Small intestine contrast ultrasonography (SICUS) for the detection of small bowel complications in crohn's disease: a prospective comparative study versus intraoperative findings

Role of imaging in the evaluation of inflammatory bowel disease: How much is too much?

Inflammatory bowel disease (IBD) is a lifelong condition with waxing and waning disease course that requires reassessment of disease status as well as screening for complications throughout a patient’s lifetime. Laboratory testing, endoscopic assessment, and fecal biomarkers are often used in the initial diagnosis and ongoing monitoring of a patient with IBD. Imaging plays an integral role in the diagnosis and evaluation of IBD. Different imaging modalities can be used over the course of a patient’s lifetime, from the initial screening and diagnosis of IBD, to determining the extent of intestinal involvement, monitoring for disease activity, and evaluating for complications of uncontrolled IBD. The various imaging modalities available to the provider each have a unique set of risks and benefits when considering cost, radiation exposure, need for anesthesia, and image quality. In this article we review the imaging techniques available for the evaluation of IBD including fluoroscopic small bowel follow-through, computed tomography enterography, magnetic resonance enterography, and transabdominal ultrasound with particular focus on the judicious use of imaging and the risks and benefits of each option. We also review the risks of ionizing radiation, strategies to reduce exposure to ionizing radiation, and current imaging guidelines among pediatric and adult patient with IBD.

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.

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.

Monitoring disease activity and progression in Crohn's disease. A Swiss perspective on the IBD ahead 'optimised monitoring' recommendations

BACKGROUND AND AIMS

The structured IBD Ahead 'Optimised Monitoring' programme was designed to obtain the opinion, insight and advice of gastroenterologists on optimising the monitoring of Crohn's disease activity in four settings: (1) assessment at diagnosis, (2) monitoring in symptomatic patients, (3) monitoring in asymptomatic patients, and (4) the postoperative follow-up. For each of these settings, four monitoring methods were discussed: (a) symptom assessment, (b) endoscopy, (c) laboratory markers, and (d) imaging. Based on literature search and expert opinion compiled during an international consensus meeting, recommendations were given to answer the question 'which diagnostic method, when, and how often'. The International IBD Ahead Expert Panel advised to tailor this guidance to the healthcare system and the special prerequisites of each country. The IBD Ahead Swiss National Steering Committee proposes best-practice recommendations adapted for Switzerland.

METHODS

The IBD Ahead Steering Committee identified key questions and provided the Swiss Expert Panel with a structured literature research. The expert panel agreed on a set of statements. During an international expert meeting the consolidated outcome of the national meetings was merged into final statements agreed by the participating International and National Steering Committee members - the IBD Ahead 'Optimized Monitoring' Consensus.

RESULTS

A systematic assessment of symptoms, endoscopy findings, and laboratory markers with special emphasis on faecal calprotectin is deemed necessary even in symptom-free patients. The choice of recommended imaging methods is adapted to the specific situation in Switzerland and highlights the importance of ultrasonography and magnetic resonance imaging besides endoscopy.

CONCLUSION

The recommendations stress the importance of monitoring disease activity on a regular basis and by objective parameters, such as faecal calprotectin and endoscopy with detailed documentation of findings. Physicians should not rely on symptoms only and adapt the monitoring schedule and choice of options to individual situations.

Failure of gastroenterologists to apply intestinal ultrasound in inflammatory bowel disease in the Asia-Pacific: a need for action

Intestinal ultrasound (IUS) is a cheap, noninvasive, risk-free procedure that is significantly underutilized in the diagnosis and management of patients with inflammatory bowel disease (IBD) in the Asia-Pacific region. More cost-effective methods of monitoring disease activity are required in light of the increasing global burden of IBD (especially in Asia), the advent of personalized medicine, and the rising cost of healthcare. IUS is a prime example of a technique that meets these needs. Its common clinical applications include assessing the activity and complications of IBD. In continental Europe, countries such as Germany and Italy use this imaging tool as the standard of care and have integrated it into management protocols. There are formal training programs in these countries to train gastroenterologists in IUS, and it is used in an outpatient setting during patient consultations. Barriers to its use in the Asia-Pacific region include lack of experience and research data, and there are few established centers with active training programs. These concerns can be addressed by investing more in IUS service provision and by increasing allocation of resources toward local research and training. Increased uptake of IUS will ultimately benefit patients with IBD.

Magnetic resonance enterography, small-intestine contrast US, and capsule endoscopy to evaluate the small bowel in pediatric Crohn's disease: a prospective, blinded, comparison study

BACKGROUND

Small-bowel (SB) disease is a severe clinical entity among the phenotypes of Crohn's disease (CD).

OBJECTIVE

To assess sensitivity, specificity, and accuracy of magnetic resonance enterography (MRE), small-intestine contrast US (SICUS), and capsule endoscopy (CE) in the diagnosis of pediatric SB-CD.

DESIGN

Prospective, blinded, comparison study.

SETTING

Tertiary center for pediatric inflammatory bowel disease.

PATIENTS

Children with known or suspected CD. Diagnosis of SB obstruction at SICUS or MRE excluded patients from the study.

INTERVENTION

Patients underwent ileocolonoscopy, MRE, SICUS, and CE over a 7-day period. For the imaging evaluation, SB was divided into 3 segments: jejunum, proximal and mid ileum, and terminal ileum.

MAIN OUTCOME MEASUREMENTS

The performance of each method was compared to a consensus reference standard for upper SB and to ileocolonoscopy for the terminal ileum.

RESULTS

Twenty-five patients completed the study. In the jejunum, the sensitivity of SICUS and CE was 92%, which was not significantly higher than MRE (75%); the specificity of CE (61%) was significantly lower than that of MRE (P = .04). In the proximal and mid ileum, MRE and CE did not have significantly higher sensitivity (100%) than SICUS (80%), but CE was less specific (P > .05). At the terminal ileum, SICUS and MRE were slightly more sensitive than CE (94% vs. 81%); however, the latter was more specific.

LIMITATIONS

Use of the consensus reference standard for upper SB. Small number of patients.

CONCLUSION

SICUS, MRE, and CE are all effective options for imaging SB. An integrated use of different tools should be suggested to achieve a complete assessment of the SB in children with suspected or confirmed CD.

Contrast-enhanced ultrasound in the diagnosis of patients suspected of having active Crohn's disease: meta-analysis

This meta-analysis was aimed at assessing the performance of oral/microbubble contrast-enhanced ultrasound (CEUS) in the detection of active Crohn's disease (CD). A literature search of PubMed, Medline, the China National Knowledge Infrastructure and the Cochrane Library was conducted. Published articles that evaluated the diagnostic potency of CEUS in CD were included in the study. A total of eight articles, which included 428 patients, were finally analyzed. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and area under the curve were calculated to examine the diagnostic accuracy of CEUS. The pooled sensitivity and specificity of CEUS for active CD were 93% (95% confidence interval: 89%-95%) and 87% (81%-91%), respectively. The summary diagnostic odds ratio was 80.35 (30.93-208.73), and the area under the curve was 0.9633. In conclusion, this meta-analysis pooled results from previous studies to evaluate the accuracy of CEUS in the detection of CD. We found that CEUS has high accuracy in the detection of active CD using endoscopy/biopsy or clinical index as the reference standard. In the future, CEUS may also be widely used in other diseases, reducing the necessity for invasive diagnostic procedure.

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.

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.

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.

Contrast-enhanced ultrasound of the small bowel in Crohn's disease

Crohn's disease (CD) is a chronic transmural inflammatory disease of the gastrointestinal tract characterized by episodes of inflammation alternating with periods of remission. Unenhanced grey-scale ultrasound may evaluate the localisation and the length of the affected intestinal segments and may detect transmural complications, including fistulas, abscesses and phlegmons, but it is less accurate to assess the CD activity. Contrast-enhanced ultrasound has become an important imaging modality in patients with CD for the grading of disease activity, the differentiation between small bowel stricture due to inflammation or mural fibrosis, and for the assessment of the response to specific therapy. New dedicated software packages allow the accurate quantification of the enhancement within the small bowel wall after microbubble contrast agent injection to obtain different kinetic semi-quantitative parameters-the percentage of the maximal enhancement, the time-to-the peak enhancement, and the area under the time-intensity curve-which are very useful to differentiate the inflammatory oedema from fibrosis and to differentiate responders from non-responders to the specific therapy among patients with CD.

Transabdominal ultrasonography of the small bowel

In the era of double balloon enteroscopy, capsule endoscopy, CT, and MRI enterography is transabdominal ultrasonography (TUS) underestimated method for evaluation of small bowel pathology. As often initial imagine method in abdominal complaints, nowadays has TUS much better diagnostic potential than two decades ago. High-resolution ultrasound probes with harmonic imaging significantly improve resolution of bowel wall in real time, with possibility to asses bowel peristalsis. Color flow doppler enables evaluation of intramural bowel vascularisation, pulse wave doppler helps to quantificate flow in coeliac and superior mesenteric arteries. Small intestine contrast ultrasonography with oral contrast fluid, as well as contrast enhanced ultrasonography with intravenous microbubble contrast also improves small bowel imaging. We present a review of small intestine pathology that should be detected during ultrasound examinations, discuss technical requirements, advantages and limitations of TUS, typical ultrasound signs of Crohn's disease, ileus, celiac disease, intussusception, infectious enteritis, tumours, ischemic and haemorrhagic conditions of small bowel. In the hands of experienced investigator, despite some significant limitations(obesity, meteorism), is transabdominal ultrasonography reliable, noninvasive and inexpensive alternative method to computerised tomography (CT) and magnetic resonance imaging (MRI) in small bowel examination.

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.

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.

Accuracy of small-intestine contrast ultrasonography, compared with computed tomography enteroclysis, in characterizing lesions in patients with Crohn's disease

BACKGROUND & AIMS

Small-intestine contrast ultrasonography (SICUS) is a radiation-free technique that can detect intestinal damage in patients with Crohn's disease (CD). We evaluated the diagnostic accuracy of SICUS in determining the site, extent, and complications of CD, compared with computed tomography (CT) enteroclysis as the standard.

METHODS

We performed a retrospective analysis of data from 59 patients with CD evaluated by SICUS and CT enteroclysis 3 months apart, between January 2007 and April 2012. We evaluated disease site (based on bowel wall thickness), extent of lesions, and presence of complications (stenosis, prestenotic dilation, abscess, or fistulas) using CT enteroclysis as the standard. Sensitivity, specificity, and diagnostic accuracy were calculated. We determined the correlations in maximum wall thickness and disease extent in the small bowel between results from SICUS and CT enteroclysis.

RESULTS

SICUS identified the site of small bowel CD with 98% sensitivity, 67% specificity, and 95% diagnostic accuracy; it identified the site of colon CD with 83% sensitivity, 97.5% specificity, and 93% diagnostic accuracy. Results from SICUS and CT enteroclysis correlated in determination of bowel wall thickness (rho, 0.79) and disease extent (rho, 0.89; P < .0001 for both). SICUS detected ileal stenosis with 95.5% sensitivity, 80% specificity, and 91.5% diagnostic accuracy, and prestenotic dilation with 87% sensitivity, 67% specificity, and 75% diagnostic accuracy. SICUS detected abscesses with 78% sensitivity, 100% specificity, and 97% diagnostic accuracy, and fistulas with 78.5% sensitivity, 95.5% specificity, and 91.5% diagnostic accuracy.

CONCLUSIONS

SICUS identified lesions and complications in patients with CD with high levels of sensitivity, specificity, and accuracy compared with CT enteroclysis. SICUS might be used as an imaging tool as part of a focused diagnostic examination of patients with CD.

Quantifying exposure to diagnostic radiation and factors associated with exposure to high levels of radiation in Korean patients with inflammatory bowel disease

BACKGROUND

Several recent studies have revealed that diagnostic imaging can result in exposure to potentially harmful levels of ionizing radiation in patients with inflammatory bowel disease (IBD). However, these studies have been conducted exclusively in Western countries, and no data are available in Asian populations. The aim of this study was to estimate the diagnostic radiation exposure in Korean patients with IBD and to determine the factors associated with high radiation exposure.

METHODS

Patients with an established diagnosis of IBD between July 1987 and January 2012 were investigated in 13 university hospitals in Korea. The cumulative effective dose (CED) was calculated retrospectively from standard tables.

RESULTS

A total of 777 patients with Crohn's disease (CD) and 1422 patients with ulcerative colitis (UC) were included in the study. The mean CED for CD and UC were 53.6 and 16.4 mSv, respectively (P < 0.001). CTof CD and UC accounted for 81.6% and 71.2% of total effective dose, respectively. Importantly, 34.7% of patients with CD and 8.4% of patients with UC were exposed to high levels of radiation (CED > 50 mSv) (P < 0.001). High radiation exposure was associated with long disease duration, ileocolonic disease, upper gastrointestinal tract involvement, surgical intervention, hospitalization, and the requirement for oral steroids in CD, and with surgical intervention, hospitalization, and the requirement for infliximab in UC.

CONCLUSIONS

A substantial proportion of patients with IBD, especially patients with CD, were exposed to significantly harmful amounts of diagnostic radiation, mainly as a result of CT examination. Given that IBD is a life-long illness, strategies to reduce radiation exposure from diagnostic imaging need to be considered.

Transcutaneous bowel sonography for inflammatory bowel disease is sensitive and specific when performed in a nonexpert low-volume North American center

OBJECTIVES

Transcutaneous bowel sonography is a nonionizing imaging modality used in inflammatory bowel disease. Although available in Europe, its uptake in North America has been limited. Since the accuracy of bowel sonography is highly operator dependent, low-volume centers in North America may not achieve the same diagnostic accuracy reported in the European literature. Our objective was to determine the diagnostic accuracy of bowel sonography in a nonexpert low-volume center.

METHODS

All cases of bowel sonography at a single tertiary care center during an 18-month period were reviewed. Bowel sonography was compared with reference standards, including small-bowel follow-through, computed tomography, magnetic resonance imaging, colonoscopy, and surgical findings.

RESULTS

A total of 103 cases were included for analysis during the study period. The final diagnoses included Crohn disease (72), ulcerative colitis (8), hemolytic uremic syndrome (1), and normal (22). The sensitivity and specificity of bowel sonography for intestinal wall inflammation were 87.8% and 92.6%, respectively. In the subset of patients who had complications of Crohn disease, the sensitivity and specificity were 50% and 100% for fistulas and 14% and 100% for strictures. One patient had an abscess, which was detected by bowel sonography. Abnormal bowel sonographic findings contributed to the escalation of treatment in 55% of cases.

CONCLUSIONS

Bowel sonography for inflammatory bowel disease can be performed in low-volume centers and provides diagnostic accuracy for luminal disease comparable with published data, although it is less sensitive for complications of Crohn disease.

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.

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.

Meta-analysis: diagnostic medical radiation exposure in inflammatory bowel disease

BACKGROUND

Diagnostic imaging plays a pivotal role in the diagnosis and management of inflammatory bowel disease (IBD); however, increasing use has led to concerns about the malignant potential of ionising radiation. Several studies have demonstrated that diagnostic imaging can result in exposure to potentially harmful levels of ionising radiation in IBD patients.

AIM

To determine the pooled prevalence of increased exposure and pooled odds ratio of risk factors associated with exposure to potentially harmful levels of diagnostic medical radiation.

METHODS

We searched Medline, EMBASE, CINHAL and reference lists of identified articles, without language restrictions in October 2011.

RESULTS

Six studies with 1704 participants provided data on the proportion of patients receiving potentially harmful levels of radiation defined as ≥50 milli-sieverts (mSv)-equivalent to 5 CT abdomen scans. The pooled prevalence was 8.8% (95% CI 4.4-16.8) for IBD patients and 11.1% (95% CI 5.7-20.5%) and 2% (95% CI 0.8-4.9%) for Crohn's disease and ulcerative colitis patients respectively. Five studies involving 2627 participants provided data for risk factors. IBD-related surgery and corticosteroid use were significant with pooled adjusted odds ratio of 5.4 (95% CI 2.6-11.2) and 2.4 (95% CI 1.7-3.4) respectively.

CONCLUSIONS

About 1 in 10 patients may be exposed to potentially harmful levels of diagnostic medical radiation. Corticosteroid use and IBD related surgery increased this risk. Strategies to reduce radiation exposure while assessing disease activity need to be considered.

Ultrasound of the small bowel in Crohn's disease

Several radiological and endoscopic techniques are now available for the study of inflammatory bowel diseases. In everyday practice, the choice of the technique to be used depends upon its availability and a careful evaluation of diagnostic accuracy, clinical usefulness, safety, and cost. The recent development of innovative and noninvasive imaging techniques has led to a new and exciting area in the exploration of the gastrointestinal tract, especially in Crohn's disease patients by using ultrasound with oral or intravenous contrast.