CT Enteroclysis

Computed tomographic enteroclysis with air and virtual enteroscopy: protocol and feasibility for small bowel evaluation

BACKGROUND AND AIMS

We describe our optimized protocol for computed tomographic enteroclysis using air as the contrast material and report an early assessment of its clinical performance.

METHODS

Thirty-one examinations of computed tomographic enteroclysis with air were performed in 30 patients in our hospital from September 2008 to September 2010. The volume of injected air and intra-intestinal pressure were monitored in 16 cases. The data were reviewed for ratios of successful whole small bowel depictions out of the total number of examinations for patients without stenosis. Efforts were made to confirm depicted abnormal findings when possible by other imaging techniques, intra-operative findings, histopathological findings, and subsequent history.

RESULTS

The injected air volume and final intra-intestinal pressure were 2925 ± 686 ml and 24.5 ± 7.1cm H₂O in cases without stenosis. In 19 examinations with anterograde air injection for patients without stenosis, whole small bowel depiction was achieved in 16 (84.2%). Computed tomographic enteroclysis with air was useful for detecting strictures (in Crohn's disease, malignant lymphoma, metastatic carcinoma), Meckel's diverticulum, and for excluding other obstructive conditions in ileus.

CONCLUSIONS

Computed tomographic enteroclysis with air has a potential to enable the exploration of the whole small bowel, thereby providing information of small bowel lesions that complements other techniques.

Crohn's disease imaging: a review

Crohn's disease is a chronic granulomatous inflammatory disease of the gastrointestinal tract, which can involve almost any segment from the mouth to the anus. Typically, Crohn's lesions attain segmental and asynchronous distribution with varying levels of seriousness, although the sites most frequently involved are the terminal ileum and the proximal colon. A single gold standard for the diagnosis of CD is not available and the diagnosis of CD is confirmed by clinical evaluation and a combination of endoscopic, histological, radiological, and/or biochemical investigations. In recent years, many studies have been performed to investigate the diagnostic potential of less invasive and more patient-friendly imaging modalities in the evaluation of Crohn's disease including conventional enteroclysis, ultrasonography, color-power Doppler, contrast-enhanced ultrasonography, multidetector CT enteroclysis, MRI enteroclysis, and 99mTc-HMPAO-labeled leukocyte scintigraphy. The potential diagnostic role of each imaging modality has to be considered in different clinical degrees of the disease, because there is no single imaging technique that allows a correct diagnosis and may be performed with similar results in every institution. The aim of this paper is to point out the advantages and limitations of the various imaging techniques in patients with suspected or proven Crohn's disease.

Recent advances in intestinal imaging

In recent years, advances in scanner technology and competition from other specialties have produced rapid changes in the way the intestines are imaged. MRI and CT scan along with the traditional enteroclysis examination have emerged at the forefront of intestinal imaging. Functional modalities such as diffusion and perfusion imaging are also changing the way tumors and inflammatory bowel diseases are evaluated. CT colonography is now a valid alterative to optical colonoscopy. Contrast-enhanced USG is being used for the assessment of inflammation and post-treatment changes. In this review, recent advances in intestinal imaging are described.

Computed tomography enteroclysis: a review

Computed tomography (CT) enteroclysis is being performed routinely for evaluation of suspected small bowel diseases. The availability of multidetector CT scanners has further increased the diagnostic yield of enteroclysis. There is excellent depiction of small bowel wall pathology on CT enteroclysis especially with use of negative enteric contrast. We discuss the CT enteroclysis technique and procedure along with the imaging spectrum of some common small bowel pathologies.

Outcomes after symptomatic capsule retention in suspected small bowel obstruction

BACKGROUND AND AIM

Capsule endoscopy (CE) has been proven to be a sensitive and a safe tool for the examination of the small bowel. However, careful patient selection is required to avoid complications, primarily capsule retention. The aims of this study were to evaluate the rate of capsule retention in patients with suspected chronic small bowel obstruction and to analyze the role and the impact of subsequent surgical intervention.

METHODOLOGY

Fifteen patients referred for CE with a clinical picture suggestive of chronic small bowel obstruction and with negative imaging studies were retrospectively analyzed.

RESULTS

Capsule retention occurred in three (20%) patients who developed symptoms of subacute obstruction and subsequently underwent surgery. Radiation enteritis, Crohn's disease, and an ileal tumor were demonstrated as the causes of the capsule retention in these patients. Surgical removal of the retained capsule was performed and the underlying small bowel disease was treated.

CONCLUSION

Capsule retention is a frequent complication of CE in patients with symptoms of chronic small bowel obstruction. Surgery, with the removal of the retained capsule, is proven to be beneficial in identifying the location of, and treating, the underlying disease in these patients.

Noninvasive imaging of the small bowel in Crohn's disease: the final frontier

The substantial morbidity and mortality associated with Crohn's disease underlines the importance of accurate assessment at presentation, during follow-up, when investigating complications, and when evaluating the response to therapeutic interventions. Accurate methods are required to quantify the severity and extent of disease.

Systematic review: the use of ultrasonography, computed tomography and magnetic resonance imaging for the diagnosis, assessment of activity and abdominal complications of Crohn's disease

BACKGROUND

Cross-sectional imaging techniques, including ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI), are increasingly used for evaluation of Crohn's disease (CD). Aim  To perform an assessment of the diagnostic accuracy of cross-sectional imaging techniques for diagnosis of CD, evaluation of disease extension and activity and diagnosis of complications, and to provide recommendations for their optimal use.

METHODS

Relevant publications were identified by literature search and selected based on predefined quality parameters, including a prospective design, sample size and reference standard. A total of 68 publications were chosen.

RESULTS

Ultrasonography is an accurate technique for diagnosis of suspected CD and for evaluation of disease activity (sensitivity 0.84, specificity 0.92), is widely available and non-invasive, but its accuracy is lower for disease proximal to the terminal ileum. MRI has a high diagnostic accuracy for the diagnosis of suspected CD and for evaluation of disease extension and activity (sensitivity 0.93, specificity 0.90), and is less dependent on the examiner and disease location compared with US. CT has a similar accuracy to MRI for assessment of disease extension and activity. The three techniques have a high accuracy for identification of fistulas, abscesses and stenosis (sensitivities and specificities >0.80), although US has false positive results for abscesses. As a result of the lack of radiation, US or MRI should be preferred over CT, particularly in young patients.

CONCLUSIONS

Cross-sectional imaging techniques have a high accuracy for evaluation of suspected and established CD, reliably measure disease severity and complications; they may offer the possibility to monitor disease progression.

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.

Malignant tumours of the small intestine: a review of histopathology, multidetector CT and MRI aspects

Small bowel neoplasms, including adenocarcinoma, carcinoid tumour, lymphoma and gastrointestinal stromal tumours, represent a small percentage of gastrointestinal cancers, yet are among those with the poorest prognosis compared with other gastrointestinal malignancies. Unclear clinical scenarios and difficult radiological diagnosis often delay treatment with negative effects on patient survival. Recently, multidetector CT (MDCT) and MRI have been introduced as feasible and accurate diagnostic techniques for the identification and staging of small bowel neoplasms. These techniques are gradually replacing conventional barium radiography as the tool of choice. However, the inherent technical and physiological challenges of small bowel imaging require a familiarity with patient preparation and scan protocols. Adequate knowledge of the histopathology and natural evolution of small bowel neoplasms is also important for differential diagnosis. The aim of this article is to review MDCT and MRI protocols for the evaluation of small bowel tumours and to provide a concise yet comprehensive guide to the most relevant imaging features relative to histopathology.

Comparison of neutral and positive enteral contrast media for MDCT enteroclysis

OBJECTIVE

To compare neutral and positive enteral contrast media for MDCT enteroclysis (MDCTE) in various small bowel diseases.

MATERIALS AND METHODS

40 patients with suspicion of small bowel diseases were divided randomly into two equal groups. In one group, water was used as neutral enteral contrast and in other group, 2% water soluble iodinated contrast was used as positive enteral contrast. All MDCTE were done on a 16-slice multidetector row CT unit. The findings of MDCTE were compared with the standards of reference.

RESULTS

There were 12 cases of abdominal tuberculosis (30%), 5 cases of bowel masses (12%), 4 cases of Crohn's disease (10%), 3 cases of small bowel adhesions (7%), 2 cases of midgut volvulus (5%), 2 cases of segmental enteritis (5%) and 12 of all cases (30%) were normal. There was no statistically significant difference between neutral and positive enteral contrast with regards to bowel distention, contrast reflux and evaluation of duodenum. Abnormal bowel wall enhancement was appreciated only with use of neutral enteral contrast (n=12). Evaluation of ileocaecal junction was possible in all 20 patients (100%) with positive enteral contrast but in only 17 patients (85%) with neutral enteral contrast. Overall sensitivity and specificity of MDCTE with use of neutral contrast medium (100 and 88% respectively) was greater for evaluation of small bowel diseases, when compared to MDCTE using positive enteral contrast medium (92.8 and 83.3% respectively).

CONCLUSIONS

Water is a good enteral contrast medium for MDCT enteroclysis examination and allows better evaluation of abnormal bowel wall enhancement. Ileocaecal junction evaluation is better with positive enteral contrast medium.

Gastrointestinal tract imaging in children: current techniques

Imaging of the gastrointestinal (GI) tract in children continues to evolve, with new techniques, both radiological and non-radiological, being added to the repertoire. This article provides a summary of current imaging techniques of the GI tract (primarily the upper GI tract) and the relationship between those techniques. It covers the upper GI series and other contrast studies, US, CT and MRI. Note is also made of the contribution now made by capsule endoscopy (CE). Abdominal emergency imaging is not covered in this article.

Imaging of malignant neoplasms of the mesenteric small bowel: new trends and perspectives

This article describes the recent advances in radiological imaging of malignant neoplasms of the mesenteric small bowel and provides an outline of new trends and perspectives that can be anticipated. The introduction of multidetector row technology, which allows the acquisition of submillimeter and isotropic voxels, has dramatically improved the capabilities of computed tomography in the investigation of the mesenteric small bowel. This technology combined with optimal filling of small bowel loops through the use of appropriate enteral contrast agents has markedly changed small bowel imaging. Computed tomography-enteroclysis, which is based on direct infusion of enteral contrast agent into the mesenteric small bowel through a naso-jejunal tube, provides optimal luminal distension. By contrast, computed tomography-enterography is based on oral administration of enteral contrast agent. These two techniques are now well-established ones for the detection and the characterization of small bowel neoplasms. During the same time, combining the advantages of unsurpassed soft tissue contrast and lack of ionizing radiation, magnetic resonance imaging has gained wide acceptance for the evaluation of patients with suspected small bowel neoplasms. Rapid magnetic resonance imaging sequences used in combination with specific enteral contrast agents generate superb images of the mesenteric small bowel so that magnetic resonance-enteroclysis and magnetic resonance-enterography are now considered as effective diagnostic tools for both the detection and the characterization of neoplasms of the mesenteric small bowel. Recent improvements in image post-processing capabilities help obtain realistic three-dimensional representations of tumors and virtual enteroscopic views of the small bowel that are useful for the surgeon and the gastroenteroenteologist to plan surgical or endoscopic interventions. Along with a better knowledge of the potential and limitations of wireless capsule endoscopy and new endoscopic techniques, these recent developments in radiological imaging reasonably suggest that substantial changes in the investigation of small bowel tumors may be anticipated in a near future, thus potentially create a new paradigm shift after standard small bowel follow-through study has been universally abandoned.

The role of nasoenteric intubation in the MR study of patients with Crohn's disease: our experience and literature review

PURPOSE

The aim of this study was to compare magnetic resonance (MR) enteroclysis with MR enterography to verify whether nasoenteric intubation in patients affected by Crohn's disease can provide supplementary information to that afforded by MR study of the small bowel.

MATERIALS AND METHODS

In a 12-month period, 40 patients (28 women and 12 men, mean age 35 years) affected by Crohn's disease underwent MR imaging. Distension of the small-bowel loops was obtained by administering polyethylene glycol: 15 patients were given the mixture by mouth (MR enterography), whereas the remaining 25 received it via nasoenteric intubation (MR enteroclysis). Our study protocol included morphological sequences taken before and after intravenous injection of contrast medium and real-time functional sequences. Accuracy criteria for the execution of the examinations were designed according to 11 bands.

RESULTS

Complete distension of the small-bowel loops was obtained in the 25 patients who underwent MR enteroclysis, with the additional advantage of a suitable assessment of those segments involved in the pathological process. This was not the case for the 15 patients who underwent MR enterography, because both the jejunum and the small-bowel loops appeared partially collapsed.

CONCLUSIONS

MR enteroclysis is the most effective technique for studying the small bowel in Crohn's disease, as it not only provides a suitable morphological assessment but also supplies functional information.

CT enterography with polyethylene glycol solution vs CT enteroclysis in small bowel disease

OBJECTIVE

The aim of the study is to compare CT enterography with polyethylene glycol solution (PEG-CT) with CT enteroclysis (CT-E) in patients with suspected small bowel disease.

METHODS

145 patients underwent abdominal contrast-enhanced 16-row multidetector CT after administration of 2000 ml of PEG by mouth (n = 75) or after administration of 2000 ml of methylcellulose by nasojejunal tube (n = 70). Small bowel distension, luminal and extraluminal findings were evaluated and compared with small bowel follow-through examination in 60 patients, double contrast enema in 50, surgery in 25 and endoscopy in 35. Statistical evaluation was carried out by χ² testing. For both techniques we have also calculated the effective dose and the equivalent dose in a standard patient.

RESULTS

Crohn's disease was diagnosed in 64 patients, neoplasms in 16, adhesions in 6. Distension of the jejunum was better with CT-E than PEG-CT (p<0.05: statistically significant difference). No significant difference was present for others sites (p>0.05). Evaluation of pathological ileal loops was good with both techniques. The values of sensitivity, specificity and diagnostic accuracy were respectively 94%, 100% and 96% with CT-E, and 93%, 94% and 93% with PEG-CT. The effective dose for PEG-CT was less than the dose for the CT-E (34.7 mSv vs 39.91 mSv).

CONCLUSION

PEG-CT shows findings of Crohn's disease as well as CT-E does, although CT-E gives better bowel distension, especially in the jejunum, and has higher specificity than PEG-CT.

MR enterographic manifestations of small bowel Crohn disease

Magnetic resonance (MR) enterography is a clinically useful technique for the evaluation of both intraluminal and extraluminal small bowel disease, particularly in younger patients with Crohn disease. MR enterography offers the advantages of multiplanar capability and lack of ionizing radiation. It allows evaluation of bowel wall contrast enhancement, wall thickening, and edema, findings useful for the assessment of Crohn disease activity. MR enterography can also depict other pathologic findings such as lymphadenopathy, fistula and sinus formation, abscesses, and abnormal fold patterns. Even subtle disease manifestations may be detected when adequate distention of the small bowel is achieved, although endoscopic and double-contrast barium small bowel techniques remain superior in the depiction of changes in early Crohn disease (eg, aphthoid ulceration). Further research will be needed to determine whether MR imaging enhancement patterns may reliably help discriminate between active and inactive disease.

Suspected anastomotic recurrence of Crohn disease after ileocolic resection: evaluation with CT enteroclysis

PURPOSE

To determine the utility of computed tomographic (CT) enteroclysis for characterization of the status of the anastomotic site in patients with Crohn disease who had previously undergone ileocolic resection.

MATERIALS AND METHODS

Written informed consent was prospectively obtained from all patients, and the institutional review board approved the study protocol. CT enteroclysis findings in 40 patients with Crohn disease who had previously undergone ileocolic resection were evaluated independently by two readers. Endoscopic findings, histopathologic findings, and/or the Crohn disease activity index was the reference standard. Interobserver agreement between the two readers was calculated with kappa statistics. Associations between CT enteroclysis findings and anastomotic site status were assessed at univariate analysis. The sensitivity, specificity, and accuracy of CT enteroclysis, with corresponding 95% confidence intervals (CIs), for the diagnosis of normal versus abnormal anastomosis and the diagnosis of anastomotic recurrence versus fibrostenosis were estimated.

RESULTS

Interobserver agreement regarding CT enteroclysis criteria was good to perfect (kappa = 0.72-1.00). At univariate analysis, stratification and anastomotic wall thickening were the two most discriminating variables in the differentiation between normal and abnormal anastomoses (P < .001). Stratification (P < .001) and the comb sign (P = .026) were the two most discriminating variables in the differentiation between anastomotic recurrence and fibrostenosis. In the diagnosis of anastomotic recurrence, severe anastomotic stenosis was the most sensitive finding (95% [20 of 21 patients]; 95% CI: 76.18%, 99.88%), both comb sign and stratification had 95% specificity (18 of 19 patients; 95% CI: 73.97%, 99.87%), and stratification was the most accurate finding (92% [37 of 40 patients]; 95% CI: 79.61%, 98.43%). In the diagnosis of fibrostenosis, both severe anastomotic stenosis and anastomotic wall thickening were 100% sensitive (eight of eight patients; 95% CI: 63.06%, 100.00%), and using an association among five categorical variables, including severe anastomotic stenosis, anastomotic wall thickening with normal or mild mucosal enhancement, absence of comb sign, and absence of fistula, yielded 88% sensitivity (seven of eight patients; 95% CI: 47.35%, 99.68%), 97% specificity (31 of 32 patients; 95% CI: 83.78%, 99.92%), and 95% accuracy (38 of 40 patients; 95% CI: 83.08%, 99.39%).

CONCLUSION

CT enteroclysis yields objective and relatively specific morphologic criteria that help differentiate between recurrent disease and fibrostenosis at the anastomotic site after ileocolic resection for Crohn disease.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.09091165/-/DC1.

CT enterography

Conventional radiologic and endoscopic evaluations of the small bowel are often limited by the length, caliber, and motility of the small bowel loops. The development of new multidetector-row CT scanners, with faster scan times and isotropic spatial resolution, allows high-resolution multiphasic and multiplanar assessment of the bowel, bowel wall, and lumen. CT Enterography (CTE) is a variant of routine abdominal scanning, geared toward more sustained bowel filling with oral contrast material, and the use of multiplanar images, that can enhance gastrointestinal (GI) tract imaging. This article examines the techniques and clinical applications of CTE in comparison with CT enteroclysis, focusing on Crohn disease, obscure GI bleeding, GI tumors, acute abdominal pain, and bowel obstruction.

Capsule retention: a feared complication of wireless capsule endoscopy

Wireless capsule endoscopy is a simple, non-invasive technique for the visualization of the entire small bowel. It was introduced in clinical praxis in 2001 and has already become the method of choice for the investigation of small-bowel pathology. Capsule retention is a major complication, with an overall incidence of 1-2%, although reported rates vary widely from 0% to 21%, depending on the indication for the examination. This complication can occur at any level of the gastrointestinal tract and in most cases runs asymptomatically. However, symptomatic bowel obstruction requiring surgical or endoscopic removal of the impacted capsule can occur. Rarely, capsule retention can lead to intestinal perforation. Despite several years of experience with wireless capsule endoscopy, there is up to the present no safe means of predicting capsule retention. Radiological studies have a low diagnostic yield and tend to underestimate or overestimate small-bowel strictures. The role of the new generation patency capsule (Agile patency capsule) needs to be further documented. The experts agree that obtaining a careful history is perhaps the best single method to detect the possibility of retention.

Imaging of superficial and deep fibromatosis

The purpose of this paper was to illustrate the role of diagnostic imaging in superficial and deep fibromatosis through a review of the use of different imaging modalities, including radiography, ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), angiography and scintigraphy. In particular, in agreement with published data, it emphasises the crucial role of MRI as the primary modality providing the information needed for management decisions, preoperative planning and follow-up of these lesions.

Magnetic resonance imaging of the small bowel with the true FISP sequence: intra- and interobserver agreement of enteroclysis and imaging without contrast material

PURPOSE

This study aimed to determine the reliability of magnetic resonance imaging (MRI) without luminal contrast medium versus MR enteroclysis for evaluating small bowel pathology, to compare MRI and MRE findings per observer, and to compare these findings with those of an expert reader in order to determine the influence of luminal contrast medium on morphological evaluations.

CONCLUSION

The use of luminal contrast medium bowel improves reliability for measuring bowel wall thickness and for the diagnosis and grading of obstruction when evaluating the small bowel.

Do radiologists agree on the quality of computed tomography enterography?

This study aimed to assess variation between radiologists evaluating the quality of multi-detector computed tomography enterography. For 40 consecutive examinations, three experienced radiologists independently rated the following quality variables: % length of adequately filled bowel, bowel lumen diameters, bowel wall delineation, superior mesenteric vein, and bowel wall enhancement, artefacts, and total quality. We calculated the mean difference between observers with standard deviation (SD) for continuous variables and % total agreement, exact Fleiss kappa, and P-values (McNemar's test) for categorical variables. Depending on bowel segment (duodenum distal to bulb, jejunum, ileum, terminal ileum), mean difference between observers ranged from two to 33 (SD from 11 to 32) for % length of adequately filled bowel judged subjectively, 0-2 (SD 0-3) mm for smallest bowel lumen diameter and 0-4 (SD 3-7) mm for largest bowel lumen diameter. Agreement on bowel wall delineation was 80%/kappa 0.50 in duodenum, 90%/kappa 0.57 in jejunum, 75%/kappa 0.14 in ileum and 88%/kappa 0.17 in terminal ileum, where ratings differed between observers (P < 0.04). Agreement was 65%/kappa 0.18 for bowel wall enhancement judged subjectively. For contrast enhancement measured in Hounsfield Units, mean difference between observers ranged from two to 11 (SD 12-15) in normal jejunum wall and zero to one (SD 4-5) in the superior mesenteric vein depending on observer pair. Agreement was 78%/kappa 0.12 for image artefacts. Rating of total examination quality (good/optimal versus poor/very poor) differed between observers (P < 0.01); agreement was 60%/kappa 0.41. Many subjective evaluations varied between observers. We believe that measurements of bowel lumen diameters and contrast enhancement may be preferable.

Small bowel obstruction: what to look for

Small bowel obstruction (SBO) is a common clinical syndrome for which effective treatment depends on a rapid and accurate diagnosis. Despite advances in imaging and a better understanding of small bowel pathophysiology, SBO is often diagnosed late or misdiagnosed, resulting in significant morbidity and mortality. A comprehensive approach that includes clinical findings, patient history, and triage examinations such as plain abdominal radiography will help the clinician develop an individualized treatment plan. When an SBO is accompanied by signs of strangulation, emergent surgical treatment is advised. If surgery cannot be performed immediately or if a partial obstruction is suspected, then a more detailed radiologic work-up is needed. The imaging techniques used subsequently vary according to the initial findings. If a low-grade partial obstruction is suspected, volume-challenge enteral examinations such as enteroclysis and computed tomographic (CT) enteroclysis are preferred. If a complete or high-grade obstruction is suspected, cross-sectional studies such as ultrasonography or multidetector CT are used to exclude strangulation. An algorithmic approach to imaging is proposed for the management of SBO to achieve accurate diagnosis of the obstruction; determine its severity, site, and cause; and assess the presence of strangulation. Radiologists have a pivotal role in clinical decision making in cases of SBO by providing answers to specific questions that significantly affect management.

CT enterography: concept, technique, and interpretation

CT enterography is a new imaging modality that has distinct advantages over conventional CT, wireless capsule endoscopy, and barium examination. CT enterography is noninvasive and allows rapid mapping of disease activity before endoscopy and in cases where the endoscope cannot reach the diseased segment. CT enterography is readily available, is operator independent, and allows evaluation of extraenteric complications of small bowel disease. This article describes the latest techniques and applications of CT enterography.

Crohn disease of the small bowel: comparison of CT enterography, MR enterography, and small-bowel follow-through as diagnostic techniques

PURPOSE

To prospectively compare the accuracy of computed tomographic (CT) and magnetic resonance (MR) enterography and small-bowel follow-through (SBFT) examination for detection of active small-bowel inflammation and extraenteric complications in patients with Crohn disease (CD).

MATERIALS AND METHODS

The institutional review board approved the study protocol; informed consent was obtained from all participants. Thirty-one consecutive patients who had CD or who were suspected of having CD underwent CT and MR enterography, SBFT, and ileocolonoscopy. Two independent readers reviewed CT and MR enterographic and SBFT images for presence of active terminal ileitis and extraenteric complications. Accuracy values of CT and MR enterography and SBFT for identification of active terminal ileitis were evaluated with the receiver operating characteristic method, with ileocolonoscopic findings as the reference standard. Sensitivity values of CT and MR enterography and SBFT for detection of extraenteric complications were compared by using the McNemar test, with results of imaging studies, surgery, and physical examination as reference standards.

RESULTS

The study population included 30 patients (17 men, 13 women; mean age, 29.0 years) with CD. Differences in areas under the receiver operating characteristic curves for CT enterography (0.900 and 0.894), MR enterography (0.933 and 0.950), and SBFT (0.883 and 0.928) for readers 1 and 2, respectively, in the detection of active terminal ileitis were not significant (P > .017). Sensitivity values for detection of extraenteric complications were significantly higher for CT and MR enterography (100% for both) than they were for SBFT (32% for reader 1 and 37% for reader 2) (P < .001).

CONCLUSION

Because MR enterography has a diagnostic effectiveness comparable to that of CT enterography, this technique has potential to be used as a radiation-free alternative for evaluation of patients with CD.

Acute inflammatory bowel disease of the small intestine in adult: MDCT findings and criteria for differential diagnosis

Inflammatory changes of the intestine leading to acute abdomen could represent a frequent diagnostic challenge for radiologists actively involved in the emergency area. MDCT imaging findings needs to be evaluated considering the clinical history and symptoms and other abdominal findings that could be of help in differential diagnosis. Several protocols have been suggested and indicated in the imaging of patient with acute intestine. However, a CT protocol in which the precontrast scanning of the abdomen is followed by i.v. administration of contrast medium using the 45-55 s delay could be effective for an optimal visualization of the bowel wall. It is important to learn to recognize how the intestine reacts to the injury and how it "talks", in order to become aware of the different patterns of disease manifestation related to an acute intestinal condition, for an effective diagnosis of active and acute inflammatory bowel disease.

CT enteroclysis in small bowel Crohn's disease

The diagnostic evaluation of small bowel Crohn's disease has changed dramatically over the last decade. The introduction of wireless capsule endoscopy, double balloon endoscopy and the introduction of newer therapeutic agents have changed the role of imaging in the small bowel. Additionally, advances in multidetector CT technology have further changed how radiologic investigations are utilized in the diagnosis and management of small bowel Crohn's disease. This article describes how we perform CT enteroclysis in the investigation of small bowel Crohn's disease and discusses the role of CT enteroclysis in the current management of small bowel Crohn's disease.

CT enterography: principles, technique and utility in Crohn's disease

CT enterography is a modification of conventional CT technique optimized for the evaluation of small bowel. This technique utilizes multidetector scanners with high spatial and temporal resolution; multiplanar reconstructions; and large volumes of enteric contrast to provide bowel distension. This article discusses the essential principles of the exam and its use in the evaluation of Crohn's disease of the small bowel.

Computed tomography enterography and magnetic resonance enterography: the future of small bowel imaging

In the last 5 years, computed tomography enterography (CTE) and to a lesser extent magnetic resonance enterography (MRE) have supplanted the routine small bowel series and enteroclysis in the evaluation of many small bowel diseases, especially Crohn's disease. Both CTE and MRE use similar methods of bowel lumen opacification and distension and both have distinct advantages and disadvantages. Both have been most extensively studied in patients with Crohn's disease. What is certain is that these cross-sectional examinations have largely replaced the historic fluoroscopic examinations in the evaluation of the small bowel.