Imaging bowel obstruction: a comparison between fast magnetic resonance imaging and helical computed tomography

[Magnetic resonance enterography/enteroclysis : Technical aspects and indications]

BACKGROUND

Magnetic resonance enterography/enteroclysma (MRE) is an examination technique without ionizing radiation that allows assessment of bowel wall changes and extraluminal pathologies/complications such as in chronic inflammatory bowel diseases, among others.

OBJECTIVES

To discuss requirements for optimal MR imaging of the small bowel, technical basis of MRE and principles for the development and optimization of a MRE protocol, and clinical indications for this specific imaging technique.

MATERIALS AND METHODS

Guidelines, basic and review papers will be analyzed.

RESULTS

MRE enables the diagnosis of inflammatory bowel diseases and neoplasms and their evaluation during therapy. In addition to intra- and transmural changes, extramural pathologies and complications can also be detected. Standard sequences include steady-state free precession sequences, T2-weighted single-shot fast spin echo sequences, and three-dimensional (3D) T1-weighted gradient echo (GRE) sequences with fat saturation after contrast administration. Prior to image acquisition, optimal patient preparation and distension of the bowel using intraluminal contrast agents is necessary.

CONCLUSIONS

Careful patient preparation for MRE, understanding of optimal imaging technique, and appropriate clinical indications are essential to achieve high-quality images of the bowel for accurate assessment and diagnosis as well as therapy monitoring of small bowel disease.

Determining the etiology of small bowel obstruction in patients without intraabdominal operative history: a retrospective study

PURPOSE

Most of the causes of small bowel obstruction (SBO) in patients without a history of abdominal surgery are unclear at initial assessment. This study was conducted to identify the etiology and clinical characteristics of SBO in virgin abdomens and discuss the proper management.

METHODS

A retrospective review involving operative cases of SBO from a single institute, which had no history of abdominal surgery, was conducted between January 2010 and December 2020. Clinical information, including radiological, operative, and pathologic findings, was investigated to determine the etiology of SBO.

RESULTS

A total of 55 patients were included in this study, with a median age of 57 years and male sex (63.6%) constituting the majority. The most frequently reported symptoms were abdominal pain and nausea or vomiting. Neoplasm as an underlying cause accounted for 34.5% of the cases, of which 25.5% were malignant cases. In patients aged ≥60 years (n=23), small bowel neoplasms were the underlying cause in 12 (52.2%), of whom 9 (39.1%) were malignant cases. Adhesions and Crohn disease were more frequent in patients aged <60 years. Coherence between preoperative computed tomography scans and intraoperative findings was found in 63.6% of the cases.

CONCLUSION

There were various causes of surgical cases of SBO in virgin abdomens. In older patients, hidden malignancy should be considered as a possible cause of SBO in a virgin abdomen. Patients with symptoms of recurrent bowel obstruction who have no history of prior abdominal surgery require thorough medical history and close follow-up.

Overview of the Large Bowel Assessment Using Magnetic Resonance Imaging: Different Techniques for Current and Emerging Clinical Applications

Radiological assessments of the small and large bowel are essential in daily clinical practice. Over plain film X-ray and ultrasound, cross-sectional techniques are considered the most comprehensive imaging modalities. In fact, computed tomography and magnetic resonance imaging take great advantage of the three-dimensional appraisal and the extensive evaluation of the abdominal cavity, allowing intestinal evaluation as well as detection of extra-intestinal findings. In this context, the chief advantage of computed tomography is the fast scan time, which is crucial for emergency cases. Nonetheless, it is undeniably impaired using ionizing radiation. As the awareness of radiation exposure is a topic of increasing importance, magnetic resonance imaging is not only becoming a mere alternative but also a primary imaging technique used in assessing intestinal diseases. Specifically, the evaluation of the large bowel through MRI can be still considered relatively uncharted territory. Although it has demonstrated superior accuracy in the assessment of some clinical entities from inflammatory bowel disease to rectal carcinoma, its role needs to be consolidated in many other conditions. Moreover, different technical methods can be applied for colonic evaluation depending on the specific disease and segment involved. This article aims to provide a thorough overview of the techniques that can be utilized in the evaluation of the large bowel and a discussion on the major findings in different colonic pathologies of primary interest.

Imaging Modalities for Evaluation of Intestinal Obstruction

It is essential for the colon and rectal surgeon to understand the evaluation and management of patients with both small and large bowel obstructions. Computed tomography is usually the most appropriate and accurate diagnostic imaging modality for most suspected bowel obstructions. Additional commonly used imaging modalities include plain radiographs and contrast imaging/fluoroscopy, while less commonly utilized imaging modalities include ultrasonography and magnetic resonance imaging. Regardless of the imaging modality used, interpretation of imaging should involve a systematic, methodological approach to ensure diagnostic accuracy.

The rare Ogilvie's Syndrome in pregnancy. How to manage? A case report and literature review

Acute colonic pseudo-obstruction, or Ogilvie's syndrome (OS), is a complication in gynaecology and obstetrics. Its occurrence during pregnancy is rare, redefining the therapeutic decision-making and treatment options. In this review we describe the case of a 37-year-old pregnant patient who developed OS at the 30th week of gestation. A laparotomy with colonic decompression was performed. Foetal condition, regularly monitored throughout the hospital stay, remained normal. The patient experienced an uncomplicated, natural delivery at 40 weeks. A comprehensive literature search, describing the occurrence of OS during pregnancy, was conducted. We identified six cases of OS arising during pregnancy. Demographic, clinical, diagnostic and therapeutic features were analysed. Non-surgical management is generally the first-line option, with intravenous drug administration, rectal and nasogastric tube positioning and colonoscopic decompression the treatments of choice. Surgical decompression in usually performed in cases of failure of the first-line treatments. Including our own experience, in all cases, neither maternal nor foetal mortality was reported. A conservative approach is mandatory as first-line treatment, but when prompt resolution is not achieved, a multidisciplinary team, involving the gynaecologist/obstetrician, the surgeon, the radiologist and the intensivist is mandatory to avoid diagnostic delays, thereby reducing morbidity and mortality rates.

Small Bowel Obstruction: the Sun Also Rises?

Small bowel obstruction (SBO) remains a common reason for emergency/unplanned admissions, and remains a significant burden to SBO patients and the healthcare system alike. The management of SBO has undergone a significant paradigm shift over the years, shifting far from the tenet to "never let the sun rise on a bowel obstruction." Not only has the timing to surgery changed, but there is also an increased utilization of diagnostic tools to aid clinical decision-making. Furthermore, the surgical management is beginning to favor a less invasive approach. This review will serve to provide an up-to-date review of the evaluation and management of SBO, based on the most recent available evidence and our experience with the methods described.

Adhesive Small Bowel Obstruction: Predictive Radiology to Improve Patient Management

Adhesive small bowel obstruction (SBO) remains one of the leading causes of emergency room visits and is still associated with high morbidity and mortality rates. Because the management of adhesive SBO has shifted from immediate surgery to nonoperative treatment in the absence of ischemia, it is crucial to rapidly detect or predict strangulation, which requires emergent surgery. CT is now established as the best imaging technique for the initial assessment of patients suspected of having adhesive SBO. CT helps confirm the diagnosis of mechanical SBO, locate the site of obstruction, establish the cause, and detect complications. This article is a review of the role of imaging in answering specific questions to help predict the management needs of each individual patient. It includes (a) an update on the best CT signs for predicting ischemia and a need for bowel resection; (b) a discussion of the CT features that help differentiate open-loop from closed-loop obstruction and a single adhesive band from matted adhesions and how these differences can influence the management; and (c) a review of the main CT predictors of the success or failure of nonoperative management in adhesive SBO.

Bowel obstruction: a narrative review for all physicians

Small and large bowel obstructions are responsible for approximately 15% of hospital admissions for acute abdominal pain in the USA and ~ 20% of cases needing acute surgical care. Starting from the analysis of a common clinical problem, we want to guide primary care physicians in the initial management of a patient presenting with acute abdominal pain associated with intestinal obstruction.

Dual-phase computed tomography angiography of intestinal carcinoid tumor as a lead point for cecocolic intussusception in a dog

In an 8-year-old Labrador Retriever with progressive anorexia, constipation, and depression, CT revealed intussusception of the cecum into the ascending colon and a small cecal mass showing strong enhancement on arterial phase. The ileocecocolic junction was surgically resected and histologically diagnosed as cecocolic intussusception with carcinoid tumor. The carcinoid tumor worked as a lead point of intussusception in this case. Dual phasic CT is useful to assess the presence of gastrointestinal tumors as lead points in old dogs with intussusception.

Emergency Medicine Evaluation and Management of Small Bowel Obstruction: Evidence-Based Recommendations

BACKGROUND

Small bowel obstruction (SBO) is a commonly diagnosed disease in the emergency department (ED). Recent literature has evaluated the ED investigation and management of SBO.

OBJECTIVE

This review evaluates the ED investigation and management of adult SBO based on the current literature.

DISCUSSION

SBO is most commonly due to occlusion of the small intestine, resulting in fluid and gas accumulation. This may progress to mucosal ischemia, necrosis, and perforation. A variety of etiologies are present, but in adults, adhesions are the most common cause. Several classification systems are present. However, the most important distinction is complete vs. partial and complicated vs. simple obstruction, as complete complicated SBO more commonly requires surgical intervention. History and physical examination can vary, but the most reliable findings include prior abdominal surgery, history of constipation, abdominal distension, and abnormal bowel sounds. Signs of strangulation include fever, hypotension, diffuse abdominal pain, peritonitis, and several others. Diagnosis typically requires imaging, and though plain radiographs are often ordered, they cannot exclude the diagnosis. Computed tomography and ultrasound are reliable diagnostic methods. Management includes intravenous fluid resuscitation, analgesia, and determining need for operative vs. nonoperative therapy. Nasogastric tube is useful for patients with significant distension and vomiting by removing contents proximal to the site of obstruction. Surgery is needed for strangulation and those that fail nonoperative therapy. Surgical service evaluation and admission are recommended.

CONCLUSION

SBO is a common reason for admission from the ED. Knowledge of recent literature can optimize diagnosis and management.

[Minimally invasive treatment of rare forms of mechanical intestinal obstruction]

AIM

To develop medical algorithms for reduction of morbidity and mortality in rare forms of mechanical intestinal obstruction.

MATERIAL AND METHODS

17 patients with mechanical intestinal obstruction have been operated in Sklifosovsky Research Institute for Emergency Care for the period 2010 - 2016. There were 13 women and 4 men aged 56 (44,5-74,5) years on the average. Phytobezoar was detected in 7 patients (41.2%), tumor in 7 patients (41.2%) and gallstone ileus in 3 patients (17.6%).

RESULTS

There were no complications in group 1. In group 2 postoperative complications occurred in 3 patients: gastrocnemius vein thrombosis followed by successful medication (Clavien-Dindo type II), abdominal abscess drained under ultrasonic control (Clavien-Dindo type IIIa) and 1 (8.3%) death (Clavien-Dindo type V). Postoperative mortality in group 2 was 8.3%.

CONCLUSION

Despite small sample size and no statistically reliable results the advantages of minimally invasive access are obvious. However, further trials are required to ensure the reliability of the results.

MRI of the Nontraumatic Acute Abdomen: Description of Findings and Multimodality Correlation

Obtaining a specific diagnosis in the nontraumatic acute abdomen can be clinically challenging, because a wide range of disease processes affecting a number of different organ systems may have very similar presentations. Although computed tomography and ultrasound examination are the imaging tests most commonly used to evaluate the acute abdomen, MRI can often offer comparable diagnostic performance, and may be considered when other modalities are equivocal, suboptimal, or contraindicated. In some circumstances, MRI is emerging as an appropriate first-line imaging test.

A Novel Diagnostic Aid for Detection of Intra-Abdominal Adhesions to the Anterior Abdominal Wall Using Dynamic Magnetic Resonance Imaging

Introduction. Abdominal adhesions can cause serious morbidity and complicate subsequent operations. Their diagnosis is often one of exclusion due to a lack of a reliable, non-invasive diagnostic technique. Development and testing of a candidate technique are described below. Method. During respiration, smooth visceral sliding motion occurs between the abdominal contents and the walls of the abdominal cavity. We describe a technique involving image segmentation and registration to calculate shear as an analogue for visceral slide based on the tracking of structures throughout the respiratory cycle. The presence of an adhesion is attributed to a resistance to visceral slide resulting in a discernible reduction in shear. The abdominal movement due to respiration is captured in sagittal dynamic MR images. Results. Clinical images were selected for analysis, including a patient with a surgically confirmed adhesion. Discernible reduction in shear was observed at the location of the adhesion while a consistent, gradually changing shear was observed in the healthy volunteers. Conclusion. The technique and its validation show encouraging results for adhesion detection but a larger study is now required to confirm its potential.

[Modern MRI of the small bowell]

CLINICAL METHODOLOGICAL ISSUES

The radiological diagnostics of diseases of the small intestine have undergone a great change in the last two decades. Through rapid progress with new treatments and an increasing therapeutic focus on transmural healing, a complete evaluation of the gastrointestinal tract is now crucial.

STANDARD RADIOLOGICAL METHODS

With the introduction of endoscopy, gastrointestinal imaging with a relatively high radiation exposure had only limited applications. The development of cross-sectional imaging allowed a much broader radiological evaluation of abdominal diseases. Due to rapid investigation techniques, excellent soft tissue contrast and the distinct advantage of eliminating exposure to radiation, magnetic resonance imaging (MRI) of the gastrointestinal tract has gained increasing importance. With sufficient filling of the intestinal lumen, simultaneous imaging of all the intestinal wall layers, the perienteric structures and associated abdominal pathologies is now possible.

METHODOLOGICAL INNOVATIONS

New MR sequences, such as diffusion-weighted sequences, dynamic contrast-enhanced sequences and MR fluoroscopy, enable the detection of morphological changes, with additional characterization of affected bowel loops as well as the assessment of functional pathologies with dynamic information about intestinal motility disturbances.

ACHIEVEMENTS

Recent guidelines of European radiological and gastroenterological organizations have confirmed the importance of cross-sectional imaging and particularly of MRI for diagnostics and follow-up in patients with Crohn's disease. Due to the possibility of assessment of all the layers of the intestinal wall and the presence of extramural complications, MRI has a significant impact on further therapeutic treatment in patients with inflammatory bowel disease.

PRACTICAL RECOMMENDATIONS

Especially in patients with inflammatory bowel disease, MR enterography and MR enteroclysis should be the methods of choice for the evaluation of small bowel pathologies because of radiation issues and the great diagnostic value they provide. A variety of MR sequences has enabled not only the detection but also the characterization of pathological changes of the small intestine, which are vital for further treatment of these patients.

Vanek’s tumor of the small bowel in adults

Inflammatory fibroid polyps (IFPs), or Vanek’s tumor, are one of the least common benign small bowel tumors. IFP affects both sexes and all age groups, with a peak of incidence in the fifth and seventh decades. They can be found throughout the gastrointestinal tract but most commonly in the gastric antrum or ileum. The underlying cause of IFPs is still unknown. Genetic study of IFP showed mutations in platelet derived growth factor alpha in some cases. At the time of diagnosis most IFPs have a diameter of 3 to 4 cm. The lesions have always been recorded as solitary polyps. Symptoms depend on the location and the size of the lesion, including abdominal pain, vomiting, altered small bowel movements, gastrointestinal bleeding and loss of weight. IFPs arising below the Treitz ligament can present with an acute abdomen, usually due to intussusceptions. Abdominal computed tomography is currently considered the most sensitive radiological method to show the polyp or to confirm intussusceptions. Most inflammatory fibroid polyps can be removed by endoscopy. Surgery is rarely needed. Exploratory laparoscopy or laparotomy is frequently recommended as the best treatment for intussusceptions caused by IFP. The operation should be performed as early as possible in order to prevent the intussusceptions from leading to ischemia, necrosis and subsequent perforation of the invaginated bowel segment. This report aims at reviewing the diagnosis, etiology, genetics, clinical presentation, endoscopy, radiology, and best treatment of IFP.

Magnetic resonance imaging of acute abdominal and pelvic pain in pregnancy

Evaluation of acute abdominal and pelvic pain in pregnancy presents a diagnostic challenge for clinicians and radiologists alike. The differential diagnosis includes obstetric and nonobstetric conditions unique to pregnancy, in addition to causes of acute abdominal and pelvic pain unrelated to the pregnancy. The clinical presentation and course of disease may be altered in pregnancy, and several pathologies are exacerbated by pregnancy. Discriminating clinical features in the diagnosis of abdominal and pelvic pain are often confounded by expected anatomic and physiologic changes in pregnancy. Moreover, while diagnostic pathways may be altered in pregnancy, the necessity for a timely and accurate diagnosis must be underscored, as delay in treatment may result in an undesirable increase in morbidity and/or mortality for both the patient and fetus. Advances in magnetic resonance imaging (MRI) through faster acquisition and motion-insensitive techniques, coupled with increased awareness and education regarding the value of MRI in diagnosing a wide range of pathology, have established MRI as a valuable strategy in the investigation of acute abdominal and pelvic pain in the pregnant patient. This review presents a practical approach to common obstetric and nonobstetric causes of acute abdominal and pelvic pain during pregnancy, as well as safety considerations for performing MRI in this patient population.

Value of the patency capsule in pre-evaluation for capsule endoscopy in cases of intestinal obstruction

OBJECTIVE

Patency capsule (PC) is a tool to screen the patency of the gastrointestinal (GI) tract. Capsule endoscopy can be performed after the patency is confirmed by the patency capsule. We aimed to estimate the diagnostic value of PC based on the existing trials.

METHODS

We searched PubMed, CENTRAL and EMBASE for studies that included patients with suspected small bowel stricture who were evaluated by both PC and a reference standard (following capsule endoscopy and/or surgical pathology and/or endoscopic findings) and who were eligible for inclusion. The quality of the eligible studies was assessed using the Quality Assessment for Diagnostic Accuracy Studies-2 criteria. Sensitivity, specificity, likelihood ratios and the area under the receiver operating characteristic curve (AUROC) were calculated.

RESULTS

Five studies including 203 patients fulfilled the eligibility criteria. The pooled data showed a PC sensitivity of 97% (95% CI 93-99%) and a specificity of 83% (95% CI 65-94%). The AUROC was 0.9557.

CONCLUSIONS

PC may be of diagnostic value in confirming the patency of the GI tract before capsule endoscopy. The routine use of PC might eliminate the contraindication of capsule endoscopy in many cases of intestinal obstruction.

Evolving role of MRI in Crohn's disease

MR enterography is playing an evolving role in the evaluation of small bowel Crohn's disease (CD). Standard MR enterography includes a combination of rapidly acquired T2 sequence, balanced steady-state acquisition, and contrast enhanced T1-weighted gradient echo sequence. The diagnostic performance of these sequences has been shown to be comparable, and in some respects superior, to other small bowel imaging modalities. The findings of CD on MR enterography have been well described in the literature. New and emerging techniques such as diffusion-weighted imaging (DWI), dynamic contrast enhanced MRI (DCE-MRI), cinematography, and magnetization transfer, may lead to improved accuracy in characterizing the disease. These advanced techniques can provide quantitative parameters that may prove to be useful in assessing disease activity, severity, and response to treatment. In the future, MR enterography may play an increasing role in management decisions for patients with small bowel CD; however, larger studies are needed to validate these emerging MRI parameters as imaging biomarkers.

Adult small bowel obstruction

BACKGROUND

Small bowel obstruction (SBO) is a clinical condition that is often initially diagnosed and managed in the emergency department (ED). The high rates of potential complications that are associated with an SBO make it essential for the emergency physician (EP) to make a timely and accurate diagnosis.

OBJECTIVES

The primary objective was to perform a systematic review and meta-analysis of the history, physical examination, and imaging modalities associated with the diagnosis of SBO. The secondary objectives were to identify the prevalence of SBO in prospective ED-based studies of adult abdominal pain and to apply Pauker and Kassirer's threshold approach to clinical decision-making to the diagnosis and management of SBO.

METHODS

MEDLINE, EMBASE, major emergency medicine (EM) textbooks, and the bibliographies of selected articles were scanned for studies that assessed one or more components of the history, physical examination, or diagnostic imaging modalities used for the diagnosis of SBO. The selected articles underwent a quality assessment by two of the authors using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Data used to compile sensitivities and specificities were obtained from these studies and a meta-analysis was performed on those that examined the same historical component, physical examination technique, or diagnostic test. Separate information on the prevalence and management of SBO was used in conjunction with the meta-analysis findings of computed tomography (CT) to determine the test and treatment threshold.

RESULTS

The prevalence of SBO in the ED was determined to be approximately 2% of all patients who present with abdominal pain. Having a previous history of abdominal surgery, constipation, abnormal bowel sounds, and/or abdominal distention on examination were the best history and physical examination predictors of SBO. X-ray was determined to be the least useful imaging modality for the diagnosis of SBO, with a pooled positive likelihood ratio (+LR) of 1.64 (95% confidence interval [CI] = 1.07 to 2.52). On the other hand, CT and magnetic resonance imaging (MRI) were both quite accurate in diagnosing SBO with +LRs of 3.6 (5- to 10-mm slices, 95% CI = 2.3 to 5.4) and 6.77 (95% CI = 2.13 to 21.55), respectively. Although limited to only a select number of studies, the use of ultrasound (US) was determined to be superior to all other imaging modalities, with a +LR of 14.1 (95% CI = 3.57 to 55.66) and a negative likelihood ratio (-LR) of 0.13 (95% CI = 0.08 to 0.20) for formal scans and a +LR of 9.55 (95% CI = 2.16 to 42.21) and a -LR of 0.04 (95% CI = 0.01 to 0.13) for beside scans. Using the CT results of the meta-analysis for the 5- to 10-mm slice subgroup as well as information on intravenous (IV) contrast reactions and nasogastric (NG) intubation management, the pretest probability threshold for further testing was determined to be 1.5%, and the pretest probability threshold for beginning treatment was determined to be 20.7%.

CONCLUSIONS

The potentially useful aspects of the history and physical examination were limited to a history of abdominal surgery, constipation, and the clinical examination findings of abnormal bowel sounds and abdominal distention. CT, MRI, and US are all adequate imaging modalities to make the diagnosis of SBO. Bedside US, which can be performed by EPs, had very good diagnostic accuracy and has the potential to play a larger role in the ED diagnosis of SBO. More ED-focused research into this area will be necessary to bring about this change.

Small Bowel Imaging: Clinical Applications of the Different Imaging Modalities—A Comprehensive Review

In the last years, MR and CT techniques have been optimized for small bowel imaging and are playing an increasing role in the evaluation of small bowel disorders. In comparison to traditional barium fluoroscopic examinations, spatial and temporal resolution is now much more improved partially thanks to modern bowel distending agents. However, there is a global interest in implementing techniques that either reduce or eliminate radiation exposure. This is especially important in patients with chronic diseases such as inflammatory bowel disease who may require multiple studies over a lifetime. Owing to the excellent soft tissue contrast, direct multiplanar imaging capabilities, new ultrafast breath-holding pulse sequences, lack of ionizing radiation, and availability of a variety of oral contrast agents, MR is well suited to play a critical role in the imaging of small bowel disorders.

Evaluation and management of small-bowel obstruction: an Eastern Association for the Surgery of Trauma practice management guideline

BACKGROUND

Small-bowel obstruction (SBO) represents as many as 16% of surgical admissions and more than 300,000 operations annually in the United States. The optimal strategies for the diagnosis and management of SBO continue to evolve secondary to advances in imaging techniques, critical care, and surgical techniques. This updated systematic literature review was developed by the Eastern Association for the Surgery of Trauma to provide up-to-date evidence-based recommendations for SBO.

METHODS

A search of the National Library of Medicine MEDLINE database was performed using PubMed interface for articles published from 2007 to 2011.

RESULTS

The search identified 53 new articles that were then combined with the 131 studies previously reviewed by the 2007 guidelines. The updated guidelines were then presented at the 2012 annual EAST meeting.

CONCLUSION

Level I evidence now exists to recommend the use of computed tomographic scan, especially multidetector computed tomography with multiplanar reconstructions, in the evaluation of patients with SBO because it can provide incremental clinically relevant information over plains films that may lead to changes in management. Patients with evidence of generalized peritonitis, other evidence of clinical deterioration, such as fever, leukocytosis, tachycardia, metabolic acidosis, and continuous pain, or patients with evidence of ischemia on imaging should undergo timely exploration. The remainder of patients can safely undergo initial nonoperative management for both partial and complete SBO. Water-soluble contrast studies should be considered in patients who do not clinically resolve after 48 to 72 hours for both diagnostic and potential therapeutic purposes. Laparoscopic treatment of SBO has been demonstrated to be a viable alternative to laparotomy in selected cases.

MR imaging of the small bowel

Small-bowel radiology has undergone dramatic changes in the past 2 decades. Despite important recent advances in small-bowel endoscopy, radiologic imaging remains important for patients suspected of having or with established small-bowel disease. Cross-sectional imaging techniques (computed tomography and magnetic resonance [MR] imaging), used to investigate both extraluminal abnormalities and intraluminal changes, have gradually replaced barium contrast examinations, which are, however, still used to examine early mucosal disease. MR imaging techniques clearly highlight endoluminal, mural and extramural enteric details and provide vascular and functional information, thereby enhancing the diagnostic value of these techniques in small-bowel diseases. Two MR imaging based techniques are currently utilized: MR enteroclysis and MR enterography. In enteroclysis, enteric contrast material is administered through a nasoenteric tube, whereas in enterography, large volumes of enteric contrast material are administered orally. MR enteroclysis ensures consistently better luminal distention than does MR enterography in both the jejunum and the ileum and more accurately depicts endoluminal abnormalities and early disease, particularly at the level of the jejunal loops. Moreover, MR enteroclysis provides a high level of accuracy in the diagnosis and exclusion of small-bowel inflammatory and neoplastic diseases and can be used for the first radiologic evaluation, while MR enterography may effectively be used to follow up both Crohn disease patients without jejunal disease and in pediatric patients where nasogastric intubation might be a problem. MR enteroclysis may also reveal subtle transition points or an obstruction in the lower small bowel, which may escape detection when more routine methods, including enterography, are used. MR imaging offers detailed morphologic information and functional data of small-bowel diseases and provides reliable evidence of normalcy, thereby allowing the diagnosis of early or subtle structural abnormalities and guiding treatment and decisions in patient care.

A rare case of small bowel volvulus after jenjunoileal bariatric bypass requiring emergency surgery: a case report

Introduction

Bariatric surgery is on the increase throughout the world. Jejunoileal bypass bariatric procedures have fallen out of favor in western surgical centers due to the high rate of associated complications. They are, however, performed routinely in other centers and as a consequence of health tourism, management of complications related to these procedures may still be encountered.

Case presentation

We describe a rare case of small bowel obstruction in a 45-year-old British Caucasian woman, secondary to a volvulus of the jejunoileal anastomosis following bariatric bypass surgery. The pre-operative diagnosis was confirmed by radiology. We describe a successful surgical technique for this rare complication.

Conclusions

Bariatric surgery may be complicated by bowel obstruction. Early imaging is vital for diagnosis and effective management. The use of our surgical technique provides a simple and effective approach for the successful management of this bariatric complication.

Adult intussusception of the descending colon due to inflammatory myofibroblastic proliferation

We present a case of an asymptomatic 70-year-old man with intussusception of the descending colon due to inflammatory myofibroblastic proliferation. Abdominal ultrasound examination showed a hypoechoic mass, 32 × 19 mm in size, accompanied by intussusception in the descending colon, and power Doppler sonography detected blood flow signals in the mass. Computed tomography revealed a hypervascular lesion, which was confirmed by barium enema and colonoscopy. The surgically excised mass was histologically diagnosed as inflammatory myofibroblastic proliferation. Although intussusception due to inflammatory myofibroblastic proliferation is rare, it should be considered in cases of adult colonic intussusception.

Malignant bowel obstruction in advanced cancer patients: epidemiology, management, and factors influencing spontaneous resolution

Malignant bowel obstruction (MBO) is a frequent complication in advanced cancer patients, especially in those with abdominal tumors. Clinical management of MBO requires a specific and individualized approach that is based on disease prognosis and the objectives of care. The global prevalence of MBO is estimated to be 3% to 15% of cancer patients. Surgery should always be considered for patients in the initial stages of the disease with a preserved general status and a single level of occlusion. Less invasive approaches such as duodenal or colonic stenting should be considered when surgery is contraindicated in obstructions at the single level. The priority of care for inoperable and consolidated MBO is to control symptoms and promote the maximum level of comfort possible. The spontaneous resolution of an inoperable obstructive process is observed in more than one third of patients. The mean survival is of no longer than 4-5 weeks in patients with consolidated MBO. Polymodal medical treatment based on a combination of glucocorticoids, strong opioids, antiemetics, and antisecretory drugs achieves very high symptomatic control. This review focuses on the epidemiological aspects, diagnosis, surgical criteria, medical management, and factors influencing the spontaneous resolution of MBO in advanced cancer patients.

Diagnostic accuracies of MR enterography and CT enterography in symptomatic Crohn's disease

OBJECTIVE

In patients, with symptomatic Crohn's disease (CD), valid information about the presence or absence of small bowel disease activity and stenosis is clinically important. Such information supports decisions about medical or surgical therapy and can be obtained with MR enterography (MRE) or CT enterography (CTE).

MATERIALS AND METHODS

A total of 50 patients with symptomatic pre-existing CD and a demand for small bowel imaging to support changes in treatment strategy were included in this prospective and blinded study. MRE and CTE were performed on the same day in alternating order and subsequently compared with the gold standard: pre-defined lesions at ileoscopy (n = 30) or surgery with (n = 12) or without (n = 3) intra-operative enteroscopy.

RESULTS

A total of 35 patients had active small bowel CD (jejunum 0, ileum 1, (neo)-terminal ileum 34) and 20 had small bowel stenosis. The sensitivity and specificity of MRE for detection of small bowel CD was 74% and 80% compared to 83% and 70% with CTE (p ≥ 0.5). MRE and CTE detected small bowel stenosis with 55% and 70% sensitivities, respectively (p = 0.3) and 92% specificities.

CONCLUSIONS

MRE and CTE have comparable diagnostic accuracies for detection of small bowel CD and stenosis. In symptomatic patients with CD and high disease prevalence, positive predictive values are favorable but negative predictive values are low. Consequently, MRE and CTE can be relied upon, if a positive result is obtained whereas a negative enterography should be interpreted with caution.

Adult intussusception in the last 25 years of modern imaging: is surgery still indicated?

BACKGROUND

Because most adult intussusceptions are reportedly due to malignancy, operative treatment is recommended. With current availability of computed tomography, we questioned the role of mandatory operative exploration for all adult intussusceptions.

METHODS

This study is a retrospective review of all adults treated from 1983 to 2008 at a large tertiary referral center for intussusception.

RESULTS

One hundred ninety-six patients had intussusception over the 25-year study period. Computed tomography was obtained in 60% of patients. Neoplasms [malignant, (21%); benign, (24%)] were the commonest etiology; 30% cases were idiopathic. One hundred twenty (61%) patients underwent operative treatment for intussusception. Six of the 58 idiopathic or asymptomatic cases were operated on with negative findings in all. Palpable mass (OR 4.56, p < 0.035), obstructive symptoms (OR 9.13, p < 0.001) or obstruction (OR 9.67, p < 0.001), GI bleeding (OR 14.41, p < 0.001), and a lead point on computed tomography (OR 10.08, p < 0.001) were associated with the need for operation.

CONCLUSION

In the current era of computed tomography, idiopathic or asymptomatic intussusception is being seen more commonly; however, the majority of adult intussusceptions still have pathologic lead points. From our experience, all patients with palpable mass, obstructive symptoms or obstruction, gastrointestinal bleeding, or a lead point on computed tomography should undergo operative exploration.

Low b-value diffusion-weighted imaging for diagnosing strangulated small bowel obstruction: a feasibility study

PURPOSE

To assess the feasibility of low b-value diffusion-weighted imaging (DWI) for diagnosing strangulated small bowel obstruction (SBO).

MATERIALS AND METHODS

Five volunteers and 14 patients with SBO underwent DWI at b-values of 0 and 50 s/mm(2). Apparent diffusion coefficients (ADCs) and signal preservation ratios (SPRs) were measured in the distal jejunum in the volunteers before and after butylscopolamine administration, and in the (strangulated) closed loop, near the obstructive site, and far from the obstructive site in the patients. Low b-value diffusion-weighted images in the patients were quantitatively evaluated for diagnosing strangulation.

RESULTS

In the volunteers, mean ADC (10(-3) mm(2)/s) and SPR (%) before butylscopolamine administration (18.3 ± 5.9 and 41.4 ± 11.5) were significantly different (P < 0.05) from those after butylscopolamine administration (6.4 ± 3.6 and 73.7 ± 12.9). In the patients, mean ADCs and SPRs among the strangulated closed loop (3.8 ± 2.2 and 83.3 ± 9.3), near the obstructive site (12.1 ± 6.9 and 57.3 ± 18.5), and far from the obstructive site (26.8 ± 10.7 and 29.9 ± 16.4) were significantly different (P < 0.05). Areas under the receiver operating characteristic curve for the diagnosis of strangulation varied between 0.937 and 1.000.

CONCLUSION

Low b-value DWI is a feasible technique to distinguish the strangulated closed loop from nonstrangulated loops in SBO, and show promise for diagnosing strangulated SBO.

Bowel obstruction and hernia

Bowel obstruction and abdominal hernia are commonly observed in patients seeking emergency care for abdominal pain. This article discusses bowel obstruction, adynamic ileus, acute colonic pseudo-obstruction, and abdominal hernias, with particular emphasis on the management of patients in the emergency department (ED). Although the diagnostic approach to bowel obstruction often requires imaging, abdominal hernia may be identified in most circumstances by history and physical examination alone. Urgent surgical consultation is indicated when there is a concern for bowel ischemia, strangulation, or complete obstruction. This article reviews an ED-based approach to the patient presenting with symptoms of bowel obstruction or hernia.

Ileal Intussusception Caused by Vanek's Tumor: A Case Report

Inflammatory fibroid polyps (Vanek's tumor) are rare benign localized lesions originating in the submucosa of the gastrointestinal tract. Intussusceptions due to inflammatory fibroid polyps are uncommon; moreover, ileo-ileal intussusception with small bowel necrosis and perforation has rarely been reported. We report a 56-year-old woman who was admitted two days after complaints of nausea and vomiting. Abdominal examination revealed distension, signs of gastrointestinal perforation and clanging intestinal sounds. The patient underwent a emergency laparotomy which found a 17-cm invaginated mid-ileal segment with necrosis, perforation and fecal peritonitis. The ileal segment was resected and single-layer end-to-end anastomosis was performed. Histopathological analysis showed an ulcerative lesion with variable cellularity, formed by spindle cells with small number of mitosis and an abundant inflammatory infiltrate comprising mainly eosinophils. Immunohistochemistry confirmed the diagnosis of ileal Vanek's tumor. Although inflammatory fibroid polyps are seen very rarely in adults, they are among the probable diagnoses that should be considered in obstructive tumors of the small bowel causing intussusception with intestinal necrosis and perforation.

Strategies for diagnosis and treatment of small bowel obstruction

Small bowel obstruction, which is caused by a variety of etiological factors and mainly manifests as abdominal pain, vomiting and distension, is one of the most common acute abdomens. A rapid and accurate diagnosis of small bowel obstruction is needed to give reasonable and effective treatment to avoid its rapid deterioration. In this paper we discuss the strategies for diagnosis and treatment of small bowel obstruction through comparing different imaging methods for diagnosis of small bowel obstruction and reviewing the current situation of diagnosis and treatment of the disease in terms of pharmacotherapy, gastrointestinal decompression, and surgical intervention.

Magnetic resonance imaging for the evaluation of acute abdominal pain in pregnancy

The investigation of acute abdominal pain in pregnancy is challenging. The use of ultrasound may be limited due to the patient's change in body habitus and computed tomography is not desirable due to fetal irradiation. Magnetic resonance imaging (MRI) has thus become increasingly popular in the evaluation of such patients, due to its lack of ionizing radiation, multiplanar capability and high contrast resolution. This review will detail the MRI technique required to image the pregnant abdomen and describe the MRI features of common causes of acute abdominal pain in pregnancy.

MR imaging of the small bowel

Cross-sectional imaging techniques are playing an increasing role in the evaluation of suspected small-bowel disorders, and a growing awareness of the risks of ionizing radiation exposure has prompted the exploration of alternative imaging techniques. Advantages of magnetic resonance (MR) imaging include a lack of ionizing radiation, the ability to provide dynamic information regarding bowel distention and motility, improved soft-tissue contrast, and a relatively safe intravenous contrast agent profile. Limitations of MR imaging include cost, imager access, variability in examination quality, and lower spatial and temporal resolution compared with those of computed tomography (CT). MR imaging of the small bowel is indicated for patients with Crohn disease, those for whom exposure to radiation is a concern, those with contraindications to CT, and those with low-grade small-bowel obstruction. MR imaging may be performed with enterography or enteroclysis. In enterography, large volumes of fluid are ingested. Several different contrast agents may be used. These agents are classified according to their signal intensity on T1- and T2-weighted images. In enteroclysis, enteric contrast material is administered through a nasoenteric tube. Crohn disease is the primary indication for MR imaging of the small bowel because many patients require multiple follow-up examinations. Findings suggestive of active inflammation include bowel wall thickening and hyperenhancement, ulcerations, increased mesenteric vascularity, and perienteric inflammation. Complications are well depicted and may include penetrating disease and small-bowel obstruction.

Assessment of appropriateness of indications for CT enterography in younger patients

BACKGROUND

The small potential risk of radiation-induced cancer is increased in younger patients undergoing serial imaging with computed tomography enterography (CTE). We sought to determine the appropriateness of CTEs based on clinical indication in patients < or =35 years old, and the potential impact of evolution of practice to alternative magnetic resonance enterography (MRE).

METHODS

Over a 7-year period, the medical records of all patients < or =35 years old undergoing CTE were reviewed to determine the clinical indications for each CTE exam. An interdisciplinary consensus panel evaluated the appropriateness of all CTE exams based on American College of Radiology appropriateness criteria and peer-reviewed literature, classifying indications into "appropriate" or "inappropriate." For repeat CTEs, an "alternative MRE suggested" pathway was created. Criteria for evolution of practice to "alternative MRE" were suspicion of obstruction and evaluation of disease activity/therapeutic response in the absence of new symptoms.

RESULTS

In all, 2022 patients < or =35 years old underwent 2295 CTEs. Ninety-nine percent (2008/2022) of first-time CTE exams were "appropriate" by the defined criteria. A total of 197 patients (9.7%) underwent multiple exams, with 73% of these patients having Crohn's disease. Repeat exams occurred in 9% (18/197) with obstructive symptoms and evaluation of disease activity/therapeutic response in the absence of new symptoms in 41% (80/197).

CONCLUSIONS

A multidisciplinary expert panel concluded that the vast majority of young patients underwent clinically appropriate first-time CTE exams. However, a shift in clinical practice to MRE appears warranted for approximately half of young patients undergoing repeat CTE examinations.