CT enterography: concept, technique, and interpretation. Radiol Clin North Am. 2009;47:117-132. [PMID: 19195538 DOI: 10.1016/j.rcl.2008.10.007]

Exploring the Use of Computed Tomography Enterography in the Evaluation of Small Bowel Disease: A Prospective Study

Background A major development in noninvasive imaging modalities, computed tomographic enterography (CTE) has a number of benefits over conventional computed tomography (CT) and capsule endoscopy. Through the utilization of multidetector computed tomography (MDCT) technology, CTE expedites the assessment of small bowel diseases, especially in those segments that are not accessible through traditional endoscopy. This study's main goal is to thoroughly evaluate CTE's diagnostic accuracy for a range of small intestinal conditions. Methodology In this investigation, which is a prospective observational study, 40 patients, 25 men and 15 women, with suspected small intestinal disorders and ages ranging from 10 to 70 underwent CTE. To evaluate diagnosis accuracy, a combination of clinical symptoms, imaging data, and histopathological/ultrasonography findings were evaluated. Throughout the research procedure, ethical issues and statistical analysis were incorporated to guarantee validity and adherence to ethical norms. Results The most frequent findings on CTE were bowel thickening and mucosal hyperenhancement, which were seen in 25 (62.5%) and 20 (50%) of the patients, respectively. The majority of patients (65%) exhibited both the ileal and jejunal loops to be adequately distended in grade III. In 35% of the patients, grade II distensibility of the ileal and jejunal loops was seen. Conclusion When it comes to accurately detecting small intestinal disorders, CTE is superior. It evaluates extraintestinal, mural, and intraluminal diseases with efficacy, particularly in places that are difficult to reach. It is essential for directing clinical decisions because of its capacity to assess disease activity prior to endoscopy and see consequences.

Non-traumatic abdominal pain: assessment of diagnostic value of MDCT enterography in small bowel diseases—a retrospective study

Background

Because of its unique anatomy, overlap of its loops, and its continuous peristaltic motion, imaging of the small bowel is a big challenge. Non-traumatic abdominal pain of small bowel origin includes a spectrum of medical and surgical conditions ranging from minor to life-threatening conditions. Accurate diagnosis of these diseases is essential to reduce morbidity and mortality. The aim of our study is to assess the role of MDCT enterography in evaluation and diagnosis of different small bowel causes of non-traumatic abdominal pain.

Results

Data analysis of 47 patients’ files included in this study revealed a high diagnostic accuracy of MDCTE in diagnosing variable small bowel-related pathologies that were confirmed histopathologically.

Conclusion

MDCTE can be used as a reliable diagnostic imaging modality for the detection of small bowel diseases. However, operative data and tissue biopsy are still the confirmatory methods for diagnosis.

Dual-energy CT enterography in evaluation of Crohn's disease: the role of virtual monochromatic images

PURPOSE

To assess the use of virtual monochromatic images (VMI) for discrimination of affected and non-affected bowel walls in patients with Crohn's disease (CD) as well as to compare mural enhancement between patients with and without CD.

MATERIALS AND METHODS

This retrospective study included 61 patients (47 with CD, 14 without CD). Attenuation value (AV), signal-to noise ratio (SNR), and contrast-to-noise ratio (CNR) were obtained at VMI energy levels from 40 to 110 keV in 10 keV increment. Analyses were performed among affected and non-affected bowel walls in CD patients, as well as from bowel walls in patients without CD. Image quality and mural enhancement were evaluated at VMI energy levels at 40, 70, and 110 keV.

RESULTS

At all energy levels of VMI, each quantitative data for AV, SNR, and CNR showed statistically significant difference between diseased and non-diseased bowel walls in CD patients. In the quantitative assessment of patients with and without CD, the optimal AV and SNR were obtained at 40 keV, and the optimal CNR was obtained at 70 keV. For the qualitative assessment, the best image quality and mural enhancement were obtained at 70 keV and 40 keV, respectively.

CONCLUSION

VMI are helpful for the differentiation of affected bowel walls in CD patients, providing high diagnostic accuracy.

Computer tomography in the diagnosis of small bowel diseases

Introduction. The relevance of the study is caused by the difficulties in diagnosing diseases of the small bowel (SB). Due to the prevalence and widespread introduction of X-ray computed tomography (CT) into clinical practice, its capabilities in the diagnosis of small bowel diseases are of great interest and potential. Objective. to reveal the possibilities of computed tomography using intravenous bolus contrast enhancement in identifying the symptom of wall thickening of the small bowel and its prognostic significance in various nosologies. Methods. Analysis of the data from MSCT studies performed according to the Protocol for the study of abdominal organs using intravenous bolus contrast enhancement and oral water intake in adult patients from 18 to 87 years of age with small bowel diseases. Results. The article shows the possibilities of multispiral computed tomography performed according to the standard Protocol in detecting thickening of the SB wall. The range of diseases was determined for which thickening of the SB wall was one of the main radiological symptoms of the lesion. The prognostic significance of this radiological symptom is presented. The features of thickening of the intestinal wall in various diseases and other distinctive features that can be used in the differential diagnosis are described. Conclusion. Thickening of the wall is a common sign of SB damage, which is convincingly detected in CT studies with bolus contrast enhancement. In our study, the common causes of thickening of the SB wall in primary disease were: Crohn's disease (37%), lymphoma (20%) and anastomosis (13%). However, we determined thickening of the SB wall as a result of primary tumors (adenocarcinoma, sarcoma) in 7% and as a result of a secondary tumor lesion in 18.6% of cases. The considered diseases were different in the degree of thickening of the intestinal wall (from 6 to 70 mm), its spreading (focal thickening 48%; segmental 52%), number of affected areas (from 1 to 3) of their localization (proximal-middle or distal section), form of the transition area from the affected part of the intestine to the unchanged one (sharply defined or smooth), the presence or absence of symptoms of intestinal obstruction, and the features of contrast enhancement (severity and type).

Mass-forming lesions of the duodenum: A pictorial review

Recent advances in imaging have resulted in marked changes in the investigation of the duodenum, which still remains primarily evaluated with videoendoscopy. However, improvements in computed tomography (CT) and magnetic resonance (MR) imaging have made detection and characterization of duodenal mass-forming abnormalities easier. The goal of this pictorial review was to illustrate the most common conditions of the duodenum that present as mass-forming lesions with a specific emphasis on CT and MR imaging. MR imaging used in conjunction with duodenal distension appears as a second line imaging modality for the characterization of duodenal mass-forming lesions. CT remains the first line imaging modality for the detection and characterization of a wide range of duodenal mass-forming lesions.

New approach to detect and classify stroke in skull CT images via analysis of brain tissue densities

BACKGROUND AND OBJECTIVE

Cerebral vascular accident (CVA), also known as stroke, is an important health problem worldwide and it affects 16 million people worldwide every year. About 30% of those that have a stroke die and 40% remain with serious physical limitations. However, recovery in the damaged region is possible if treatment is performed immediately. In the case of a stroke, Computed Tomography (CT) is the most appropriate technique to confirm the occurrence and to investigate its extent and severity. Stroke is an emergency problem for which early identification and measures are difficult; however, computer-aided diagnoses (CAD) can play an important role in obtaining information imperceptible to the human eye. Thus, this work proposes a new method for extracting features based on radiological density patterns of the brain, called Analysis of Brain Tissue Density (ABTD).

METHODS

The proposed method is a specific approach applied to CT images to identify and classify the occurrence of stroke diseases. The evaluation of the results of the ABTD extractor proposed in this paper were compared with extractors already established in the literature, such as features from Gray-Level Co-Occurrence Matrix (GLCM), Local binary patterns (LBP), Central Moments (CM), Statistical Moments (SM), Hu's Moment (HM) and Zernike's Moments (ZM). Using a database of 420 CT images of the skull, each extractor was applied with the classifiers such as MLP, SVM, kNN, OPF and Bayesian to classify if a CT image represented a healthy brain or one with an ischemic or hemorrhagic stroke.

RESULTS

ABTD had the shortest extraction time and the highest average accuracy (99.30%) when combined with OPF using the Euclidean distance. Also, the average accuracy values for all classifiers were higher than 95%.

CONCLUSIONS

The relevance of the results demonstrated that the ABTD method is a useful algorithm to extract features that can potentially be integrated with CAD systems to assist in stroke diagnosis.

Intestinal tuberculosis versus crohn's disease: Clinical and radiological recommendations

Intestinal tuberculosis is a common clinical problem in India. The clinical features of this disease are nonspecific and can be very similar to Crohn's disease. Radiological evaluation of the small bowel has undergone a paradigm shift in the last decade. This long tubular organ that has traditionally been difficult to evaluate can now be well-visualized by some innovative imaging and endoscopic techniques. This article highlights the state-of-the-art evaluation of ulceroconstrictive diseases of the bowel and provides recommendations for the differentiation of intestinal tuberculosis from Crohn's disease.

CT of the Abdomen with Reduced Tube Voltage in Adults: A Practical Approach

Recent innovations in computed tomographic (CT) hardware and software have allowed implementation of low tube voltage imaging into everyday CT scanning protocols in adults. CT at a low tube voltage setting has many benefits, including (a) radiation dose reduction, which is crucial in young patients and those with chronic medical conditions undergoing serial CT examinations for disease management; and (b) higher contrast enhancement. For the latter, increased attenuation of iodinated contrast material improves the evaluation of hypervascular lesions, vascular structures, intestinal mucosa in patients with bowel disease, and CT urographic images. Additionally, the higher contrast enhancement may provide diagnostic images in patients with renal dysfunction receiving a reduced contrast material load and in patients with suboptimal peripheral intravenous access who require a lower contrast material injection rate. One limitation is that noisier images affect image quality at a low tube voltage setting. The development of denoising algorithms such as iterative reconstruction has made it possible to perform CT at a low tube voltage setting without compromising diagnostic confidence. Other potential pitfalls of low tube voltage CT include (a) photon starvation artifact in larger patients, (b) accentuation of streak artifacts, and (c) alteration of the CT attenuation value, which may affect evaluation of lesions on the basis of conventional enhancement thresholds. CT of the abdomen with a low tube voltage setting is an excellent radiation reduction technique when properly applied to imaging of select patients in the appropriate clinical setting.

CT and MR enterography in children and adolescents with inflammatory bowel disease

The term inflammatory bowel disease (IBD) is used to describe multiple idiopathic disorders of the gastrointestinal tract. As many as one-quarter of patients with IBD initially present in childhood or adolescence. Multiple methods can be used to diagnose IBD in this age group, including computed tomographic (CT) enterography, magnetic resonance (MR) enterography, small bowel follow-through examination, ileocolonoscopy, and capsule endoscopy. However, CT enterography and MR enterography have become the imaging modalities of choice due to their exquisite image quality, rapid acquisition time, lack of need for bowel preparation, and ability to help diagnose the extraintestinal complications of IBD. In addition to being radiation free, MR enterography can help evaluate peristalsis, has high contrast resolution, and allows the use of diffusion-weighted imaging. The authors discuss the use of CT enterography and MR enterography in the context of pediatric IBD in terms of advantages and disadvantages, protocol, and imaging findings.

Spectrum of imaging findings on MDCT enterography in patients with small bowel tuberculosis

Abdominal tuberculosis (TB) is the sixth most common extrapulmonary site of involvement. The sites of involvement in abdominal tuberculosis, in descending order of frequency, are lymph nodes, genitourinary tract, peritoneal cavity, and gastrointestinal tract. The radiological armamentarium for evaluating tuberculosis of the small bowel (SBTB) includes barium studies (small bowel follow-through, SBFT), CT (multidetector CT, CT enterography, and CT enteroclysis), ultrasound (sonoenteroclysis), and magnetic resonance imaging (MRI; enterography and enteroclysis). In this review, we illustrate the abnormalities at MDCT enterography in 20 consecutive patients with SB TB and also describe extraluminal findings in these patients. MDCT enterography allows non-invasive good-quality assessment of well-distended bowel loops and the adjacent soft tissues. It displays the thickness and enhancement of the entire bowel wall in all three planes and allows examination of all bowel loops, especially the ileal loops, which are mostly superimposed. The terminal ileum and ileocaecal junction are the most common sites of small bowel involvement in intestinal TB. The most common abnormality is short-segment strictures with symmetrical concentric mural thickening and homogeneous mural enhancement. Other findings include lymphadenopathy, ascites, enteroliths, peritoneal thickening, and enhancement. In conclusion, MDCT enterography is a comprehensive technique for the evaluation of SB TB.

Application of MSCT enterography in the evaluation of Crohn's disease

The assessment of small bowel abnormalities has always been a challenging task for radiologists and gastroenterologists. Conventional radiologic and endoscopic evaluations are often limited by the length and caliber of small bowel loops. CT enterography, a robust new method with high spatial and isotropic spatial resolution, is a variant of conventional CT technique optimized for the evaluation of the small bowel. Crohn's disease is an inflammatory disease which can involve different areas of the gastrointestinal tract, and it was characterized by segmental and transmural inflammation, with the terminal ileum being the most common site of involvement. CT enterography is well tolerated by these patients and enables accurate, efficient assessment of lesions arising from the small bowel wall or surrounding organs. In this article, we discuss the principle of CT enterography and its use in the evaluation of Crohn's disease.

Endoscopic and radiographic evaluation of the small bowel in 2012

Traditionally, the diagnosis of small bowel disorders has been challenging secondary to the small intestine's length, tortuosity, and anatomic location. Recent technologic advancements in the field of enteroscopy and radiographic imaging have facilitated a more thorough endoscopic evaluation of patients with small bowel disease ranging from obscure gastrointestinal bleeding to inflammatory bowel disease and small bowel tumors. Such developments have made it possible to avoid invasive surgical procedures in certain clinical scenarios where they were previously the gold standard. In this review, we report an update on the diagnostic and management approach to patients with small bowel disease, emphasizing the advantages and limitations of the latest modalities now available to primary care physicians and gastroenterologists for evaluating patients with presumed disease of the small intestine.

Computed tomography of the bowel: a prospective comparison study between four techniques

OBJECTIVES

The major objective was to prospectively compare the grade of bowel distension obtained with four different computed tomography (CT) techniques dedicated for the examination of the small intestine (CT enteroclysis [CTE] and enterography [CTe]), of the colon (CT with water enema [CT-WE]), or both (CTe with water enema [CTe-WE]). The secondary objective was to assess patients' tolerance toward each CT protocol.

MATERIALS AND METHODS

Recruitment was designed to obtain four groups of the same number of patients (30). Each group corresponded to a specific CT technique, for a total of 120 consecutive outpatients (65 male and 55 female, mean age 51.09 ± 13.36 years). CTE was performed after injection of methylcellulose through a nasojejunal tube, while in the CTe protocol a polyethylene glycol electrolyte solution was orally administered to patients prior to the CT acquisition. In the CT-WE protocol intraluminal contrast (water) was administered only by a rectal enema, while CTe-WE technique included both a rectal water enema and oral ingestion of neutral contrast material to obtain a simultaneous distension of small and large bowel. CT studies were reviewed in consensus by two gastrointestinal radiologists who performed a quantitative and qualitative analysis of bowel distension on a per segment basis. The presence and type of adverse effects were recorded.

RESULTS

CTE provided the best distension of jejunal loops (median diameter 27 mm, range 17-32 mm) when compared to all the other techniques (p<0.0001). The frequency of patients with an adequate distension of the terminal ileum was not significantly different among the four groups (p=0.0608). At both quantitative and qualitative analysis CT-WE and CTe-WE determined a greater and more consistent luminal filling of the large intestine than that provided by both CTE and CTe (p<0.0001 for all colonic segments). Adverse effects were more frequent in patients belonging to the CTE group (p<0.0028).

CONCLUSIONS

CTE allows an optimal distension of jejunal loops, but it is the most uncomfortable CT protocol. When performing CT-WE, an adequate retrograde distension of the terminal ileum was provided in a particularly high percentage of patients. CTe-WE provides a simultaneous optimal distension of both small and large bowel.

Role of computed tomography enterography/magnetic resonance enterography: is it in prime time?

Today, cross-sectional imaging modalities, such as computed tomography enterography (CTE) and magnetic resonance enterography (MRE), are particularly suited to evaluate small bowel diseases, especially Crohn's disease (CD). It is well known that CTE/MRE can provide excellent assessment of disease activity as well as the macroscopic features, extramural abnormalities, and complications of the small intestine in patients with CD. In general, CTE is considered as the first-line modality for the evaluation of suspected inflammatory bowel disease and for long-term assessment or follow-up of these patients. Because of the advantage of lack of radiation, MRE is being used more frequently, especially in children or young patients with CD.

A look into the small bowel in Crohn's disease

Crohn's disease (CD) is an inflammatory bowel disease that can affect the entire gastrointestinal tract, with the small bowel (SB) being the most commonly affected site. In some patients, refractory inflammation or chronic strictures of the SB are responsible for a debilitating course of the disease that might lead to severely reduced quality of life. Therefore, SB imaging is a crucial element in diagnosing and/or managing SB CD, and continues to evolve because of technologic advances. SB endoscopy (capsule endoscopy and device-assisted enteroscopy) and cross-sectional radiologic imaging (computed tomography enterography and magnetic resonance enterography) have become key players to diagnose and/or manage CD. In everyday practice, the choice of the imaging modalities is based on the presence and availability of the techniques and of experienced operators in each institute, clinical usefulness, safety, and cost. Here, SB endoscopy and radiologic imaging in suspected or known CD patients will be addressed and discussed.

64-section multiphase CT enterography as a diagnostic tool in the evaluation of obscure gastrointestinal bleeding

BACKGROUND AND AIM

Small bowel follow through (SBFT) and enteroclysis have low sensitivity in picking up lesions in obscure gastrointestinal bleed (OGIB). Computed tomographic enterography (CT-EG), performed with 64-slice multiphase CT system by using large volumes of ingested neutral enteric contrast material, has high spatial and temporal resolution in visualization of the small bowel wall and lumen. The role of 64-slice multiphase CT-EG in the evaluation of OGIB is still evolving, and data on this role are scarce. We evaluated the efficacy of 64-slice multiphase CT-EG using polyethylene glycol (PEG) electrolyte solution as neutral contrast in patients of OGIB.

METHODS

CT-EG was performed with 64-slice multiphase CT system using large volume (2,000 mL) of PEG electrolyte solution as oral contrast in patients of OGIB.

RESULTS

Thirty-five patients (21 men, age 41.4 [13.5] y, range 19-70 year) with OGIB underwent CT-EG; 20 patients had overt OGIB whereas 15 patients had occult OGIB. Among 15 patients with occult OGIB, 10 patients had iron deficiency anemia (IDA) with fecal occult blood test (FOBT) positive and 5 had IDA with FOBT negative. Thirty-two patients (92 %) completed the procedure successfully. The total time taken for the ingestion of 2,000 mL of PEG electrolyte solution was median 64 (range 60-78) minutes. Adequate luminal distension of small bowel was seen in 29 (90.6 %) patients for successful interpretation of radiological images. Fifteen of 32 (46.9 %) patients had positive findings on CT-EG; 12 of them underwent exploratory laparotomy. The surgical findings were in conformity with CT-EG findings in all patients, which included gastrointestinal stromal tumors (GIST; n = 6), carcinoid (1), Meckel's diverticulum (1), small bowel adenocarcinoma (2) and jejunal vascular malformation (2).

CONCLUSION

64-slice multiphase CT-EG is a useful investigation in the evaluation of both occult and overt OGIB.

Evaluation of inflammatory activity in Crohn’s disease and ulcerative colitis

Crohn’s disease and ulcerative colitis evolve with a relapsing and remitting course. Determination of inflammatory state is crucial for the assessment of disease activity and for tailoring therapy. However, no simple diagnostic test for monitoring intestinal inflammation is available. Noninvasive markers give only indirect assessments of disease activity. Histopathological or endoscopical examinations accurately assess inflammatory activity, but they are invasive, time consuming and expensive and therefore are unsuitable for routine use. Imaging procedures are not applicable for ulcerative colitis. The usefulness of ultrasound and Doppler imaging in assessing disease activity is still a matter of discussion for Crohn’s disease, and an increased interest in computed tomography enterograph (CTE) has been seen, mainly because it can delineate the extent and severity of bowel wall inflammation, besides detecting extraluminal findings. Until now, the available data concerning the accuracy of magnetic resonance enterography in detecting disease activity is less than CTE. Due to this, clinical activity indices are still commonly used for both diseases.

Long-term outcomes of obscure gastrointestinal bleeding after CT enterography: does negative CT enterography predict lower long-term rebleeding rate?

BACKGROUND AND AIM

Computed tomography enterography (CTE) is a promising modality for small bowel imaging. However, the role of CTE in the evaluation of obscure gastrointestinal bleeding (OGIB) has not been established. We investigated the efficacy of CTE in diagnosing OGIB and the long-term outcomes based on CTE findings, with special reference to negative CTE.

METHODS

A total of 63 consecutive patients who had undergone CTE for OGIB were enrolled, and their pre- and post-CTE clinical data were collected. "Specific treatments" were defined as treatments directly aimed at resolving presumed bleeding causes, including hemostasis and operation, while "non-specific treatments" were defined as symptomatic treatments for anemia.

RESULTS

Among 60 patients for whom long-term follow-up data were available, positive lesions were found in 16 patients (26.7%). The overall rebleeding rate was 21.7% during a mean follow up of 17.6 ± 4.7 months. There was no significant difference in the cumulative rebleeding rates between patients with positive and negative CTE results (P = 0.241). All patients who received specific treatments after CTE did not rebleed (0/8). In positive CTE patients, specific treatments significantly reduced the rebleeding rate (P = 0.023).

CONCLUSIONS

CTE has a high rate of detecting overt OGIB. However, negative CTE results do not predict lower long-term rebleeding, and such patients with OGIB should be closely observed. In patients with positive CTE, more vigorous management significantly reduces the incidence of rebleeding.

CT enterography: principles, trends, and interpretation of findings

Computed tomographic (CT) enterography is an emerging alternative to traditional fluoroscopy for the assessment of disorders of the small bowel. The greatly improved spatial and temporal resolution provided by multidetector CT scanners, combined with good luminal distention provided by negative oral contrast agents and with good bowel wall visualization, have made CT enterography the main imaging modality not only for investigating proved or suspected inflammatory bowel disease but also for detecting occult gastrointestinal tract bleeding, small bowel neoplasms, and mesenteric ischemia. CT enterography is particularly useful for differentiating between active and fibrotic bowel strictures in patients with Crohn disease, thus enabling selection of the most appropriate treatment (medical management or intervention) for an improved outcome. CT enterography allows excellent visualization of the entire thickness of the bowel wall and depicts extraenteric involvement as well, providing more detailed and comprehensive information about the extent and severity of the disease process.

A single-institution experience with 491 cases of small bowel adenocarcinoma

BACKGROUND

The optimal treatment of small bowel adenocarcinoma is unknown.

METHODS

The records of 491 patients with small bowel adenocarcinoma diagnosis between 1970 and 2005 were reviewed for patient and tumor characteristics, treatment effects, and survival.

RESULTS

The median age at diagnosis was 62 years. The most common tumor locations were the duodenum (57%), jejunum (29%), and ileum (10%). The median overall survival was 20.1 months, with a 5-year overall survival of 26%. Greater age, male sex, higher stage and grade, residual disease after resection, and a lymph node ratio of 50% or greater predicted decreased overall survival in univariate analysis. Age and stage were predictive of survival in multivariate analysis. The overall survival with metastatic disease was poor. Adjuvant therapy was not associated with longer overall survival (P = .44).

CONCLUSIONS

The prognosis of patients with small bowel adenocarcinoma is poor. Complete resection provides the only means of cure, and the role for adjuvant therapy remains uncertain.

MDCT appearance of the appendix: how does the low-density barium sulfate oral contrast agent affect it?

We compared the effect of low-density barium sulfate neutral oral contrast agent on the diameter of normal appendix and its luminal content versus that of water on multidetector-row CT. CT scans of 24 patients who had been imaged on two separate occasions for the evaluation of pancreatic pathology, once with water and subsequently with low-density barium sulfate as the neutral oral contrast agent were evaluated (total of 48 scans). Studies were randomized and reviewed in consensus on a workstation in the stack mode by two radiologists blinded to the type of oral contrast. The appendix was measured at baseline and 10 days later to obtain an average diameter. Results of the water and low-density barium sulfate groups were compared using paired t test. Contents of the appendiceal lumen were also noted (gas, fluid, mixed, and collapsed appendix). The average diameter of the appendix for scans obtained with water and low-density barium sulfate was 4.09 ± 0.87 mm (median, 4.22 mm; range, 2.50-5.65 mm) and 4.13 ± 0.93 mm (median, 4 mm, range, 2.2-5.65 mm), respectively. This difference was not statistically significant (P = 0.69). There was no statistically significant difference in the appendiceal content when water or low-density barium sulfate were used as oral contrast (χ (2) = 4.25, P = 0.89). Low-density barium sulfate does not affect appendiceal content or diameter and, therefore, should not adversely affect evaluation of the appendix on multidetector row CT.

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.