Graded compression and power Doppler ultrasonography versus endoscopy to assess paediatric Crohn disease activity pre- and posttreatment

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Clinical Impact of Sonographic Transmural Healing After Anti-TNF Antibody Treatment in Patients with Crohn's Disease

AIM

To assess the clinical benefits of transmural healing (TH) shown on intestinal ultrasound (IUS) after treatment with tumor necrosis factor-alpha antibodies (anti-TNF) in patients with Crohn's disease.

MATERIALS AND METHODS

This prospective study included consecutively 36 patients who underwent IUS in the week prior to start anti-TNF treatment, at 12 weeks, and 1 year after starting treatment. The clinical response to treatment was assessed using the Crohn's disease activity index and C-reactive protein (CRP) values. TH was defined as the normalization of bowel wall thickness on IUS. Treated patients were considered to have a good outcome if none of the following situations presented: need to reintroduce corticosteroids or intensify maintenance therapy and/or need for surgery.

RESULTS

After the induction regimen, 29 patients (80.6%) achieved clinical remission, and serum CRP values returned to normal in 20 patients (55.6%). In the IUS at 12 weeks, treatment induced a statistically significant reduction in the wall thickness (p < 0.001) and color Doppler grade (p < 0.001), as well as resolution of complications in 66.7% of patients (p < 0.03). IUS after 1 year of biological therapy showed TH in 14/33 patients (42.4%). During the follow-up (median 48.5 months), 23 of the 33 (69.7%) patients in remission or response after induction therapy presented a good outcome. Sonographic TH was significantly related with better outcomes, with only 1/14 patients having a poor outcome compared to 9/19 without TH (OR 11.7, 95% CI 1.2-108.2 p = 0.01, Chi-squared test).

CONCLUSION

Patients who achieve TH on IUS with biological treatment have better clinical outcomes.

Assessment of Crohn's disease activity by Doppler sonography

Objectives:

To investigate the diagnostic accuracy of ultrasound for evaluation of inflammatory activity in patients with Crohn’s disease (CD).

Methods:

Fifty-six patients with histologically proven CD (39 with active, 17 with inactive disease) and 30 healthy volunteers as a control group were enrolled in the study at WeiFang People’s Hospital, Weifang Province, China from October 2012 to December 2014. Bowel wall thickness, and vascularity pattern were measured by Doppler ultrasound.

Results:

There was a significant difference in flow volume of the superior mesenteric artery (585 ± 235 ml/min) in the patients with active disease, compared with those with inactive disease (401 ± 238 ml/min) and the control group (390 ± 189 ml/min, p<0.001). Wall thickness was 5.1 ± 1.5 mm in the active CD group, 3.3 ± 1.6 mm in the inactive disease group (p<0.001) and <3 mm in the control group. Resistance index in the thickened bowel wall showed some differences: 0.68 ± 0.05 in the active disease group, 0.78 ± 0.08 in the inactive disease group, and 0.85 ± 0.07 in the control group (p<0.05).

Conclusion:

Doppler ultrasound is a useful diagnostic tool in detecting CD and assessing inflammatory activity.

Emergency ultrasonography of the gastrointestinal tract of children

Ultrasonography (US) is widely used to evaluate most body parts in pediatric patients because it is simple, noninvasive, easy to use, and applicable in a wide variety of clinical situations. US is the modality of choice for the initial evaluation of acute abdominal pain in pediatric patients because of their small body habitus and the presence of less fat tissue in the abdominal wall and peritoneal cavity. The most important factor in performing pediatric emergency US is the graded compression technique and selection of the proper transducer. The careful evaluation of bowel wall thickening combined with ancillary findings such as fluid collection, increased echogenicity of the mesenteric fat tissue, enlarged lymph nodes, hyperemic bowel changes, and abnormal bowel peristalsis can increase the diagnostic capability of US.

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

Bowel Ultrasonography in the Management of Crohn's Disease. A Review with Recommendations of an International Panel of Experts

BACKGROUND

Bowel ultrasonography (US) is considered a useful technique for assessing mural inflammation and complications in Crohn's disease (CD). The aim of this review is to appraise the evidence on the accuracy of bowel US for CD. In addition, we aim to provide recommendations for its optimal use.

METHODS

Publications were identified by literature search from 1992 to 2014 and selected based on predefined criteria: 15 or more patients; bowel US for diagnosing CD, complications, postoperative recurrence, activity; adequate reference standards; prospective study design; data reported to allow calculation of sensitivity, specificity, agreement, or correlation values; articles published in English.

RESULTS

The search yielded 655 articles, of which 63 were found to be eligible and retrieved as full-text articles for analysis. Bowel US showed 79.7% sensitivity and 96.7% specificity for the diagnosis of suspected CD, and 89% sensitivity and 94.3% specificity for initial assessment in established patients with CD. Bowel US identified ileal CD with 92.7% sensitivity, 88.2% specificity, and colon CD with 81.8% sensitivity, 95.3% specificity, with lower accuracy for detecting proximal lesions. The oral contrast agent improves the sensitivity and specificity in determining CD lesions and in assessing sites and extent.

CONCLUSIONS

Bowel US is a tool for evaluation of CD lesions in terms of complications, postoperative recurrence, and monitoring response to medical therapy; it reliably detects postoperative recurrence and complications, as well as offers the possibility of monitoring disease progression.

Pediatric Small Bowel Crohn Disease: Correlation of US and MR Enterography

Small bowel Crohn disease is commonly diagnosed during the pediatric period, and recent investigations show that its incidence is increasing in this age group. Diagnosis and follow-up of this condition are commonly based on a combination of patient history and physical examination, disease activity surveys, laboratory assessment, and endoscopy with biopsy, but imaging also plays a central role. Ultrasonography (US) is an underutilized well-tolerated imaging modality for screening and follow-up of small bowel Crohn disease in children and adolescents. US has numerous advantages over computed tomographic (CT) enterography and magnetic resonance (MR) enterography, including low cost and no required use of oral or intravenous contrast material. US also has the potential to provide images with higher spatial resolution than those obtained at CT enterography and MR enterography, allows faster examination than does MR enterography, does not involve ionizing radiation, and does not require sedation or general anesthesia. US accurately depicts small bowel and mesenteric changes related to pediatric Crohn disease, and US findings show a high correlation with MR imaging findings in this patient population.

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.

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.

Resistance index in mural arteries of thickened bowel wall: predictive value for Crohn disease activity assessment in pediatric patients

OBJECTIVE

To define reliable Doppler parameters in mural arteries of affected bowel loops for quantitative assessment of Crohn disease (CD) activity in pediatric population and compare Doppler parameters with Pediatric Crohn Disease Activity Index (PCDAI).

PATIENTS AND METHODS

Thirty-four pediatric patients (7 with inactive, 27 with active disease of different severity; 13 male and 21 female; mean age 13; range 7-18) with CD were prospectively evaluated by Doppler ultrasound (DUS) of affected bowel segments. Using semiquantitative color and power Doppler assessment of vascularization of thickened bowel wall and mesentery, patients were divided in four grades. Spectral measurements (peak systolic velocity (PSV), end diastolic velocity (EDV), resistance index (RI)) of mural arteries were compared with PCDAI.

RESULTS

There was a significant difference in distribution of semiquantitative color values between inactive and active group. PSV and EDV values showed no significant difference between inactive and active group, while mean RI was significantly higher in the inactive group. RI was also significantly negatively correlated with PCDAI.

CONCLUSION

Intensity of color and power Doppler signals and RI measurement of mural arteries in thickened bowel wall is linked to CD activity and therefore might be of use in pediatric patients.

Radiation exposure in children with inflammatory bowel disease

PURPOSE OF REVIEW

Radiation exposure due to medical imaging has grown exponentially over the past two decades and the awareness has increased in the last few years with a number of articles in scientific publications and lay press. Radiation increases the risk of cancer and is particularly a concern in children. Limiting radiation exposure is most important in children, who are more sensitive to radiation, and specifically in children with a chronic lifelong disease such as inflammatory bowel disease (IBD).

RECENT FINDINGS

Children with IBD and specifically Crohn's disease demonstrate high exposure to ionizing radiation due to medical imaging. The yearly rate of medical imaging radiation exposure may seem small at approximately 3-5 mSv/year, which is only slightly higher than typical background radiation (3 mSv/year). However, this extra yearly radiation exposure to children with a lifelong chronic disease may increase the risk of cancer. Additionally, recent literature suggests that some children with more severe disease are exposed to high radiation doses within the first few years of diagnosis. Imaging modalities that do not utilize radiation, such as MRI and ultrasonography, have demonstrated utility in diagnosing and managing IBD and are particularly important for children.

SUMMARY

Pediatricians caring for children with chronic diseases should consider radiation exposure and limit exposure when possible. Future quality outcome benchmarks should include limiting exposure to radiation in children with chronic diseases.