Diagnostic accuracy of small intestine ultrasonography using an oral contrast agent in Crohn’s disease: comparative study from the UK. Clin Radiol. 2012;67:553-559. [PMID: 22212635 DOI: 10.1016/j.crad.2011.11.005]

Diagnostic Accuracy of Intestinal Ultrasound in the Detection of Intra-Abdominal Complications in Crohn's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Crohn's disease [CD] is frequently associated with the development of strictures and penetrating complications. Intestinal ultrasound [IUS] is a non-invasive imaging modality ideal for point-of-care assessment. In this systematic review and meta-analysis we provide a current overview on the diagnostic accuracy of IUS and its advanced modalities in the detection of intra-abdominal complications in CD compared to endoscopy, cross-sectional imaging, surgery, and pathology.

METHOD

We conducted a literature search for studies describing the diagnostic accuracy of IUS in adult patients with CD-related intra-abdominal complications. Quality of the included studies was assessed with the QUADAS-2 tool. Meta-analysis was performed for both conventional IUS [B-mode] and oral contrast IUS [SICUS].

RESULTS

Of the 1498 studies we identified, 68 were included in this review and 23 studies [3863 patients] were used for the meta-analysis. Pooled sensitivities and specificities for strictures, inflammatory masses, and fistulas by B-mode IUS were 0.81 and 0.90, 0.87 [sensitivities] and 0.95, and 0.67 and 0.97 [specificities], respectively. Pooled overall log diagnostic odds ratios were 3.56, 3.97 and 3.84, respectively. Pooled sensitivity and specificity of SICUS were 0.94 and 0.95, 0.91 and 0.97 [sensitivities], and 0.90 and 0.94 [specificities], respectively. The pooled overall log diagnostic odds ratios of SICUS were 4.51, 5.46, and 4.80, respectively.

CONCLUSION

IUS is accurate for the diagnosis of intra-abdominal complications in CD. As a non-invasive, point-of-care modality, IUS is recommended as the first-line imaging tool if there is a suspicion of CD-related intra-abdominal complications.

Systematic review: Defining, diagnosing and monitoring small bowel strictures in Crohn's disease on intestinal ultrasound

BACKGROUND

Stricturing Crohn's disease (CD) occurs most commonly in the terminal ileum and poses a clinical problem. Cross-sectional imaging modalities such as intestinal ultrasound (IUS), computed tomography enterography (CTE), and magnetic resonance enterography (MRE) allow for assessment of the entire bowel wall and associated peri-enteric findings. Radiologic definitions of strictures have been developed for CTE and MRE; their reliability and responsiveness are being evaluated in index development programs. A comprehensive assessment strategy for strictures using IUS is needed.

AIMS

To provide a detailed summary of definitions, diagnosis and monitoring of strictures on IUS as well as technical aspects of image acquisition.

METHODS

We searched four databases up to 6 January 2024. Two-stage screening was done in duplicate. We assessed risk of bias using QUADAS-2.

RESULTS

There were 56 studies eligible for inclusion. Definitions for strictures on IUS are heterogeneous, but the overall accuracy for diagnosis of strictures is high. The capability of IUS for characterising inflammation versus fibrosis in strictures is not accurate enough to be used in clinical practice or trials. We summarise definitions for improvement of strictures on IUS, and discuss parameters for image acquisition and standardisation.

CONCLUSIONS

This systematic review is the first step for a structured program to develop a stricture IUS index for CD.

Small Intestinal Contrast Ultrasonography (SICUS) in Crohn's Disease: Systematic Review and Meta-Analysis

The diagnosis of Crohn's Disease (CD) is based on a combination of clinical symptoms, laboratory tests, endoscopy, and imaging data. In Small Intestine Contrast Ultrasonography (SICUS), the ingestion of a macrogol solution as an oral contrast medium may optimize image quality. We performed a meta-analysis to evaluate the diagnostic performance of SICUS for CD. A literature search was performed in August 2023. We selected only studies where SICUS was compared to a technique that allows the assessment of the whole gastrointestinal tract, such as an MRE, a CT scan, or a surgical evaluation. We estimated pooled weighted sensitivity, specificity, and likelihood ratio for positive and negative tests (PLR/NLR) of SICUS. Summary receiver operating characteristic curves (SROC) were drawn, and pooled areas under the curve (AUC) were calculated. Five studies with 325 CD patients were included. SICUS showed a pooled sensitivity for the diagnosis of 95% (95% confidence interval CI 89-99%), a specificity = 77% (95% CI 60-90%), and the AUC was 0.94. SICUS demonstrated a pooled sensitivity for strictures of 78% (95% CI 63-88%) and a specificity = 96% (95% CI 85-99%), with AUC = 0.93. For abscesses, SICUS demonstrated a pooled sensitivity of 100% (95% CI 59-100%) and a specificity of 90% (95% CI 74-98%). Fistulae were detected with a pooled sensitivity of 77% (95% CI 46-95%) and a specificity of 92% (95% CI 75-99%). SICUS demonstrated excellent diagnostic performance compared to the gold standard despite some clinical scenarios (stenosis/fistulae) showing suboptimal diagnostic effectiveness.

Intestinal submucous fibrovascular hamartoma: A case report

Intestinal submucosal fibrovascular hamartoma is considered as a rare intestinal lesion. We present the case of a 63-year-old female with abdominal symptoms, bleeding, and increased serum tumor markers. The abdominal ultrasound revealed that the left abdominal intestinal wall and mesentery were thickened with enlarged multiple lymph nodes, suggesting intestinal obstruction. Other imaging findings confirmed the ultrasound findings. Histopathology of the removed lesion provided the diagnosis of intestinal submucosal fibrovascular hamartoma with hemorrhage, inflammation, and amyloidosis. Intestinal submucosal fibrovascular hamartoma is a hemorrhagic lesion with macroscopic tumor due to the abnormal mixing of the organ's normal components, which still remains a challenge for clinicians and pathologists. We consider routine abdominal ultrasonography and contrast-enhanced ultrasonography (SICUS) to be safe and effective in the diagnosis of intestinal neoplastic lesions.

Comparison of small intestinal contrast ultrasound with magnetic resonance enterography in pediatric Crohn's disease

Aim

To compare the diagnostic yield of small intestinal contrast ultrasonography (SICUS) with magnetic resonance enterography (MRE) in routine clinical practice in a cohort of pediatric patients investigated for Crohn's disease (CD) attending a UK tertiary center.

Methods and Results

Patients with suspected or established CD who underwent SICUS were identified retrospectively. SICUS was compared to conventional transabdominal ultrasound (TUS), ileocolonoscopy (IC), and MRE. The accuracy and agreement of SICUS in detecting small bowel lesions and CD-related complications were assessed using kappa (κ) coefficient statistics. A total of 93 patients (median age 15 years, range 2-17, 49 male) underwent SICUS; 58 had suspected and 35 had established CD. In suspected CD, sensitivity and specificity of SICUS in detecting CD small bowel lesions were 81.8 and 100% and for TUS 85.7 and 87.5%, respectively. In established CD, sensitivity and specificity of SICUS were 98.7 and 100% and TUS 80 and 100%, respectively. Agreement between SICUS and IC was substantial for the presence of lesions (κ = 0.73) but fair in TUS (κ = 0.31). Agreement between SICUS and IC was almost perfect for detecting strictures (κ = 0.84), with a sensitivity of 100% and specificity of 97.6%. When comparing SICUS and TUS with MRE, agreement for the presence of lesions was substantial (κ = 0.63) and moderate (κ = 0.53), respectively. Agreement between SICUS and MRE was substantial for detecting strictures (κ = 0.77) and dilatation (κ = 0.68).

Conclusions

SICUS offers a radiation-free alternative for assessing pediatric small bowel CD, with diagnostic accuracy that is comparable to MRE and IC, supporting its wider use in routine practice.

European Society of Paediatric Radiology abdominal imaging task force: statement on imaging in very early onset inflammatory bowel disease

Very early onset inflammatory bowel disease (VEO-IBD) is defined as disease presenting before the age of 6. These children require a tailored imaging approach because conventional imaging studies can be difficult to perform at such a young age. Unlike inflammatory bowel disease in older children and adults, colonic disease predominates in VEO-IBD, and small-bowel disease is rare. Distinguishing Crohn disease from ulcerative colitis is challenging both clinically and on histology. Radiology offers the greatest utility for detecting small-bowel disease because it helps to distinguish the two main disease entities and guide clinical management. Small-bowel ultrasound is recommended as the first-line investigation because it requires relatively little preparation, is readily available and is generally well tolerated in young children. We present these recommendations, based on the current evidence for radiologic management in this group, and propose an imaging algorithm for investigating VEO-IBD.

SICUS and CEUS imaging in Crohn's disease: an update

Endoscopy remains the main technique in the diagnosis and treatment of Crohn's disease (CD); nevertheless, the recent development of innovative and non-invasive imaging techniques has led to a new tool in the exploration of small bowel in CD patients. This paper reviews the available data on ultrasound imaging used for the evaluation of CD, highlighting the role of small intestine contrast-enhanced ultrasonography with the use of oral and intravenous contrast agents.

Bowel Thickening in Crohn's Disease: Fibrosis or Inflammation? Diagnostic Ultrasound Imaging Tools

The high frequency of intestinal strictures in patients with Crohn's disease and the different treatment approaches specific for each type of stenosis make the differentiation between fibrotic and inflammatory strictures crucial in management of the disease. However, there is no standardized approach to evaluate and discriminate intestinal strictures, and until now, there was no established cross-sectional imaging modality to detect fibrosis. New techniques, such as contrast-enhanced ultrasound and sonoelastography allow the assessment of vascularization and mechanical properties of stenotic bowel tissue, respectively. These techniques have shown great potential to characterize strictures in Crohn's disease. The aim of this review is to sum up the current knowledge on bowel ultrasound tools to discriminate inflammatory from fibrotic stenosis in Crohn's disease considering the most recent published studies in the field.

Utility of MR enterography and ultrasound for the investigation of small bowel Crohn's disease

Cross sectional Imaging plays an increasingly important role the diagnosis and management of Crohn's disease. Particular emphasis is placed on MRI and Ultrasound as they do not impart ionising radiation. Both modalities have reported high sensitivity for disease detection, activity assessment and evaluation of extra-luminal complications, and have positive effects on clinical decision making. International Guidelines now recommend MRI and Ultrasound in the routine management of Crohn's disease patients. This article reviews the current evidence base supporting both modalities with an emphasis on the key clinical questions. We describe current protocols, basic imaging findings and highlight areas in need of further research.

LEVEL OF EVIDENCE

5 Technical Efficacy: Stage 4 J. MAGN. RESON. IMAGING 2017;45:1573-1588.

The first joint ESGAR/ ESPR consensus statement on the technical performance of cross-sectional small bowel and colonic imaging

Objectives

To develop guidelines describing a standardised approach to patient preparation and acquisition protocols for magnetic resonance imaging (MRI), computed tomography (CT) and ultrasound (US) of the small bowel and colon, with an emphasis on imaging inflammatory bowel disease.

Methods

An expert consensus committee of 13 members from the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) and European Society of Paediatric Radiology (ESPR) undertook a six-stage modified Delphi process, including a detailed literature review, to create a series of consensus statements concerning patient preparation, imaging hardware and image acquisition protocols.

Results

One hundred and fifty-seven statements were scored for agreement by the panel of which 129 statements (82 %) achieved immediate consensus with a further 19 (12 %) achieving consensus after appropriate modification. Nine (6 %) statements were rejected as consensus could not be reached.

Conclusions

These expert consensus recommendations can be used to help guide cross-sectional radiological practice for imaging the small bowel and colon.

Key points

• Cross-sectional imaging is increasingly used to evaluate the bowel

• Image quality is paramount to achieving high diagnostic accuracy

• Guidelines concerning patient preparation and image acquisition protocols are provided

Small intestine contrast ultrasonography for the detection and assessment of Crohn disease: A meta-analysis

BACKGROUND

Crohn disease (CD) is a chronic relapsing disease. Imaging modalities are essential for the diagnosis and assessment of CD. Small intestine contrast ultrasonography (SICUS) is a well-tolerated, noninvasive and radiation-free modality and has shown potential in CD assessment. We aimed at evaluating the diagnostic accuracy of SICUS in the detection and assessment of small-bowel lesions and complications in CD.

METHODS

We searched PubMed database for relevant studies published before April 24, 2016. We integrated the true positive, false positive, false negative, and true negative into the pooled estimates of sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio. Forest plots were to represent the pooled results of all studies.

RESULTS

Thirteen articles were finally considered eligible. The pooled sensitivity and specificity of SICUS in detecting small-bowel lesions were 0.883 (95% confidence interval (CI) 0.847-0.913) and 0.861 (95% CI 0.828-0.890), respectively. The pooled diagnostic odds ratio was 39.123 (95% CI 20.014-76.476) and the area under the curve of summary receiver operating characteristic was 0.9273 (standard error: 0.0152). In subgroup analyses, SICUS represented fine sensitivity and specificity in proximal and distal small intestine lesion, as well as in CD-related complications such as stricture, dilation, abscess, and fistula.

CONCLUSION

SICUS is accurate enough to make a complete assessment about the location, extent, number, and almost all kinds of complications in CD small-bowel lesions.

Diagnostic imaging and radiation exposure in inflammatory bowel disease

Diagnostic imaging plays a key role in the diagnosis and management of inflammatory bowel disease (IBD). However due to the relapsing nature of IBD, there is growing concern that IBD patients may be exposed to potentially harmful cumulative levels of ionising radiation in their lifetime, increasing malignant potential in a population already at risk. In this review we explore the proportion of IBD patients exposed to high cumulative radiation doses, the risk factors associated with higher radiation exposures, and we compare conventional diagnostic imaging with newer radiation-free imaging techniques used in the evaluation of patients with IBD. While computed tomography (CT) performs well as an imaging modality for IBD, the effective radiation dose is considerably higher than other abdominal imaging modalities. It is increasingly recognised that CT imaging remains responsible for the majority of diagnostic medical radiation to which IBD patients are exposed. Magnetic resonance imaging (MRI) and small intestine contrast enhanced ultrasonography (SICUS) have now emerged as suitable radiation-free alternatives to CT imaging, with comparable diagnostic accuracy. The routine use of MRI and SICUS for the clinical evaluation of patients with known or suspected small bowel Crohn’s disease is to be encouraged wherever possible. More provision is needed for out-of-hours radiation-free imaging modalities to reduce the need for CT.

Small intestinal contrast ultrasonography for the detection of small bowel complications in Crohn's disease: correlation with intraoperative findings and magnetic resonance enterography

BACKGROUND AND AIMS

In evaluating small bowel Crohn's disease (CD), small intestine contrast-enhanced ultrasonography (SICUS) is emerging as an alternative to magnetic resonance enterography (MRE). This retrospective study compared the diagnostic accuracy of SICUS and MRE with surgical findings, and their level of agreement.

METHODS

We identified a cohort of CD patients investigated by either SICUS and/or MRE that subsequently required resective bowel surgery within 6 months. The accuracy and agreement of SICUS and MRE to detect small bowel complications were compared with intraoperative findings using kappa coefficient (κ). Agreement between SICUS and MRE in those undergoing both modalities was also assessed.

RESULTS

A total of 67 patients were evaluated; 25 underwent SICUS and 17 underwent MRE prior to surgery. Another 25 patients underwent both SICUS and MRE. When compared with intraoperative findings, the sensitivity of SICUS and MRE was 87.5% and 100%, respectively, in detecting strictures, 87.7% and 66.7% for fistulae, 100% for both in identifying abscesses, 100% and 66.7% for bowel dilatation, and 94.7% and 81.8% in defining bowel wall thickening. When correlating SICUS and MRE with surgery, there was a high level of agreement in localizing strictures (κ = 0.75, 0.88, respectively), fistulae (κ = 0.82, 0.79) and abscesses (κ = 0.87, 0.77). Concordance between SICUS and MRE was substantial or almost complete in identifying stricturing disease (κ = 0.84), their number and location (κ = 0.85), fistulae (κ = 0.65), and mucosal thickening (κ = 0.61).

CONCLUSION

SICUS accurately identified small bowel complications and correlated well with MRE and intraoperative findings. SICUS offers an alternative in the preoperative assessment of CD.

Common and uncommon applications of bowel ultrasound with pathologic correlation in children

OBJECTIVE

The purpose of this article is to describe the indications and techniques for bowel ultrasound for inflammatory bowel disease and other common and uncommon entities and describe and illustrate their imaging appearances, including endoscopic or surgical correlation.

CONCLUSION

Ultrasound is a useful tool for the evaluation of inflammatory bowel disease and many other bowel diseases. Radiologists must become familiar with the full potential of ultrasound in the evaluation of the bowel in children because the need for alternative radiation-free imaging techniques continues to grow.

Predictive factors for clinically actionable computed tomography findings in inflammatory bowel disease patients seen in the emergency department with acute gastrointestinal symptoms

BACKGROUND

The wide use of abdomino-pelvic computed tomography (APCT) in emergency departments (ED) has raised the concern for radiation exposure, costs and potential reactions to contrast agents. The aim of this study was to determine the yield and predictive factors for clinically actionable findings (CAF) in APCTs performed in patients with inflammatory bowel disease (IBD) who visit the ED.

METHODS

We performed a cross-sectional study including patients with IBD who visited the ED. Variables considered were demographics, IBD phenotype, clinical symptoms, IBD medication use prior to ED visit, laboratory values, and imaging results. The primary outcome was a composite of CAF, defined as new, intra-abdominal abscess or tumor, bowel obstruction, fistulae, diverticulitis, choledocholithiasis, or appendicitis.

RESULTS

354 patients were included. One or more CAF were reported in 26.6% of the APCTs (32.1% in CD and 12.8% in UC [p<0.01]). Independent predictive variables of CAF in CD were: CRP level ≥5mg/dl (p=0.04), previous history of IBD surgery (p=0.037), Black race (p<0.01) and low body mass index (p<0.01). None of the study variables predicted CAF in UC.

CONCLUSIONS

The yield for CAF with APCT in the ED was high for CD patients but minimal for those with UC and was not improved by the use of contrast. Elevated CRP, low BMI, Black race and previous history of IBD surgery predicted CAF in CD but no variables were predictive of CAF in UC.

Temporal trends in imaging and associated radiation exposure in inflammatory bowel disease

OBJECTIVES

Increasing use of diagnostic imaging in inflammatory bowel disease (IBD) has led to concerns about the malignant potential of ionising radiation in a cohort that have an increased lifetime risk of gastrointestinal malignancy. The aim was to quantify radiation exposure in IBD patients referred from primary care, determine predictors of high exposure and evaluate temporal trends in diagnostic imaging over a 20-year period.

METHODS

This was a retrospective cohort study whereby IBD patients were recruited from the outpatient clinic and evaluated retrospectively. The total cumulative effective dose (CED) received from tests was calculated for each subject. Cox regression was performed to assess factors associated with potentially harmful levels of ionising radiation defined as total CED > 50 milli-sieverts (mSv; equivalent to five CT abdomen scans).

RESULTS

The cohort included 415 patients. Median total CED was 7.2 mSv (IQR: 3.0-22.7) in Crohn's disease and 2.8 mSv (IQR: 0.8-8.9) in ulcerative colitis patients, respectively. A total of 32 patients (8%) received a CED > 50 mSv. A history of IBD-related surgery was associated with high exposure (HR 7.7). During the study period, usage of abdominal CT increased by 310%.

CONCLUSION

Approximately 1 in 13 patients in the study cohort were exposed to potentially harmful levels of ionising radiation. Strategies to minimise exposure to diagnostic medical radiation in IBD patients are required.

A phase 1 open-label trial shows that smad7 antisense oligonucleotide (GED0301) does not increase the risk of small bowel strictures in Crohn’s disease

BACKGROUND

In Crohn's disease (CD), knockdown of Smad7, an inhibitor of Transforming Growth Factor (TGF)-β1 activity, with a specific antisense oligonucleotide (GED0301) seems to be safe and tolerable and associates with TGF-β1-mediated suppression of inflammatory pathways.

AIM

Since TGF-β1 has pro-fibrogenic effects in many organs, we evaluated whether GED0301 treatment associates with the formation of small bowel strictures.

METHODS

Fifteen patients with active, inflammatory CD, receiving oral GED0301 once daily for 7 days, were monitored for the formation of small bowel strictures by Small Intestine Contrast Ultrasonography (SICUS). Serum basic fibroblast growth factor (bFGF) and human chitinase 3-like 1 (also known as YKL-40), two markers of CD-related intestinal strictures, and matrix metalloproteinases (MMP) and tissue inhibitor 1 of MMPs (TIMP1) were analysed at day 0 and day 180 by ELISA. Crohn's disease activity index (CDAI) changes were also monitored.

RESULTS

Fourteen patients completed the 6-month study; the remaining underwent intestinal resection for a severe relapse not responsive to medical treatment. No patient developed small bowel stricture and none experienced obstructive symptoms during the study period. GED0301 treatment induced no significant change in the circulating levels of bFGF, YKL-40, MMPs and TIMP1. Seven of 12 patients who reached clinical remission following GED0301 treatment maintained a CDAI < 150 at day 180.

CONCLUSION

Short-term treatment of patients with Crohn's disease using GED0301 is not associated with the development of small bowel stricture, thus reinforcing the concept that this drug is safe at least at early time points.

Progress in the diagnosis of ileocecal lesions

The ileocecal area includes the ileocecal valve, terminal ileum, cecum, appendix, and top ascending colon. Since this area may be affected by pathologic conditions that are either common throughout the gastrointestinal system or exclusive to this area, a great variety of intestinal diseases may arise in this region, making the diagnosis of ileocecal lesions difficult. In clinic, the diagnosis of ileocecal lesions depends on the combination of disease history, clinical features, imaging and endoscopic findings. The development of advanced imaging and endoscopy technology has greatly increased the detection rate of ileocecal lesions. In this review, we discuss the use of imaging and endoscopic examinations for evaluation of ileocecal area to help ensure accurate diagnosis and appropriate treatment.