Activity of Crohn disease: value of Color-Power-Doppler and contrast-enhanced ultrasonography

Contrast-enhanced ultrasonography in dogs with inflammatory bowel disease

Background

Contrast‐enhanced ultrasonography (CEUS) is used to evaluate vascularity of the gastrointestinal wall in neoplastic and inflammatory diseases.

Objective

To assess the feasibility of CEUS for the evaluation of duodenal perfusion in dogs with inflammatory bowel disease (IBD).

Animals

Forty‐two dogs with IBD and 20 clinically healthy dogs.

Methods

All CEUS studies of the duodenum were analyzed to obtain time‐intensity curves and perfusion parameters. The procedure was repeated in 12 IBD dogs 2 months after a standardized treatment.

Results

On CEUS, the duodenal wall showed a typical perfusion pattern characterized by a radial and simultaneous enhancement of the wall in all dogs. On qualitative assessment, no differences were observed in contrast medium distribution between healthy and affected dogs, or between dogs with IBD before and after treatment. Peak intensity (PI) and area under the curve (AUC) significantly differed between healthy (PI = 3.58 arbitrary units [au; 1.86‐4.93 au] and AUC = 47.63 au seconds [aus, 22.68‐62.15]) and affected dogs (PI = 5.10 au [0.63‐15.16 au] and AUC = 63.62 aus [5.31‐212.20 aus]; P = .03 and .03, respectively). No significant differences were found for the perfusion parameters before and after treatment.

Conclusions and Clinical Importance

We showed that CEUS allows discrimination between IBD affected dogs and healthy dogs by evaluation of time‐intensity curves, but did not provide useful information for monitoring therapeutic response. The qualitative assessment identified no significant differences between healthy and affected dogs, or between dogs before and after treatment.

Small bowel radiology

PURPOSE OF REVIEW

Recent advances in computed tomography (CT), ultrasound (US), magnetic resonance imaging (MRI), and nuclear radiology have improved the diagnosis and characterization of small bowel pathology. Our purpose is to highlight the current status and recent advances in multimodality noninvasive imaging of the small bowel.

RECENT FINDINGS

CT and MR enterography are established techniques for small bowel evaluation. Dual-energy CT is a novel technique that has shown promise for the mesenteric ischemia and small bowel bleeding. Advanced US techniques and MRI sequences are being investigated to improve assessment of bowel inflammation, treatment response assessment, motility, and mural fibrosis. Novel radiotracers and scanner technologies have made molecular imaging the new reference standard for small bowel neuroendocrine tumors. Computational image analysis and artificial intelligence (AI) have the potential to augment physician expertise, reduce errors and variability in assessment of the small bowel on imaging.

SUMMARY

Advances in translational imaging research coupled with progress in imaging technology have led to a wider adoption of cross-sectional imaging for the evaluation and management of small bowel entities. Ongoing developments in image acquisition and postprocessing techniques, molecular imaging and AI have the strongest potential to transform the care and outcomes of patients with small bowel diseases.

Contrast-enhanced ultrasound of the pediatric bowel

Contrast-enhanced ultrasound (CEUS) has emerged as a valuable modality for bowel imaging in adults and children. CEUS enables visualization of the perfusion of the bowel wall and of the associated mesentery in healthy and disease states. In addition, CEUS images can be used to make quantitative measurements of contrast kinetics, allowing for objective assessment of bowel wall enhancement. Bowel CEUS is commonly applied to evaluate inflammatory bowel disease and to monitor treatment response. It has also been applied to evaluate necrotizing enterocolitis, intussusception, appendicitis and epiploic appendagitis, although experience with these applications is more limited. In this review article, we present the current experience using CEUS to evaluate the pediatric bowel with emphasis on inflammatory bowel disease, extrapolating the established experience from adult studies. We also discuss emerging applications of CEUS as an adjunct or problem-solving tool for evaluating bowel perfusion.

Color Doppler Ultrasound Assessment of Clinical Activity in Inflammatory Bowel Disease

BACKGROUND

Ulcerative colitis (UC) and Crohn's disease (CD) are two varieties of inflammatory bowel disease (IBD). Clinicians need a monitoring technique in the IBD. The disease activity can be assessed with endoscopy, activity indexes, and imaging techniques. Color Doppler US (CDUS) is also a non-invasive, radiation, and contrast material free examination which shows the intramural blood flow.

OBJECTIVE

To evaluate the usefulness of B-mode, CDUS, and a newly developed software Color Quantification (CQ) to determine the activity of the IBD.

METHODS

The disease activity was assessed by clinical activity indexes. Caecum, terminal ileum, ascending colon, transverse colon, and descending colon were evaluated by B-mode, CDUS, and the CQ. Bowel wall thickness (BWT), loss of bowel stratification, loss of haustration, and the presence of enlarged lymph nodes, mesenteric masses, abscesses, fistula, visual vascular signal patterns of the bowel as "hypo and hyper-flow" and the CQ values were investigated. BWT was compared with laboratory results and clinical activities. Vascular signal patterns and the CQ values were compared with BWT and clinical activity. The diagnostic performances of the CQ were investigated.

RESULTS

Fifty-two patients with IBD were evaluated. Patients with increased BWT at the transverse colon had an increased frequency of "hyper-flow" pattern. Clinically active patients had an increased incidence of "hyper-flow" pattern at the terminal ileum, ascending colon, and whole segments. They had increased CQ values at the terminal ileum, ascending colon, and descending colon, and whole segments. A cut-off value for the CQ (24.7%) was obtained at the terminal ileum. In the diagnostic performances of CQ, we observed utilities significantly at the ascending colon, descending colon, terminal ileum, and whole segments. There was a positive correlation between the CQ values and BWT at the caecum, ascending colon, transverse colon, and descending colon.

CONCLUSION

Increased visual vascular signal scores and CQ values might be useful for monitoring the disease activity in patients with IBD.

Intestinal ultrasonography in adults with Crohn's disease: a 2020 update

In the last years intestinal ultrasonography (IUS) has increased its role in the management of inflammatory bowel diseases (IBD), that include Crohn's disease (CD) and ulcerative colitis. This is due to the fact that IUS is a non-invasive, inexpensive, and well-tolerated examination technique. Furthermore, it allows a real-time diagnosis with no radiation exposure. Usually, convex and linear probes with frequency between 3.5 and 12 MHz are used, also with the Color- Power Doppler. Focusing on CD, the IUS images of clinical interest are: bowel wall thickening (greater than 3 mm), pseudostratification and the wall vascularization. Moreover, IUS demonstrates inflammatory mass, loss of colonic haustration and the complications of the disease, such as stenosis, abscesses, and fistulas as well as other extraintestinal manifestations, such as lymph node enlargement and changes in the appearance of the mesenteric adipose tissue (creeping fat). Oral and intravenous contrast are used to obtain a better visualization of the bowel wall and to increase the diagnostic accuracy of IUS. In particular, intravenous contrast, administered during the procedure, allows to differentiate between active disease (bowel wall enhancement) and the fibrostenotic complications. Contrast-enhanced ultrasonography (CEUS) was proven to be useful in the follow-up and the disease recurrence detection. Beyond the support in the initial diagnosis, IUS has an important role in the follow-up of patients with CD, to monitor the response to the medical therapy and to detect possible complications. Furthermore, it can predict the recurrences after surgery, with more accuracy if Color-Doppler is used.

Intravenous Contrast-Enhanced Ultrasound for Assessing and Grading Postoperative Recurrence of Crohn's Disease

PURPOSE

The aim was to investigate the contribution of contrast-enhanced ultrasound (CEUS) to improve the results of US in the evaluation of recurrence in postsurgical Crohn's disease (CD) and establish its role in the assessment of the severity.

METHODS

Anastomotic site was assessed in 108 postsurgical CD patients with B-mode, color Doppler and CEUS. Bowel wall thickness (WT), transmural complications or stenosis, color Doppler grade, and bowel wall contrast enhancement (BWCE)-using time-intensity curves-were correlated with endoscopic Rutgeerts score. A receiver operating characteristic (ROC) curve was built to establish the best cutoff to predict recurrence and the severity. A US scoring system was elaborated in order to determine the grade of recurrence.

RESULTS

Ileocolonoscopy detected recurrence in 90 (83.3%) subjects and severe recurrence in 62. WT ≥ 3 mm had an accuracy of 90.7% in the detection of endoscopic recurrence. The combination of parameters-WT ≥ 3 mm and BWCE (≥ 46%)-demonstrated similar accuracy (90.7%). A WT ≥ 5 mm showed the best specificity (100%) for the diagnosis of recurrence and a WT ≥ 6 mm the best specificity (95.7%) for the detection of severe recurrence. The combination of sonographic parameters-WT ≥ 6 mm or WT between 5 and 6 mm with BWCE ≥ 70%, or complications-obtained the best results grading the recurrence (sensitivity, specificity, and accuracy of 90.3%, 87%, and 88.9%, respectively).

CONCLUSIONS

US shows high sensitivity and specificity for the diagnosis of postsurgical recurrence. When combined with CEUS, it can improve the detection of severe recurrence.

Magnetic resonance enterography (MRE) and ultrasonography (US) in the study of the small bowel in Crohn's disease: state of the art and review of the literature

Crohn’s disease (CD) is a chronic idiopathic disease and its diagnosis is based on a combination of clinical symptoms, laboratory tests and imaging data. There isn’t a diagnostic gold standard: the ileocolonoscopy with mucosal biopsies represents the standard for luminal disease, while cross-sectional imaging such as Ultrasound (US), Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) can show transmural alterations and extraintestinal manifestations. CD is usually diagnosed in the young age and after baseline diagnosis, the patients have to undergo to variable follow-up depending on remission or active disease. The aim of our review is to compare Magnetic Resonance Enterography (MRE) to Ultrasonography (US) in the follow-up of CD. (www.actabiomedica.it)

Usefulness of contrast-enhanced ultrasound (CEUS) in Inflammatory Bowel Disease (IBD)

Intestinal ultrasonography has emerged as a cheap, non-invasive and readily accessible modality for the assessment of a number of gastroenterological diseases. Over the last decade, particularly due to the widespread use of biological agents in Inflammatory Bowel Disease (IBD), guidelines regarding management and follow-up advise more regular disease assessment and surveillance in order to guide treatment adjustments, and provide more personalised care. Given the young age of the majority of patients with IBD the availability of an alternative modality to harmful radiation or the risks of endoscopy for this indication offers an appealing advantage. Intestinal ultrasonography has been shown to be as sensitive and specific for detecting IBD as both computed tomography and magnetic resonance enterography, and endoscopic evaluation. More recent developments in the technology of ultrasonography equipment and the use of intravenous contrast agents (contrast enhanced ultrasonography, known as CEUS), have significantly increased the ability to both detect disease location, determine the disease activity and also potentially the difference between fibrotic and inflammatory segments. This review focusses specifically on the value of CEUS for the diagnosis of both Crohn's disease and Ulcerative Colitis, in determining disease activity, extraintestinal complications, determination of fibrosis as well as its more recent use in assessing and predicting response to biological and immunosuppressive therapies.

Usefulness of Contrast-Enhanced Ultrasound in Differentiating Inflammatory Bowel Disease From Colon Cancer

To evaluate the diagnostic performance of contrast-enhanced ultrasound (CEUS) in differential diagnosis of inflammatory bowel disease (IBD) and colon cancer, we enrolled 51 patients with thickened bowel walls (13 with IBD and 38 with colon cancer). Ultrasound and CEUS were performed and both qualitative and quantitative features were analyzed. The intestinal wall stratification was preserved in 63.6% of the IBD group but in only 2.6% of the colon cancer group (p <0.01). On CEUS, disordered enhancement and heterogeneous enhancement were shown in only 9.1% and 0%, respectively, of the IBD group while in 94.7% and 78.9%, respectively, of the colon cancer group (p <0.01). For quantitative analysis, compared to IBD, colon cancer showed later enhancement and slower wash-out with less speed to reach peak intensity (p <0.05). In conclusion, CEUS may prove useful for the differential diagnosis of IBD and colon cancer, but more studies are required.

Real-time elastography for the detection of fibrotic and inflammatory tissue in patients with stricturing Crohn's disease

PURPOSE

The distinction between active inflammation and fibrosis of the bowel wall is essential for therapeutic decisions in stricturing Crohn's disease. We aimed to assess whether real-time elastography (RTE) with strain ratio measurement could be useful in differentiating fibrotic from inflamed bowel strictures and to evaluate the possible relationship between US techniques and the histology of the stenotic bowel wall.

MATERIALS AND METHODS

Bowel ultrasonography (including RTE, color-Doppler and CEUS examination) was prospectively evaluated in 26 patients with symptomatic stricturing Crohn's disease, before surgery. RTE was adopted to evaluate bowel stiffness: five loops of 20 RTE frames were recorded for each stenotic segment and the mean strain ratio (MSR) was obtained. Histology scoring systems both for inflammation and fibrosis were established for surgical specimens.

RESULTS

No significant correlation was found between MSR and fibrosis score (P = 0.877). Color-Doppler score was significantly related to gut wall and submucosal thicknesses (P = 0.006 and P = 0.032, respectively). There was no significant correlation between the number of vessels counted at histology and color-Doppler and CEUS examinations (P = 0.170 and P = 0.302, respectively).

CONCLUSION

MSR detection was not able to distinguish fibrotic from inflammatory tissue in our selected population. This result could be influenced by the presence of the superimposed inflammation. Larger cohort of patients, further analysis with shear wave elastography, and validated histopathology classification systems for fibrosis and inflammation are necessary to assess if intestinal fibrosis could be reliably detected on the basis of bowel elastic properties.

Repeatability and reproducibility of quantitative contrast-enhanced ultrasonography for assessing duodenal perfusion in healthy dogs

Contrast-enhanced ultrasonography (CEUS) with microbubbles as a contrast agent allows the visualization and quantification of tissue perfusion. The assessment of canine intestinal perfusion by quantitative CEUS may provide valuable information for diagnosing and monitoring chronic intestinal disorders. This study aimed to assess the repeatability (intraday variability) and reproducibility (interday variability) of quantitative duodenal CEUS in healthy dogs. Six healthy beagles underwent CEUS three times within one day (4-hr intervals) and on two different days (1-week interval). All dogs were sedated with a combination of butorphanol (0.2 mg/kg) and midazolam (0.1 mg/kg) prior to CEUS. The contrast agent (Sonazoid^®) was administered using the intravenous bolus method (0.01 ml/kg) for imaging of the duodenum. Time-intensity curves (TIC) were created by drawing multiple regions of interest (ROIs) in the duodenal mucosa, and perfusion parameters, including the time-to-peak (TTP), peak intensity (PI), area under the curve (AUC), and wash-in and wash-out rates (WiR and WoR, respectively), were generated. Intraday and interday coefficients of variation (CVs) for TTP, PI, AUC, WiR and WoR were <25% (range, 2.27–23.41%), which indicated that CEUS was feasible for assessing duodenal perfusion in healthy sedated dogs. A further study of CEUS in dogs with chronic intestinal disorders is necessary to evaluate its clinical applicability.

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

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

The use of ultrasound in inflammatory bowel disease

Imaging in inflammatory bowel disease (IBD) plays a pivotal role in the primary diagnosis, as well as during the management of patients with known IBD. The evolution of ultrasound equipment and the growing expertise of examiners have both enhanced the role of intestinal ultrasound in the assessment of the gastrointestinal tract in IBD patients. Intestinal ultrasound has been shown to have high sensitivity and specificity, as well as high positive and negative predictive value, in the detection or exclusion of intestinal inflammatory activity in IBD. The obvious advantages of intestinal ultrasound over other imaging modalities include non-invasiveness, rapid availability and low costs. This review summarizes the current developments in the use of intestinal ultrasound for the detection of IBD and its complications, and discusses its use in the management of patients with IBD. Indications for the use of intestinal ultrasound in daily practice are presented, expanded by new developments such as contrast-enhanced ultrasonography and elastography.

Preliminary Analysis of Clinical Situations Involved in Quantification of Contrast-Enhanced Ultrasound in Crohn's Disease

To assess influencing factors for quantitative analysis of contrast-enhanced ultrasound (CEUS) in Crohn's disease (CD), dynamic CEUS examinations from 77 consecutive CD patients were recorded. Peak intensity (PI) values were calculated using the pre-installed quantification software of the ultrasound scanner. The influence of depth, pressure from the ultrasound probe and intraluminal gas was analyzed. The PI value of the anterior wall was lower than that of the posterior wall when the depth was ≤3.4 cm (17.9 dB vs. 21.3 dB; p < 0.05) or evident pressure was exerted (19.1 dB vs. 22.5 dB; p < 0.01). In the presence of intraluminal gas, the PI of the anterior wall was higher than that of the posterior wall (20.7 dB vs. 18.8 dB; p < 0.05). Nevertheless, no significant difference was found between the PI value of anterior and posterior walls when the depth was >3.4 cm (19.8 dB vs. 20.3 dB), moderate pressure was exerted (20.5 dB vs. 21.1 dB) or luminal gas was excluded between the two bowel walls (18.9 dB vs. 21.2 dB; p ≥ 0.05). The factors of depth, pressure from the ultrasound probe and intraluminal gas can affect the quantification results of CEUS. It is preferable to place the region of interest in the posterior wall when luminal gas is absent and in the anterior wall when luminal gas is present. In the latter case, more attention should be paid to reducing pressure by the ultrasound probe.

ACR Appropriateness Criteria Crohn Disease

Crohn disease is a chronic inflammatory disorder involving the gastrointestinal tract, characterized by episodic flares and times of remission. Underlying structural damage occurs progressively, with recurrent bouts of inflammation. The diagnosis and management of this disease process is dependent on several clinical, laboratory, imaging, endoscopic, and histologic factors. In recent years, with the maturation of CT enterography, and MR enterography, imaging has played an increasingly important role in relation to Crohn Disease. In addition to these specialized examination modalities, ultrasound and routine CT have potential uses. Fluoroscopy, radiography, and nuclear medicine may be less beneficial depending on the clinical scenario. The imaging modality best suited to evaluating this disease may change, depending on the target population, severity of presentation, and specific clinical situation. This document presents seven clinical scenarios (variants) in both the adult and pediatric populations and rates the appropriateness of the available imaging options. They are summarized in a consolidated table, and the underlying rationale and supporting literature are presented in the accompanying narrative. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

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

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

Current Role of Ultrasound in Small Bowel Imaging

Bowel ultrasound is cheap, relatively quick, allows dynamic evaluation of the bowel, has no radiation burden, is well tolerated by patients, and allows repeat imaging. Bowel ultrasound requires a systematic assessment of the entire bowel using high-frequency probes. In addition, hydrosonography and contrast-enhanced ultrasound may be performed. We present the normal sonographic appearances of large and small bowel and the sonographic appearances of acute appendicitis, Crohn's disease, celiac disease, intussusception, infectious enteritis, intestinal tuberculosis, small bowel ileus and obstruction, small bowel ischemia, and malignant tumors.

Contrast-enhanced Ultrasound for Detection of Crohn's Disease Activity: Systematic Review and Meta-analysis

BACKGROUND AND AIMS

Reports on imaging of active Crohn's disease (aCD) using contrast-enhanced ultrasound (CEUS) are encouraging. However, the statistical power of most published papers is limited due to the small size of the patient groups included. This study was performed to verify the diagnostic value of CEUS in detecting aCD.

METHODS

A systematic literature search was performed by two independent reviewers for articles on the test characteristics of CEUS for the identification of aCD. The quality of the analysed studies was evaluated using a quality assessment tool for diagnostic accuracy studies (QUADAS-2). Pooling was performed using a diagnostic random-effect model and bivariate analysis.

RESULTS

Eight articles were included in the final analysis, with a total of 332 patients. There was no significant publication bias. Significant heterogeneity was found regarding CEUS methodology and sonographic definitions of aCD. In a bivariate analysis, pooled sensitivity was 0.94 (95% CI 0.87-0.97) and pooled specificity was 0.79 (95% CI 0.67-0.88). Spearman correlation statistics presented no significant diagnostic threshold effect (r = 0.12, p > 0.9). Subgroup analysis showed that relative intestine wall enhancement had the highest diagnostic value (area under the curve 94%), while the presence of enhancement and analysis of the slope were less useful (area under the curve 91 and 90%, respectively).

CONCLUSIONS

CEUS presents good sensitivity and moderate specificity in the detection of the aCD. Large-scale randomized trials with quantitative evaluation of CEUS images are necessary to promote this technique in clinical practice.

Bowel Ultrasonography in Inflammatory Bowel Disease

BACKGROUND

The diagnosis of inflammatory bowel disease (IBD) is based on a combination of endoscopic, clinical and biochemical investigations as well as cross-sectional imaging. The applications of cross-sectional imaging in IBD are manifold. Ultrasonography has emerged as an important imaging modality in the diagnosis of Crohn's disease (CD) as well as for monitoring disease progression and in the therapeutic response to CD and ulcerative colitis (UC). Key Messages: Ultrasonography is non-invasive, radiation free, cheap, easy to use and well tolerated and accepted by patients. Bowel ultrasonography can be used for the primary diagnosis of CD as it has a similar sensitivity and specificity like that of MRI and CT, particularly in the case of CD. Ultrasonography can also be used to monitor treatment response to therapy and to detect disease recurrence of CD as well as UC. In CD, ultrasonography can also be used to detect complications such as strictures as well as extramural complications, including abscesses and fistulas. Contrast-enhanced ultrasonography is a useful tool that might be helpful to detect certain indications in CD, in particular the differentiation between abscesses and inflammation.

CONCLUSION

A variety of advantages of bowel ultrasonography over other imaging modalities suggest the more frequent use of this method to manage IBD patients in daily practice. Bowel ultrasonography should be a standard tool in IBD centers.

Ultrasonography in gastroenterology

Ultrasonography (US) is a safe and available real-time, high-resolution imaging method, which during the last decades has been increasingly integrated as a clinical tool in gastroenterology. New US applications have emerged with enforced data software and new technical solutions, including strain evaluation, three-dimensional imaging and use of ultrasound contrast agents. Specific gastroenterologic applications have been developed by combining US with other diagnostic or therapeutic methods, such as endoscopy, manometry, puncture needles, diathermy and stents. US provides detailed structural information about visceral organs without hazard to the patients and can play an important clinical role by reducing the need for invasive procedures. This paper presents different aspects of US in gastroenterology, with a special emphasis on the contribution from Nordic scientists in developing clinical applications.

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.

Power Doppler sonography to predict the risk of surgical recurrence of Crohn's disease

PURPOSE

The aim of this work is to investigate the role of power Doppler sonography as an additional predictor of surgical recurrence in Crohn's disease.

METHODS

A sample of 33 patients, with ileal or ileocolonic Crohn's disease, that had underwent intestinal resection, were retrospectively enrolled. All patients had bowel ultrasonography 7-16 months after resection. Power Doppler sonography of the preanastomotic ileum was evaluated as a possible prognostication tool to assess the risk of long-term need for reoperation.

RESULTS

The absolute incidence of surgical recurrence in those who had a positive power Doppler was 42 %, while that of those who had a negative power Doppler was 28.6 %. Combining the power Doppler with bowel wall thickness, the surgical recurrence risk grew from 41.2 % of those with a positive power Doppler and thickness >3 mm to 55.6 % of those with a positive power Doppler and thickness >6 mm.

CONCLUSIONS

Power Doppler look to be another useful prediction tool for the personalization of patient's care. It could be useful to perform power Doppler in all patients with a wall thickness >5 mm: for those who have a positive power Doppler it may be indicated as a more aggressive prophylactic therapy.

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.

Advances in the diagnosis and management of inflammatory bowel disease: challenges and uncertainties

Over the past two decades, several advances have been made in the management of patients with inflammatory bowel disease (IBD) from both evaluative and therapeutic perspectives. This review discusses the medical advancements that have recently been made as the standard of care for managing patients with ulcerative colitis (UC) and Crohn's Disease (CD) and to identify the challenges associated with implementing their use in clinical practice. A comprehensive literature search of the major databases (PubMed and Embase) was conducted for all recent scientific papers (1990-2013) giving the recent updates on the management of IBD and the data were extracted. The reported advancements in managing IBD range from diagnostic and evaluative tools, such as genetic tests, biochemical surrogate markers of activity, endoscopic techniques, and radiological modalities, to therapeutic advances, which encompass medical, endoscopic, and surgical interventions. There are limited studies addressing the cost-effectiveness and the impact that these advances have had on medical practice. The majority of the advances developed for managing IBD, while considered instrumental by some IBD experts in improving patient care, have questionable applications due to constraints of cost, lack of availability, and most importantly, insufficient evidence that supports their role in improving important long-term health-related outcomes.

US elastography-derived shear wave velocity helps distinguish acutely inflamed from fibrotic bowel in a Crohn disease animal model

PURPOSE

To determine if acoustic radiation force impulse elastography-derived bowel wall shear wave velocity (SWV) allows distinction of acutely inflamed from fibrotic intestine in a Crohn disease animal model.

MATERIALS AND METHODS

University Committee on the Use and Care of Animals approval was obtained. An acute inflammation Crohn disease model was produced by treating eight Lewis rats with a single administration of trinitrobenzenesulfonic acid (TNBS) enema, with imaging performed 2 days later in the surviving six rats. Colonic fibrosis in an additional eight Lewis rats was achieved by administering repeated TNBS enemas during 4 weeks, with imaging performed in the surviving seven rats 7 days later to allow acute inflammation resolution. Nine transcutaneous bowel wall SWV measurements were obtained from the colon in all rats without and with applied strain. Mean SWVs without and with applied strain were compared between animal cohorts by using the Student t test, and receiver operating characteristic (ROC) curves were created to assess diagnostic performance.

RESULTS

Mean bowel wall SWVs were significantly higher for fibrotic versus acute inflammation cohort of rats at 0% (3.4 ± 1.1 vs 2.3 ± 0.5 m/sec; P = .047) and 30% (6.3 ± 2.2 vs 3.6 ± 0.9 m/sec; P = .02) applied strain. Both acute inflammation and fibrotic cohort of rats demonstrated linear increases in mean SWV with increasing applied strain, with significantly different mean slopes (P = .02) and y-intercepts (P = .02). The area under the ROC curve of the SWV ratio (mean SWV/applied strain) for differentiating histopathologically confirmed fibrotic from inflamed bowel was 0.971.

CONCLUSION

Bowel wall SWV helps distinguish acutely inflamed from fibrotic intestine in a Crohn disease animal model.

Prospective qualitative and quantitative non-invasive evaluation of intestinal acute GVHD by contrast-enhanced ultrasound sonography

Intestinal acute GVHD (I-aGVHD) is a life-threatening complication after allografting. Non-invasive bed-side procedures to evaluate extension and treatment response are still lacking. We hypothesized that, during I-aGVHD, contrast-enhanced ultrasound sonography (CEUS) could detect microcirculation changes (MVC) of the bowel wall (BW) and help to monitor treatment response. We prospectively employed CEUS in 83 consecutive patients. Of these, 14 patients with biopsy-proven intestinal GVHD (I-GVHD) were defined as the study group, whereas 16 patients with biopsy-proven stomach GVHD (U-GVHD) without intestinal symptoms, 6 normal volunteers and 4 patients with neutropenic enterocolitis were defined as the control group. All patients were evaluated with both standard ultrasonography (US) and CEUS at the onset of intestinal symptoms, during clinical follow-up and at flare of symptoms. Standard US revealed BW thickening of multiple intestinal segments, useful to determine the extension of GVHD. CEUS showed MVC, which correlated with GVHD activity, treatment response, and predicted flare of intestinal symptoms. US and CEUS findings were superimposable at diagnosis and in remission. CEUS was, however, more sensitive and specific to identify subclinical activity in patients with clinical relevant improvement. These findings were not observed in the control groups. CEUS is a non-invasive, easily reproducible bed-side tool useful to monitor I-aGVHD.

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.

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.

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.

Contrast-enhanced ultrasound in abdominal imaging

The administration of a contrast agent is considered an essential tool to evaluate abdominal diseases using Ultrasound. The most targeted organ is the liver, especially to characterize focal liver lesions and to assess the response to percutaneous treatment. However, the expanding abdominal indications of contrast-enhanced ultrasound make this technique an important tool in the assessment of organ perfusion including the evaluation of ischemic, traumatic, and inflammatory diseases.

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.

Contrast-enhanced ultrasonography (CEUS) vs. MRI of the small bowel in the evaluation of Crohn's disease activity

PURPOSE

The presence of disease activity in Crohn's disease (CD) is one of the main parameters used to establish whether optimal therapy should be drug therapy or surgery. However, a major problem in monitoring CD is the common mismatch between the patient's symptoms and imaging objective signs of disease activity. Bowel ultrasonography (US) has emerged as a low-cost, noninvasive technique in the diagnosis and follow-up of patients with CD. Accordingly, the use of contrast-enhanced US (CEUS) has made possible an evaluation of the vascular enhancement pattern, similar to the use of magnetic resonance imaging (MRI). The aim of our study was to evaluate the role of CEUS in comparison with small-bowel MRI for assessing Crohn's disease activity.

MATERIALS AND METHODS

We prospectively enrolled 30 consecutive patients with known CD. Clinical and laboratory data were compared with imaging findings obtained from MRI and CEUS of the small bowel. MRI was performed with a 1.5-T system using phased-array coils and biphasic orally administered contrast agent prior to and after gadolinium chelate administration. We performed US with a 7.5-MHz linear-array probe and a second-generation contrast agent. The parameters analysed in both techniques were the following: lesion length, wall thickness, layered wall appearance, comb sign, fibroadipose proliferation, presence of enlarged lymph nodes and stenosis. We classified parietal enhancement curves into two types in relation to the contrast pattern obtained with the time-intensity curves at MRI and CEUS: (1) quick washin, quick washout, (2) slow washin, plateau with a slow washout.

RESULTS

Comparison between Crohn's disease activity index (CDAI) and MRI showed a low correlation, with an rho=0.398; correlation between CDAI-laboratory data and CEUS activity was low, with rho=0.354; correlation between MRI activity and CEUS activity was good, with rho = 0.791; high correlation was found between CEUS and MRI of the small bowel when assessing wall-thickness, lymph nodes and comb sign; good correlation was fund when assessing layered wall appearance, disease extension and fibroadipose proliferation. At MRI, time-intensity curves for 12/30 patients were active, compared with for 14/30 patients at CEUS; therefore there was a poor correlation between curve on CEUS and curve on MRI (r=0.167; p=0.36).

CONCLUSIONS

The use of CEUS can be recommended if there is a discrepancy between MRI and clinical/laboratory parameters. MRI of the small bowel remains the most accurate method for evaluating disease activity.

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.

Contrast-enhanced ultrasonography of the small bowel in healthy cats

We characterized the pattern of ultrasonographic contrast enhancement of the small intestinal wall using a commercial contrast medium (Sonovue(®) ) in 10 healthy awake cats. Subjectively, a rapid intense enhancement of the serosal and submucosal layers was followed by gradual enhancement of the entire wall section during the early phase. At peak enhancement, there was a subjective loss of demarcation between intestinal wall layers. In the late phase, there was a gradual wash out of signal from the intestinal wall. Submucosal wash out occurred last. Time-intensity curves were generated for selected regions in the intestinal wall and multiple perfusion parameters were calculated for each cat. Perfusion parameters included arrival time (7.64 ± 2.23 s), baseline intensity (1.04 ± 0.04 a.u.), time to peak from injection (10.74 ± 2.08 s), time to peak from initial rise (3.1 ± 1.15), peak intensity (8.92 ± 3.72 a.u.), wash-in rate (2.06 ± 0.70 a.u./s) and wash-out rate (-1.07 ± 0.91 a.u./s). The perfusion pattern of normal feline small bowel may be useful for characterizing feline gastrointestinal disorders that involve the intestinal wall.

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.

Diagnostic value and clinical utility of contrast enhanced ultrasound in intestinal diseases

Contrast enhanced ultrasound (CEUS) has recently gained increasing attention as it clearly improves the visualisation of perfusion in various tissues. The development of second generation contrast enhancing agents used in low-mechanical-index harmonic ultrasound has enabled real-time assessment of the microvascular circulation and quantification of bowel wall vascularity. For this review Medline was searched for clinical studies using CEUS to investigate the gastrointestinal tract. Many studies demonstrate that acute or chronic inflammation of the intestinal wall is accompanied by increased perfusion of the mesentery, which can be displayed semi-quantitatively using contrast enhanced ultrasound analyzing time intensity curves. In contrast, ischemia is characterized by hypoperfusion of the mesenteric arteries and the bowel wall. The most promising sonographic approach in assessing splanchnic arteries and the bowel wall is combining the analysis of superior and inferior mesenteric inflow by pulsed Doppler scanning (systolic and diastolic velocities, resistance index) with the end-organ vascularity by CEUS. CEUS at a preliminary stage has been described as clinically important in a variety of gastrointestinal disorders, particularly in patients with Crohn's disease. CEUS facilitates the detection of disease extent and activity, and its luminal and extraluminal complications.

ACR Appropriateness Criteria on Crohn's disease

In the past decade, new therapeutic agents have been developed that permit gastroenterologists to treat virtually all forms of Crohn's disease. The success of these treatments depends on an accurate diagnosis of the nature and extent of disease. Fortunately, radiologists now possess a powerful arsenal of imaging techniques to guide the choice of therapy. This article discusses the usefulness of both traditional and newer imaging techniques in the management of Crohn's disease and its various clinical presentations.

Predictive value of time-intensity curves obtained with contrast-enhanced ultrasonography (CEUS) in the follow-up of 30 patients with Crohn's disease

OBJECTIVES

CEUS can provide accurate quantitative estimates of intestinal wall microvascularization in Crohn's disease. We hypothesized that inflammation of the intestinal wall is correlated not with the amount of wall vascularization (study of vascularization patterns, SVP) but with the degree of wall flow during a period of time (time-intensity study, TIS). Our objective was to discover whether CEUS SPV and/or CEUS-TIS reflect(s) vascular inflammation of the intestinal wall and display(s) correlation with clinical activity of the disease at the time of the examination (T0) or at the 3- and 6-month follow-up (T3, T6).

MATERIALS AND METHODS

30 patients with Crohn's disease (12 men, 18 women, mean age: 41.96 years; treatment: 5-ASA (n = 8), steroids (n = 13), anti-TNF (n = 7), azathioprine (n = 2) were studied with CEUS SPV and CEUS-TIS and followed for at least 6 months. The sonographic examinations were performed with SonoVue (BR1, Bracco) and a dedicated scanner (TECHNOS MPX, Esaote) equipped with software for calculation of time-intensity curves. Four vascular patterns (1: vascularization of the entire wall; 2: vascularization of >50% of the wall; 3: flow exclusively within the submucosal layer; 4: no signal). The semiquantitative analysis consisted in measurement of the area under the curve (AUC) (cut-off between active and inactive disease, 15), mean intesnity (IMA) (cut-off = 10). Each examination (180 s) was digitally recorded and analyzed.

RESULTS

T0: cDAI <150 in 22 pts; cDAI > 150 in 8; T3: 22 pts. with cDAI<150, 8 with cDAI >150. At T0 CEUS SPV and CEUS-TIS both displayed low specificity, diagnostic accuracy, and negative predictive values (p = ns). At T0, CEUS SPV produced 8 true positives (TP), 15 true negatives (TN), 8 false positives (FP), 0 false negative (FN) (sensitivity: 100%; specificity: 68.2%; diagnostic accuracy: 69.5%; Positive predictive value (PPV): 100%; negative predictive value (NPV: 53.3%), and CEUS-TIS produced 6 TP, 18 TN, 4 FP, 2 FN (sensitivity 75%; specificity: 81.8%; diagnostic accuracy: 75%; PPV: 60%; NPV: 90%). At T3, CEUS SPV produced 8 TP, 12 TN, 7 FP, 3 FN (sensitivity: 72.7%; specificity: 63.2%; diagnostic accuracy: 50%; PPV: 53.3%; NPV: 80%), and CEUS SIT produced the following results: 10 TP, 19 TN, 0 FP, 1 FN (sensitivity: 90,9%; specificity: 100%; diagnostic accuracy: 96,5%; PPV: 100%; NPV: 95%). At T3 CEUS-SVP displayed low sensitivity and low diagnostic accuracy, whereas SIT was able to predict clinical activity during follow-up in all but one case (which showed reactivation after 6 months) (p = 0.001)

CONCLUSION

CEUS-TIS alone was found to reflect vascular inflammation of the intestinal wall in Crohn's disease and predicted clinical activity during follow-up.

Abdominal bowel ultrasound can predict the risk of surgery in Crohn's disease: proposal of an ultrasonographic score

OBJECTIVE

Abdominal bowel ultrasound (US) is widely used in the management of Crohn's disease (CD). The aim of this study was to evaluate the prognostic role of bowel-wall US morphology on the short-term risk of surgery.

MATERIAL AND METHODS

The 147 CD patients recruited in a case-control study comprised 49 cases operated on within 30 days after US examination and 98 matched non-operated controls. Clinical and US characteristics were analysed. Bowel-wall thickness was recorded, bowel-wall patterns were grouped into five types, but for final analysis they were grouped as "preserved" or "disrupted stratification".

RESULTS

Wall thickness and US patterns were significantly different between cases and controls (p<0.0001). A wall thickness >4.5 mm was observed in 45/49 cases and 47/98 controls (OR = 12.21), while "disrupted stratification" was observed in 34/49 cases and 12/98 controls (OR = 16.24). Among the clinical and US characteristics recorded, only 4 US variables were independently associated with surgery (pattern, thickness, presence of fistulae/abscesses and stenoses) and considered for the US score=(2.5*US pattern)+(1.5*Bowel thickness)+(3*Presence of fistulae/abscesses)+(1.5*Presence of stenoses). Based on this score, up to 84% of patients were correctly classified according to actual status (operated/non-operated).

CONCLUSIONS

Although it needs further prospective validation, the score we propose seems to be a reliable prognostic marker for the short-term risk of surgery in CD. In particular, the score points out those patients with an impending risk of surgery who need careful and frequent control in order to decide on the right time for surgery.

Crohn disease: correlation of findings at contrast-enhanced US with severity at endoscopy

PURPOSE

To evaluate the effectiveness of visualization of vascularization at contrast material-enhanced ultrasonography (US) for assessment of the activity of Crohn disease, with severity grade determined at endoscopy as the reference standard.

MATERIALS AND METHODS

Ethics committee approval and written informed consent were obtained. Sixty-one patients (age range, 21-67 years; median age, 36 years) who had Crohn disease underwent both colonoscopy and US, including color Doppler and contrast-enhanced US, prospectively. To assess the vascularization of the involved bowel loop in a region expected to be seen at colonoscopy, the contrast agent uptake was measured by using quantitative analysis of the enhancement in regions of interest. Measurement of contrast enhancement was assessed as the increase in wall brightness with respect to the baseline brightness. Results were compared with the severity grade determined at endoscopy by using the area under the receiver operating characteristic curve and logistic regression analysis.

RESULTS

Colonoscopy showed inflammatory lesions in 53 patients (mild disease, seven; moderate disease, 12; and severe disease, 34). Bowel wall thickness and grade at color Doppler US (P = .019 and .002, respectively) correlated with severity grade at endoscopy. Mural contrast enhancement in patients with active disease at endoscopy was markedly increased in comparison with enhancement in patients with inactive disease (P < .001). Multivariate logistic regression analysis revealed that an increase in wall brightness was a significant and independent variable predictive of severity grade at endoscopy. A threshold brightness value of percentage of increase of 46% had a sensitivity and specificity of 96% and 73%, respectively, in the prediction of moderate or severe grade for inflammation at endoscopy.

CONCLUSION

Quantitative measurements of bowel enhancement obtained by using contrast-enhanced US correlate with severity grade determined at endoscopy. Contrast-enhanced US could be a useful technique to monitor the activity of Crohn disease.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.2531082269/-/DC1.

Contrast-enhanced ultrasonographic evaluation of inflammatory activity in Crohn's disease

BACKGROUND & AIMS

We sought to test the diagnostic accuracy of ultrasound (US), color Doppler US (CD-US), and contrast-enhanced US (CE-US) in the evaluation of inflammatory activity in patients with Crohn's disease (CD), and to correlate the findings of these sonographic studies with inflammatory activity, as scored by the CD activity index (CDAI).

METHODS

Patients with CD were enrolled in the study. Radiologists performing the scans were blinded to clinical status. Baseline US, CD-US, and CE-US examinations were conducted with high-frequency probes (8-14 and 5-7 MHz) before and after injection of sulfur hexafluoride-filled microbubbles. The diagnostic accuracy of baseline US, CD-US, and CE-US were calculated by using the endoscopic and histologic findings as reference standards and correlated with the CDAIs by using the Pearson linear correlation coefficient.

RESULTS

Forty-seven patients (20 men; 27 women; mean age +/- SD, 38 +/- 14 years) with a CDAI > 150 (n = 30) or < 150 (n = 17), were recruited. CE-US showed the highest performance, with 93.5% sensitivity, 93.7% specificity, and 93.6% overall accuracy. CE-US revealed 3 bowel wall perfusion patterns after microbubble injection: submucosal enhancement and inward and outward transparietal enhancement. The linear correlation coefficient for CE-US versus CDAI was 0.74 (P < .0001); for baseline US (assessing thickness, length, and multilayer appearance of the diseased bowel) versus the CDAI, the coefficients were 0.68 (P < .0001), 0.47 (P = .0009), and 0.60 (P < .0001), respectively; and for CD-US versus CDAI the coefficient was 0.73 (P < .0001).

CONCLUSIONS

CE-US has a high sensitivity and specificity in detecting inflammatory activity and a strong correlation with the CDAI.

Sonographic assessments of gastrointestinal and biliary functions

Ultrasound has been established as a routine work-up imaging method in abdominal diseases. It assesses the morphology of intra-abdominal organs and depicts the normal and pathological anatomy of the gastrointestinal tract as well as of the biliopancreatic system. Ultrasound is the method of choice for visualisation of motion sequences since it is, in contrast to other imaging methods, a real-time method. The non-invasiveness and the repeatability of the method are important advantages when performing investigations of functional processes. Therefore, ultrasound is most suited for functional studies. Up to now, functional ultrasound and its potential have been undervalued. Functional ultrasound provides a widely available method to increase our understanding of functional processes and motility. The authors review the options of functional ultrasound and discuss its practical relevance.

Comparison of sonographically measured bowel wall vascularity, histology, and disease activity in Crohn's disease

The purposes of this study was to provide a retrospective comparison of semiquantitatively measured bowel wall vascularity by power Doppler sonography, endoscopic-histopathological biopsy findings, and disease activity in patients with confirmed Crohn's disease. Thirty-two out of 1,332 patients with histologically confirmed Crohn's disease (18 female, 14 male; mean age 38.8 years) met the inclusion criteria: ileocolonoscopy with biopsy and power Doppler sonographic determination of bowel wall vascularity with assessment of disease activity within a period of 5 days. Sonographic determination of bowel wall vascularity was based on a semiquantitative score. Endoscopic bowel wall biopsy specimens were assessed using a self-developed inflammation score and the disease activity was calculated using Crohn's disease activity index (CDAI). A significant association (p < 0.05) was shown for results of histology and bowel wall vascularity in the terminal ileum (kappa = 0.66; sensitivity 95%; specificity 69%). There was no observed association between CDAI and histology, although there was an association between CDAI and bowel wall vascularity (sensitivity 82%). Increased bowel wall vascularity in the terminal ileum measured by power Doppler ultrasound reflects inflammatory activity in histologically examined bowel wall. Power Doppler ultrasound may be able to monitor activity changes of the bowel wall determined by pharmaceutical treatment.