Comment on "Ultrasonographic scores for ileal Crohn's disease assessment: better, worse or the same as contrast‑enhanced ultrasound?"

We read with interest the study by Freitas et al. comparing contrast-enhanced ultrasound (CEUS) and parameters from a time-intensity curve (TIC) with the SUS-CD score and IBUS-SAS score in patients with Crohn's disease (CD) undergoing gastrointestinal ultrasound (GIUS) and ileocolonoscopy. The aim was to compare the accuracy of CEUS and aforementioned scores in predicting terminal ileal inflammatory activity in patients with CD. In this retrospective study of 50 patients, inflammatory activity was defined as a segmental score of SES-CD ≥ 7 in the terminal ileum. The study found 30 patients with active endoscopic disease demonstrating no significant difference between the "inactive" and "active" SUS CD and IBUS-SAS scores. However, the CEUS peak enhancement derived from the TIC was shown to be significantly different. The authors conclude CEUS was superior for detecting inflammation in the terminal ileum, as opposed to ultrasound scores relying on bowel wall thickness and color Doppler.

Point-of-care Ultrasound of the Gastrointestinal Tract

The widespread use of portable ultrasound scanners has promoted the concept of point of care ultrasound (POCUS), namely "ultrasound performed bedside and interpreted directly by the clinician." The purpose of this short review is to outline how POCUS can be used in patients with diseases of the gastrointestinal (GI) tract. POCUS is not a replacement for comprehensive ultrasound, but rather allows physicians immediate access to clinical imaging for rapid diagnosis and efficient work-up and treatment of the patients. There are many indications for doing POCUS of the GI tract, including abdominal pain, diarrhea, palpable masses, and to detect fluid or free air in the abdominal cavity. To improve the visibility of deeper parts of the abdomen, the graded compression technique with the scan head is useful. During POCUS, the operator should look for signs of severe pathology including target lesions, the pseudo-kidney sign, the onion sign, dilated bowel loops, gastric retention, free fluid, and free air, depending on the actual clinical problem. We conclude that POCUS of the GI tract is very useful to provide a rapid diagnosis in many clinical scenarios.

Intestinal Ultrasound Early on in Treatment Follow-up Predicts Endoscopic Response to Anti-TNFα Treatment in Crohn's Disease

BACKGROUND

To assess treatment response, objective measures are superior to clinical improvement in Crohn's disease [CD]. Intestinal ultrasound [IUS] is an attractive, non-invasive alternative to endoscopy, demonstrating early transmural changes after treatment initiation. Therefore, we investigated IUS and contrast-enhanced ultrasound [CEUS] to predict [early] endoscopic treatment response.

METHODS

Consecutive patients with endoscopically active CD, starting anti-TNFα therapy, were included. Clinical, biochemical, IUS, and CEUS parameters at baseline [T0], after 4-8 weeks [T1] and 12-34 weeks [T2] were collected. The most severely inflamed segment at endoscopy (highest segmental Simplified Endoscopic Score for Crohn's Disease [SES-CD]) and IUS (highest segmental bowel wall thickness [BWT]) was identified. At T2, endoscopic response [decrease in SES-CD ≥ 50%] and remission [SES-CD = 0] were scored.

RESULTS

A total of 40 patients were included: 14 reached endoscopic remission and 17 endoscopic response. At T1 (3.1 mm [1.9-4.2] vs 5.3 mm [3.8-6.9], p = 0.005) and T2 (2.0 mm [1.8-3.1] vs 5.1 [3.0-6.3] mm, p = 0.002) BWT was lower in patients with endoscopic remission. At T1 and T2, 18% (area under the receiver operating curve [AUROC]: 0.77; odds ratio [OR]: 10.80, p = 0.012) and 29% [AUROC: 0.833; OR: 37.50, p = 0.006] BWT decrease predicted endoscopic response, respectively. To determine endoscopic remission, BWT 3.2 mm was most accurate [AUROC: 0.94; OR: 39.42, p < 0.0001] at T2. In addition, absence of colour Doppler signal [OR: 13.76, p = 0.03] and the CEUS parameter wash-out rate [OR: 0.76, p = 0.019] improved the prediction model.

CONCLUSIONS

Reduction in BWT, already after 4-8 weeks of follow-up, predicted endoscopic response and remission. CEUS parameters were of limited value. Furthermore, we have provided accurate cut-offs for BWT reflecting endoscopic response and remission at different time points.

Gastrointestinal Ultrasound Can Predict Endoscopic Activity in Crohn's Disease

PURPOSE

 To explore the ability of gastrointestinal ultrasound (GIUS) to separate patients in endoscopic remission from patients with active disease in a heterogeneous hospital cohort with Crohn's disease (CD).

MATERIALS AND METHODS

 145 CD patients scheduled for ileocolonoscopy were prospectively included. The endoscopic disease activity was quantified using the Simple Endoscopic Score for Crohn's disease (SES-CD), and mucosal healing was strictly defined as SES-CD = 0. Ultrasound remission was defined as wall thickness < 3 mm (< 4 mm in the rectum). Additionally, SES-CD was compared to color Doppler, Harvey Bradshaw's index (HBI), C-reactive protein (CRP) and calprotectin. 23 patients were examined by two investigators for interobserver assessment.

RESULTS

 102 had active disease and 43 patients were in remission. GIUS yielded a sensitivity of 92.2 % and a specificity of 86 % for wall thickness and a sensitivity of 66.7 % and a specificity of 97.7 % for color Doppler. The sensitivity and specificity were 34.3 % and 88.4 %, respectively, for HBI, 35.7 % and 82.9 %, respectively, for CRP and 55.9 % and 82.1 %, respectively, for calprotectin. The interobserver analysis revealed excellent agreement for wall thickness (k = 0.90) and color Doppler (k = 0.91) measurements.

CONCLUSION

 GIUS has a high sensitivity for detecting endoscopic activity. Accordingly, bowel ultrasound has the potential to reduce the number of routine ileocolonoscopies in patients with CD.

Assessment of Small Bowel Motility and SMA Blood Flow Studied with Transabdominal Ultrasound

Purpose Gastrointestinal ultrasound (GIUS) is a noninvasive imaging technique that may be used to study physiological changes in the small bowel. The aim of the study was to investigate the feasibility of measuring blood flow (BF) in the superior mesenteric artery (SMA) and regional motility in the small bowel with GIUS before and after a test meal and to compare ultrasound parameters to demographic factors such as age, sex, height, weight, and smoking habits.

Materials and Methods 122 healthy volunteers aged 20 to 80 were examined after an overnight fast. Small bowel motility was registered in the upper left and lower right quadrants (ULQ and LRQ) with TUS and BF in the SMA with pulsed wave Doppler. The first 23 volunteers also received a 300 Kcal test meal and were re-examined 30 min postprandial.

Results The feasibility of measuring BF was 97% in fasting patients while motility could be detected in 52% and 62% in the ULQ and LRQ, respectively. Females had a lower resistive index (RI) and a higher mean velocity than males, while the overall BF correlated with height. The RI had a negative correlation with age. Healthy volunteers with motility in the ileum were on average younger than those without motility. After the test meal, motility could be detected in the ULQ and LRQ in 95% and 90%, respectively, and the mean number of contractions in the ULQ increased significantly. As expected, there was a clear increase in all BF-parameters postprandially.

Conclusion Regional motility in the small bowel was easier to detect after a test meal. There were some associations between demographic parameters and ultrasound parameters but overall the effects were relatively small.

Defining Transabdominal Intestinal Ultrasound Treatment Response and Remission in Inflammatory Bowel Disease: Systematic Review and Expert Consensus Statement

BACKGROUND AND AIMS

No consensus exists on defining intestinal ultrasound response, transmural healing, or transmural remission in inflammatory bowel disease, nor clear guidance for optimal timing of assessment during treatment. This systematic review and expert consensus study aimed to define such recommendations, along with key parameters included in response reporting.

METHODS

Electronic databases were searched from inception to July 26, 2021, using pre-defined terms. Studies were eligible if at least two intestinal ultrasound [IUS] assessments at different time points during treatment were reported, along with an appropriate reference standard. The QUADAS-2 tool was used to examine study-level risk of bias. An international panel of experts [n = 18] rated an initial 196 statements [RAND/UCLA process, scale 1-9]. Two videoconferences were conducted, resulting in additional ratings of 149 and 13 statements, respectively.

RESULTS

Out of 5826 records, 31 full-text articles, 16 abstracts, and one research letter were included; 83% [40/48] of included studies showed a low concern of applicability, and 96% [46/48] had a high risk of bias. A consensus was reached on 41 statements, with clear definitions of IUS treatment response, transmural healing, transmural remission, timing of assessment, and general considerations when using intestinal ultrasound in inflammatory bowel disease.

CONCLUSIONS

Response criteria and time points of response assessment varied between studies, complicating direct comparison of parameter changes and their relation to treatment outcomes. To ensure a unified approach in routine care and clinical trials, we provide recommendations and definitions for key parameters for intestinal ultrasound response, to incorporate into future prospective studies.

Intestinal Ultrasound to Assess Disease Activity in Ulcerative Colitis: Development of a novel UC-Ultrasound Index

INTRODUCTION

Intestinal ultrasound [IUS] is useful to assess inflammation in ulcerative colitis [UC] patients. We aimed to develop an ultrasonographic activity index using endoscopy as the reference standard.

METHODS

Patients were included consecutively. IUS was performed within 3 weeks from endoscopy. IUS parameters and endoscopy were compared for each colonic segment [except the rectum]. The best parameters were used to construct a UC-IUS index, which was correlated with endoscopic disease activity using the Spearman's rank test.

RESULTS

In 60 patients, 207 colonic segments were evaluated endoscopically. Bowel wall thickness [BWT] > 2.1 mm was optimal to discriminate between Mayo 0 and Mayo 1-3 (sensitivity 82.6%; specificity 93.0%; area under the curve [AUC] 0.910), a cut-off of 3.2 mm was optimal to discriminate between Mayo 0-1 and Mayo 2-3 [sensitivity 89.1%; specificity 92.3%; AUC 0.946] and BWT > 3.9 mm was optimal for detection of Mayo 3 [sensitivity 80.6%; specificity 84.1%; AUC 0.909]. The presence of colour Doppler signal [CDS] predicted active disease, stretches of CDS were associated with Mayo 2-3, lack of haustrations predicted active disease and fat wrapping was associated with severe disease. Inter- and intra-rater intraclass correlation for BWT was substantial. Inter-rater agreement for CDS was substantial and ranged from slight to substantial for haustrations. Intra-rater agreement for CDS was substantial and ranged from moderate to almost perfect for haustrations. The index showed strong correlation with endoscopic disease activity [Mayo: ρ 0.830; p < 0.001, UCEIS: ρ 0.759; p < 0.001].

CONCLUSION

We developed an UC-IUS index which showed strong correlation with endoscopic disease activity using internal validation. It is currently being validated in prospective studies.

Expert Consensus on Optimal Acquisition and Development of the International Bowel Ultrasound Segmental Activity Score [IBUS-SAS]: A Reliability and Inter-rater Variability Study on Intestinal Ultrasonography in Crohn's Disease

BACKGROUND AND AIMS

Intestinal ultrasound [IUS] is an accurate, patient-centreed monitoring tool that objectively evaluates Crohn's disease [CD] activity. However no current, widely accepted, reproducible activity index exists to facilitate consistent IUS identification of inflammatory activity. The aim of this study is to identify key parameters of CD inflammation on IUS, evaluate their reliability, and develop an IUS index reflecting segmental activity.

METHODS

There were three phases: [1] expert consensus Delphi method to derive measures of IUS activity; [2] an initial, multi-expert case acquisition and expert interpretation of 20 blinded cases, to measure inter-rater reliability for individual measures; [3] refinement of case acquisition and interpretation by 12 international experts, with 30 blinded case reads with reliability assessment and development of a segmental activity score.

RESULTS

Delphi consensus: 11 experts representing seven countries identified four key parameters including: [1] bowel wall thickness [BWT]; [2] bowel wall stratification; [3] hyperaemia of the wall [colour Doppler imaging]; and [4] inflammatory mesenteric fat. Blind read: each variable exhibited moderate to substantial reliability. Optimal, standardised image and cineloop acquisition were established. Second blind read and score development: intra-class correlation coefficient [ICC] for BWT was almost perfect at 0.96 [0.94-0.98]. All four parameters correlated with the global disease activity assessment and were included in the final International Bowel Ultrasound Segmental Activity Score with almost perfect ICC (0.97 [0.95-0.99, p <0.001]).

CONCLUSIONS

Using expert consensus and standardised approaches, identification of key activity measurements on IUS has been achieved and a segmental activity score has been proposed, demonstrating excellent reliability.

A Rare Case of Unilateral Renal Cortical Necrosis

Unilateral cortical necrosis is a rare condition, and only described in a few case reports. We present a case of a previously healthy 24-year-old male with acute unilateral cortical necrosis, where contrast-enhanced ultrasound (CEUS) became a valuable diagnostic tool. Antiphospholipid syndrome was subsequently diagnosed. Primary antiphospholipid syndrome is a well-known, but rare cause of cortical necrosis. It promotes thrombosis in renal arteries, capillaries and veins, and usually affects both kidneys. Unilateral cortical necrosis due to antiphospholipid syndrome has, to our knowledge, not been previously described.

Ultrasound imaging for assessing functions of the GI tract

OBJECTIVE

In the following review we outline how ultrasound can be used to measure physiological processes in the gastrointestinal tract.

APPROACH

We have investigated the potential of ultrasound in assessing gastrointestinal physiology including original research regarding both basic methodology and clinical applications.

MAIN RESULTS

Our main findings show the use of ultrasound to study esophageal motility, measure volume and contractility of the stomach, assess motility, wall thickness, and perfusion of the small bowel, and evaluate wall vascularization and diameters of the large bowel.

SIGNIFICANCE

Ultrasound is a widely accessible technology that can be used for both scientific and clinical purposes. Being radiation-free and user friendly, the examination can be frequently repeated enabling longitudinal studies. Furthermore, it does not influence normal GI physiology, thus being useful to estimate motility and subtle changes in physiology. Accordingly, ultrasound scanning and physiological measurements may make a big difference for the scientist and the doctor; and for the patients who receive an efficient work-up.

Gastrointestinal Ultrasound (GIUS) in Intestinal Emergencies - An EFSUMB Position Paper

An interdisciplinary group of European experts summarizes the value of gastrointestinal ultrasound (GIUS) in the management of three time-critical causes of acute abdomen: bowel obstruction, gastrointestinal perforation and acute ischemic bowel disease. Based on an extensive literature review, statements for a targeted diagnostic strategy in these intestinal emergencies are presented. GIUS is best established in case of small bowel obstruction. Metanalyses and prospective studies showed a sensitivity and specificity comparable to that of computed tomography (CT) and superior to plain X-ray. GIUS may save time and radiation exposure and has the advantage of displaying bowel function directly. Gastrointestinal perforation is more challenging for less experienced investigators. Although GIUS in experienced hands has a relatively high sensitivity to establish a correct diagnosis, CT is the most sensitive method in this situation. The spectrum of intestinal ischemia ranges from self-limited ischemic colitis to fatal intestinal infarction. In acute arterial mesenteric ischemia, GIUS may provide information, but prompt CT angiography is the gold standard. On the other end of the spectrum, ischemic colitis shows typical ultrasound features that allow correct diagnosis. GIUS here has a diagnostic performance similar to CT and helps to differentiate mild from severe ischemic colitis.

Development and Validation of a Simple Ultrasound Activity Score for Crohn's Disease

BACKGROUND AND AIMS

To improve management of patients with Crohn's disease, objective measurements of disease activity are needed. Ileocolonoscopy is the current reference standard but has limitations that restrict repeated use. Ultrasonography is potentially useful for activity monitoring, but no validated sonographic activity index is currently in widespread use. Thus, we aimed to construct and validate a simple ultrasound score for Crohn's disease.

METHODS

Forty patients were prospectively examined with ultrasound and endoscopy in the development phase. The Simple Endoscopic Score for Crohn's Disease [SES-CD] was used as a reference standard. Seven ultrasound variables [bowel wall thickness, length, colour Doppler, stenosis, fistula, stratification and fatty wrapping] were initially included, and multiple linear regression was used to select the variables that should be included in the final score. Second, the ultrasound data from each patient were re-examined for interobserver assessment using weighted kappa and intraclass correlation. Finally, the activity index was validated in a new cohort of 124 patients.

RESULTS

Length, fistula and stenosis were excluded. The combination of the remaining variables provided a multiple correlation coefficient of r = 0.78. Interobserver analysis revealed poor agreement for stratification and fatty wrapping and these were thus excluded. There was excellent interobserver agreement for the remaining score consisting of wall thickness and colour Doppler. In both patient cohorts, the ultrasound score correlated well with SES-CD [Development cohort: rho = 0.83, p < 0.001, Validation cohort: rho = 0.78, p < 0.001]. A receiver operating characteristic curve analysis revealed an area under the curve of 0.92 and 0.88 for detecting endoscopic activity and moderate endoscopic activity, respectively.

CONCLUSIONS

A simple ultrasound activity index for Crohn's disease consisting of bowel wall thickness and colour Doppler was constructed and validated and correlated well with endoscopic disease activity.ClinicalTrials. gov ID: NCT03481751.

Plasma levels of guanylins are reduced in patients with Crohn's disease

Background: Guanylin (GN) and uroguanylin (UGN) are endogenous ligands for the intestinal receptor guanylate cyclase C (GC-C), an important regulator of intestinal fluid homeostasis. Gene expression and protein levels of GN are suppressed in inflamed intestinal tissue from patients with inflammatory bowel disease (IBD), but knowledge about plasma levels of guanylins in these conditions is sparse. We aimed to investigate the fasting plasma levels of the prohormones proGN and proUGN in patients with Crohn's Disease (CD) and relate these to levels found in persons with other diarrheal conditions, as well as persons with normal bowel habits.Methods: Plasma from patients with CD, patients with Familial GUCY2C Diarrheal Disease (FGDS), diarrhea-predominant irritable bowel syndrome (IBS-D) and healthy controls (HC) was analyzed using ELISA assays.Results: Significantly lower fasting plasma levels of proguanylins were found in CD and FGDS patients, compared to HC. In CD patients, plasma proGN levels correlated negatively with Harvey Bradshaw Index and with number of stools/24 h.Conclusion: Our data indicate that diarrhea may be a determinant for levels of proGN in plasma, and should be further explored in studies of different diarrheal disorders.

EFSUMB Gastrointestinal Ultrasound (GIUS) Task Force Group: Celiac sprue and other rare gastrointestinal diseases ultrasound features

Transabdominal gastrointestinal ultrasound (GIUS) is unique in its capacity to examine the bowel non-invasively and in its physiological condition, including extra-intestinal features such as the splanchnic vessels, mesentery, omentum and lymph nodes- even at the bedside. Despite this, and its extensive documentation for its usefulness, it has only been fully implemented in a few European countries and expert centres. Therefore, the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) established a GIUS Task Force Group in 2014 consisting of international experts from 9 European countries with the objectives to standardize and promote the use of GIUS in a clinical setting. This is achieved by publishing clinical guidelines and recommendations on indications and use of GIUS and so far,4 guidelines have been published: first on "examination techniques and normal findings", second on "inflammatory bowel disease", third on "acute appendicitis and diverticulitis" and fourth on "transrectal and perineal ultrasound".This paper describes the ultrasound features of miscellaneous disorders such as celiac disease, cystic fibrosis, omental infarction, Meckel's diverticle, endometriosis, intestinal neoplasia, mucocele, amyloidosis, GVHD, foreign bodies, vasculitis, and pneumatosis cystoides intestinalis. Bowel ultrasound can be indicated in most of these conditions to investigate intestinal symptoms but in other cases the alterations of the bowel can be also an incidental finding that suggest other examinations which finally help to discover an unknown pathological condition.

EFSUMB Position Paper: Recommendations for Gastrointestinal Ultrasound (GIUS) in Acute Appendicitis and Diverticulitis

An interdisciplinary task force of European experts summarizes the value of gastrointestinal ultrasound (GIUS) in the management of acute appendicitis and diverticulitis. Based on an extensive literature review, clinical recommendations for these highly common diseases in visceral medicine are presented.In patients with acute appendicitis, preoperative sonography has been established as a routine procedure in most European countries for medical and legal reasons. Routine sonography in these patients may reduce the rate of unnecessary surgery by half. The sensitivity, specificity, and accuracy of ultrasound reach values above 90 % and are equivalent to CT and MRI. However, the high operator dependence may be a problem, for example in point-of-care ultrasound in emergency departments. Structured training programs, quality controls and standardized ultrasound reporting should be increasingly implemented.In the case of suspected acute diverticulitis, "ultrasound first" should also be a basic element in the approach to all patients. Sonography can confirm the diagnosis and allows early risk stratification. As treatment strategies have become less aggressive and more tailored to the stage of diverticulitis, accurate staging has become increasingly important. GIUS and CT have proven to have similar sensitivity and specificity. Especially in cases of uncomplicated diverticulitis, GIUS will be the one and only imaging procedure. CT may work as a backup and has particular advantages for diverticulitis located in the distal sigmoid, inflammation deep in the small pelvis and insufficient ultrasound scanning conditions. This step-up approach (ultrasound first and CT only in case of a negative or inconclusive ultrasound result) has proven to yield the best accuracy.

Endorectal ultrasound and magnetic resonance imaging for staging of early rectal cancers: how well does it work in practice?

BACKGROUND

Rectal tumor treatment strategies are individually tailored based on tumor stage, and yield different rates of posttreatment morbidity, mortality, and local recurrence. Therefore, the accuracy of pretreatment staging is highly important. Here we investigated the accuracy of staging by magnetic resonance imaging (MRI) and endorectal ultrasound (ERUS) in a clinical setting.

MATERIAL AND METHODS

A total of 500 patients were examined at the rectal cancer outpatient clinic at Haukeland University Hospital between October 2014 and January 2018. This study included only cases in which the resection specimen had a histopathological staging of adenoma or early rectal cancer (pT1-pT2). Patients with previous pelvic surgery or preoperative radiotherapy were excluded. The 145 analyzed patients were preoperatively examined via biopsy (n = 132), digital rectal examination (n = 77), rigid rectoscopy (n = 127), ERUS (n = 104), real-time elastography (n = 96), and MRI (n = 84).

RESULTS

ERUS distinguished between adenomas and early rectal cancer with 88% accuracy (95% CI: 0.68-0.96), while MRI achieved 75% accuracy (95% CI: 0.54-0.88). ERUS tended to overstage T1 tumors as T2-T3 (16/24). MRI overstaged most adenomas to T1-T2 tumors (18/22). Neither ERUS nor MRI distinguished between T1 and T2 tumors.

CONCLUSIONS

In a clinical setting, ERUS differentiated between benign and malignant tumors with high accuracy. The present findings support previous reports that ERUS and MRI have low accuracy for T-staging of early rectal cancer. We recommend that MRI be routinely combined with ERUS for the clinical examination of rectal tumors, since MRI consistently overstaged adenomas as cancer. In adenomas, MRI had no additional benefit for preoperative staging.

Ultrasound for Assessing Disease Activity in IBD Patients: A Systematic Review of Activity Scores

BACKGROUND AND AIMS

Ultrasound [US] indices for assessing disease activity in IBD patients have never been critically reviewed. We aimed to systematically review the quality and reliability of available ultrasound [US] indices compared with reference standards for grading disease activity in IBD patients.

METHODS

Pubmed, Embase and Medline were searched for relevant literature published within the period 1990 to June 2017. Relevant publications were identified through full text review after initial screening by two investigators. Data on methodology and index characteristics were collected. Study quality was assessed using a modified version of the Quadas-2 tool for risk of bias assessment.

RESULTS

Of 20 studies with an US index, 11 studies met the inclusion criteria. Out of these 11 studies, 7 and 4 studied Crohn's disease [CD] and ulcerative colitis [UC0 activity indices, respectively. Parameters that were used in these indices included bowel wall thickness [BWT], Doppler signal [DS], wall layer stratification [WLS], compressibility, peristalsis, haustrations, fatty wrapping, contrast enhancement [CE], and strain pattern. Study quality was graded high in 5 studies, moderate in 3 studies and low in 3 studies. Ileocolonoscopy was used as the reference standard in 9 studies. In 1 study a combined index of ileocolonoscopy and barium contrast radiography and in 1 study histology was used as the reference standard. Only 5 studies used an established endoscopic index for comparison with US.

CONCLUSIONS

Several US indices for assessing disease activity in IBD are available; however, the methodology for development was suboptimal in most studies. For the development of future indices, stringent methodological design is required.

EFSUMB Recommendations and Clinical Guidelines for Intestinal Ultrasound (GIUS) in Inflammatory Bowel Diseases

The accuracy and usefulness of gastrointestinal ultrasound (GIUS) for detecting activity and complications of inflammatory bowel diseases (IBD), has been reported in studies, promoting this technique as an important tool for the management of IBD patients. Whilst well recognised by international guidelines, standardization and general agreement in the definition of the luminal and extra-intestinal features, still need to be well defined.A task force group of 17 experts in GIUS faced this issue, by developing recommendations and clinical guidelines for the use of GIUS in IBD, under the auspices of EFSUMB. This article presents the consensus on the current data on sonographic features of IBD and summarises the accuracy of different sonographic modalities for the management of IBD patients.

Contrast-enhanced ultrasonography of the pancreas shows impaired perfusion in pancreas insufficient cystic fibrosis patients

Background

Perfusion assessment of the pancreas is challenging and poorly evaluated. Pancreatic affection is a prevalent feature of cystic fibrosis (CF). Little is known about pancreatic perfusion in CF. We aimed to assess pancreatic perfusion by contrast-enhanced ultrasound (CEUS) analysed in the bolus-and-burst model and software.

Methods

We performed contrast enhanced ultrasound of the pancreas in 25 CF patients and 20 healthy controls. Perfusion data was analysed using a dedicated perfusion model providing the mean capillary transit-time (MTT), blood flow (BF) and blood-volume (BV). CF patients were divided according to exocrine function.

Results

The pancreas insufficient CF patients had longer MTT (p ≤ 0.002), lower BF (p < 0.001) and lower BV (p < 0.05) compared to the healthy controls and sufficient CF patients. Interrater analysis showed substantial agreement for the analysis of mean transit time.

Conclusion

The bolus-and-burst method used on pancreatic CEUS-examinations demonstrates reduced perfusion in CF patients with pancreas affection. The perfusion model and software requires further optimization and standardization to be clinical applicable for the assessment of pancreatic perfusion.

Electronic supplementary material

The online version of this article (10.1186/s12880-018-0259-3) contains supplementary material, which is available to authorized users.

Prolonged intestinal transit and diarrhea in patients with an activating GUCY2C mutation

Introduction

Increased intestinal hydration by activation of the epithelial enzyme linked receptor guanylate cyclase C (GC-C) is a pharmacological principle for treating constipation. Activating mutations in the GUCY2C gene encoding GC-C cause Familial GUCY2C diarrhea syndrome (FGDS) which has been diagnosed with severe dysmotility.

Aim

To investigate gut motility and hormones before and after a meal in FGDS patients and compare with healthy controls (HC).

Subjects and methods

Bristol stool chart and stool frequency was assessed. Before and after a meal occlusive and non-occlusive contractions were obtained using ultrasound. A wireless motility capsule (WMC) recorded gut transit time, pH, contractions and pressure. Plasma levels of selected gut hormones were measured at different time points.

Results

The FGDS patients had 4 (range 1–10) loose stools/day and prolonged total gut transit time compared to HC, 55.5 h vs 28.5 h, respectively,with significantly increased colon transit time. In FGDS patients, pH in duodenum, small bowel and colon was increased and the number of contractions and the intraluminal pressure were significantly decreased, measured by WMC. Ultrasound showed in small bowel increased number of non-occlusive contractions in the FGDS patients. Serotonin (5-HT) plasma levels in the HC peaked 30 min after the meal, while the FGDS patients had no response.

Conclusion

Despite having diarrhea, the FGDS patients have prolonged transit time through the gut compared to HC, particularly in colon. The reduced number of intestinal contractions and lack of 5-HT release after a meal in FGDS patients surprisingly resemble colonic motility disturbances seen in patients with constipation.

Interobserver Variation of the Bolus-and-Burst Method for Pancreatic Perfusion with Dynamic - Contrast-Enhanced Ultrasound

PURPOSE

Dynamic contrast-enhanced ultrasound (DCE-US) can be used for calculating organ perfusion. By combining bolus injection with burst replenishment, the actual mean transit time (MTT) can be estimated. Blood volume (BV) can be obtained by scaling the data to a vessel on the imaging plane. The study aim was to test interobserver agreement for repeated recordings using the same ultrasound scanner and agreement between results on two different scanner systems.

MATERIALS AND METHODS

Ten patients under evaluation for exocrine pancreatic failure were included. Each patient was scanned two times on a GE Logiq E9 scanner, by two different observers, and once on a Philips IU22 scanner, after a bolus of 1.5 ml Sonovue. A 60-second recording of contrast enhancement was performed before the burst and the scan continued for another 30 s for reperfusion. We performed data analysis using MATLAB-based DCE-US software. An artery in the same depth as the region of interest (ROI) was used for scaling. The measurements were compared using the intraclass correlation coefficient (ICC) and Bland Altman plots.

RESULTS

The interobserver agreement on the Logiq E9 for MTT (ICC=0.83, confidence interval (CI) 0.46-0.96) was excellent. There was poor agreement for MTT between the Logiq E9 and the IU22 (ICC=-0.084, CI -0.68-0.58). The interobserver agreement for blood volume measurements was excellent on the Logiq E9 (ICC=0.9286, CI 0.7250-0.98) and between scanners (ICC=0.86, CI=0.50-0.97).

CONCLUSION

Interobserver agreement was excellent using the same scanner for both parameters and between scanners for BV, but the comparison between two scanners did not yield acceptable agreement for MTT. This was probably due to incomplete bursting of bubbles in some of the recordings on the IU22.

EFSUMB Recommendations and Guidelines for Gastrointestinal Ultrasound

In October 2014 the European Federation of Societies for Ultrasound in Medicine and Biology formed a Gastrointestinal Ultrasound (GIUS) task force group to promote the use of GIUS in a clinical setting. One of the main objectives of the task force group was to develop clinical recommendations and guidelines for the use of GIUS under the auspices of EFSUMB. The first part, gives an overview of the examination techniques for GIUS recommended by experts in the field. It also presents the current evidence for the interpretation of normal sonoanatomical and physiological features as examined with different ultrasound modalities.

EFSUMB Recommendations and Guidelines for Gastrointestinal Ultrasound

In October 2014 the European Federation of Societies for Ultrasound in Medicine and Biology formed a Gastrointestinal Ultrasound (GIUS) task force group to promote the use of GIUS in a clinical setting. One of the main objectives of the task force group was to develop clinical recommendations and guidelines for the use of GIUS under the auspices of EFSUMB. The first part, gives an overview of the examination techniques for GIUS recommended by experts in the field. It also presents the current evidence for the interpretation of normal sonoanatomical and physiological features as examined with different ultrasound modalities.

An activating gucy2c mutation causes impaired contractility and fluid stagnation in the small bowel

OBJECTIVE

Familial GUCY2C diarrhoea syndrome (FGDS) is caused by an activating mutation in the GUCY2C gene encoding the receptor guanylate cyclase C in enterocytes. Activation leads to increased secretion of fluid into the intestinal lumen. Twenty percent of the patients have increased risk of Crohn's disease and intestinal obstruction (CD, 20%) and the condition resembles irritable bowel syndrome with diarrhoea. We aimed to describe fluid content, contractility, peristaltic activity and bowel wall thickness in the intestine in fasting FGDS patients, using ultrasound, with healthy volunteers serving as controls.

METHODS

Twenty-three patients with FGDS and 22 healthy controls (HC) were examined with a Logiq E9 scanner in a fasting state. Bowel wall thickness was measured and fluid-filled small bowel loops were counted using three-dimensional (3D) magnetic positioning navigation. The HC ingested 500 ml PEG solution, an electrolyte balanced, non-absorbable solution, in order to investigate the contractions of the small bowel.

RESULTS

The fasting 23 FGDS patients had significantly higher number of fluid-filled small bowel segments compared to 22 fasting HC, p < 0.001. A high number of non-occlusive contractions in the ileum was observed, which was significant when compared to HC after ingesting PEG solution, p < 0.016. An increase in intestinal wall thickness or other signs of CD were not observed.

CONCLUSIONS

FGDS is characterised by multiple, fluid-filled small bowel loops with incomplete contractions and fluid stagnation in fasting state. These findings may play a role in the increased risk of bowel obstruction as well as IBS-like symptoms observed in these patients.

Multimodal approach to assess tumour vasculature and potential treatment effect with DCE-US and DCE-MRI quantification in CWR22 prostate tumour xenografts

The aim of this study was to compare intratumoural heterogeneity and longitudinal changes assessed by dynamic contrast-enhanced ultrasound (DCE-US) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in prostate tumour xenografts. In vivo DCE-US and DCE-MRI were obtained 24 h pre- (day 0) and post- (day 2) radiation treatment with a single dose of 7.5 Gy. Characterization of the tumour vasculature was determined by Brix pharmacokinetic analysis of the time-intensity curves. Histogram analysis of voxels showed significant changes (p < 0.001) from day 0 to day 2 in both modalities for kep , the exchange rate constant from the extracellular extravascular space to the plasma, and kel , the elimination rate constant of the contrast. In addition, kep and kel values from DCE-US were significantly higher than those derived from DCE-MRI at day 0 (p < 0.0001) for both groups. At day 2, kel followed the same tendency for both groups, whereas kep showed this tendency only for the treated group in intermediate-enhancement regions. Regarding kep median values, longitudinal changes were not found for any modality. However, at day 2, kep linked to DCE-US was correlated to MVD in high-enhancement areas for the treated group (p = 0.05). In contrast, correlation to necrosis was detected for the control group in intermediate-enhancement areas (p < 0.1). Intratumoural heterogeneity and longitudinal changes in tumour vasculature were assessed for both modalities. Microvascular parameters derived from DCE-US seem to provide reliable biomarkers during radiotherapy as validated by histology. Furthermore, DCE-US could be a stand-alone or a complementary technique.

Absolute ultrasound perfusion parameter quantification of a tissue-mimicking phantom using bolus tracking [Correspondence]

This study presents three methods for absolute quantification in ultrasound perfusion analysis based on bolus tracking. The first two methods deconvolve the perfusion time sequence with a measured AIF, using a nonparametric or a parametric model of the tissue residue function, respectively. The third method is a simplified approach avoiding deconvolution by assuming a narrow AIF. A phantom with a dialyzer filter as a tissue-mimicking model was used for evaluation. Estimated mean transit times and blood volumes were compared with the theoretical values. A match with a maximum error of 12% was achieved.

Blind deconvolution in dynamic contrast-enhanced MRI and ultrasound

This paper is focused on quantitative perfusion analysis using MRI and ultrasound. In both MRI and ultrasound, most approaches allow estimation of rate constants (Ktrans, kep for MRI) and indices (AUC, TTP) that are only related to the physiological perfusion parameters of a tissue (e.g. blood flow, vessel permeability) but do not allow their absolute quantification. Recent methods for quantification of these physiological perfusion parameters are shortly reviewed. The main problem of these methods is estimation of the arterial input function (AIF). This paper summarizes and extends the current blind-deconvolution approaches to AIF estimation. The feasibility of these methods is shown on a small preclinical study using both MRI and ultrasound.

Quantitative contrast-enhanced ultrasound comparison between inflammatory and fibrotic lesions in patients with Crohn's disease

The aim of this study was to determine whether there are differences in absolute blood flow between patients with Crohn's disease with inflammation or fibrosis using contrast-enhanced ultrasound. Eighteen patients with fibrotic disease and 19 patients with inflammation were examined. Video sequences of contrast data were analyzed using a pharmacokinetic model to extract the arterial input and tissue residue functions with a custom software, enabling calculation of the absolute values for mean transit time, blood volume and flow. Feasibility of the examination was 89%. The fibrosis group had lower blood volume (0.9 vs. 3.4 mL per 100 mL tissue; p = 0.001) and flow (22.6 vs. 45.3 mL/min per 100 mL tissue; p = 0.003) compared with the inflammation group. There was no significant difference in mean transit time (3.9 vs. 5.5 s). In conclusion, absolute perfusion measurement in the gastrointestinal wall using contrast-enhanced ultrasound is feasible. There seems to be reduced blood volume and blood flow in patients with fibrotic disease.

Ultrasound perfusion analysis combining bolus-tracking and burst-replenishment

A new signal model and processing method for quantitative ultrasound perfusion analysis is presented, called bolus-and-burst. The method has the potential to provide absolute values of blood flow, blood volume, and mean transit time. Furthermore, it provides an estimate of the local arterial input function which characterizes the arterial tree, allowing accurate estimation of the bolus arrival time. The method combines two approaches to ultrasound perfusion analysis: bolus-tracking and burst-replenishment. A pharmacokinetic model based on the concept of arterial input functions and tissue residue functions is used to model both the bolus and replenishment parts of the recording. The pharmacokinetic model is fitted to the data using blind deconvolution. A preliminary assessment of the new perfusion-analysis method is presented on clinical recordings.

Gastrointestinal wall thickness measured with transabdominal ultrasonography and its relationship to demographic factors in healthy subjects

PURPOSE

To describe the gastrointestinal (GI) wall thickness and the thickness of individual wall layers in healthy subjects using ultrasound and to determine whether demographic factors, the ultrasound transducer frequency, or a fasting state influences these measurements.

MATERIALS AND METHODS

After overnight fasting, the GI wall thickness and wall layers were measured in several regions with transabdominal, high-frequency ultrasound. 122 healthy subjects aged 23 - 79 were included. All measurements were performed with both 8 and 12-MHz transducers except for the rectum measurement (4 MHz). 23 patients were given a 300 Kcal test meal and re-examined after 30 minutes.

RESULTS

Wall thickness measurements of the GI tract with transabdominal ultrasonography are dependent on transducer frequency (p < 0.001), weight (p < 0.001) and age (p < 0.018). The thickness of individual wall layers in the ileum and the sigmoid colon was found to be dependent on both age (p = 0.007) and weight (p < 0.001). The mean wall thickness from the jejunum to the sigmoid colon ranged from 0.9 to 1.2 mm with standard deviations (SD) of 0.3 mm or less. The mean (SD) was 2.9 (0.8) mm in the gastric antrum, 1.6 (0.3) mm in the duodenum, and 2.1 (0.5) mm in the rectum. The gastric antrum was thinner and the ileum and sigmoid colon were thicker after the test meal (p < 0.05).

CONCLUSION

GI wall thickness depends on weight and age. Provided adequate measurement, an abnormal GI wall should be suspected if the thickness exceeds 2 mm except for in the gastric antrum, duodenum and rectum. Reference values for wall thickness can be used regardless of fasting state or probe frequency except for in the gastric antrum.

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

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

Methods for chemical analysis of contaminated soil samples--tests of their reproducibility between Nordic laboratories

In an effort to develop common analytical methods for contaminated soil samples the Environmental Authorities of the Nordic countries have, together with Nordtest, published the report Nordic Guidelines for Chemical Analysis of Contaminated Soil Samples. The aim of these guidelines has been to describe analytical methods which could be accepted in all the Nordic countries and in that way contribute to reducing the variation in the analytical results between laboratories. The methods covered, reflects environmental concerns and priorities in the Nordic countries for now, i.e. heavy metals, chlorophenols, creosote, volatile organic compounds, PCB, THC and PAH. The repeatability and reproducibility of the guideline methods were determined in a Nordic inter-laboratory test in 1996, and the results showed some variations. The analytical methods and the results from the inter-laboratory tests are given for heavy metals, chlorophenols, creosote, volatile organic compounds and PCB.

Sonography of the small intestine

In the last two decades, there has been substantial development in the diagnostic possibilities for examining the small intestine. Compared with computerized tomography, magnetic resonance imaging, capsule endoscopy and double-balloon endoscopy, ultrasonography has the advantage of being cheap, portable, flexible and user- and patient-friendly, while at the same time providing the clinician with image data of high temporal and spatial resolution. The method has limitations with penetration in obesity and with intestinal air impairing image quality. The flexibility ultrasonography offers the examiner also implies that a systematic approach during scanning is needed. This paper reviews the basic scanning techniques and new modalities such as contrast-enhanced ultrasound, elastography, strain rate imaging, hydrosonography, allergosonography, endoscopic sonography and nutritional imaging, and the literature on disease-specific findings in the small intestine. Some of these methods have shown clinical benefit, while others are under research and development to establish their role in the diagnostic repertoire. However, along with improved overall image quality of new ultrasound scanners, these methods have enabled more anatomical and physiological changes in the small intestine to be observed. Accordingly, ultrasound of the small intestine is an attractive clinical tool to study patients with a range of diseases.

Crohn's disease: Comparison of in vitro ultrasonographic images and histology

OBJECTIVE

To examine some typical histological findings in Crohn's disease using high-frequency ultrasound and to define the echo properties of these findings.

MATERIAL AND METHODS

Bowel resection specimens from 14 patients operated on for Crohn's disease were examined with a 10 MHz linear array ultrasound transducer in a saline reservoir. Needles were placed in the specimen corresponding to the ultrasound plane. After formalin fixation, histological sections were taken according to these markings. Fifty-eight ultrasonographic images with 123 regions of interest were compared with corresponding histology.

RESULTS

A thickened muscularis mucosae (>0.3 mm) was found in 48 of 69 regions of interest on histology. Submucosa with slight to moderate fibrosis was imaged as an echo-rich layer with sporadic, echo-poor elements (36/56), while severe fibrosis was seen as an echo-rich layer with diffuse, echo-poor elements (40/55). Muscularis propria with slight to moderate fibrosis was seen as an echo-poor layer with sporadic, echo-rich elements (49/66) while severe fibrosis was seen as an echo-poor layer with diffuse, echo-rich elements (17/22). Crohn's rosary was seen as echo-poor extensions of the 4th echo layer (31/50).

CONCLUSIONS

Typical histological findings in Crohn's disease such as a thickened muscularis mucosae and Crohn's rosary can be imaged with high-frequency ultrasound in vitro. Fibrosis in the submucosa and muscularis propria is associated with decreasing and increasing echogenicity, respectively.

A comparison of proximal plaque removal using floss and interdental brushes

The removal of interproximal plaque was compared using a standard toothbrush alone, a toothbrush with unwaxed dental floss and a toothbrush with an interdental brush. 30 previously treated periodontal patients were given the cleaning aids in a three-way crossover study design. After each 1 month trial period, scores for gingivitis, buccal/lingual plaque and proximal plaque were recorded. Mean GI scores for subjects were 0.37 using the toothbrush only, 0.36 using the toothbrush with floss and 0.32 using the toothbrush with the interdental brush. Mean buccal/lingual plaque scores were 0.64 using the toothbrush only, 0.62 using the toothbrush with floss and 0.51 using the toothbrush with the interdental brush. Mean plaque scores were 2.32 with the toothbrush only, 1.71 using the toothbrush with floss and 1.22 using the toothbrush with the interdental brush. Statistically significant differences were seen in proximal plaque scores between the 3 treatment groups. The results indicate that the interdental brush used in combination with a toothbrush is more effective in the removal of plaque from proximal tooth surfaces than a toothbrush used alone or in combination with dental floss.

Antimicrobial irrigation of periodontal furcation lesions to supplement oral hygiene instruction and root debridement

The purpose of the present study was to evaluate the effects of subgingival irrigations with tetracycline as a supplement to mechanical plaque control and root debridement on clinical conditions of periodontal furcation pockets. 20 subjects with molar teeth having furcation pockets of varying depths and different grades of furcation involvement served for the study. Following oral hygiene instruction and root debridement at baseline, test teeth were irrigated subgingivally by a professional with a solution of 50 mg/ml of tetracycline, and control teeth with saline every 2nd week for 3 months. Records of dental plaque, bleeding on probing, probing depth and probing attachment level were obtained at 0, 1, 2, 3, 6, 9 and 12 months. The results failed to demonstrate any significant differences between test and control teeth for any of the subgroups of furcation sites at any observation interval. It is suggested that future studies may need to be performed over longer periods of time, and that the antimicrobial agents may need to be administered in vehicles, which provide prolonged periods of active subgingival concentrations.

Diagnostic predictability of scores of plaque, bleeding, suppuration and probing depth for probing attachment loss. 3 1/2 years of observation following initial periodontal therapy

Recordings of supragingival plaque, bleeding, suppuration and probing depth were obtained for 42 months following initial periodontal therapy. Scores accumulated after various time intervals during monitoring were studied for their predictive value in revealing probing attachment loss as determined by regression analysis during the 0-42 month period. Accumulated plaque scores demonstrated low predictability. Accumulated bleeding scores showed modest predictive values. Suppuration on probing was not a frequent finding during the observation interval and also had modest predictive power. Increase in probing depth compared to baseline and deep residual probing depth had modest predictability after 3 and 12 months, but showed increasing accuracy in revealing probing attachment loss over later time intervals. After a few years of maintenance, increase in probing depth, particularly if combined with high frequency of bleeding on probing, showed the highest predictive value for probing attachment loss of the scores examined.

Clinical effects of root debridement in molar and non-molar teeth. A 2-year follow-up

12 patients were studied longitudinally to monitor the effects of basic periodontal therapy in molar and non-molar teeth. Periodontal sites were grouped into molar furcation sites, molar flat-surface sites and non-molar sites. Clinical measurements were taken at baseline and directly followed by full mouth root debridement. Subsequently, measurements were taken every 3rd month until 24 months. At each of these appointments, the patients were monitored for their oral hygiene performance and given supragingival prophylaxis. The mean results indicated that initially moderately deep and deep molar furcation sites responded less favorably to therapy compared to non-molar sites and molar flat-surface sites of similar probing depth. Initial improvements in probing measurements for moderately deep and deep molar furcation sites were limited and also tended to revert during the observation interval. Identification of individual sites with probing attachment loss disclosed that 25% of molar furcation sites lost probing attachment as compared to 7% for non-molar sites and 10% for molar flat-surface sites. These results corroborate previous findings and call for additional or alternative treatment regimens for periodontal furcation pockets.