Ultrasonographic imaging of inflammatory bowel disease in pediatric patients

Intestinal ultrasonography in pediatric population

Bowel ultrasound (US) is a low-cost, non-invasive, bed side practice and a reproducible procedure that represents a high yield tool in clinical practice and in the diagnostic workup of a consistent group of acute and chronic gastrointestinal (GI) tract disease. Moreover, in case of GI diseases of neonatal and pediatric age, it allows an easier evaluation due to the small body size and scarce presence of fat tissue in the abdominal wall and peritoneal cavity and gas content. No particular preparation of the patient is needed, nevertheless a 3- to 5-hour fasting state improves the quality of the examination. The exam focuses on wall thickness and stratification, lumen content, distensibility and compressibility, presence of peristalsis of explorable segment of the GI tract and includes the investigation of mesentery, perivisceral tissues and nodes features. Color doppler flowmetry admits a qualitative evaluation of GI wall and mesentery vascularization. Healthy GI wall appears at a US evaluation as a multilayered structure in which hyperechoic and hypoechoic layers alternate sequentially. In this article we provide a quickly available overview on findings, signs and applications of US in major GI pediatric diseases.

Pediatric Patient and Caregiver Satisfaction With the Use of Transabdominal Bowel Ultrasound in the Assessment of Inflammatory Bowel Diseases

OBJECTIVES

Transabdominal bowel ultrasound (TABUS) is emerging as an attractive, noninvasive tool in inflammatory bowel disease (IBD). Patient and caregiver experience with TABUS is not well described. We aimed to determine pediatric patient and caregiver satisfaction with TABUS and the impact of IBD severity, gender, age, and a history of anxiety on satisfaction.

METHODS

Pediatric patients (0-18 years old) with suspected IBD prospectively underwent baseline TABUS, magnetic resonance enterography (MRE), blood work, stool studies, and endoscopy. Patients and their caregiver each completed a cross-sectional satisfaction questionnaire (5-point Likert scale) after the baseline investigations.

RESULTS

There were 54 patients included (67% male). The majority were completely satisfied and strongly agree TABUS was better tolerated than other investigations, regardless of disease severity ( P > 0.05). Patients with higher Simple Endoscopic Score for Crohn Disease (SES-CD) scores felt that TABUS increased their understanding of their IBD ( P < 0.05) and disease location ( P < 0.05). Patients with Crohn disease had similar responses to those with ulcerative colitis, but more strongly agreed that TABUS was better than MRE and endoscopy ( P < 0.05). Those with anxiety did not have an increased level of worry about potential ultrasound findings ( P > 0.05).

CONCLUSIONS

Pediatric patients and their caregivers were highly satisfied with TABUS, preferring it to other modalities. It did not lead to increased worry, and was particularly important in those with severe IBD. These findings support wider implementation of this well tolerated and preferred monitoring tool in pediatrics.

European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB): An Update on the Pediatric CEUS Registry on Behalf of the "EFSUMB Pediatric CEUS Registry Working Group"

The European Federation of Ultrasound in Medicine and Biology (EFSUMB) created the "EFSUMB Pediatric Registry" (EFSUMB EPR) with the purpose of collecting data regarding the intravenous application of pediatric contrast-enhanced ultrasound (CEUS). The primary aim was to document the current clinical practice and usefulness of the technique and secondarily to assess CEUS safety in children. We issue the preliminary results of this database and examine the overall practice of CEUS in children in Europe.

Bowel ultrasound measurements in healthy children - systematic review and meta-analysis

BACKGROUND

Ultrasound (US) is a noninvasive method of assessing the bowel that can be used to screen for bowel pathology, such as Inflammatory Bowel Disease, in children. Knowledge about US findings of the bowel in healthy children is important for interpreting US results in cases where disease is suspected.

OBJECTIVE

To assess the bowel wall thickness in different bowel segments in healthy children and to assess differences in bowel wall thickness among pediatric age categories.

MATERIALS AND METHODS

We conducted a systematic search in the PubMed, Embase, Cochrane, and CINAHL databases for studies describing bowel wall thickness measured by transabdominal US in healthy children. We excluded studies using contrast agent. We calculated the pooled mean and standard deviation scores and assessed differences among age categories (0-4 years, 5-9 years, 10-14 years, 15-18 years), first with analysis of variance (ANOVA) and further with subsequent Student's t-tests for independent samples, corrected for multiple testing.

RESULTS

We identified 191 studies and included 7 of these studies in the systematic review. Reported bowel wall thickness values ranged from 0.8 mm to 1.9 mm in the small bowel and from 1.0 mm to 1.9 mm in the colon. The mean colonic bowel wall thickness is larger in children ages 15-19 years compared to 0-4 years (range in difference: 0.3-0.5 mm [corrected P<0.02]).

CONCLUSION

The reported upper limit of bowel wall thickness in healthy children is 1.9 mm in the small bowel and the colon, and mean thickness increases slightly with age in jejunum and colon. These values can be used as guidance when screening for bowel-related pathology in children.

Diagnostic Accuracy of Transabdominal Ultrasound in Detecting Intestinal Inflammation in Paediatric IBD Patients-a Systematic Review

BACKGROUND AND AIMS

Currently used non-invasive tools for monitoring children with inflammatory bowel disease [IBD], such as faecal calprotectin, do not accurately reflect the degree of intestinal inflammation and do not provide information on disease location. Ultrasound [US] might be of added value. This systematic review aimed to assess the diagnostic test accuracy of transabdominal US in detecting intestinal inflammation in children with IBD in both diagnostic and follow-up settings.

METHODS

We systematically searched PubMed, Embase [Ovid], Cochrane Library, and CINAHL [EBSCO] databases for studies assessing diagnostic accuracy of transabdominal US for detection of intestinal inflammation in patients diagnosed or suspected of IBD, aged 0-18 years, with ileo-colonoscopy and/or magnetic resonance enterography [MRE] as reference standards. Studies using US contrast were excluded. Risk of bias was assessed with QUADAS-2.

RESULTS

The search yielded 276 records of which 14 were included. No meta-analysis was performed, because of heterogeneity in study design and methodological quality. Only four studies gave a clear description of their definition for an abnormal US result. The sensitivity and specificity of US ranged from 39-93% and 90-100% for diagnosing de novo IBD, and 48-93% and 83-93% for detecting active disease during follow-up, respectively.

CONCLUSIONS

The diagnostic accuracy of US in detecting intestinal inflammation as seen on MRE and/or ileo-colonoscopy in paediatric IBD patients remains inconclusive, and there is currently no consensus on defining an US result as abnormal. Prospective studies with adequate sample size and methodology are needed before US can be used in the diagnostics and monitoring of paediatric IBD.

Ultrasound in the evaluation of necrotic bowel in children: A pictorial essay

Necrotic bowel is a serious condition involving death of gastrointestinal tissue. The diagnosis is difficult to make clinically, and plain radiography is often inconclusive. Ultrasonography is an inexpensive, portable and readily available complementary diagnostic tool. In some cases, ultrasonography can detect features of necrotic bowel earlier than plain radiography or when plain radiography is equivocal and does not correlate with the clinical findings. This pictorial essay aims to compare the ultrasonography features of normal bowel and necrotic bowel in children. The role of ultrasonography and the ultrasonographic features of necrotic bowel will be illustrated by discussing some of the causes of necrotic bowel in children. Correlation with plain radiographs and pathological specimens is made. Frequent causes of necrotic bowel in neonates include necrotising enterocolitis, malrotation with small bowel volvulus and incarcerated inguinal hernias. Causes in older children include intussusception, complications of Meckel's diverticulum, post-surgical adhesions, internal hernias and vasculitic abnormalities. Ultrasonography features suggestive of necrotic bowel include persistently dilated loops of aperistaltic bowel, increase or decrease of bowel wall thickness, intramural or portal venous gas, loss of bowel wall perfusion, and free intraperitoneal gas and fluid. The diagnosis of necrotic bowel may be made earlier on ultrasonography than on abdominal radiographs alone. This pictorial essay will familiarise the reader with the role of ultrasonography and the ultrasonographic features of necrotic bowel through a wide range of conditions that may cause necrotic bowel in children. Familiarity with these findings will facilitate timely imaging diagnosis of necrotic bowel before complications develop.

Usefulness of Strain Elastography, ARFI Imaging, and Point Shear Wave Elastography for the Assessment of Crohn Disease Strictures

OBJECTIVES

The aim of this study was to evaluate the diagnostic performance of strain elastography, acoustic radiation force impulse (ARFI) imaging and point shear wave elastography (p-SWE) for assessment of the predominant types of intestinal stenosis in Crohn disease.

METHODS

Twenty-five patients were enrolled in this study, among whom 25 suspicious stenoses in 25 intestinal segments were studied using gray scale ultrasonography. All 3 elastography methods were performed, and all patients underwent endoscopy within 24 hours with pathologic biopsy. The sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), Youden index, and area under the receiver operating characteristic curve (AUROC) were calculated. Pathologic findings were regarded as the gold standard.

RESULTS

For SE, the optimal cutoff value was a score of 4 or greater (sensitivity, 75%; specificity, 66.7%; accuracy, 68%; PPV, 30%; NPV, 93.3%; AUROC, 0.708; however, P > .05). The results of ARFI imaging were similar: the optimal cutoff value was a score of 4 or greater (sensitivity, 50%; specificity, 81%; accuracy, 76%; PPV, 33.3%; NPV, 89.4%; AUROC, 0.669; P < .05). However, for p-SWE, the optimal cutoff value was reached when the shear wave velocity exceeded 2.73 m/s (sensitivity, 75%; specificity, 100%; accuracy, 96%; PPV, 100%; NPV, 95.5%; AUROC, 0.833; P < .05).

CONCLUSIONS

p-SWE had the best performance for evaluating and differentiating intestinal stenosis in Crohn disease, while neither SE nor ARFI imaging achieved satisfactory outcomes for evaluating inflammatory stenosis and fibrotic stenosis of Crohn disease.

The pediatric gastrointestinal tract: ultrasound findings in acute diseases

The study of the gastrointestinal tract by imaging, particularly using ultrasound, is a required instrument for diagnosis of acute and chronic gastrointestinal pathologies in pediatric age. Actually, ultrasound plays an increasing role in the evaluation of gastrointestinal tract in neonatal and pediatric patients because of their small body habitus and the presence of less fat tissue in the abdominal wall and peritoneal cavity. Ultrasound has certain advantages, thanks to the new wide-spectrum frequency probes able to assess a detailed study of the morphological aspects and functional characteristics of bowel loops, adding a new dimension to the imaging of this body system. In this paper, we review anatomy, ultrasound technique and sonographic findings of bowel pathology frequently encountered in neonatal and pediatric emergency setting.

Detection of Intestinal Pneumatosis Location by Following Hyperechoic Foci in the Portal Vein Along Its Branches With Real-time Ultrasound

Portal venous gas is occasionally encountered in children with intestinal pneumatosis, identified on real-time ultrasound imaging as hyperechoic foci with quick movement. The origin of the portal venous gas can be identified by following the hyperechoic foci along the branches of the portal vein, providing an estimate of the location of intestinal pneumatosis. This approach may be useful for predicting the patient's prognosis. Our report describes 2 cases of portal venous gas while estimating the area of intestinal pneumatosis, which were evaluated with real-time ultrasound.

Pediatric Crohn's Disease in Bahrain

OBJECTIVES

Our study aimed to report the epidemiology, clinical presentations, diagnostic and therapeutic approaches, and outcomes of Crohn's disease (CD) in pediatric patients in Bahrain.

METHODS

We conducted a retrospective review of the medical records of patients with CD diagnosed in the pediatric department, Salmaniya Medical Complex, Bahrain, between 1984 and 2017. We used the data to calculate the annual incidence and cumulative prevalence. Data about gender, nationality, clinical presentation, age at presentation and diagnosis, duration of illness, consanguinity, family history, contact with smokers, and comorbidities were gathered. Results of hematological, biochemical, and serological tests were also collected. All radiological, endoscopic, and histopathological findings were reviewed. Data about medical therapy, relapse episodes, hospital admissions, complications, and outcomes were collected.

RESULTS

Of 108 pediatric patients diagnosed with inflammatory bowel disease (IBD), 51 (47.2%) patients had CD. The annual incidence was 1 in 100 000 per year (range = 0-5 patients/year) with significant rise on comparing the three decades (p = 0.0001). Prevalence was 9.32 patients per 100 000 pediatric populations. Thirty-four patients (66.7%) were males, and the median age was 18.5 years (range = 6.4-35.0). Common clinical presentations were recurrent abdominal pain and weight loss. Family history of IBD was found in 10 patients. One patient had positive antineutrophil cytoplasmic antibody. The terminal ileum was involved in 68.1%, colon in 63.8%, and perianal area in 17.0% patients. Biological therapy was used in five patients. Surgical intervention was required in six patients. The mean follow-up period was 9.2±5.6 years.

CONCLUSIONS

The clinical characteristics of our population are comparable to that reported in neighboring countries and worldwide.

Enhancing the role of paediatric ultrasound with microbubbles: a review of intravenous applications

Contrast-enhanced ultrasound (CEUS) represents a complementary technique to greyscale and colour Doppler ultrasonography which allows for real-time visualization and characterization of tissue perfusion. Its inherent advantages in the child makes ultrasonography an ideal imaging modality; repeatability and good tolerance along with the avoidance of CT, a source of ionizing radiation, renders ultrasonography imaging desirable. Although currently paediatric CEUS is principally used in an "off-label" manner, ultrasonography contrast agents have received regulatory approval for assessment of paediatric focal liver lesions (FLL) in the USA. The safety of ultrasound contrast-agents is well documented in adults, as safe as or even surpassing the safety profile of CT and MR contrast agents. Except for the established intracavitary use of CEUS in voiding urosonography, i.v. paediatric applications have been introduced with promising results in the abdominal trauma initial diagnosis and follow-up, characterization and differential diagnosis of FLL and characterization of lung, pleura, renal and splenic pathology. CEUS has also been used to detect complications after paediatric transplantation, evaluate inflammatory bowel disease activity and assess tumour response to antiangiogenic therapy. The purpose of this review was to present these novel i.v. paediatric applications of CEUS and discuss their value.

Abdominal ultrasonography of the pediatric gastrointestinal tract

Ultrasound is an invaluable imaging modality in the evaluation of pediatric gastrointestinal pathology; it can provide real-time evaluation of the bowel without the need for sedation or intravenous contrast. Recent improvements in ultrasound technique can be utilized to improve detection of bowel pathology in children: Higher resolution probes, color Doppler, harmonic and panoramic imaging are excellent tools in this setting. Graded compression and cine clips provide dynamic information and oral and intravenous contrast agents aid in detection of bowel wall pathology. Ultrasound of the bowel in children is typically a targeted exam; common indications include evaluation for appendicitis, pyloric stenosis and intussusception. Bowel abnormalities that are detected prenatally can be evaluated after birth with ultrasound. Likewise, acquired conditions such as bowel hematoma, bowel infections and hernias can be detected with ultrasound. Rare bowel neoplasms, vascular disorders and foreign bodies may first be detected with sonography, as well. At some centers, comprehensive exams of the gastrointestinal tract are performed on children with inflammatory bowel disease and celiac disease to evaluate for disease activity or to confirm the diagnosis. The goal of this article is to review up-to-date imaging techniques, normal sonographic anatomy, and characteristic sonographic features of common and uncommon disorders affecting the gastrointestinal tract in children.

Progress in the treatment and outcome of pediatric inflammatory bowel disease patients

INTRODUCTION

The number of pediatric patients with inflammatory bowel disease (IBD), namely Crohn´s disease, ulcerative colitis and unclassified colitis, has rapidly increased in Western countries. Areas covered: This review discusses how the treatment of pediatric IBD patients has improved,with attention given to therapeutic quality and cost. The literature search covers Medline-PubMed and the Cochrane Library, with February 2016 as the last search dates. Similarly to what has been the trend in the management of adult IBD, pediatric IBD therapy has become more active than before. High use of immunosuppressants and the availability of biological therapeutic agents has helped to control the extensive and aggressive course of pediatric IBD. Full disease control at an early phase has advantages such as preserving normal child growth and development, maintaining overall good health and quality of life, as well as decreasing the psychosocial burden of the disease. Expert commentary: A key research direction is to tailor treatment modalities according to anticipated individual phenotype and disease course. Another is to reduce healthcare costs by decreasing the so-far high rate of surgery of pediatric IBD patients, and, instead, to develop a more active approach to treatment than before.

Particularities of Crohn's disease in pediatric patients: current status and perspectives regarding imaging modalities

A consensus on the best imaging modality evaluating inflammatory bowel disease in the pediatric population is lacking and it is often unclear which modality to choose in specific clinical circumstances. Children with inflammatory bowel disease are exposed to ionizing radiation from multiple imaging studies performed at initial diagnosis, throughout treatment and during the follow-up period. This paper discusses the value of different imaging techniques in pediatric patients with inflammatory bowel disease and gives a review of the literature. In addition, particular features of inflammatory bowel disease in children including the predilection of affected segments in the gastrointestinal tract are highlighted. Based on current literature knowledge, we encourage an integrative approach to the interpretation of clinical and imaging data for diagnosis and follow-up in daily clinical settings.

Assessment of stricturing Crohn's disease: Current clinical practice and future avenues

Crohn’s disease (CD) is a chronic remittent idiopathic disease. Although the early phase of the disease is commonly characterized by inflammation-driven symptoms, such as diarrhea, the frequency of fibrostenotic complications in patients with CD increases over the long-term course of the disease. This review presents the current diagnostic options for assessing CD-associated strictures. In addition to the endoscopic evaluation of CD strictures, this review summarizes the currently available imaging modalities, including ultrasound and cross-sectional imaging techniques. In addition to stricture detection, differentiating between the primarily inflammatory strictures and the predominantly fibrotic ones is essential for selecting the appropriate treatment strategy (anti-inflammatory medical treatment vs endoscopical or surgical approaches). Therefore, recent imaging advances, such as contrast-enhanced ultrasound and ultrasound elastography, contribute to the development of non-invasive non-radiating imaging of CD-associated strictures. Finally, novel magnetic resonance imaging techniques, such as diffusion-weighted, motility and magnetization transfer imaging, as well as ¹⁸F-FDG PET/CT, molecular imaging approaches and biomarkers, are critically reviewed with regard to their potential role in assessing stricturing CD.

Monitoring of renal ischemia reperfusion injury in rabbits by ultrasonic contrast and its relationship with expression of VEGF in renal tissue

OBJECTIVE

To evaluate the renal ischemia reperfusion injury (IRI) in rabbits using the ultrasonic contrast technique and discuss the clinical value of ultrasonic contrast technique in the diagnosis of renal IRI by comparing the time-intensity curve of renal cortex and the expression of vascular endothelial growth factor (VEGF) of renal tissue.

METHODS

Twenty 3-month-old New Zealand rabbits were randomly divided into 4 groups, namely Ctrl group, IRI-12 h, IRI-24 h and IRI-48 h groups. The two dimensional gray-scale ultrasonography was employed to determine and mark the position of rabbit kidney. Rabbits were given the intraperitoneal anesthesia with 20% urethane with the dosage of 5 mL/kg. The aseptic operation was performed after the local skin disinfection in the area of both kidneys. The right kidney of animals in the control group was excised without any treatment for the left kidney. After excising the right kidney of animals in groups of IRI-12 h, IRI-24 h and IRI-48 h, the aneurysm clip was used to clip the renal pedicle vessel of left kidney, in order to simulate the ischemia. Because of the tissue ischemia, it could be seen that the color of kidney was changed from bright red to dark red, which indicated the successful modeling of ischemia. The aneurysm clip was released after one hour of maintaining the ischemia. Then the kidney turned out to be bright red from dark red, which indicated that the reperfusion was completed. Taking this moment as the time of ischemia reperfusion, the wound was stitched up. A total of 12, 24 and 36 h after the operation, the two-dimensional and color Doppler flow imaging and ultrasonic contrast were employed for the examination. The dynamic changes of ultrasonic contrast were recorded. The quantitative analysis software (QontraXt) was adopted to analyze the time-intensity curve of echo at different positions of renal cortex. After the ultrasonic contrast testing, rabbits were put to death. The renal cortex tissue was isolated and the tissue RNA and total protein were extracted respectively. Real-time PCR and western blotting were used to detect the VEGF and the Pearson product moment correlation coefficient was used to measure the linear relationship between these two variables.

RESULTS

The ultrasonic contrast could clearly reflect the process of IRI. The results of testing at mRNA and protein level indicated that the expression of VEGF in IRI groups was significantly increased (P < 0.05) and the expression of VEGF was also increased by the time of reperfusion.

CONCLUSIONS

There is the certain correlation between the expression of VEGF and process of IRI. The correlation coefficient between the ultrasonic contrast parameters of AT and TTP and the relative expression of VEGF is over 0.9, which indicates the relatively high correlation. But there is no significant difference in the change of perfusion peak intensity between groups, which has no correlation with the expression of VEGF.