Enteric Contrast Research Articles

Magnetic resonance enterography.

Crohn's disease is a condition of chronic inflammation that may involve any part of the gastrointestinal tract, although it more frequently affects the terminal ileum. Longstanding inflammation may lead to several bowel complications including obstruction, stricture, fistula and abscesses which often necessitate surgery. Cross-sectional imaging methods such as computed tomography and magnetic resonance imaging are being utilized more frequently to assess mural and extramural inflammatory bowel disease manifestations. Magnetic resonance enterography (MRE) for assessment of small bowel is optimal because of absence of ionizing radiation, better soft tissue contrast, development of motion-free sequences and high resolution images. A typical protocol includes pre and postcontrast sequences utilizing an enteric contrast agent for adequate bowel distention and an antiperistaltic agent. Overall, MRE allows the evaluation of disease activity, extraenteric complication and response to therapy with a great impact on patient management. In this review we discuss the features of MRE from patient's preparation and exam protocol to pathological findings.

Pneumoperitoneum and PEG Dislodgement Secondary to Noninvasive Ventilation after PEG Tube Placement

We present a previously undescribed complication after noninvasive ventilation (NIV) for respiratory failure in a patient who required percutaneous endoscopic gastrostomy (PEG) tube placement for long-term nutrition after a complicated coronary bypass operation. A 54-year-old female diagnosed with unilateral vocal cord paralysis after emergent coronary artery bypass grafting (CABG) underwent an uncomplicated PEG tube placement. She was placed on intermittent NIV because of respiratory failure 24 hours after PEG placement, and NIV was continued for several days. Three days later, she was noted to have pneumoperitoneum on an upright chest X-ray. Abdominal CT scan revealed a large amount of pneumoperitoneum with the PEG tube in the correct position and no extravasation of enteric contrast from the stomach. Tube feeds were held and NIV was discontinued. Nonetheless, six days later, the patient was found on CT scan to have partial displacement of the PEG tube with leakage from the gastrotomy requiring operative repair. This case highlights the vulnerability of PEG tubes to management practices in the early postoperative period. Abdominal distention secondary to NIV likely caused pressure necrosis of the PEG site with dislodgement of the tube. This case elicits considerations regarding future management practices of patients receiving NIV in the early postoperative period after PEG placement.

2167 Endoscopic Closure of a Duodeno-Pleural Fistula Secondary to Transarterial Chemoembolization

INTRODUCTION: Transarterial chemoembolization (TACE) is an increasingly performed treatment for advanced stage hepatocellular carcinoma (HCC) not amenable to surgical intervention. Though effective, it is not without risk. Notable complications include post-embolization syndrome, decompensation of cirrhosis, acute cholecystitis, and acute pancreatitis, and rarely hepatic artery injury, liver abscess, duodenal perforation, and bile duct injury. Fistula formation appears to be among the rarest of complications. We describe the presentation of a duodeno-pleural fistula as a complication of TACE and its endoscopic closure with an over-the-scope clip (OTSC). CASE DESCRIPTION/METHODS: A 49-year-old woman with a history of chronic hepatitis B cirrhosis and HCC presented to the emergency room with right-sided chest pain. She was diagnosed with HCC 16 years ago in China and underwent partial hepatectomy and chemotherapy. Two years prior to current presentation, MRI demonstrated a 2.0 × 2.7 × 3.3 cm liver lesion consistent with recurrent HCC. TACE was performed. She subsequently reported abdominal pain. Endoscopy discovered a duodenal ulcer, and imaging noted a developing phlegmon and free air. Management with bowel rest and parenteral nutrition led to clinical improvement without the need for surgery. On this presentation, she described new onset pleuritic chest pain and dyspnea. Imaging revealed a large loculated right pleural effusion with gas foci and visible extraluminal enteric contrast surrounding the duodenal bulb, suggestive of an empyema secondary to a duodeno-pleural fistula (Figure 1). Pleural fluid analysis showed a pH < 6.8, high amylase and lipase levels, and cultures of multiple enteric organisms. Fistula closure was attempted endoscopically. A 4 mm opening was found in the duodenal bulb (Figure 2). The mucosa was denuded with argon beam plasma coagulation and an 11/6t OTSC successfully closed the defect (Figure 3a,b). Extravasated contrast was not seen on imaging two days later. DISCUSSION: Endoscopic interventions for enteric fistula closure include suturing, stents, and clips. The OTSC is increasingly recognized as a minimally invasive technique for fistula closure, with strong immediate technical success rates and variable long-term clinical success depending on location. To our knowledge, we demonstrated the first endoscopic closure of a duodeno-pleural fistula. This case supports the role of endoscopic closure with OTSC for enteric fistulae in the non-surgical candidate.

2129 Lumen-Apposing Metal Stent for Benign Gastric Outlet Obstruction!

INTRODUCTION: Lumen-apposing metal stent (LAMS) placement via endoscopic ultrasound (EUS)-guided gastroenterostomy has recently emerged as a promising technique for the management of malignant gastric outlet obstruction (GOO). This is safe, effective and technically feasible if performed by trained advanced endoscopists. Despite that LAMS use in malignant GOO is well defined, it is rarely performed for benign etiologies of GOO and only 4 cases have been reported in the literature. We report the case of a patient with GOO secondary to benign duodenal stricture that was successfully managed by LAMS placement. CASE DESCRIPTION/METHODS: A 60-year-old man with history of recurrent duodenal ulcers presented for vomiting and food intolerance for few days. Two years ago he had a GOO secondary to his ulcer disease and was managed by surgical gastrojejunostomy (GJ). A subsequent marginal ulcer perforation required resection of the GJ with small bowel anastomosis and insertion of a GJ tube. Upon presentation, physical examination was notable for epigastric tenderness with no rebound or rigidity. Contrast computed tomography (CT) scan of the abdomen showed a markedly distended stomach and proximal duodenum with focal narrowing near the pancreatic head (Figure 1). Enteric contrast reached the rectum indicating the absence of complete obstruction. Upper endoscopy showed retained solid material in stomach and an almost completely occluded “pin hole” duodenal lumen that could not be traversed with the endoscope. A wire-guided through the scope dilation with a balloon was performed in conjunction with fluoroscopy but was unsuccessful (Figure 2) so a 10 mm × 15 mm EUS-guided LAMS was successfully deployed. Patient’s symptoms resolved and he was able to tolerate diet. DISCUSSION: GOO usually occurs secondary to malignancy-related mass effect or luminal invasion. Less commonly GOO can be attributed to benign etiologies namely ulcers, caustic ingestion and inflammation. Often managed by endoscopic balloon dilation, benign strictures can recur. Other less favored options include self-expandable metal stents which use is limited by a high rate of migration and failure and surgical approach which provides definitive treatment but is associated with a high risk of mortality and morbidity. LAMS is a novel and appealing less invasive approach proven to be a safe alternative allowing early restoration of enteral luminal access with good short term success and satisfying safety profile. Further studies and long term follow up are recommended.

An international survey to assess use of oral and rectal contrast in CT protocols for penetrating torso trauma.

There is controversy regarding the administration of oral and rectal contrast for CT performed to detect bowel injury in the context of penetrating torso trauma. Given the lack of published societal guidelines, our goal was to survey radiologists from the American Society of Emergency Radiology membership database to determine consensus on CT protocols for penetrating trauma. With ethics board approval, an anonymous ten-question online survey was distributed via email to 589 radiologists in the American Society of Emergency Radiology (ASER) member database. The survey was open for a 4-week period in February 2018. A commercially available website that allows subscribers to create and analyze survey results was used for analysis. We received 124 responses (21% response rate) with a majority from U.S. institutions (82%). Seventy-four percent of respondents indicated they do not routinely administer oral contrast in penetrating trauma, 68% do not administer rectal contrast, and 90% do not use commercially available software to assess penetrating injury trajectory. Results from U.S. and non-U.S. practices were comparable. The decision to administer intraluminal contrast is made by the referring physician at 52% of institutions. There is in-house attending level radiology coverage at 54% of institutions and when asked if trauma scans are reviewed before removing the patient from the table, 41% of respondents answered "No." Enteric contrast is used in a minority of respondents' centers for penetrating trauma cases, which is likely driven by a perceived lack of added benefit and delays in patient care.

In Brief

<dm:abstracts xmlns:dm="http://www.elsevier.com/xml/dm/dtd"><ce:abstract xmlns:ce="http://www.elsevier.com/xml/common/dtd" id="abs0001" view="all" class="author"><ce:section-title id="cesectitle0001">In brief </ce:section-title><ce:abstract-sec id="abss0001" view="all"><ce:simple-para id="spara0001" view="all">Intestinal obstruction accounts for approximately 15% of all acute abdominal pain. Whereas the mainstay of management has historically been operative intervention, non-operative management, consisting of observation, pharmacologic, and endoscopic therapy, continues to assume a more prominent role, especially depending on the underlying cause of the obstruction. In addition to relying upon the history of present illness to start devising the differential diagnosis and plan of care, there is increasing reliance on radiographic imaging as a means to determine the cause of the obstruction and probability of success with non-operative management.</ce:simple-para><ce:simple-para id="spara0002" view="all">Whereas the diagnostic work-up of patients with suspected bowel obstruction has traditionally started with an abdominal x-ray series, there is an increasing role for initial computerized tomography (CT) in evaluating these patients. This modality allows for identification of both the cause and severity of bowel obstruction in many, if not most, cases. Enteral contrast was thought to be necessary for adequate diagnostic yield, but studies have found that administration of oral contrast delays imaging and does not contribute significantly to diagnostic yield. Specific findings on CT scan are associated with failure of non-operative management, and therefore increased mortality and morbidity, due to a delay to operative intervention. Such findings include: a closed loop obstruction, volvulus (particularly small bowel), ischemic changes, and bowel perforation. Moreover, bowel obstruction due to a hernia, either external or internal, is not likely to resolve without intervention. In this review we will cover the various causes, evaluation and treatment of small and large bowel obstruction.</ce:simple-para></ce:abstract-sec></ce:abstract></dm:abstracts>

Single-Contrast CT for Detecting Bowel Injuries in Penetrating Abdominopelvic Trauma.

Many centers advocate use of triple-contrast (IV, oral, and rectal) CT for assessing hemodynamically stable patients with penetrating abdominopelvic trauma. Enteric contrast material has several disadvantages, leading our practice to pursue use of single-contrast (IV) CT. We conducted a retrospective review of electronic medical records at our institution to assess the accuracy of single-contrast CT for diagnosing bowel injuries in cases of penetrating abdominopelvic trauma. We retrospectively reviewed patients who presented to our emergency department between January 1, 2004, and March 1, 2014, with penetrating abdominopelvic trauma, underwent an abdominopelvic CT, and had surgery performed thereafter. We reviewed pertinent emergency department records for details regarding the site of injury, the number of injuries per patient, and the type of weapon used. We correlated CT reports with operative notes for presence and sites of bowel injury. A total of 274 patients (median age, 27 years old) met our inclusion criteria; 77% had sustained gunshot wounds (GSWs). CT showed bowel injury in 173 cases; surgery revealed bowel injury in 162 cases. CT had 142 true-positive, 31 false-positive, 81 true-negative, and 20 false-negative cases, resulting in sensitivity of 88%, specificity of 72%, positive predictive value of 82%, and negative predictive value of 80% for detecting bowel injuries. CT had the highest sensitivity and specificity in patients with multiple GSWs (94% and 79%, respectively) and those with injuries to the stomach and rectum. Single-contrast CT can show bowel injuries in patients with penetrating abdominopelvic trauma with accuracy comparable with that reported for triple-contrast CT.

Endoscopic full-thickness resection of a gastric subepithelial tumor.

Incidental subepithelial tumors are found in about 1 in 300 upper endoscopies. EUS-guided FNA can aid in establishing a diagnosis, but it cannot provide appropriate information about malignant potential because of the absence of a histologic mitotic count. In a small subset of patients, FNA is inconclusive. Inconclusive diagnosis and lack of prognostic histologic features can submit patients to continued endoscopic surveillance. We present a case of a full-thickness resection (FTR) of a gastric subepithelial nodule followed by endoscopic suturing to close the defect (Video 1, available online at www.VideoGIE.org). An 81-year-old man was found to have an incidental gastric body nodule during upper endoscopy for GERD (Fig. 1A). EUS revealed a 1.5-cm × 1.4-cm subepithelial tumor arising from the submucosa and muscularis propria (Fig. 1B). Cytologic analysis from FNA showed spindle cells, and immunostains were positive for CD34 and CD117, suggestive of a GI stromal tumor. The decision was made to perform endoscopic FTR after discussion with the patient about risks, benefits, and alternatives. Using an IT nanoknife (Olympus Optical Co, Tokyo, Japan), we performed a 360° circumferential mucosal incision defining the boundaries of the subepithelial nodule (Fig. 1C). The 360° incision was then extended deeper into the muscularis propria along the line of the initial incision. Finally, with an IT nanoknife, we completed the 300° full-thickness incision. We intentionally avoided the last 60° of the serosal layer to prevent migration of the resected specimen into the peritoneum. Hemostasis was achieved for bleeding vessels encountered during dissection by coagulation forceps. A 4-cm full-thickness defect was seen when the mesenteric fat was visualized endoscopically. The remaining pedicle was resected with a hot snare and retrieved with a Roth net (Fig. 1D). The defect was closed by 2 series of running nonabsorbable sutures by use of the endoscopic suturing device (Fig. 1E). A helix device was used to facilitate suturing. Pathologic examination of the nodule confirmed an FTR of the gastric subepithelial tumor. CT of the abdomen with enteric contrast material confirmed adequate closure of the resection site. The patient was discharged after a 23-hour observation period. A 2-month follow-up endoscopy showed hyperplastic tissue at the suture site without any residual nodule (Fig. 1F). This technique of endoscopic FTR for gastric subepithelial nodule and closure by use of an endoscopic suturing device can be safe and can provide a definitive diagnosis with malignant risk stratification, eliminating the need for continued endoscopic surveillance. All authors disclosed no financial relationships relevant to this publication. eyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiI4ZTE3YjdiZDk1YWFlYTg1MzBiNzhjNmMwOTQ1ZjI4ZiIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNjc4Njg4NDE1fQ.HLb7sIdJm7iiZ2xE3kOeRrGr_85vINonX9jhLHqH8jKk1DpbmKTkYfCicOMGKUie4LIvHMtEVeIgehB2_aXCLH3ENgkLHboRQp2o4lb8lIt2JOppUtAtVotXSFt04r-cGFEFi5qy2IkeP18TVDz_MJ8AOyeCYBuwgV76cR8ZiybR06afWFj2uHPjcledsq0nHh2c3foLNux4BQgbQ2L0TKWo9fjqElS-UycU3uXkjpMufg7pqWiIzvCppTFv1jTPKrP3k0dCoD_ZMy3W4kx8E47mQ6xIHaVU9jFGDFtwUQpGzFFsYd3D2lhJIzQfj3FC0LiDx-jfwAYtPSDKFa6gSA Download .mp4 (108.52 MB) Help with .mp4 files Video 1Video demonstrating endoscopic full-thickness resection (EFTR) of a gastric subepithelial nodule.eyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiJlOWNlNGMwZTczNWQ0ZjNjMzg1NzQ3ODY1MTNmMmI0YyIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNjc4Njg4NDE1fQ.isUNWZpZ3rpU1cKIn8qyW3rluqAVY4e-VjFofPMn9IqC_-m2nOan9tdEP5pfPRa9bRwvJJJL8bSuYPItx2TJHcOtqR_1jhCY8_EOAfRJTexJsxE4SRAaQsOStIHxTEPU9htpYr4wj7JoKgA8qv0EXKJWeshtq7Ks8BvT_RNzEdicwbI2m8fToFSEbmsATLjvr8JykWaC6KdCkTjjxQawcvB7NkRsPMFOeZ7jmdsetXJYThvq-PjB4msxAD3AR5qmaNnQQnGDlCUyxOBuwlu9PJfb1uWFMA13pnO9lLusuMiGvSNLaQzOdr_glBA5vQO2IkZs8fSjQUI7yfVTtIGogA Download .mp4 (167.22 MB) Help with .mp4 files Video 2 Download .docx (.01 MB) Help with docx files Video Script

The Small Bowel: An Imaging Guide

Background: This article reviews the latest radiological advances in the evaluation of small bowel disease. MRI and CT have been optimized in recent years for small bowel imaging including the development of enteric agents to distend the bowel, multiplanar thin-section imaging, advanced imaging applications, and radiation dose optimization techniques. Discussion: MR enterography, with the absence of ionizing radiation exposure, excellent tissue contrast, ultrafast breath-holding pulse sequences, and the ability to perform real-time functional imaging, has become the first-line imaging modality for the evaluation of the majority of small bowel disorders. Advanced MR applications including diffusion-weighted imaging, dynamic contrast-enhanced MRI, and motility imaging are becoming central in the imaging evaluation of small bowel disease. Conclusion: CT enterography is the preferred modality in patients with known or suspected inflammatory bowel disease in the acute setting to assess for extra-luminal complications. The enteroclysis technique is of use in selected cases in which adequate small bowel distention is not achieved with oral enteral contrast administration. Capsule endoscopy is reserved for patients in whom the clinical suspicion of small bowel disease remains high despite negative evaluations with endoscopy and imaging. Keywords: Small bowel, MR enterography, CT enterography, enteroclysis, dose optimization, Crohn's disease.

Reproducible imaging features of biologically aggressive gastrointestinal stromal tumors of the small bowel.

To identify reproducible CT imaging features of small bowel gastrointestinal stromal tumors (GIST) that are associated with biologic aggressiveness. Patients with histologically proven small bowel GISTs and CT enterography or abdominopelvic CT were included. Biologic aggressiveness was established based on initial histologic grading (very low risk to malignant), with "malignant" assigned if recurrence or metastases developed subsequently. CT exams were independently evaluated by three gastrointestinal radiologists for tumor size, growth pattern, enhancement, tumor borders, necrosis, calcification, ulceration, multiplicity, internal air or enteric contrast, nodal metastasis, liver metastasis, peritoneal metastasis, ascites, and draining vein size. Inter-observer variability and imaging features associated with high-grade and malignant small bowel GISTs were determined. Of 78 patients with small bowel GISTs, 10/78 (13%) were high grade and 18/78 (23%) were malignant. There was moderate to substantial inter-observer agreement (Kappa>0.4) for all findings except tumor border, ulceration, and nodal metastases. Tumor size, irregular or invasive tumor border, necrosis, liver metastasis, ascites, and iso-enhancement were associated with high-grade/malignant small bowel GISTs (p<0.04). Internal air or enteric contrast and peritoneal metastases additionally predicted malignant behavior (p<0.03). When imaging features predicting malignant small bowel GISTs were absent and size was≤3cm, 0% (0/16), 5% (1/19), and 5% (1/17) of patients had high grade, and 0% (0/16, 0/19, and 0/17) had malignant tumors for the three readers, respectively. Multiple, reproducibly identified, small bowel GIST imaging features suggest biologic aggressiveness. The absence of these imaging features may identify small tumors that can be followed in asymptomatic or high-risk patients.

Endoscopic Full Thickness Resection (EFTR) of a Gastric Submucosal Tumor

Incidental submucosal tumors can be found in about one in three hundred upper endoscopies. Currently, EUS can aid in establishing diagnosis of highly malignant features of a nodule, but it cannot provide appropriate malignant potential due to absence of histological mitotic count. FNA is useful for making a definitive diagnosis, but many times it can be inconclusive which submits the patient to continued endoscopic surveillance. We present a case of a full thickness resection of a gastric submucosal nodule followed by endoscopic suturing to close the defect. We present an 81-year-old male complaining of GERD. An EGD showed an incidental gastric body nodule. An EUS revealed a 1.5 cm by 1.4 cm submucosal tumor extending into the muscularis propria. Cytology from FNA showed spindle cells, suggestive of a GIST. Using an IT nano knife, we made a 360-degree circumferential incision extending into the sub-mucosa. Hemostasis was achieved by using coagulation forceps for small vessels, and hemostatic clip for larger vessels. The incision was then extended deeper into the muscularis layers along the line of the initial incision. With the IT nano knife, we completed the 300-degree full thickness incision. We intentionally avoided the last 60 degrees of the serosal layer to prevent migration of the resected specimen into the peritoneum. A four centimeter full thickness defect was seen visualizing the mesenteric fat endoscopically. The remaining pedicle was resected using a hot snare and retrieved using a roth net. The defect was closed with interrupted sutures using an overstich device. A helix device was used to facilitate suturing. Pathology confirmed full thickness resection. CT abdomen with enteric contrast confirmed adequate closure of the resection site. Patient was discharged after 23-hour observation. A two month follow up endoscopy showed hyperplastic tissue at the suture site without any residual nodule. This technique of endoscopic full thickness resection using an overstich device for closure is technically feasible, safe and provides definitive diagnosis with malignant risk stratification eliminating the need for continued endoscopic surveillance. Watch the video: https://goo.gl/QAEuLg

Impact of CT enterography on the diagnosis of small bowel gastrointestinal stromal tumors.

Our purpose is to determine the impact of CT enterography on small bowel gastrointestinal stromal tumor (GIST) detection and biologic aggressiveness, and to identify any imaging findings that correlate with biologic aggressiveness. Records of patients with histologically confirmed small bowel GISTs who underwent CT imaging were reviewed. Biologic aggressiveness was based on initial histologic grading (very low, low, intermediate, high grade; or malignant), with upgrade to malignant category if local or distant metastases developed during clinical follow-up. Imaging indications, findings, and type of CT exam were compared with the biologic aggressiveness. 111 small bowel GISTs were identified, with suspected small bowel bleeding being the most common indication (45/111; 40.5%). While the number of malignant GISTs diagnosed by CT remained relatively constant (2-3 per year), the number of non-malignant GISTs increased substantially (mean 1.5/year, 1998-2005; 8.4/year, 2006-2013). In patients with suspected small bowel bleeding, CT enterography identified 33 GISTs (7/33, 21% malignant) compared to 12 GISTs by abdominopelvic CT (6/12, 50% malignant; p<0.03). Tumor size (p<0.0001), internal necrosis (p=0.005), internal air or enteric contrast (p≤0.021), and ulceration (p≤0.021) were significantly associated with high-grade and malignant tumors, and irregular or invasive tumor borders (p<0.01) was associated with malignant tumors. The detection of small bowel GISTs can increase due to the use of CT enterography in patients with suspected small bowel bleeding. The large majority of small bowel GISTs detected by CT enterography are not malignant.

Selecting appropriate gastroenteric contrast media for diagnostic fluoroscopic imaging in infants and children: a practical approach.

In our experience, questions about the appropriate use of enteric contrast media for pediatric fluoroscopic studies are common. The purpose of this article is to provide a comprehensive review of enteric contrast media used for pediatric fluoroscopy, highlighting the routine use of these media at a large tertiary care pediatric teaching hospital.

Achalasia after Bariatric Roux-en-Y Gastric Bypass Surgery Reversal

Introduction: Achalasia is rare esophageal motility disorder that leads to loss of peristalsis in the distal esophagus and a failure of lower esophageal sphincter (LES) relaxation. It usually manifests as dysphagia for solids and liquids, and regurgitation of undigested food or saliva. The development of esophageal motility disorders including achalasia following bariatric surgery is still controversial and differ according to the type of surgery. Many cases of achalasia as a consequence of gastric band placement have been described. However, the development of achalasia and other motility disorders after Roux-en-Y gastric bypass (RYGB) are rare and only reported in some case reports. Case report: 70-year-old female patient with past medical history of morbid obesity presented to with complains of persistent nausea and regurgitation for the last 1 month. Her surgical history was significant for a laparoscopic cholecystectomy in addition to a laparoscopic Roux-en-Y gastric bypass (RYGB) approximately 2 years ago. Her surgery was revised 2 months prior to her presentation. Physical examination showed the wound of her recent surgery with no evidence of discharge or poor healing. Initial laboratory workup including complete blood count, comprehensive metabolic panel, and stool analysis were unremarkable. CT-scan of the abdomen and pelvis with contrast showed enteric contrast within the dilated distal esophagus, and was suspicious for mild stricture at gastro-esophageal sphincter (GES). Esophagogastroduodenoscopy showed a tortuous and dilated esophagus with large amounts of thick secretions. No strictures or stenosis was noted. Barium study was done afterward and showed persistent narrowing of the GES with a moderately dilated esophagus proximally and tertiary esophageal contractions. It was suggestive of achalasia. An outpatient manometry study revealed high LES pressure with abnormal relaxation, in addition to aperistalsis and those findings were consistent with type II achalasia. She was referred to surgery for possible laparoscopic heller's myotomy. Conclusion: We are presenting a rare case of achalasia after RYGB. As of our best knowledge there are only 3 cases reported for achalasia after RYGB and this is the first case described after revision of RYGB. The exact pathophysiology is not clearly understood, but local trauma due to surgery may play a role. An important consideration in similar cases is to rule out stenosis of the gastrojejunostomy.Figure 1Figure 2Figure 3

Oral contrast for CT in patients with acute non-traumatic abdominal and pelvic pain: what should be its current role?

Positive oral contrast agents, including barium suspensions and water-soluble iodinated solutions, have traditionally been used in conjunction with the CT evaluation of patients with abdominal and pelvic pain. Due to continued advancements in CT technology, and due to increasing obesity and correspondingly a general increase in the intra-abdominal and intra-pelvic fat separating bowel loops in North American patients and in patients in other parts of the world over the past few decades, the ability of radiologists to accurately evaluate the cause of acute symptoms has substantially improved. Recent research and evolving imaging society guidelines/systematic reviews increasingly support performing CT scans of the abdomen and pelvis without the need for positive oral contrast in these types of adult patient populations, in most clinical situations. Increased patient throughput, patient preference, patient safety, and most importantly, retention of high diagnostic accuracy, are reasons for this recent change in practice to routinely omit the use of enteric contrast agents for the majority of patients presenting with acute abdominal and pelvic pain whom are undergoing emergency CT.

The Use of Enteric Contrast Media for Diagnostic CT, MRI, and Ultrasound in Infants and Children: A Practical Approach.

Enteric contrast media are commonly administered for diagnostic cross-sectional imaging studies in the pediatric population. The purpose of this manuscript is to review the use of enteric contrast media for CT, MRI, and ultrasound in infants, children, and adolescents and to share our experiences at a large tertiary care pediatric teaching hospital. The use of enteric contrast material for diagnostic imaging in infants and children continues to evolve with advances in imaging technology and available enteric contrast media. Many principles of enteric contrast use in pediatric imaging are similar to those in adult imaging, but important differences must be kept in mind when imaging the gastrointestinal tract in infants and children, and practical ways to optimize the imaging examination and the patient experience should be employed where possible.

Endoluminal contrast for abdomen and pelvis magnetic resonance imaging.

Magnetic resonance (MR) imaging of the abdomen and pelvis can be limited for assessment of different conditions when imaging inadequately distended hollow organs. Endoluminal contrast agents may provide improved anatomic definition and detection of subtle pathology in such scenarios. The available routes of administration for endoluminal contrast agents include oral, endorectal, endovaginal, intravesicular, and through non-physiologic accesses. Appropriate use of endoluminal contrast agents requires a thorough understanding of the clinical indications, available contrast agents, patient preparation, and interaction of the contrast agent with the desired MR imaging protocol. For example, biphasic oral enteric contrast agents are preferred in MR enterography as their signal properties on T1- and T2-weighted imaging allow for evaluation of both intraluminal and bowel wall pathology. In specific situations such as with MR enterography, MR defecography, and accurate local staging of certain pelvic tumors, the use of an endoluminal contrast agent is imperative in providing adequate diagnostic imaging. In other clinical scenarios, the use of an endoluminal contrast agent may serve as an indispensable problem-solving tool.

In vivo comparison of tantalum, tungsten, and bismuth enteric contrast agents to complement intravenous iodine for double-contrast dual-energy CT of the bowel.

To assess the ability of dual-energy CT (DECT) to separate intravenous contrast of bowel wall from intraluminal contrast, we scanned 16 rabbits on a clinical DECT scanner: n = 3 using only iodinated intravenous contrast, and n = 13 double-contrast enhanced scans using iodinated intravenous contrast and experimental enteric non-iodinated contrast agents in the bowel lumen (five bismuth, four tungsten, and four tantalum based). Representative image pairs from conventional CT images and DECT iodine density maps of small bowel (116 pairs from 232 images) were viewed by four abdominal imaging attending radiologists to independently score each comparison pair on a visual analog scale (-100 to +100%) for (1) preference in small bowel wall visualization and (2) preference in completeness of intraluminal enteric contrast subtraction. Median small bowel wall visualization was scored 39 and 42 percentage points (95% CI 30-44% and 36-45%, both p < 0.001) higher for double-contrast DECT than for conventional CT with enteric tungsten and tantalum contrast, respectively. Median small bowel wall visualization for double-contrast DECT was scored 29 and 35 percentage points (95% CI 20-35% and 33-39%, both p < 0.001) higher with enteric tungsten and tantalum, respectively, than with bismuth contrast. Median completeness of intraluminal enteric contrast subtraction in double-contrast DECT iodine density maps was scored 28 and 29 percentage points (95% CI 15-31% and 28-33%, both p < 0.001) higher with enteric tungsten and tantalum, respectively, than with bismuth contrast. Results suggest that in vivo double-contrast DECT with iodinated intravenous and either tantalum- or tungsten-based enteric contrast provides better visualization of small bowel than conventional CT. Copyright © 2016 John Wiley & Sons, Ltd.

Abdominal MRI without Enteral Contrast Accurately Detects Intestinal Fibrostenosis in Patients with Inflammatory Bowel Disease

Patients with inflammatory bowel disease (IBD) presenting for surgical evaluation require thorough small bowel surveillance as it improves accuracy of diagnosis (ulcerative colitis versus Crohn's) and differentiates those who may respond to nonoperative therapy, preserving bowel length. MRI has not been validated conclusively against histopathology in IBD. Most protocols require enteral contrast. This study aimed to 1) evaluate the accuracy of MRI for inflammation, fibrosis, and extraluminal complications and 2) compare MRI without enteral contrast to standard magnetic resonance enterography. Adults with Crohn's disease or ulcerative colitis who underwent abdominal MRI and surgery were retrospectively reviewed. Of 65 patients evaluated, 55 met inclusion criteria. Overall sensitivity and specificity of MRI for disease involvement localized by segment were 93 per cent (95% confidence interval = 89.4-95.0) and 95 per cent (95% confidence interval = 92.3-97.0), respectively (positive predictive value was 86%, negative predictive value was 98%). Sensitivity and specificity between MRI with and without oral and rectal contrast were similar (96% vs 91% and 99% vs 94%, P > 0.10). As were positive predictive value and negative predictive value (85% vs 96%, P = 0.16; 97% vs 99%, P = 0.42). Magnetic resonance is highly sensitive and specific for localized disease involvement and extraluminal abdominal sequelae of IBD. It accurately differentiates patients who have chronic transmural (fibrotic) disease and thus may require an operation from those with acute inflammation, whose symptoms may improve with aggressive medical therapy alone. MRI without contrast had comparable diagnostic yield to standard magnetic resonance enterography.

Acute Perforated Diverticulitis: Assessment With Multidetector Computed Tomography

Colonic diverticulitis is a common condition in the western population. Complicated diverticulitis is defined as the presence of extraluminal air or abscess, peritonitis, colon occlusion, or fistulas. Multidetector row computed tomography (MDCT) is the modality of choice for the diagnosis and the staging of diverticulitis and its complications, which enables performing an accurate differential diagnosis and addressing the patients to a correct management. MDCT is accurate in diagnosing the site of perforation in approximately 85% of cases, by the detection of direct signs (focal bowel wall discontinuity, extraluminal gas, and extraluminal enteric contrast) and indirect signs, which are represented by segmental bowel wall thickening, abnormal bowel wall enhancement, perivisceral fat stranding of fluid, and abscess. MDCT is accurate in the differentiation from complicated colon diverticulitis and colon cancer, often with a similar imaging. The computed tomography-guided classification is recommended to discriminate patients with mild diverticulitis, generally treated with antibiotics, from those with severe diverticulitis with a large abscess, which may be drained with a percutaneous approach.