, its use in inflammatory bowel disease (IBD) is not widespread in Spain. For this reason, this document reviews the advantages and disadvantages of the technique to promote knowledge about it and implementation of it in IBD Units.

Usefulness of intestinal ultrasound in inflammatory bowel disease

Imaging techniques play a fundamental role in the initial diagnosis and follow-up of inflammatory bowel disease. Intestinal ultrasound has high sensitivity and specificity in patients with suspected Crohn's disease and in the detection of inflammatory activity. This technique enables the early diagnosis of intra-abdominal complications such as stenosis, fistulas, and abscesses. It has also proven useful in monitoring the response to treatment and in detecting postsurgical recurrence. Technical improvements in ultrasound scanners, technological advances such as ultrasound contrast agents and elastography, and above all increased experience have increased the role of ultrasound in the evaluation of the gastrointestinal tract. The features that make ultrasound especially attractive include its wide availability, its noninvasiveness and lack of ionizing radiation, its low cost, and its good reproducibility, which is important because it is easy to repeat the study and the study is well tolerated during follow-up. This review summarizes the role of intestinal ultrasound in the detection and follow-up of inflammatory bowel disease.

Bowel ultrasound: examination techniques and normal and pathologic patterns

Ultrasound is being increasingly used to study the digestive tract because it has certain advantages over other techniques such as endoscopy, CT enterography, and MR enterography. Ultrasound can be used to evaluate the bowel wall and the elements that surround it without the need for contrast agents; its ability to evaluate the elasticity and peristalsis of these structures is increasing interest in its use. This article describes the techniques and modalities of bowel ultrasound, as well as the normal features of the bowel wall and contiguous structures. It uses a practical approach to review the main pathological findings and their interpretation, and the different patterns of presentation, which will help orient the diagnosis.

Acoustic biosensors for ultrasound imaging of enzyme activity

Visualizing biomolecular and cellular processes inside intact living organisms is a major goal of chemical biology. However, existing molecular biosensors, based primarily on fluorescent emission, have limited utility in this context due to the scattering of light by tissue. In contrast, ultrasound can easily image deep tissue with high spatiotemporal resolution, but lacks the biosensors needed to connect its contrast to the activity of specific biomolecules such as enzymes. To overcome this limitation, we introduce the first genetically encodable acoustic biosensors-molecules that 'light up' in ultrasound imaging in response to protease activity. These biosensors are based on a unique class of air-filled protein nanostructures called gas vesicles, which we engineered to produce nonlinear ultrasound signals in response to the activity of three different protease enzymes. We demonstrate the ability of these biosensors to be imaged in vitro, inside engineered probiotic bacteria, and in vivo in the mouse gastrointestinal tract.

Molecular imaging of inflammation - Current and emerging technologies for diagnosis and treatment

Inflammation is a key factor in multiple diseases including primary immune-mediated inflammatory diseases e.g. rheumatoid arthritis but also, less obviously, in many other common conditions, e.g. cardiovascular disease and diabetes. Together, chronic inflammatory diseases contribute to the majority of global morbidity and mortality. However, our understanding of the underlying processes by which the immune response is activated and sustained is limited by a lack of cellular and molecular information obtained in situ. Molecular imaging is the visualization, detection and quantification of molecules in the body. The ability to reveal information on inflammatory biomarkers, pathways and cells can improve disease diagnosis, guide and monitor therapeutic intervention and identify new targets for research. The optimum molecular imaging modality will possess high sensitivity and high resolution and be capable of non-invasive quantitative imaging of multiple disease biomarkers while maintaining an acceptable safety profile. The mainstays of current clinical imaging are computed tomography (CT), magnetic resonance imaging (MRI), ultrasound (US) and nuclear imaging such as positron emission tomography (PET). However, none of these have yet progressed to routine clinical use in the molecular imaging of inflammation, therefore new approaches are required to meet this goal. This review sets out the respective merits and limitations of both established and emerging imaging modalities as clinically useful molecular imaging tools in addition to potential theranostic applications.

Utility of gastrointestinal ultrasound in functional gastrointestinal disorders: A narrative review

Gastrointestinal (GI) ultrasound (GIUS) is valuable in the evaluation of GI diseases such as inflammatory bowel disease, but its use in functional GI disorders (FGIDs) is largely unknown although promising. In order to review the current knowledge on current and potential uses of GIUS in FGIDs, information was obtained via a structured literature search through PubMed, EMBASE and Google Scholar databases with a combination of MESH and keyword search terms: “ultrasound”, “functional GI disorders”, “irritable bowel syndrome”, “functional dyspepsia”, “intestinal ultrasound”, “point of care ultrasonography”, “transabdominal sonography”, “motility”, “faecal loading”, “constipation”. GIUS is currently used for various settings involving upper and lower GI tracts, including excluding organic diseases, evaluating physiology, guiding treatment options and building rapport with patients. GIUS can be potentially used to correlate mechanisms with symptoms, evaluate mechanisms behind treatment efficacy, and investigate further the origin of symptoms in real-time. In conclusion, GIUS is unique in its real-time, interactive and non-invasive nature, with the ability of evaluating several physiological mechanisms with one test, thus making it attractive in the evaluation and management of FGIDs. However, there are still limitations and concerns of operator dependence and lack of validation data for widespread implementation of GIUS in FGIDs.

Sonographic assessment of infectious diseases of the gastrointestinal tract: from scanning to diagnosis

BACKGROUND

Sonography of the gastrointestinal (GI) tract is a practical, safe, inexpensive, and reproducible diagnostic tool for the evaluation, diagnosis, and follow-up of infectious bowel disease. The modality is rapidly gaining prominence among clinicians on a global scale. In the United States, however, ultrasound of the bowel remains underutilized primarily due to insufficient experience among radiologists and sonographers in performing sonographic bowel assessment. This lack of experience and knowledge results in misinterpretations, missed diagnoses, and underutilization of this modality in patients with acute abdomen, with the majority of GI pathology on sonography discovered incidentally.

OBJECTIVES

This article aims to demonstrate the characteristic sonographic findings associated with GI infectious processes as well as provide dedicated ultrasound protocols for evaluation of the GI tract.

CONCLUSION

This article serves a twofold purpose, raising awareness of the utility of this imaging modality within the radiology community and also providing practical teaching points for sonographic evaluation of infectious disorders of the GI tract.

Ultrasound as First Line Step in Anaemia Diagnostics

This review covers the role of ultrasonography as an essential non-invasive diagnostic approach when facing patients with anaemia, a common clinical problem. Abdomen ultrasound is well recognised as a first-line examination in the setting of blood loss, both acute and chronic. Less is clear about the additional opportunities, given by ultrasound in anaemia, due to the many other possible causes. Here we provide information on the utility of ultrasound in different contexts and a practical guide for clinicians facing anaemic patients.

A universal ultrasound diagnostic system developed to support urology and coloproctological applications

In this study, we sought to describe a novel imaging apparatus that is lightweight, inexpensive, and highly effective for use in colorectal diagnostic and treatment settings. Typical probes for use in colorectal ultrasonic imaging applications are developed for surgeons to diagnose and stage rectal tumors and image the rectum and anus. Here we outline a new technique and use it for colorectal imaging in an animal. This technique involves use of an ultrasound array module positioned along the axis of rotation such that improved rotation is possible. This module is in the shape of a linear rod with a rotary linear component that allows for emission of focused ultrasonic echo signals from a linear section of the probe. The usability of the transducer and rectal image quality are satisfactory in a porcine model with the technique proposed here, axial/lateral resolution as 0.96/2.24 mm with 6 dB applied through the contour map using the point spread function. When compared to currently available methods, this technique provides superior diagnostic 3D volumetric image quality with reduced acquisition time. Given this, the ultrasound device proposed here may prove a viable and preferable method to those currently available for urology and colorectal imaging applications.

Beyond appendicitis: ultrasound findings of acute bowel pathology

Bowel pathology is a common unexpected finding on routine abdominal and pelvic ultrasound. However, radiologists are often unfamiliar with the ultrasound appearance of the gastrointestinal tract due to the underutilization of ultrasound for bowel evaluation in the USA. The purpose of this article is to familiarize radiologists with the characteristic ultrasound features of a variety of bowel pathologies. Basic ultrasound technique for bowel evaluation, ultrasound appearance of normal bowel, and key ultrasound features of common acute bowel abnormalities will be reviewed.

Pitfalls in ultrasound imaging of the stomach and the intestines

The gastrointestinal tract is an extraordinary human organ in terms of its morphology and function. Its complex structure and enormous length as well as frequent presence of gas discourage many doctors performing ultrasound examination from its exploration. Moreover, there are anatomical structures in multiple locations which can mimic certain abnormalities. It is difficult to present an exhaustive account of the problem of gastrointestinal tract ultrasound imaging errors in a single work; therefore, this study focuses mainly on false positive errors which usually result from a lack of knowledge of anatomical variants of the gastrointestinal tract structure. In the case of the stomach, rugae and muscle layer thickening towards the pylorus have been mentioned, which constitute variants of the structure of this organ examined when empty. Diagnostic pitfalls in the small intestine may include the dudenojejunal flexure (ligament of Treitz), the horizontal part of the duodenum and the ileocaecal valve. The status of the apparent lesions in all of the cases mentioned will be resolved following fluid intake by the patient. In the colon, the varied structure of semilunar folds should be taken note of. Their large thickness can warrant suspicion of wall invasion or a polyp. In addition, the study emphasises the importance of appropriate preparation of a patient for gastrointestinal tract examination since it determines the accuracy of the diagnosis. The authors also take note of common ‘sins’ of physicians such as hasty examination and failure to comply with the stomach and appendix examination protocol.

Small bowel imaging in Crohn's disease patients

Crohn’s disease (CD) is a lifelong, chronic inflammatory bowel disorder. The small bowel (SB) is involved to varying extents, and the clinical course may vary from an inflammatory type to a more complicated one with stricture, fistula, and abscess formation. Esophagogastroduodenoscopy and ileocolonoscopy with biopsies are the conventional endoscopic techniques that usually establish the diagnosis. On the other hand, CD may affect SB segments that cannot be reached through these procedures. Video capsule endoscopy and enteroscopy are additional endoscopic techniques that may allow further SB evaluation in such circumstances. Computed tomographic enterography, magnetic resonance enterography, and ultrasonography are radiologic techniques that serve as a crucial adjunct to endoscopic assessment. They enable the assessment of parts of the bowel that may be difficult to reach with conventional endoscopy; this allows for the detection of active inflammation, penetrating or stricturing disease, and the appreciation of extraintestinal complications. Both endoscopic and radiologic modalities play a role in establishing the diagnosis of CD, as well as determining the disease extent, activity and response to therapy. This review is intended to evaluate these modalities in terms of specificity, sensitivity, potential side-effects, and limiting factors. This should serve as a guide to the clinician for establishing the most appropriate and reliable test within a particular clinical context.

Sonography of the Cecum: Gateway to the Right Lower Quadrant

Sonography of the cecum has come of age largely as a consequence of the successful evolution of appendiceal sonography as a useful tool in the evaluation of patients with right lower-quadrant pain. At some medical centers, graded-compression sonography (GCS) has become the initial imaging study of choice in the assessment of these individuals. The cecum serves as a helpful anatomic landmark for localization of the appendix in these examinations-providing a sonographic starting point in the search for the appendix. During GCS, primary pathology within the cecum itself can become evident, including a variety of processes, such as infectious, inflammatory, or neoplastic disorders, whose presentations commonly mimic that of appendicitis. The accurate diagnosis of cecal abnormalities and their differentiation from acute appendicitis play valuable roles in the management of affected patients because the options for further workup and subsequent treatment vary greatly according to the diagnosis at hand. Additionally, the compressed cecum often becomes an acoustic window into the right lower quadrant, revealing pathology apart from the appendix within the right iliac fossa. The purpose of this pictorial essay is to highlight the importance and value of performing a careful evaluation of the cecum during GCS of patients with suspected appendicitis and to review the differential diagnosis and imaging findings of primary cecal abnormalities whose clinical presentations can mimic that of acute appendicitis.

Role of ultrasound in colorectal diseases

Ultrasound is an undervalued non-invasive examination in the diagnosis of colonic diseases. It has been replaced by the considerably more expensive magnetic resonance imaging and computed tomography, despite the fact that, as first examination, it can usefully supplement the diagnostic process. Transabdominal ultrasound can provide quick information about bowel status and help in the choice of adequate further examinations and treatment. Ultrasonography, as a screening imaging modality in asymptomatic patients can identify several colonic diseases such as diverticulosis, inflammatory bowel disease or cancer. In addition, it is widely available, cheap, non-invasive technique without the use of ionizing radiation, therefore it is safe to use in childhood or during pregnancy, and can be repeated at any time. New ultrasound techniques such as elastography, contrast enhanced and Doppler ultrasound, mini-probes rectal and transperineal ultrasonography have broadened the indication. It gives an overview of the methodology of various ultrasound examinations, presents the morphology of normal bowel wall and the typical changes in different colonic diseases. We will pay particular attention to rectal and transperineal ultrasound because of their outstanding significance in the diagnosis of rectal and perineal disorders. This article seeks to overview the diagnostic impact and correct indications of bowel ultrasound.

Sonography of Gastrointestinal Tract Diseases: Correlation With Computed Tomographic Findings and Endoscopy

Sonographic evaluation of the gastrointestinal (GI) tract may be difficult because of overlying intraluminal bowel gas and gas-related artifacts. However, in the absence of these factors and with the development of high-resolution scanners and the technical experience of radiologists, sonography can become a powerful tool for GI tract assessment. This pictorial essay focuses on sonographic findings of GI tract lesions compared with endoscopic, computed tomographic, and magnetic resonance imaging findings. Neoplastic and non-neoplastic diseases and postoperative complications are illustrated, and the distinctive sonographic characteristics of these entities are highlighted.

Ultrasonography in gastroenterology

Ultrasonography (US) is a safe and available real-time, high-resolution imaging method, which during the last decades has been increasingly integrated as a clinical tool in gastroenterology. New US applications have emerged with enforced data software and new technical solutions, including strain evaluation, three-dimensional imaging and use of ultrasound contrast agents. Specific gastroenterologic applications have been developed by combining US with other diagnostic or therapeutic methods, such as endoscopy, manometry, puncture needles, diathermy and stents. US provides detailed structural information about visceral organs without hazard to the patients and can play an important clinical role by reducing the need for invasive procedures. This paper presents different aspects of US in gastroenterology, with a special emphasis on the contribution from Nordic scientists in developing clinical applications.