Role of US in detection of Crohn disease: meta-analysis

Imaging for Inflammatory Bowel Disease

Multiple imaging modalities exist for inflammatory bowel disease. This article explores the use of plain radiographs, contrast radiologic imaging, computed tomography, MRI, ultrasound, and capsule endoscopy. History, technique, indications for use, limitations, and future directions are discussed for each modality.

Ultrasound features of pediatric Crohn disease: a guide for case interpretation

With the emerging use of ultrasound in the evaluation of children with Crohn disease presenting with acute abdominal symptoms, there is a need to become familiar with the sonographic features of this disease. Our aim is to provide a primer of the characteristic intramural and extramural US findings in children with Crohn disease to serve as a practical and systematic guide to interpretation.

Contrast Enhanced Abdominal Ultrasound in the Assessment of Ileal Inflammation in Crohn's Disease: A Comparison with MR Enterography

BACKGROUND AND AIMS

To prospectively examine the feasibility and accuracy of Contrast Enhanced Ultrasound (CEUS) in the assessment of Crohn's disease (CD) activity in the terminal ileum in comparison to Magnetic Resonance Enterography (MRE), using endoscopy as a reference standard.

METHODS

105 consecutive patients with alleged clinically active CD were assessed by MRE and CEUS. CEUS of the terminal ileum was performed using an intravenous microbubble contrast enhancer. Accuracy values of CEUS and MRE for the presence of active terminal ileitis were evaluated using the Receiver Operating Characteristic method, using endoscopic findings as a reference standard. Sensitivity and specificity values of MRE and CEUS were compared by the McNemar test.

RESULTS

CEUS was feasible in 98% of patients, MRE in all. Optimal diagnostic accuracy in CEUS was obtained at a peak intensity value of 10%, showing 100% sensitivity, 92% specificity and an accuracy of 99% in demonstrating ileal mucosal inflammation. For MRE, overall sensitivity, specificity and accuracy were, 87%, 100%, and 88%, respectively. CEUS and MRE were highly correlated in assessing length and wall thickness of the terminal ileum. CEUS identified 11 of 16 MRE-detected strictures, but no fistulae.

CONCLUSION

The accuracy of CEUS is comparable to that of MRE in the assessment of active, uncomplicated terminal ileal CD and therefore a valuable bedside alternative to MRE in the follow-up of these patients.

Use of Imaging Techniques in Inflammatory Bowel Diseases That Minimize Radiation Exposure

The use of imaging in the management of inflammatory bowel disease (IBD) has grown exponentially in the last few years. This has raised concerns about the risk of high cumulative level of radiation exposure from medical imaging in IBD patients during their lifetime, especially when the disease begins in pediatric age. Physicians caring for IBD children should be aware of the malignant potential of ionizing radiation and of the availability of alternative radiation-free techniques such as magnetic resonance imaging (MRI) and ultrasonography (US), in order to use them whenever possible. This review will focus on the value of US and MRI in pediatric IBD.

Ultrasonographic imaging of inflammatory bowel disease in pediatric patients

Inflammatory bowel disease (IBD) is one of the most common chronic gastrointestinal diseases in pediatric patients. Choosing the optimal imaging modality for the assessment of gastrointestinal disease in pediatric patients can be challenging. The invasiveness and patient acceptance, the radiation exposure and the quality performance of the diagnostic test need to be considered. By reviewing the literature regarding imaging in inflammatory bowel disease the value of ultrasound in the clinical management of pediatric patients is highlighted. Transabdominal ultrasound is a useful, noninvasive method for the initial diagnosis of IBD in children; it also provides guidance for therapeutic decisions and helps to characterize and predict the course of the disease in individual patients. Ultrasound techniques including color Doppler imaging and contrast-enhanced ultrasound are promising imaging tools to determine disease activity and complications. Comparative studies between different imaging methods are needed.

Intestinal blood flow in patients with chronic heart failure: a link with bacterial growth, gastrointestinal symptoms, and cachexia

BACKGROUND

Blood flow in the intestinal arteries is reduced in patients with stable heart failure (HF) and relates to gastrointestinal (GI) symptoms and cardiac cachexia.

OBJECTIVES

The aims of this study were to measure arterial intestinal blood flow and assess its role in juxtamucosal bacterial growth, GI symptoms, and cachexia in patients with HF.

METHODS

A total of 65 patients and 25 controls were investigated. Twelve patients were cachectic. Intestinal blood flow and bowel wall thickness were measured using ultrasound. GI symptoms were documented. Bacteria in stool and juxtamucosal bacteria on biopsies taken during sigmoidoscopy were studied in a subgroup by fluorescence in situ hybridization. Serum lipopolysaccharide antibodies were measured.

RESULTS

Patients showed 30% to 43% reduced mean systolic blood flow in the superior and inferior mesenteric arteries and celiac trunk (CT) compared with controls (p < 0.007 for all). Cachectic patients had the lowest blood flow (p < 0.002). Lower blood flow in the superior mesenteric artery and CT was correlated with HF severity (p < 0.04 for all). Patients had more feelings of repletion, flatulence, intestinal murmurs, and burping (p < 0.04). Burping and nausea or vomiting were most severe in patients with cachexia (p < 0.05). Patients with lower CT blood flow had more abdominal discomfort and immunoglobulin A-antilipopolysaccharide (r = 0.76, p < 0.02). Antilipopolysaccharide response was correlated with increased growth of juxtamucosal but not stool bacteria. Patients with intestinal murmurs had greater bowel wall thickness of the sigmoid and descending colon, suggestive of edema contributing to GI symptoms (p < 0.05). In multivariate regression analysis, lower blood flow in the superior mesenteric artery, CT (p < 0.04), and inferior mesenteric artery (p = 0.056) was correlated with the presence of cardiac cachexia.

CONCLUSIONS

Intestinal blood flow is reduced in patients with HF. This may contribute to juxtamucosal bacterial growth and GI symptoms in patients with advanced HF complicated by cachexia.

Imaging techniques in IBD and their role in follow-up and surveillance

The assessment of extent and severity of IBD is crucial for directing treatment decisions. Clinical symptoms alone are neither sensitive nor specific for the assessment of lesion severity in IBD. Cross-sectional imaging techniques, as well as small-bowel capsule endoscopy (SBCE) and device-assisted enteroscopy, have a high accuracy for assessing the extent of mucosal lesions, and are reliable alternatives to ileocolonoscopy. New endoscopic techniques and devices are emerging for improved follow-up and surveillance. In this Review, we discuss different imaging techniques that are used to assess IBD activity and to survey patients with IBD, and highlight the latest developments in each area. Moreover, technical improvements and new tools that aim to measure intestinal fibrosis, postoperative recurrence, activity indices and endoscopic features are analysed. All of these imaging techniques are aimed at changing the paradigm from symptom-driven to lesion-driven treatment of IBD.

Advancing magnetic resonance imaging in Crohn's disease

Crohn's disease (CD) is a lifelong chronic inflammatory bowel disease associated with diarrhea, abdominal pain, bloody stool and often perianal fistulae. Inflammation in CD involves the entire gastrointestinal tract, especially including the small and large bowels, causing irreversible bowel damage. Frequent imaging examinations are necessary to monitor disease activity and to evaluate response to therapeutic interventions, and, furthermore, to predict recurrence in order to provide appropriate treatment. The suitable imaging modality should be reproducible, well tolerated, safe and free of ionizing radiation. In recent years, imaging used in CD has dramatically changed. Cross-sectional imaging techniques such as computed tomography and magnetic resonance imaging (MRI) are used to investigate not only extraluminal abnormalities, but also intraluminal changes. Recently, new techniques such as MR enteroclysis, enterography, colonography and enterocolonography have been developed. These recent advances enable the use of MRI to assess bowel disorders with high sensitivity, specificity and accuracy. MRI can evaluate simultaneously the bowel surface, bowel wall, abdominal abscesses and perianal lesions, such as perianal fistulae and perianal abscesses, without the problem of overlapping bowel loops. Therefore, MRI has the potential for evaluation of the overall disease activity of CD without radiation exposure. We believe that MRI is a suitable first choice imaging modality in the assessment of CD.

Usefulness of abdominal ultrasonography in the analysis of endoscopic activity in patients with Crohn's disease: changes following treatment with immunomodulators and/or anti-TNF antibodies

OBJECTIVE

The objective of this study was to analyze the accuracy of abdominal ultrasonography (AUS) in the assessment of mucosal healing in patients with Crohn's disease (CD) receiving immunomodulators and/or biological treatment, with ileocolonoscopy as the reference standard.

MATERIALS AND METHODS

Thirty patients were included in a prospective longitudinal study. All patients underwent ileocolonoscopy and AUS before and after a minimum of one year of treatment. The Crohn's Disease Endoscopic Inflammatory Index of Severity (CDEIS) was used for endoscopic assessment whereas AUS was analyzed by means of bowel wall thickness, color Doppler grade and percentage of increase of parietal enhancement after contrast injection.

RESULTS

In the segmental analysis, endoscopic healing was found in 71.2% of the segments and AUS findings were normalized in 62.8%, with a significant correlation between the two techniques (κ=0.76, p<0.001). In the overall assessment performed after treatment, 18 (60%) patients exhibited endoscopic remission (CDEIS <6 points); of these patients, 15 (83.3%) had normalized sonographic findings, with a good correlation between endoscopic remission and sonographic normalization (κ=0.73, p<0.001). Of the three variables assessed by AUS, parietal thickness was the best variable to predict mucosal healing in both analyses, segmental and global.

CONCLUSION

Abdominal ultrasonography is a useful and reliable technique for the assessment of the endoscopic response to treatment with immunomodulators and/or biological drugs in Crohn's disease. AUS is a highly accurate technique for evaluating the healing of the intestinal mucosa.

METRIC (MREnterography or ulTRasound in Crohn's disease): a study protocol for a multicentre, non-randomised, single-arm, prospective comparison study of magnetic resonance enterography and small bowel ultrasound compared to a reference standard in those aged 16 and over

Background

Crohn’s disease (CD) is a lifelong, relapsing and remitting inflammatory condition of the intestine. Medical imaging is crucial for diagnosis, phenotyping, activity assessment and detecting complications. Diverse small bowel imaging tests are available but a standard algorithm for deployment is lacking. Many hospitals employ tests that impart ionising radiation, of particular concern to this young patient population. Magnetic resonance enterography (MRE) and small bowel ultrasound (USS) are attractive options, as they do not use ionising radiation. However, their comparative diagnostic accuracy has not been compared in large head to head trials. METRIC aims to compare the diagnostic efficacy, therapeutic impact and cost effectiveness of MRE and USS in newly diagnosed and relapsing CD.

Methods

METRIC (ISRCTN03982913) is a multicentre, non-randomised, single-arm, prospective comparison study. Two patient cohorts will be recruited; those newly diagnosed with CD, and those with suspected relapse. Both will undergo MRE and USS in addition to other imaging tests performed as part of clinical care. Strict blinding protocols will be enforced for those interpreting MRE and USS. The Harvey Bradshaw index, C-reactive protein and faecal calprotectin will be collected at recruitment and 3 months, and patient experience will be assessed via questionnaires. A multidisciplinary consensus panel will assess all available clinical and imaging data up to 6 months after recruitment of each patient and will define the standard of reference for the presence, localisation and activity of disease against which the diagnostic accuracy of MRE and USS will be judged. Diagnostic impact of MRE and USS will be evaluated and cost effectiveness will be assessed. The primary outcome measure is the difference in per patient sensitivity between MRE and USS for the correct identification and localisation of small bowel CD.

Discussion

The trial is open at 5 centres with 46 patients recruited. We highlight the importance of stringent blinding protocols in order to delineate the true diagnostic accuracy of both imaging tests and discuss the difficulties of diagnostic accuracy studies in the absence of a single standard of reference, describing our approach utilising a consensus panel whilst minimising incorporation bias.

Trial registration

METRIC - ISRCTN03982913 – 05.11.13.

Ultrasonography of the colon in pediatric ulcerative colitis: a prospective, blind, comparative study with colonoscopy

OBJECTIVES

To evaluate the usefulness of colonic ultrasonography (US) in assessing the extent and activity of disease in pediatric ulcerative colitis (UC) and to compare US findings with clinical and endoscopic features.

STUDY DESIGN

Consecutive pediatric patients (n = 60) with a diagnosis of UC and suspected disease flare-up were prospectively enrolled; of these, 50 patients were eligible for the study. All underwent clinical evaluation, bowel US with color Doppler examination and colonoscopy. Blind US was performed the day before endoscopy in all patients. The US assessed variables were bowel wall thickness >3 mm, bowel wall stratification, vascularity, presence of haustra coli, and enlarged mesenteric lymph nodes.

RESULTS

The endoscopic extent of disease was independently confirmed in 47 patients by US that yielded a 90% concordance with endoscopy (95% CI 0.82-0.96). Multiple regression analysis showed that US measurements with an independent predictive value of severity at endoscopy were increased bowel wall thickness (P < .0008), increased vascularity (P < .002), loss of haustra (P = .031), and loss of stratification of the bowel wall (P = .021). Each variable was assigned a value of 1 if present. The US score strongly correlated with clinical (r = 0.94) and endoscopic activity (r = 0.90) of disease (P < .0001).

CONCLUSIONS

Colonic US is a useful first line noninvasive tool to assess the extent and activity of disease in children with UC and to estimate the severity of a flare-up, prior to further invasive tests.

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.

Doppler ultrasound findings correlate with tissue vascularity and inflammation in surgical pathology specimens from patients with small intestinal Crohn's disease

Background

Crohn’s disease (CD) is routinely evaluated using clinical symptoms, laboratory variables, and the CD activity index (CDAI). However, clinical parameters are often nonspecific and do not precisely reflect the actual activity of CD small-intestinal lesions. The purposes of this prospective study were to compare color Doppler ultrasound (US) findings with histological findings from surgically resected specimens and confirm the hypothesis that color Doppler US can distinguish tissue inflammation and fibrosis.

Methods

Among 1764 consecutive patients who underwent color Doppler US examinations, 10 patients with CD (12 small-intestinal CD lesions) who underwent US examinations before elective small-intestine resection were evaluated in the present study. Areas of thickened intestinal walls were evaluated in terms of blood flow using color Doppler US imaging. The blood flow was semiquantitatively classified as “hyper-flow” and “hypo-flow” according to the Limberg score. Resected lesions were macroscopically and histopathologically processed. Inflammatory cell infiltration, fibrosis and vascularity were evaluated by myeloperoxidase (granulocytes), CD163 (macrophages), CD79a (B cells), CD3 (T cells), Masson’s trichrome (fibrosis), and factor VIII staining (vascular walls). All histopathological images were entered into virtual slide equipment and quantified using a quantitative microscopy integrated system (TissueMorph™).

Results

There were no significant differences in disease features or laboratory findings between “hypo-flow” lesions (n = 4) and “hyper-flow” lesions (n = 8). Histopathologically, “hyper-flow” lesions showed significantly greater bowel wall vascularity (factor VIII) (p = 0.047) and inflammatory cell infiltration, including CD163 macrophages (p = 0.008), CD3 T cells, and CD79a B cells (p = 0.043), than did “hypo-flow” lesions. There was no apparent association between the blood flow and CDAI.

Conclusions

In this study, active CD lesions were macroscopically visible in surgical specimens of patients with increased blood flow on preoperative color Doppler US imaging. Additionally, these CD lesions exhibited significantly greater vascularity and numbers of inflammatory leukocytes microscopically. Color Doppler US may predict tissue inflammation and fibrosis in small-intenstinal CD lesions.

Diagnostic imaging in Crohn's disease: what is the new gold standard?

Historically Barium and isotope studies been used for imaging of inflammatory bowel disease (IBD) but carry risk of radiation exposure. Use of Barium is declining resulting in fewer radiologists that have the necessary expertise. Isotopes studies lack anatomical definition but 18F - fludeoxyglucose (FDG) positron emission tomography (PET) shows promise in accurate assessment of disease compared to endoscopy. Computerised tomography (CT) is particularly useful in assessment of complications of Crohn's disease (CD) but radiation exposure is high. CT enterography (CTE) has improved visualisation of small bowel mucosal disease and allows assessment of disease activity. Ultrasound is increasingly used for preliminary assessment of patients with potential IBD. Although widely available and economically attractive, the expertise required is not widespread. Finally magnetic resonance imaging (MRI) is proving to be the most accurate tool for assessment of disease extent and distribution. MRI of the pelvis has superseded other techniques in assessment of peri-anal fistulation.

Ultrasonographic findings in Crohn's disease

In recent years transabdominal bowel sonography has become a first-line modality both in the diagnosis and in the follow-up of inflammatory bowel diseases, especially Crohn's disease, reaching values of sensitivity ranging from 84 to 93 %. In particular, its role is very useful in the early diagnosis of complications such as stenosis, phlegmons, abscesses and fistulae. According to the available literature the ability of US to provide information about disease activity is still under debate and further studies are necessary. In this regard, of fundamental importance is the use of additional techniques such as color- and power-Doppler and contrast-enhanced ultrasound. The purpose of this paper is to report the main sonographic intestinal and extraintestinal findings detectable in Crohn's disease.

Endoscopic ultrasound of the colon for the differentiation of Crohn's disease and ulcerative colitis in comparison with healthy controls

BACKGROUND

Diagnosis of inflammatory bowel disease (IBD) is based on clinical presentation, colonoscopy and histology. Differentiation of Crohn's disease (CD) and ulcerative colitis (UC) can be difficult in some patients. Endoscopic ultrasound (EUS) provides high resolution images of the gastrointestinal wall (GI) and may be an alternative to differentiate CD/UC.

AIM

EUS of the GI layers in patients with IBD and healthy controls (HC) for the differential diagnosis of UC/CD in a prospective, blinded study.

METHODS

Consecutive patients with CD, UC or HC underwent EUS in the mid sigmoid colon with a forward-viewing radial echoendoscope. Mucosal, submucosal, total wall thickness (TWT) and locoregional lymphnodes (LN) were assessed by EUS in a blinded fashion. TWT was correlated with macroscopic IBD scores and histological inflammation scores.

RESULTS

Total wall thickness of 61 HC was 1.71 ± 0.02 mm, and 3.51 ± 0.15 mm in n = 52 with active IBD. In patients with active UC significant thickening of the mucosa was observed but nearly normal submucosa and m.propria. In active CD significant thickening of the submucosal layer was seen with nearly normal mucosa and m.propria [MucosaUC  = 2.08 ± 0.11 mm, MucosaCD  = 1.32 ± 0.17 mm (P = 0.0001); SubmucosaUC  = 1.01 ± 0.08 mm, SubmucosaCD  = 2.01 ± 0.22 mm (P = 0.0001)]. In 73.7% of patients with active CD, but in none with UC, paracolonic lymph nodes were detected. When mucosal-submucosal and TWT and LNs were combined, the sensitivity was 92.3% for the differentiation of active UC/CD. There was a strong correlation of TWT with histological inflammation scores (UC: r = 0.43; CD: r = 0.69).

CONCLUSIONS

Increased total wall thickness has a high positive predictive value for active IBD. EUS can differentiate active UC from CD and quantify the level of colonic inflammation.

Use of color Doppler ultrasonography for evaluating vascularity of small intestinal lesions in Crohn's disease: correlation with endoscopic and surgical macroscopic findings

OBJECTIVE. Ultrasonography (US) is a simple, inexpensive and minimally invasive method. We evaluated the vascularity of small intestinal lesions in Crohn's disease using color Doppler US (CD-US) and retrospectively compared them with endoscopic and surgical macroscopic findings. MATERIAL AND METHODS. In order to compare CD-US and endoscopic findings, 108 Crohn's disease patients who underwent examination of the terminal ileum by both colonoscopy and CD-US were included in the study. Vascularity was evaluated in CD-US using a semiquantitative method, the Limberg score. We analyzed correlations between Limberg score and simple endoscopic score for Crohn's disease (SES-CD), an index reflecting endoscopic activity. Scores of SES-CD 3 and higher were defined as endoscopically active. For comparison with surgical macroscopic findings, 22 Crohn's disease patients who received CD-US and subsequent iliectomies were included. Lesions with apparent open ulcers were defined as active, and those without as non-active. These findings were compared with the Limberg score. RESULTS. A substantial positive correlation was observed between Limberg scores and SES-CD (ρ = 0.709 [p < 0.001]). Notably, all 27 cases with a Limberg score of 3 or 4 were classified as endoscopically active. Compared to surgical macroscopic activity, Limberg scores of active lesions were significantly higher than those of non-active lesions (p = 0.005). In particular, all 11 cases with a Limberg score of 3 or 4 were classified as active lesions. CONCLUSION. Vascularity of small intestinal lesions of Crohn's disease evaluated by CD-US with Limberg score is well correlated with endoscopic and surgical macroscopic findings.

Bowel ultrasonography as an aid for diagnosis of intestinal acute graft-versus-host-disease after allogeneic haematopoietic stem cell transplantation

OBJECTIVE

Aim of our prospective study was to investigate accuracy of bowel ultrasonography in detecting gastrointestinal acute graft versus host disease (GVHD), when using clinical assessment as gold standard. In a subgroup of patients, bowel ultrasonography was compared with colonoscopy and histology in diagnosing of gastrointestinal acute GVHD.

METHODS

Fifty-two patients underwent allogeneic hematopoietic stem cell transplantation and developed gastrointestinal symptoms.

RESULTS

Clinical assessment lead to a diagnosis of gastrointestinal acute GVHD in 17/52 patients, no gastrointestinal acute GVHD was detected in 20/52 patients, while 15 patients were not able to complete the study. Bowel ultrasonography detected either bowel wall thickness of the ileum and the colon or dilation in 16/17 patients and showed 94% sensitivity (95% CI 0.69-0.99), 95% specificity (95% CI 0.73-0.99), and 94.5% accuracy. Colonoscopy was performed in 13/52 patients, showing gastrointestinal acute GVHD in 11/13. In these 11 patients, histology confirmed the diagnosis of gastrointestinal acute GVHD, and bowel ultrasonography detected findings compatible with gastrointestinal acute GVHD in all 11 patients, and was negative in the 2 patients with no gastrointestinal acute GVHD.

CONCLUSION

Bowel ultrasonography can be considered a valuable tool to add to clinical assessment for patients with suspected gastrointestinal acute GVHD for addressing a prompt and appropriate treatment.

Surgery and diagnostic imaging in abdominal Crohn's disease

Surgery is well-established option for the treatment of Crohn's disease that is refractory to medical therapy and for complications of the disease, including strictures, fistulas, abscesses, bleeding that cannot be controlled endoscopically, and neoplastic degeneration. For a condition like Crohn's disease, where medical management is the rule, other indications for surgery are considered controversial, because the therapeutic effects of surgery are limited to the resolution of complications and the rate of recurrence is high, especially at sites of the surgical anastomosis. In the authors' opinion, however, surgery should not be considered a last-resort treatment: in a variety of situations, it should be regarded as an appropriate solution for managing this disease. Based on a review of the literature and their own experience, the authors examine some of the possibilities for surgical interventions in Crohn's disease and the roles played in these cases by diagnostic imaging modalities.

Cross-sectional imaging modalities in Crohn's disease

The standard tools assessing the activity of Crohn's disease (CD) measure the severity of symptoms (the Crohn's Disease Activity Index) or the degree of endoscopic lesions (the Crohn's Disease Endoscopic Index of Severity, the Simplified Endoscopy Score), not the global bowel damage. It is necessary to find new instruments able to assess the structural and functional damage to the intestine and the progression over time. We reviewed recent publications on the accuracy of abdominal ultrasound (US), computed tomography enterography (CTE), and magnetic resonance imaging enterography (MRE) for the assessment of CD. US, CTE and MRE have been shown to have a high and comparable diagnostic accuracy for both the diagnosis and complications of CD, but US and MRE have the major advantage of not imparting ionizing radiation. In summary, findings from these imaging modalities with endoscopic lesions and surgical history incorporating into the Lémann score will allow measuring the global bowel damage at specific time and the progression of disease over time and assessing the impact of different strategies.

Small intestine contrast ultrasonography in pediatric Crohn's disease

OBJECTIVE

To evaluate the diagnostic accuracy of small intestine contrast ultrasonography (SICUS) in pediatric Crohn's disease (CD).

STUDY DESIGN

A total of 51 consecutive patients (median age 15 years; range 3-20, 31 male patients), 21 with suspected and 30 with proven CD, were studied. All patients underwent standard ultrasonography (ie, transabdominal ultrasonography [TUS]), SICUS, small bowel follow-through, and upper and lower endoscopy. SICUS was performed in patients after they ingested an oral contrast solution. TUS and SICUS were compared with small bowel follow-through and endoscopy via use of the final diagnosis as reference standard.

RESULTS

In undiagnosed patients, the sensitivity and specificity of TUS and SICUS in detecting CD small bowel lesions were 75% and 100% and 100% and 100%, respectively. In patients with proven CD, the sensitivity and specificity of TUS and SICUS were 76% and 100% and 96% and 100%, respectively. The agreement (k) with radiology for site of lesions was almost perfect for SICUS (0.93), both for jejunal and ileal lesions, and it was fair (0.40) for jejunal and substantial (0.68) for ileal lesions for TUS. Compared with radiology SICUS correctly assessed the length of lesions, whereas TUS underestimated it (P = .0001).

CONCLUSIONS

The radiation-free technique SICUS is comparable with radiology and more accurate than TUS in assessing small bowel lesions in pediatric CD, mainly in the detection of proximal small bowel disease.

Ultrasound as a diagnostic tool in detecting active Crohn's disease: a meta-analysis of prospective studies

OBJECTIVES

To evaluate the diagnostic accuracy of ultrasound in assessing active Crohn's disease (CD) in adults.

METHODS

We systematically searched PubMed, EMBASE, Web of Science and the Cochrane Library for prospective studies in which ultrasound was performed to evaluate active CD in adults from January 1993 to April 2013. Pooled sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR-) and diagnostic odds ratios (DORs) in a per-patient-based analysis were estimated. Additionally, the area under the receiver-operating characteristic (ROC) curve was calculated to measure the diagnostic accuracy of ultrasound in patients with known or suspected CD.

RESULTS

Fifteen studies involving 1,558 patients were included in this meta-analysis. Overall, the pooled sensitivity (0.88) and LR- (0.14) were not heterogeneous, whereas the pooled specificity (0.97, I(2) = 72.9 %) and LR + (15.10, I(2) = 71.8 %) were. The DOR of ultrasound for assessing active CD was 121.70, with significant heterogeneity (I(2) = 63.3 %). A symmetrical summary ROC curve was plotted showing that the area under the curve was 0.94, indicating good diagnostic accuracy. Meta-regression and subgroup analysis showed that the disease location may be a major cause of heterogeneity.

CONCLUSIONS

This meta-analysis suggests that ultrasound has high diagnostic accuracy in detecting active CD in adults, especially for small bowel CD.

KEY POINTS

• Ultrasound can detect active Crohn's disease (CD). • A meta-analysis of ultrasound for detecting active CD was carried out. • This revealed that ultrasound has high diagnostic accuracy for detecting CD.

Transmural healing evaluated by bowel sonography in patients with Crohn's disease on maintenance treatment with biologics

BACKGROUND

Both thiopurines and anti-tumor necrosis factor (TNF) α agents are effective for treating Crohn's disease (CD) as they can induce clinical remission (CR) and mucosal healing (MH) in most patients. Nevertheless, data on transmural healing (TH) induced by thiopurines and anti-TNF-α agents are still lacking. This study aimed to explore the rate of TH evaluated by bowel sonography in patients with CD treated with biologics and immunosuppressors and its correlation with CR and MH.

METHODS

We performed an observational longitudinal study evaluating TH, CR, and MH in all patients with CD attending our clinic who would complete 2 years of maintenance treatment with biologics or thiopurines. CR and MH were assessed in accordance with current literature, whereas TH was recorded using bowel sonography. All patients underwent endoscopy and bowel sonography before starting treatment and 2 years later.

RESULTS

The study included 66 patients with CD treated with biologics and 67 patients receiving thiopurines. Finally, TH was present in 17 patients on biologics and only 3 patients treated with thiopurines (25% versus 4%; P < 0.01; odds ratio = 6.2). CR was achieved in 37 patients on biologics and in 34 patients on thiopurines (59.7% versus 53%; P = not significant), whereas MH was more frequent in patients treated with anti-TNF-α agents even though without statistical significance (38% versus 25%; P = not significant).

CONCLUSIONS

TH can be achieved in approximately 25% of patients with CD treated with anti-TNF-α agents and significantly correlates with MH. Further studies are needed to define the potential role of TH as long-term prognostic factor.

Imaging techniques for assessment of inflammatory bowel disease: joint ECCO and ESGAR evidence-based consensus guidelines

The management of patients with IBD requires evaluation with objective tools, both at the time of diagnosis and throughout the course of the disease, to determine the location, extension, activity and severity of inflammatory lesions, as well as, the potential existence of complications. Whereas endoscopy is a well-established and uniformly performed diagnostic examination, the implementation of radiologic techniques for assessment of IBD is still heterogeneous; variations in technical aspects and the degrees of experience and preferences exist across countries in Europe. ECCO and ESGAR scientific societies jointly elaborated a consensus to establish standards for imaging in IBD using magnetic resonance imaging, computed tomography, ultrasonography, and including also other radiologic procedures such as conventional radiology or nuclear medicine examinations for different clinical situations that include general principles, upper GI tract, colon and rectum, perineum, liver and biliary tract, emergency situation, and the postoperative setting. The statements and general recommendations of this consensus are based on the highest level of evidence available, but significant gaps remain in certain areas such as the comparison of diagnostic accuracy between different techniques, the value for therapeutic monitoring, and the prognostic implications of particular findings.

Update in pediatric inflammatory bowel disease

The incidence of inflammatory bowel disease (IBD), Crohn's disease and ulcerative colitis, in children is on the rise. Pediatric patients with IBD are especially vulnerable to the physical and psychosocial morbidities of this disorder. Unique aspects of pediatric IBD patients compared to adult patients warrants an individualized approach to management regardless of age. This review focuses on the special aspects of pediatric IBD and the implications for the diagnosis and management of this disease.

Contrast-enhanced ultrasonography: usefulness in the assessment of postoperative recurrence of Crohn's disease

AIM

The aim of this study was to assess whether the contrast-enhanced ultrasonography (CEUS) can increase the value of the ultrasonography in the study of postoperative recurrence of Crohn's disease (CD).

MATERIALS AND METHODS

60 patients with CD who had previously undergone ileocolic resection underwent prospectively both CEUS and colonoscopy within a 3-day period. The sonographic examination included evaluation of bowel wall thickness, transmural complications, colour Doppler grade and contrast-enhanced US. In addition a sonographic score was established. The capacity of CEUS to diagnose endoscopic recurrence, as well as its severity, was assessed by calculating the sensitivity, specificity and positive and negative predictive values, accuracy and odds ratio, with their respective 95% confidence intervals. The areas under the receiver operating characteristic (ROC) curves were also calculated.

RESULTS

49 out of 60 patients showed endoscopic postoperative recurrence. Severe endoscopic recurrence was present in 34 patients (57%). Classic ultrasound parameters (wall thickness >3mm and colour Doppler flow) revealed an accuracy of 88.3% for the diagnosis of recurrence. Sonographic score 2, including thickness >5mm or contrast enhancement >46%, improved the results with a sensitivity, specificity and accuracy of 98%, 100% and 98.3%, respectively, in the diagnosis of endoscopic recurrence. The area under the ROC curve was 0.99, in remarkable agreement with endoscopy (k: 0.946). Sonographic score 3, including thickness >5mm, contrast enhancement >70% or fistula identified 32 out of 34 (94.1%) severe endoscopic recurrences. The area under the ROC curve was 0.836, in good agreement with endoscopy (k: 0.688).

CONCLUSION

CEUS shows excellent sensitivity and specificity for the diagnosis of postoperative recurrence in CD and can also detect severe recurrences.

Noninvasive diagnosis of small bowel Crohn's disease: direct comparison of bowel sonography and magnetic resonance enterography

BACKGROUND

The diagnosis of small bowel Crohn's disease (CD) is performed by ileocolonoscopy, whereas the assessment of its extension can be achieved by radiologic studies or, noninvasively, by magnetic resonance (MR) enterography and bowel sonography (BS). However, few comparative studies exist directly comparing the diagnostic accuracy of BS and MRI. The aim of this study was to evaluate the diagnostic accuracy of BS and MRI for the diagnosis of small bowel CD.

METHODS

We prospectively performed a noninferiority diagnostic study including 234 consecutive subjects with suspected small bowel CD. All patients underwent IC (used as gold standard for diagnosis), BS, and MR enterography performed in random order by physicians who were blinded about the results.

RESULTS

The diagnosis of small bowel CD was made in 120 of 249 subjects (48%). Sensitivity, specificity, positive predictive value, and negative predictive value for CD diagnosis were 94%, 97%, 97%, and 94% for BS and 96%, 94%, 94%, and 96% for MR enterography, respectively. BS was less accurate than MR enterography in defining CD extension (r = 0.69), whereas the concordance in terms of CD location between the 2 procedures was high (k = 0.81). Also, MRI showed a fair concordance with BS about strictures (k = 0.82) and abscesses (k = 0.88), with better detection of enteroenteric fistulas (k = 0.67).

CONCLUSIONS

BS and MR enterography are 2 accurate procedures for the diagnosis of small bowel CD, although MR seems to be more sensitive in defining its extension. BS could be used to select the patients for subsequent MRI examination.

Transabdominal ultrasound for bowel evaluation

This article considers the case for a strategic place for ultrasound (US) bowel evaluation focusing on three common clinical contexts. These include imaging for suspected acute appendicitis and acute diverticulitis, as well as the role of US in a multimodality approach for the diagnosis and management of inflammatory bowel disease and associated complications.

Mucosal healing in Crohn's disease: a systematic review

The traditional goals of Crohn's disease therapy, to induce and maintain clinical remission, have not clearly changed its natural history. In contrast, emerging evidence suggests that achieving and maintaining mucosal healing may alter the natural history of Crohn's disease, as it has been associated with more sustained clinical remission and reduced rates of hospitalization and surgical resection. Induction and maintenance of mucosal healing should therefore be a goal toward which therapy is now directed. Unresolved issues pertain to the benefit of achieving mucosal healing at different stages of the disease, the relationship between mucosal healing and transmural inflammation, the intensity of treatment needed to achieve mucosal healing when it has not been obtained using standard therapy, and the means by which mucosal healing is defined using current endoscopic disease activity indices. The main clinical challenge relates to defining the means of achieving high rates of mucosal healing in clinical practice.

Doppler US measurement of the superior mesenteric artery blood flow in children and adolescents

BACKGROUND

Blood flow volume in the superior mesenteric artery (SMA) measured by pulsed Doppler has been used in adults to evaluate Crohn disease but has not been utilized in children and adolescents.

OBJECTIVE

To establish a cutoff point for normal SMA blood flow using pulsed Doppler US measurement in healthy children and adolescents.

MATERIALS AND METHODS

The study included healthy volunteers from an urban community, divided into two age groups, children (5-9 years) and adolescents (10-17 years). Anthropometric measurements included waist circumference and body surface area classified according to the z-score of body mass index. Heart rate, blood pressure, oxygen saturation and temperature were measured immediately before US evaluation.

RESULTS

The average age of the 60 participants was 12.2 years. Of these, 21 (35%) were ages 5-9 years and 39 (65%) were ages 10-17 years; 21 (35%) were boys. Findings of the two examiners coincided for 58 of the 60 (96.7%) participants. SMA blood flow was significantly lower in the children (mean ± SD = 556 ± 122 ml/min) than in adolescents (mean ± SD 775 ± 311 ml/min) (P < 0.001). SMA blood flow showed statistically significant positive associations with body surface area.

CONCLUSION

We found that superior mesenteric artery blood flow is significantly lower in children than in adolescents and is associated with body surface area.

Small intestine contrast ultrasonography vs computed tomography enteroclysis for assessing ileal Crohn's disease

AIM: To compare computed tomography enteroclysis (CTE) vs small intestine contrast ultrasonography (SICUS) for assessing small bowel lesions in Crohn's disease (CD), when using surgical pathology as gold standard.

METHODS: From January 2007 to July 2008, 15 eligible patients undergoing elective resection of the distal ileum and coecum (or right colon) were prospectively enrolled. All patients were under follow-up. The study population included 6 males and 9 females, with a median age of 44 years (range: 18-80 years). Inclusion criteria: (1) certain diagnosis of small bowel requiring elective ileo-colonic resection; (2) age between 18-80 years; (3) elective surgery in our Surgical Unit; and (4) written informed consent. SICUS and CTE were performed ≤ 3 mo before surgery, followed by surgical pathology. The following small bowel lesions were blindly reported by one sonologist, radiologist, surgeon and histolopathologist: disease site, extent, strictures, abscesses, fistulae, small bowel dilation. Comparison between findings at SICUS, CTE, surgical specimens and histological examination was made by assessing the specificity, sensitivity and accuracy of each technique, when using surgical findings as gold standard.

RESULTS: Among the 15 patients enrolled, CTE was not feasible in 2 patients, due to urgent surgery in one patients and to low compliance in the second patient, refusing to perform CTE due to the discomfort related to the naso-jejunal tube. The analysis for comparing CTE vs SICUS findings was therefore performed in 13 out of the 15 CD patients enrolled. Differently from CTE, SICUS was feasible in all the 15 patients enrolled. No complications were observed when using SICUS or CTE. Surgical pathology findings in the tested population included: small bowel stricture in 13 patients, small bowel dilation above ileal stricture in 10 patients, abdominal abscesses in 2 patients, enteric fistulae in 5 patients, lymphnodes enlargement (> 1 cm) in 7 patients and mesenteric enlargement in 9 patients. In order to compare findings by using SICUS, CTE, histology and surgery, characteristics of the small bowel lesions observed in CD each patient were blindly reported in the same form by one gastroenterologist-sonologist, radiologist, surgeon and anatomopathologist. At surgery, lesions related to CD were detected in the distal ileum in all 13 patients, also visualized by both SICUS and CTE in all 13 patients. Ileal lesions > 10 cm length were detected at surgery in all the 13 CD patients, confirmed by SICUS and CTE in the same 12 out of the 13 patients. When using surgical findings as a gold standard, SICUS and CTE showed the exactly same sensitivity, specificity and accuracy for detecting the presence of small bowel fistulae (accuracy 77% for both) and abscesses (accuracy 85% for both). In the tested CD population, SICUS and CTE were also quite comparable in terms of accuracy for detecting the presence of small bowel strictures (92% vs 100%), small bowel fistulae (77% for both) and small bowel dilation (85% vs 82%).

CONCLUSION: In our study population, CTE and the non-invasive and radiation-free SICUS showed a comparable high accuracy for assessing small bowel lesions in CD.

MR imaging of the small bowel

Small-bowel radiology has undergone dramatic changes in the past 2 decades. Despite important recent advances in small-bowel endoscopy, radiologic imaging remains important for patients suspected of having or with established small-bowel disease. Cross-sectional imaging techniques (computed tomography and magnetic resonance [MR] imaging), used to investigate both extraluminal abnormalities and intraluminal changes, have gradually replaced barium contrast examinations, which are, however, still used to examine early mucosal disease. MR imaging techniques clearly highlight endoluminal, mural and extramural enteric details and provide vascular and functional information, thereby enhancing the diagnostic value of these techniques in small-bowel diseases. Two MR imaging based techniques are currently utilized: MR enteroclysis and MR enterography. In enteroclysis, enteric contrast material is administered through a nasoenteric tube, whereas in enterography, large volumes of enteric contrast material are administered orally. MR enteroclysis ensures consistently better luminal distention than does MR enterography in both the jejunum and the ileum and more accurately depicts endoluminal abnormalities and early disease, particularly at the level of the jejunal loops. Moreover, MR enteroclysis provides a high level of accuracy in the diagnosis and exclusion of small-bowel inflammatory and neoplastic diseases and can be used for the first radiologic evaluation, while MR enterography may effectively be used to follow up both Crohn disease patients without jejunal disease and in pediatric patients where nasogastric intubation might be a problem. MR enteroclysis may also reveal subtle transition points or an obstruction in the lower small bowel, which may escape detection when more routine methods, including enterography, are used. MR imaging offers detailed morphologic information and functional data of small-bowel diseases and provides reliable evidence of normalcy, thereby allowing the diagnosis of early or subtle structural abnormalities and guiding treatment and decisions in patient care.

Crohn's disease: prevalence of intestinal and extraintestinal manifestations detected by computed tomography enterography with water enema

BACKGROUND

Computed tomography enterography (CTE) may detect the presence, severity, and extent of bowel inflammation in patients with Crohn's disease (CD). The aim of our study was to assess, among a cohort of 22 histologically proven CD patients, the prevalence of disease distribution, behavior, anastomotic recurrence and extraintestinal manifestations detected by an original CTE technique.

METHODS

Two radiologists reviewed 221 CTEs performed providing both small and large bowel distension by oral administration of neutral contrast material and trans-rectal introduction of a water enema (CTE-WE).

RESULTS

Ileal CD was detected in 116 CTE-WEs (52.4%), including 71/116 (61.2%) non-stricturing/non-penetrating, 17/116 (14.6%) stricturing, and 28/116 (24.1%) penetrating forms. Colonic CD was appreciable in 35 (15.8%) patients, including 18/35 (51.4%) non-stricturing/non-penetrating, 6/35 (17.1%) stricturing, and 11/35 (31.4%) penetrating forms. Ileocolic CD was present in 52 (23.5%) CTE-WEs, including 30/52 (57.7%) non-stricturing/ non-penetrating; 3/52 (5.7%) stricturing, and 19/52 (36.5%) penetrating forms. In 10/221 patients (4.5%), upper gastrointestinal involvement (UGI) was present. Perianal disease was observed in 17/221 patients (7.7%). Fistulas were present in 52 (23.5%) and abscesses in 24 (10.8%) CTE-WEs, respectively. Among 57/221 (25.8%) patients who had undergone a disease-related intestinal resection, in 30/57 cases (52.6%) CD recurrence at the anastomosis was present. 4/221 patients (1.8%) with a histologically confirmed intestinal neoplastic stenosis were observed. Sacroiliitis (24%) was found to be prevalent over hepatic steatosis (10.8%), cholelithiasis (8.6%), and nephrolithiasis (4%).

CONCLUSIONS

CTE-WE represents a comprehensive imaging technique which may demonstrate bowel inflammation and CD extraintestinal manifestations. A peculiar prevalence of UGI involvement and neoplastic strictures were observed. In our study the prevalence of sacroiliitis resulted higher than previously reported.

Ileal Crohn's disease: CEUS determination of activity

Transabdominal ultrasound is currently accepted as a clinical first-line tool in the assessment of Crohn's disease activity. During recent years, great improvements have been achieved in ultrasound examination with the introduction of high-frequency transducers, ultrasonographic microbubble contrast agents, and dedicated contrast-specific ultrasound software. Therefore, contrast-enhanced ultrasonography (CEUS) is emerging as one of the most important imaging techniques in the diagnosis and follow-up of patients with ileal Crohn's disease. It is non-invasive and non-ionizing, easily repeatable, well-tolerated by patients and has significant diagnostic accuracy. Moreover, the possibility to monitor response to therapies, describing, and quantifying contrast enhancement behavior by specific software, represents an interesting aspect of its utilization, considering the still open questions about the correct use of immunosuppressive and biological agents. The aim of our review is to provide an updated overview of the role of CEUS in the patients who have an ileal localization of Crohn's disease, defining its qualitative and quantitative features.

Increased wall thickness using ultrasonography is associated with inflammation in an animal model of experimental colitis

Experimentally induced colitis is used in animals to investigate pathophysiological mechanisms in inflammatory bowel disease. When following disease course and treatment effects, it should be possible to perform repeated measurements without harming the animals. This pilot study was performed to investigate whether transabdominal ultrasound using a clinical scanner could be used on rats to demonstrate bowel inflammation in an experimental colitis model. Colitis was induced by either 5% dextran sodium sulfate (DSS) in drinking water for 7 days or a single dose of intracolonic trinitrobenzene sulfonic acid (TNBS). Using ultrasonography, wall thickness of distal colon, cecum, and small bowel was recorded prior to and after DSS, and prior to, 2, and 7 days after TNBS. Blood (tumor necrosis factor [TNF]-alpha) and fecal samples (HemoFEC occult blood) were taken from each group on the same days as sonography. Thereafter, rats were killed and specimens for histology were taken. Wall thickness of distal colon, not of cecum or small bowel, increased significantly after 7 days of DSS, and wall thickness of both distal colon and small bowel increased on day 2 and 7 after TNBS. TNF-alpha increased after 7 days in the latter group only. There was a significant correlation between ultrasonographic measurements and combined histology score of distal colon in the DSS group. HemoFEC was also positive in accordance with sonographic and histological features. Increased intestinal wall thickness in response to both DSS- and TNBS-induced colitis was able to be visualized by transabdominal sonography. Moreover, ultrasound findings, occult blood sampling, and histological findings supported each other, indicating that ultrasonography can be used to assess inflammation in a rat experimental model.

Development of a numerical index quantitating small bowel damage as detected by ultrasonography in Crohn's disease

Small intestine contrast ultrasonography (SICUS) has emerged as a valuable tool in the detection of intestinal damage in Crohn's disease (CD). Our aim was to develop a numerical index quantitating small bowel damage as detected by SICUS in patients with an established diagnosis of CD. One hundred and ten patients with ileal or ileocolonic CD were prospectively enrolled and followed up for one year. Disease activity was assessed by CDAI and CRP levels. Study variables included bowel wall thickness, lumen diameter, lesion length and number of lesion site. Fistula, mesenteric adipose tissue alteration, abscess and lymphnodes were also considered. Bowel segments were considered as a hollow cylinder. Standardized variations of variables were combined into a statistical and mathematical model to create an algorithm scoring an index value ranging from 0 to 200. Index was subdivided into a severity scale with 5 classes from the lower (A) to the higher score (E). Median lesion index value was significantly higher (p<0.005) in patients with a CDAI>150 and in patients with CRP>5 mg/l (p=0.003). Patients classified in class E and D at SICUS underwent surgery within one year follow up more frequently than those in class C, B and A (p<0.0001). We propose a new index for assessment of small bowel lesions in CD (SLIC: sonographic lesion index for CD) developed by using SICUS. This index may turn ultrasonography in CD from a descriptive qualitative assessment to a quantitative numerical index suitable for comparison studies.

Evaluation of inflammatory activity in Crohn’s disease and ulcerative colitis

Crohn’s disease and ulcerative colitis evolve with a relapsing and remitting course. Determination of inflammatory state is crucial for the assessment of disease activity and for tailoring therapy. However, no simple diagnostic test for monitoring intestinal inflammation is available. Noninvasive markers give only indirect assessments of disease activity. Histopathological or endoscopical examinations accurately assess inflammatory activity, but they are invasive, time consuming and expensive and therefore are unsuitable for routine use. Imaging procedures are not applicable for ulcerative colitis. The usefulness of ultrasound and Doppler imaging in assessing disease activity is still a matter of discussion for Crohn’s disease, and an increased interest in computed tomography enterograph (CTE) has been seen, mainly because it can delineate the extent and severity of bowel wall inflammation, besides detecting extraluminal findings. Until now, the available data concerning the accuracy of magnetic resonance enterography in detecting disease activity is less than CTE. Due to this, clinical activity indices are still commonly used for both diseases.

Manifestations of small bowel disease in pediatric Crohn's disease on magnetic resonance enterography

BACKGROUND

We report the manifestations of Crohn's disease (CD) observed on magnetic resonance enterography (MRE) in a pediatric population at the time of CD diagnosis.

METHODS

MRE of 95 consecutive pediatric patients with inflammatory bowel disease (IBD) examined in 2006-2009 were retrospectively analyzed, with documentation of findings based on type and location of the small bowel (SB) disease.

RESULTS

In all, 51 were boys and 44 girls. 54 had CD, 31 non-CD IBD, and 10 no IBD. The most common site of SB involvement in CD was the terminal ileum seen in 29 (53.7%) patients, followed by ileum in 10 (18.5%) and jejunum in 9 (16.7%) patients. Solitary jejunal inflammation (3.7%), SB stenoses (1.9%), fistula formation (0.95%), and abscess (0.95%) were much less common. Perienteric lymphadenopathy was seen in 30 (55.6%) patients and fatty proliferation in 9 (16.7%). The most common manifestation of SB inflammation was increased contrast enhancement of bowel wall (93.5%), thickening of the bowel wall (90.3%), and derangement of bowel shape with saccular formations (25.8%).

CONCLUSIONS

MRE in the pediatric population often demonstrates increased contrast uptake, bowel wall thickening, and perienteral lymphadenopathy in CD. More chronic small bowel changes seen commonly in adults and solitary jejunal involvements are less commonly seen.

Sonographic Findings in a Case of Crohn Disease

Crohn disease is an incurable inflammatory bowel disease that can involve the large or small bowel but typically is located at the terminal ileum. The disease ranges from mild inflammation to bowel obstruction, fistula, and abscess formation and is typically diagnosed during adolescence or the early 20s. Patients with Crohn disease undergo multiple follow-up imaging examinations for the disease during the course of their lives. Sonographic findings in an adolescent patient diagnosed with Crohn disease are discussed. Sonography is emerging not only as an effective imaging modality for long-term disease follow-up but also, with the addition of hydrosonography and improved transducer technology, as a primary diagnostic tool.

Crohn's disease imaging: a review

Crohn's disease is a chronic granulomatous inflammatory disease of the gastrointestinal tract, which can involve almost any segment from the mouth to the anus. Typically, Crohn's lesions attain segmental and asynchronous distribution with varying levels of seriousness, although the sites most frequently involved are the terminal ileum and the proximal colon. A single gold standard for the diagnosis of CD is not available and the diagnosis of CD is confirmed by clinical evaluation and a combination of endoscopic, histological, radiological, and/or biochemical investigations. In recent years, many studies have been performed to investigate the diagnostic potential of less invasive and more patient-friendly imaging modalities in the evaluation of Crohn's disease including conventional enteroclysis, ultrasonography, color-power Doppler, contrast-enhanced ultrasonography, multidetector CT enteroclysis, MRI enteroclysis, and 99mTc-HMPAO-labeled leukocyte scintigraphy. The potential diagnostic role of each imaging modality has to be considered in different clinical degrees of the disease, because there is no single imaging technique that allows a correct diagnosis and may be performed with similar results in every institution. The aim of this paper is to point out the advantages and limitations of the various imaging techniques in patients with suspected or proven Crohn's disease.

Color-coded duplex sonography compared to multidetector computed tomography for the diagnosis of crohn disease relapse and complications

OBJECTIVES

The purpose of this study was to evaluate the accuracy of color-coded duplex sonography for the diagnosis of Crohn disease relapse and complications compared to multidetector computed tomography (CT).

METHODS

The Institutional Ethics Committee approved the protocol research, and written consent forms were obtained. Patients with a diagnosis of Crohn disease presenting with symptoms of relapse or complications (54 patients; 27 female; ages 9-80 years; mean, 34.6 years) were enrolled. Patients underwent color-coded duplex sonography and multidetector CT examinations within 2 weeks of each other. Multidetector CT was the reference standard. The location and extent of diseased bowel, wall thickness, stenosis, hyperemia, mesenteric fat thickening, lymphadenopathy, abscesses, fistulas, peritoneal fluid, and signs of hepatobiliary disease were searched for.

RESULTS

About of 80% of the patients had terminal ileal involvement, and 55% had disease confined to the ileum. A significant correlation between the two modalities was found regarding wall thickness, abscesses, and fistulas (P < .05). Color-coded duplex sonography had sensitivity and specificity of 88% and 53%, respectively, for diagnosis of luminal stenosis. Hyperemia was more commonly diagnosed on color-coded duplex sonography. Color-coded duplex sonography had sensitivity and specificity of 84% and 83% for diagnosis of mesenteric fat thickening and lymphadenopathy and 66% and 86% for peritoneal fluid. Fatty liver was found in 18% and gallstone disease in 6%.

CONCLUSIONS

Color-coded duplex sonography was accurate in diagnosing the disease location, wall thickness, and extraintestinal inflammatory findings associated with Crohn disease, potentially placing it as the first-line imaging modality for the diagnosis of Crohn disease relapse and complications.

Gastroenterology review and perspective: the role of cross-sectional imaging in evaluating bowel damage in Crohn disease

OBJECTIVE

This article will review the performance and limitations of cross-sectional imaging methods to detect and display critical features of Crohn disease (CD)-related bowel damage, including stenosis and penetrating complications (i.e., fistula, abscess). International efforts to incorporate cross-sectional imaging findings along with endoscopic and surgical findings to create a global bowel damage score over the length of the gastrointestinal tract are summarized along with the rationale for these efforts.

CONCLUSION

The first digestive damage score, the Lémann score, will incorporate surgical history, endoscopic findings, and imaging findings of stenosis and penetrating complications to provide a global assessment of CD-related destruction of the gastrointestinal tract. It is anticipated that the score will permit better understanding of the impact of modern therapeutics on the natural history of CD. Because CT is a technique that involves ionizing radiation and accuracy of ultrasound is highly related to CD location, MRI is proposed as first choice for nonemergent follow-up of CD patients.

Ultrasound contrast media in paediatric patients: is it an off-label use? Regulatory requirements and radiologist's liability

The use of ultrasound contrast media is yet to be validated in children. The rare reports in the scientific literature denote their "sporadic" and "experimental" use. Their most likely use is in the setting of off-label prescription of medications. As there are still no guidelines available in Italy for the off-label use of medications, we aim to define the duties, obligations and liability of ultrasound radiologists according to the laws in force.

Contrast-enhanced ultrasound (CEUS) in Crohn's disease: technique, image interpretation and clinical applications

BACKGROUND: Recent meta-analysis has demonstrated no significant differences in diagnostic accuracy among different imaging techniques (US, MRI and CT) in the evaluation of Crohn's disease (CD). High-resolution bowel ultrasound has emerged as an alternative imaging technique for the diagnosis and follow-up of patients with CD, being as accurate as CT and MR for detecting intramural and extramural extension of the disease. B-Mode US can evaluate the localization and length of the affected intestinal segments and allow identification of transmural complications, stenosis and intestinal obstruction. Doppler techniques are tools that visualize and quantify bowel vascularization. Contrast-enhanced ultrasound (CEUS) is a new technique that involves IV administration of an ultrasound contrast agent with real-time examination, providing an accurate depiction of the bowel wall microvascularization and the perienteric tissues. The introduction of imaging quantification techniques enables an objective quantitative measurement of the enhancement. METHOD AND RESULTS: The article reviews the technique, sonographic findings, advantages and limitations, and clinical applications of contrast-enhanced US in the evaluation of Cohn's disease. Current CEUS applications in CD are: CD activity assessment, evaluation of inflammatory masses, distinguishing phlegmons from abscesses, characterization of stenosis by differentiating fibrosis from inflammation, monitoring the efficacy of drug treatments and improving the detection of disease recurrence. CONCLUSION: CEUS is an emerging technique that is part of the entire sonographic evaluation, with a role in the diagnosis and follow-up of CD, thus improving therapy planning and monitoring of the efficacy of treatment. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13244-011-0124-1) contains supplementary material, which is available to authorized users.

Diagnostics in inflammatory bowel disease: Ultrasound

Diagnosis of chronic inflammatory bowel diseases (IBD) is based on a combination of clinical symptoms, laboratory tests and imaging data. Imaging of the morphological characteristics of IBD includes the assessment of mucosal alterations, transmural involvement and extraintestinal manifestations. No single imaging technique serves as a diagnostic gold standard to encompass all disease manifestations. Ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) allow cross-sectional imaging of the transmural alterations and extraintestinal manifestations. While in the USA the technique of choice is CT, in Europe the focus is more on MRI and ultrasound (US). Most patients with chronic IBD are diagnosed at a young age. After baseline diagnosis many of these young patients have to undergo repetitive imaging procedures during the variable clinical course of the disease, characterized by alternate periods of remission and active disease, and in monitoring the response to treatment. US has the advantage of being noninvasive, less costly, and easily repeatable, and thus can be very useful in following up patients with IBD. In addition, rising concern about radiation exposure in young adults indicates the demand for radiation-sparing techniques like US and MRI. This article focuses on the current clinical practice of US in IBD, describing the current technologies used in transabdominal intestinal US and the characteristic sonographic findings in Crohn´s disease and ulcerative colitis.

Development of the Crohn's disease digestive damage score, the Lémann score

Crohn's disease (CD) is a chronic progressive destructive disease. Currently available instruments measure disease activity at a specific point in time. An instrument to measure cumulative structural damage to the bowel, which may predict long-term disability, is needed. The aim of this article is to outline the methods to develop an instrument that can measure cumulative bowel damage. The project is being conducted by the International Program to develop New Indexes in Crohn's disease (IPNIC) group. This instrument, called the Crohn's Disease Digestive Damage Score (the Lémann score), should take into account damage location, severity, extent, progression, and reversibility, as measured by diagnostic imaging modalities and the history of surgical resection. It should not be "diagnostic modality driven": for each lesion and location, a modality appropriate for the anatomic site (for example: computed tomography or magnetic resonance imaging enterography, and colonoscopy) will be used. A total of 24 centers from 15 countries will be involved in a cross-sectional study, which will include up to 240 patients with stratification according to disease location and duration. At least 120 additional patients will be included in the study to validate the score. The Lémann score is expected to be able to portray a patient's disease course on a double-axis graph, with time as the x-axis, bowel damage severity as the y-axis, and the slope of the line connecting data points as a measure of disease progression. This instrument could be used to assess the effect of various medical therapies on the progression of bowel damage.