Upper gastrointestinal tract and abdomen: water as an orally administered contrast agent for helical CT

Water as a Contrast Medium: A Re-evaluation Using the Multidetector-row Computed Tomography

Water as an intraluminal negative contrast medium produces improved image quality with reduced artefact. However, rapid absorption of oral water in the bowel relative to speed and timing of image capturing has limited its clinical application. These findings predate advances in multidetector-row computed tomography (CT). To re-evaluate differences in image quality, we studied image clarity and luminal distention between the same group of patients who received both a pancreas protocol CT (PPCT) that uses oral water and a conventional positive oral contrast scan. We reviewed 66 patients who had previously undergone both a PPCT and an oral contrast abdominal CT. CT images were independently reviewed by two board-certified radiologists who scored degree of hollow viscus distention and visualization of mural detail using a Likert 5-point scale. Results were evaluated by using the Wilcoxon-signed rank test. Student's t test was applied to evaluate the differences in radiation dosage and Spearman's correlational test was used to evaluate interrater correlation between the radiologists. In comparing the mean radiation dosage, there was no statistical difference between the two protocols, and there was good interrater association with ratios of 0.595 and 0.51 achieved for the PPCT and conventional oral scan, respectively. The Wilcoxon signed-rank test showed statistical differences in the stomach ( P < 0.001) for both clarity ( P < 0.001) and distention ( P < 0.001), the duodenum for both clarity ( P < 0.001) and distention ( P = 0.02), and the ileum for distention ( P = 0.02) with the PPCT having a better median score for organ clarity in the stomach and duodenum and better luminal distention in the stomach, equal distention in the duodenum, and slightly worse distention in the ileum. For the remainder of the bowel and organs evaluated, there was no statistically significant difference in the ratings between the two protocols. Using present CT scan technology, water can be an effective contrast medium causing better or equal distention in the bowel and better or equal clarity than routine barium contrast. This calls for a need to reconsider the use of water as a contrast medium in clinical practice.

Value of contrast-enhanced multidetector computed tomography in imaging of symptomatic patients after laparoscopic Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy

Background

To assess the role of contrast-enhanced multidetector computed tomography (MDCT) in the assessment of symptomatic patients following laparoscopic Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy.

Results

We reviewed the studies of 129 cases and found complications in 113 patients: 55 early complications and 48 late complications. All of these complications were diagnosed with intravenous contrast-enhanced MDCT. Statistically significant difference was found between UGIS and MDCT in the diagnosis of many cases.

Conclusion

The rate of complications in bariatric surgery is high and the associated mortality is not negligible. The interpreting radiologists should know the normal postoperative findings and be aware of possible complications.

JOURNAL CLUB: Preparative Fasting for Contrast-Enhanced CT in a Cancer Center: A New Approach

OBJECTIVE

Most diagnostic imaging centers ask patients to fast for 4-6 hours before contrast-enhanced CT. Previous studies have shown that prolonged fasting can be harmful. In addition, manufacturers of contrast agents claim that there is no special preparation needed before examination. The aim of this study was to evaluate the effects of preparative fasting on contrast-enhanced CT at a cancer center.

SUBJECTS AND METHODS

Outpatients (n = 3206) were prospectively evaluated and randomly assigned to two groups: the 1619 patients in group 1 fasted for at least 4 hours before the examination, whereas the 1587 patients in group 2 received a light meal. Adverse symptoms observed before and after contrast agent administration were compared between groups.

RESULTS

Adverse symptoms occurring after IV contrast agent administration were reported by 45 patients (1.5%) in group 1 and 30 patients (0.9%) in group 2. The most common symptoms were nausea (n = 32), weakness (n = 12), and vomiting (n = 5). The frequency of symptoms did not differ statistically significantly between groups (p > 0.05).

CONCLUSION

In this sample of patients with cancer undergoing contrast-enhanced CT, very few adverse symptoms were reported regardless of preparative fasting. These results support the idea that preparation for contrast-enhanced CT can be simplified, decreasing the discomfort and inconvenience experienced by patients.

Acquired constricting and restricting lesions of the descending duodenum

The descending duodenum is a structure with distinct pathologic processes and anatomic relationships that requires a systematic approach to the differential diagnosis. Because of its tubular shape and fixed position in the retroperitoneum, both intrinsic duodenal and juxtaduodenal diseases are capable of producing luminal narrowing and obstruction. Duodenal lesions may be located in the mucosa or submucosa. Extraduodenal lesions may originate in adjacent structures--such as the pancreas, liver, gallbladder, colon, and lymph nodes--or from other retroperitoneal structures. Causes of duodenal obstruction include intraluminal masses, such as bezoars; duodenal inflammation, such as as peptic ulcers and Crohn disease; hematomas; and benign or malignant mucosal and intramural tumors. Pancreatic inflammation; tumors; and extrinsic compression caused by gallbladder processes, hepatic masses, retroperitoneal fluid collections, and tumors, including lymphoma, may produce duodenal obstruction. Abdominal radiography, barium studies, multidetector computed tomography, magnetic resonance imaging, and positron emission tomography may be used to depict and characterize duodenal strictures. Integration of imaging, clinical, laboratory, and endoscopic findings plays a major role in establishing a diagnosis of obstructive duodenal strictures.

Contrast Media in PET/Computed Tomography Imaging

Is there a need for the contrast-enhanced PET/computed tomography (CT) scan or is the low-dose, non-contrast-enhanced PET/CT scan sufficient? The topic has been debated time and again. Although low-dose noncontrast CT serves the purpose of simple anatomic correlation and attenuation correction of PET images, many times patients have to undergo additional contrast-enhanced diagnostic imaging modalities, which may lead to a delay in decision-making. In this review, the authors have addressed various such issues related to the use of contrast agents and special techniques of clinical interest based on their utility in dual-modality PET/CT.

Use of positive oral contrast agents in abdominopelvic computed tomography for blunt abdominal injury: meta-analysis and systematic review

OBJECTIVES

To determine whether positive oral contrast agents improve accuracy of abdominopelvic CT compared with no, neutral or negative oral contrast agent.

METHODS

Literature was searched for studies evaluating the diagnostic performance of abdominopelvic CT with positive oral contrast agents against imaging with no, neutral or negative oral contrast agent. Meta-analysis reviewed studies correlating CT findings of blunt abdominal injury with positive and without oral contrast agents against surgical, autopsy or clinical outcome allowing derivation of pooled sensitivity and specificity. Systematic review was performed on studies with common design and reference standard.

RESULTS

Thirty-two studies were divided into two groups. Group 1 comprised 15 studies comparing CT with positive and without oral contrast agents. Meta-analysis of five studies from group 1 provided no difference in sensitivity or specificity between CT with positive or without oral contrast agents. Group 2 comprised 17 studies comparing CT with positive and neutral or negative oral contrast agents. Systematic review of 12 studies from group 2 indicated that neutral or negative oral contrasts were as effective as positive oral contrast agents for bowel visualisation.

CONCLUSIONS

There is no difference in accuracy between CT performed with positive oral contrast agents or with no, neutral or negative oral contrast agent.

KEY POINTS

• There is no difference in the accuracy of CT with or without oral contrast agent. • There is no difference in the accuracy of CT with Gastrografin or water. • Omission of oral contrast, utilising neutral or negative oral contrast agent saves time, costs and decreases risk of aspiration.

Utility of negative oral contrast (milk with 4% fat) in PET-CT studies

AIMS

The aim of this study was to evaluate whether low-attenuation oral contrast agent (milk with 4% fat) in PET-CT gastrointestinal studies(GIT) improves the diagnostic accuracy.

JUSTIFICATION FOR THE STUDY

Traditional high-contrast oral agents like iodine solutions, and barium suspensions which due to overcorrection problems in PET-CT interpretation lowers the accuracy of diagnosis. Traditional low-attenuation oral contrast agents are water, air, fat containing agents used with 12.5% corn oil and polyethylene glycol. Volumen is a 0.1% barium suspension and has found favor in visualization of mural features as well as for GIT distension. Milk with 4% fat content has also been tested out in radiological studies and found to be as effective as Volumen. As the former is more easily available, palatable, and acceptable especially, by children it needed to be tested in the visualization of the GIT in the PET-CT scenario.

MATERIALS AND METHODS

Total of 112 patients were divided into 3 groups. Group I: No intervention (18 subjects) Group II: Water (55 subjects): All these patients had 500-750 ml of water 5-10 min before PET examination. Group III: Milk (39 subjects) 500 ml of milk (4% fat content with no additives) was given 40-45 min after 18F-Fluorodeoxyglucose (FDG) injection and another 500 ml 5 min before scan was started. For patients intolerant to milk the same procedure was carried out with soya milk. Group IV comparison with data with Volumen.

RESULTS

CRITERIA FOR EVALUATION OF GUT DISTENSION ON CT IMAGES: (0) No distension, (1) 1 cm distension, (2) 1-2 cm distension, (3) >2 cm distension. For the study analysis, % of patients with criteria 2 and 3 were considered as good visualization. Stomach distension was16%, 47%, 88%, 75% in Gr1-4 respectively, Duodenum-11%, 27% 88%, 86%, Jejunum-33%, 49%, 89%, 76%(*) Ileum-40%, 77%, 82%, 80%(*) and Colon-55%, 58%, 7 4%. Visualization of bowel wall with enhancement of stomach, duodenum, jejunum, and ileum and proximal colon was significantly better with milk than with water or no intervention. Intensity of FDG uptake was mild to moderate with no overcorrection in normal bowel loops and in patients with GIT lesions. Gaseous distension was not increased with milk as an oral contrast agent. Images of patients with bowel tumor was well-delineated with milk administration as the FDG uptake ratio of tumor to gut was high.

CONCLUSION

Distension and visualization of the stomach, duodenum, jejunum, and proximal bowel was significantly improved with milk as a low-attenuation contrast agent. Intensity of FDG uptake was not significantly increased in normal gut and delineation of tumor with increased FDG uptake was improved as overcorrection was minimal.

Accuracy of hydro-multidetector row CT in the local T staging of oesophageal cancer compared to postoperative histopathological results

OBJECTIVE

To evaluate the accuracy of multidetector computed tomography with water filling (Hydro-MDCT) in the T-staging of patients with oesophageal cancer.

MATERIALS AND METHODS

There were 131 consecutive patients who were preoperatively and prospectively examined in the prone position on arterial phase contrast-enhanced MDCT, after ingestion of 1,000-1,500 ml tap water and effervescent granules. Two readers staged the local tumour growth (T-staging) independently. They assessed tumour location, size, presence of stenosis, and morphology of the outer border of the oesophageal wall and perioesophageal fat planes on CT. CT findings were compared with histopathological results from resected specimens. Data were analyzed using the SPSS statistical package.

RESULTS

Both readers obtained a high sensitivity of 95% and a high positive predictive value of 96%. Accurate local staging was achieved in 76.3% and 68.7% for readers 1 and 2, respectively. Inter-reader agreement was excellent (weighted κ value of 0.93 and un-weighted κ of 0.89).

CONCLUSION

Using the hydro-technique and applying specific assessment criteria, MDCT appears to be an accurate, non-invasive diagnostic tool for local tumour staging of oesophageal cancer.

Part 1: CT characterisation of pancreatic neoplasms: a pictorial essay

The pancreas is a site of origin of a diverse range of benign and malignant tumours, and these are frequently detected, diagnosed and staged with computed tomography (CT). Knowledge of the typical appearance of these neoplasms as well as the features of locoregional invasion is fundamental for all general and abdominal radiologists. This pictorial essay aims to outline the characteristic CT appearances of the spectrum of pancreatic neoplasms, as well as important demographic and clinical information that aids diagnosis. The second article in this series addresses common mimics of pancreatic neoplasia.

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.

Three-dimensional MDCT for preoperative local staging of gastric cancer using gas and water distention methods: a retrospective cohort study

OBJECTIVE

The purpose of this article is to compare the T-staging accuracy and lesion detectability of MDCT with gas distention versus water distention according to the surgical and histopathologic findings, for the preoperative evaluation of gastric cancer.

MATERIALS AND METHODS

For a 3-month period, 113 consecutive patients (72 men and 41 women; age range, 23-85 years; mean age, 58 years) with 116 surgically confirmed gastric cancers from a single institution were included in our study. All patients had undergone preoperative MDCT with either effervescent granules taken orally (n = 55) or after having drunk 1,000 mL of tap water (n = 58) to create gastric distention. In addition to transverse images, multiplanar reformation images and 3D surface shaded display images were also obtained with gas distention CT, and multiplanar reformation images were obtained with water distention CT. The CT images were retrospectively reviewed by two abdominal radiologists separately with regard to T staging and lesion detectability. The accuracy values were compared between the two methods using Fisher's exact test.

RESULTS

The T-staging accuracy for gastric cancer did not differ significantly between gas distention and water distention CT scans, according to both radiologists (p > 0.05). Furthermore, the staging accuracy values for T1a cancers on gas distention CT scans for radiologists 1 and 2 were also comparable with those of water distention CT scans (91.1% vs 85% for radiologist 1 and 89.3% vs 85% for radiologist 2; p > 0.05). However, the tumor detection rate was significantly higher on gas distention CT scans using 2D and surface shaded display images for both radiologists (94.6% for radiologist 1 and 91.1% for radiologist 2), compared with the rates for water distention CT scans (78.3% and 73.3%) or gas distention CT scans using only 2D images (75.0% and 67.9%) (p < 0.05).

CONCLUSION

MDCT using the gas distention technique showed performance comparable to that of the water distention technique for the T staging of preoperative gastric cancer with better lesion detectability.

Efficacy of hydrogastric sonography and spiral Computed Tomography in staging of gastric carcinoma--a comparative study

OBJECTIVE

Accurate preoperative diagnosis and staging of patients with gastric cancer is essential for optimal treatment. The standard of care for staging gastric carcinoma is helical CT. This study was conducted to compare the efficacy of hydrogastric sonography (HGS) with that of helical CT in the staging of patients with gastric carcinoma.

METHODS

A total of 42 consecutive patients (29 men and 13 women) diagnosed with gastric carcinoma after endoscopy and biopsy were staged on the basis of TNM classification, preoperatively with HGS and helical CT and postoperatively with histopathologic examination (HPE). The findings of HGS and helical CT were compared with those on HPE with respect to TNM stage.

RESULTS

Regarding T stage, the accuracy of HGS was 78.6% (kappa = 0.68) and that of helical CT was 66.7% (kappa = 0.48). In evaluating the nodal status, the accuracy of HGS was 66.7% (kappa = 0.52) and that of helical CT was 54.6% (kappa = 0.39). Regarding distant metastases, accuracy was the same with HGS and helical CT (accuracy 95.2%, kappa = 0.89).

CONCLUSIONS

When compared with HPE, HGS was found to be more accurate than helical CT for assessment of T and N staging. Sonographic and helical CT were equally accurate for the assessment of M stage.

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.

Validation of nurse-performed FAST ultrasound

BACKGROUND

Patients presenting to Emergency Departments (EDs) with abdominal trauma benefit from FAST (Focused Assessment with Sonography in Trauma). Not all doctor members of the trauma team are credentialed in FAST; therefore occasionally no one is available in the hospital to undertake a FAST. Hence, the aim of this study was to determine the accuracy of nurse-performed FAST as a practical alternative where suitably trained doctors are not available.

METHODS

This was a prospective study of a convenience sample of patients with multisystem trauma in whom abdominal injury was clinically suspected. Senior nurses trained in FAST performed and reported FAST scans for each patient. Accuracy of nurse-performed FAST was determined by comparing results with computerised tomography (CT) scan or operation report.

RESULTS

242 indicated nurse-performed FAST scans were included in the study. Nurse-performed FAST demonstrated sensitivity of 84.4% (95% CI 72.1-92.2) and specificity of 98.4% (CI 94.9-99.6), a positive predictive value (PPV) of 94.2% (CI 83.1-98.5) and a negative predictive value (NPV) of 95.3% (91.0-97.7). Overall accuracy of nurse-performed FAST for the detection of free fluid was 95.0% (95% CI 91.3-97.3).

CONCLUSION

This study demonstrates that, in a convenience sample of injured patients, nurse-performed FAST achieved similar accuracy to previously published results of doctor-performed FAST. Future studies with greater patient numbers would be valuable.

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.

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.

Helical CT evaluation of the preoperative staging of gastric cancer in the remnant stomach

OBJECTIVE

The objective of our study was to evaluate the diagnostic performance of helical CT for evaluating the preoperative staging of gastric cancer in the remnant stomach.

MATERIALS AND METHODS

Preoperative helical CT images of 67 patients with gastric cancer in the remnant stomach were independently analyzed regarding staging of the tumor by two radiologists who were blinded to histopathologic and surgical results. The differences in their assessments were resolved by consensus including the opinion of a third radiologist. The radiologists were asked to determine the depth of tumor invasion of the gastric wall (T stage), classifying it as </= T2, T3, or T4; local lymph node involvement (N stage); and solid organ metastasis or peritoneal involvement (M stage). TNM staging on CT was correlated with the histopathologic results of the resected specimen or with the surgical findings. Interobserver agreement was assessed using weighted kappa statistics.

RESULTS

The overall accuracy of T staging for reviewers 1 and 2 and for the consensus reading were 83.6%, 78.2%, and 85.4%, respectively. Five of 34 </= T2 lesions were misdiagnosed as T3. The cause of the overstaging was the misconception of the postoperative fibrotic change of the anastomotic site as perigastric tumoral infiltration. Three of 18 T4 lesions were understaged because of inadequate gastric distention (n = 1) and misinterpretation of adjacent organ involvement as partial volume averaging (n = 2). The accuracy of N staging and M staging were 81.8% and 94.0% for reviewer 1; 78.2% and 91.0% for reviewer 2; and 81.8% and 94.0% for the consensus reading, respectively. The weighted kappa values of T staging, N staging, and M staging were 0.676, 0.619, and 0.924, respectively.

CONCLUSION

Contrast-enhanced helical CT can be used successfully to preoperatively evaluate the staging of remnant stomach cancer in patients who have undergone previous gastric resection.

Routine use of positive oral contrast material is not required for oncology patients undergoing follow-up multidetector CT

The purpose of this retrospective medical audit was to evaluate the effect of discontinuing routine administration of oral contrast material to oncology patients undergoing follow-up multidetector computed tomography (CT) on reader evaluation of study adequacy. Analysis of 100 patients' experience of CT shows that positive oral contrast material was their least pleasant experience (P < .0001). Abandoning the routine use of positive oral contrast material for follow-up scans in general oncology patients undergoing multidetector CT, with section reconstruction thickness of 2.5 mm, was audited for 447 patents and included 5-13-month follow-up. The patient satisfaction study and clinical audit were performed according to local institutional audit guidelines. Since this was a clinical audit project, ethical approval was not required under UK National Health Service research governance arrangements. No patient needed to be recalled, no related diagnostic error has been reported, and follow-up CT, available in 285 of 447 cases (64%), revealed no error on the audited scan. We conclude that the routine use of positive oral contrast material is unnecessary for follow-up multidetector CT for general oncology indications.

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.

Cost-effectiveness and patient tolerance of low-attenuation oral contrast material: milk versus VoLumen

OBJECTIVE

The purpose of our study was to prospectively compare the cost, effectiveness, and patient tolerance of milk and VoLumen, a 0.1% barium suspension, in patients undergoing abdominal and pelvic CT with oral and i.v. contrast media.

SUBJECTS AND METHODS

Two hundred fifteen consecutive outpatients were randomly assigned to receive either whole milk (n = 115) or VoLumen (n = 100). Results were independently reviewed by two radiologists who were blinded to the oral contrast agent used. Degree of bowel distention was qualitatively scored on a 4-point scale, and bowel wall visibility was graded qualitatively on a yes-or-no basis. A questionnaire regarding oral contrast tolerability was provided to each patient. Cost comparison of the two agents was performed.

RESULTS

No statistically significant differences were seen between whole milk and VoLumen with respect to degree of bowel distention and mural visualization for all segments of bowel studied (p > 0.05 for both reviewers). Significantly more patients ranked milk as pleasant in taste compared with VoLumen (p < 0.0001). More patients preferred milk compared with VoLumen (p < 0.0001). Milk was better tolerated than VoLumen, with fewer abdominal side effects, including abdominal discomfort (p = 0.019), cramping (p = 0.019), nausea (p = 0.016), and diarrhea (p = 0.0002). The cost per patient for VoLumen is $18 compared with $1.48 for milk.

CONCLUSION

Whole milk is comparable to VoLumen with respect to bowel distention and bowel wall visualization and has a lower cost, better patient acceptance, and fewer adverse symptoms. Milk is a cost-effective alternative to VoLumen as a low-attenuation oral contrast agent.

Comparison of neutral oral contrast versus positive oral contrast medium in abdominal multidetector CT

To determine whether neutral contrast agents with water-equivalent intraluminal attenuation can improve delineation of the bowel wall and increase overall image quality for a non-selected patient population, a neutral oral contrast agent (3% mannitol) was administered to 100 patients referred for abdominal multidetector row computed tomography (MDCT). Their results were compared with those of 100 patients given a positive oral contrast agent. Qualitative and quantitative measurements were done on different levels of the gastrointestinal tract by three experienced readers. Patients given the neutral oral contrast agent showed significant better qualitative results for bowel distension (P < 0.001), homogeneity of the luminal content (P < 0.001), delineation of the bowel-wall to the lumen (P < 0.001) and to the mesentery (P < 0.001) and artifacts (P < 0.001), leading to a significant better overall image quality (P < 0.001) than patients receiving positive oral contrast medium. The quantitative measurements revealed significant better distension (P < 0.001) and wall to lumen delineation (P < 0.001) for the patients receiving neutral oral contrast medium. The present results show that the neutral oral contrast agent (mannitol) produced better distension, better homogeneity and better delineation of the bowel wall leading to a higher overall image quality than the positive oral contrast medium in a non-selected patient population.

Depiction of normal gastrointestinal anatomy with MDCT: Comparison of low- and high-attenuation oral contrast media

PURPOSE

To compare low- and high-attenuation oral contrast media for depiction of normal gastrointestinal anatomy with multidetector-row computed tomography (MDCT).

MATERIALS AND METHODS

A prospective, randomized study of 90 consecutive patients without known or suspected gastrointestinal disease was conducted after the approval of our Institutional Review Board. All patients underwent IV contrast-enhanced abdominal and pelvic CT scans after oral administration of 900 ml of either low- or high-attenuation barium sulphate suspension. Using a five-point scale, two radiologists independently graded distention and wall visualization of stomach, duodenum, jejunum, and ileum. The degree of distention and wall visualization was compared using Mann-Whitney U-test.

RESULTS

Duodenal, jejunal and ileal distention (p<0.05, <0.001, <0.001, respectively) and wall visualization (p<0.05, <0.01, <0.05, respectively) scores with low-attenuation contrast medium were significantly higher than those with high-attenuation barium sulphate preparation, for reader 1. Duodenal and jejunal wall visualization scores with low-attenuation contrast medium (p<0.05, <0.01, respectively) were significantly higher than those with high-attenuation contrast medium, for reader 2. Interobserver agreement was fair to good for both distention (kappa-range: 0.41-0.74) and wall visualization (kappa-range: 0.48-0.71).

CONCLUSION

MDCT with low-attenuation contrast medium provides distention and wall visualization of the GI tract that is equal or better than high-attenuation contrast medium.

Preoperative diagnosis of gastric tumors by three-dimensional multidetector row ct and double contrast barium meal study: correlation with surgical and histologic results

BACKGROUND/PURPOSE

Recent three-dimensional multidetector row computed tomography (3D MDCT) can provide detailed images of a gastric tumor, including its general contour, location and depth. We therefore evaluated the efficacy of MDCT in the differential diagnosis and staging of gastric tumors in patients prepared for surgery.

METHODS

Seventy-nine patients with gastric tumors identified by gastric optical endoscopy were admitted for preoperative evaluation. All patients received double-contrast barium meal (DCBM) study and abdominal MDCT with 3D reconstruction before surgery. We compared the accuracy of MDCT with DCBM study in detecting and differentiating gastric tumors. In addition, the MDCT findings were correlated with surgical and pathologic results in gastric cancers for Borrmann type, T and N stages.

RESULTS

Among the 79 patients with gastric tumors, there were 24 cases of early gastric cancer, 40 cases of advanced gastric cancer, 12 cases of gastrointestinal stromal tumor, and three cases of gastric lymphoma. Both MDCT and DCBM were very accurate in picking up the lesions (100%). The diagnostic accuracies of MDCT and DCBM were similar (94% vs. 96%) in differentiating mucosal and submucosal lesions as well as classification of Borrmann type in advanced gastric cancer (70% vs. 63%). In 64 patients with gastric cancers, there was good correlation between MDCT images and pathology in 73% of T staging and 69% of N staging.

CONCLUSION

MDCT has a similar high accuracy in the preoperative diagnosis of different gastric tumors compared with DCBM and provides additional information including tumor depth, lymph node and hepatic metastasis. Therefore, MDCT may be used as a primary tool for preoperative tumor diagnosis and staging.

CT Enteroclysis

Computed tomographic (CT) enteroclysis is a hybrid technique that combines the methods of fluoroscopic intubation-infusion small-bowel examinations with that of abdominal CT. The use of multidetector CT technology has made this a versatile examination that has evolved into two distinct technical modifications. CT enteroclysis can be performed by using positive enteral contrast material without intravenous contrast material and neutral enteral contrast material with intravenous contrast material. CT enteroclysis has been shown to be superior to other imaging tests such as peroral small-bowel examinations, conventional CT, and barium enteroclysis, except in the demonstration of early apthous ulcers of Crohn disease. CT enteroclysis is complementary to capsule endoscopy in the elective investigation of small-bowel disease, with a specific role in the investigation of Crohn disease, small-bowel obstruction, and unexplained gastrointestinal bleeding.

Gastric cancer: preoperative local staging with 3D multi-detector row CT--correlation with surgical and histopathologic results

PURPOSE

To prospectively evaluate accuracy of multi-detector row computed tomographic (CT) images for preoperative staging of gastric cancer by using surgical and histopathologic results as reference standards.

MATERIALS AND METHODS

This study had institutional review board approval; informed consent was obtained from all patients. Multi-detector row CT included acquisition of virtual gastroscopy images after air distention and contrast material-enhanced dynamic transverse and multiplanar reformation (MPR) images after water distention. Fifty-five consecutive patients with gastric cancer (38 men, 17 women; age range, 37-84 years; mean age, 63 years) underwent preoperative CT. All received 6 g of gas-producing crystals before unenhanced CT scanning for gastric distention and virtual gastroscopy. Patients drank 800-1000 mL of tap water to establish a background for dynamic contrast-enhanced CT scans. Images were obtained in late arterial, portal venous, and delayed phases with start delays of 40, 70, and 150 seconds, respectively. All patients underwent surgery. CT findings were compared with surgical and histopathologic results. Differences in accuracy of transverse and MPR images for T and N staging were assessed with the McNemar exact test. Statistical significance was inferred at P < .05.

RESULTS

Detection rates of primary tumors with transverse images, MPRs, and combinations of MPR and virtual gastroscopy images were 91% (50 of 55), 96% (53 of 55), and 98% (54 of 55), respectively. Overall accuracy in assessment of tumor invasion of the gastric wall (T stage) was significantly better with MPR images (89% [49 of 55]) than with transverse images (73% [40 of 55]) (P < .01). Overall accuracy for lymph node (N) staging was 78% (43 of 55) with MPR images and 71% (39 of 55) with transverse images. This difference was not significant (P = .103).

CONCLUSION

Multi-detector row CT with combined water and air distention can improve the accuracy of preoperative staging of gastric cancer. MPRs yield significantly better overall accuracy than transverse images for tumor staging but not for lymph node staging.

Radiologische Bildgebung des oberen Gastrointestinaltraktes

CT, and multi-detector row computed tomography in particular, play a very important role in staging malignant tumors of the stomach. The optimized technique of so called "Hydro-CT", including distension to the gastric wall with 1-1.5 l oral contrast media, mainly water, has fostered the diagnostic value of CT in the diagnosis of diseases of the stomach. By using the "Hydro-CT" technique, the detection rate for gastric carcinoma is now between 89% and 94%, and for liver metastasis between 85% and 92%. For overall T staging, the sensitivity is rather low at between 43% and 65%, and for the lymph nodes between 64 and 88%. Depending on tumor type, multislice computed tomography (MSCT) supplies morphological details for defining the type of lesion (polyps, gastritis, lymphoma, gastrointestinal stromal tumours, carcinoma). Nevertheless, a definite differential diagnosis remains difficult. In addition, multiplanar reconstruction (MPR), derived from multi-detector row computed tomography data sets, is very helpful in localizing these pathologies and demonstrating their anatomic relationship to adjacent organs and vascular structures. MRI plays no major part in the diagnostic evaluation of the upper GI-tract.

Hydro-MRI of the small bowel: effect of contrast volume, timing of contrast administration, and data acquisition on bowel distention

OBJECTIVE

The purpose of this study was to assess oral contrast agents, volumes of the agents, and time points of data acquisition in regard to small-bowel distention and patient acceptance.

SUBJECTS AND METHODS

Six healthy volunteers underwent imaging on 16 different days. Four volumes (450, 900, 1,350, and 1,800 mL) of each of the four contrast compounds (0.2% locust bean gum plus 2.5% mannitol, VoLumen containing 2.0% sorbitol, VoLumen containing 1.4% sorbitol, and tap water) were used. Two-dimensional true fast imaging with steady-state free precession data sets were acquired at 5-minute intervals after contrast ingestion. Distention values for small-bowel segments (duodenum, proximal and distal jejunum, ileum) and occurrence of side effects were documented.

RESULTS

Analysis of bowel distention revealed significantly greater distention for all carbohydrate sugar alcohol-containing solutions compared with water but no significant difference among the three contrast agents. Sufficient duodenal distention was achieved with 900 mL of any of the contrast agents, but imaging had to be performed soon after ingestion. For MRI of the distal jejunum and ileum, a volume of 1,350 mL is preferable, and the time point of data acquisition plays a minor role. Ingestion of 1,800 mL of the carbohydrate sugar alcohol solutions led to a significantly higher rate of side effects such as abdominal cramps than did ingestion of smaller volumes.

CONCLUSION

The data indicate that sufficient contrast consumption and optimal timing of data acquisition are essential to distention of the small bowel. Oral contrast agent protocols should be adapted to the bowel region in question.

Low-attenuation oral GI contrast agents in abdominal-pelvic computed tomography

BACKGROUND

We designed and evaluated a low-attenuation oral contrast agent for abdominal-pelvic computed tomography (CT).

METHODS

In vitro studies, were performed initially to evaluate the imaging characteristics of multiple solutions. These studies resulted in two solutions being compared with the presently accepted oral CT agents of dilute iodinated contrast and water. Ninety-eight consecutive subjects already scheduled for routine outpatient abdominal-pelvic CT were enrolled. Subjects were randomized to water (n = 30), fiber solution (n = 32), polyethylene glycol (PEG; n = 11), or dilute iodinated solution (DI; n = 25). Examinations were then evaluated for gastric distention, small bowel distention, small bowel wall visualization, and colonic transit. A questionnaire was given to the study subjects for feedback concerning taste and potential side effects from these agents.

RESULTS

PEG tended to provide better bowel distention, wall visualization, and colonic transit compared with water, fiber solution, and DI. Areas of statistical significance included: (1) average bowel diameter in the left upper quadrant for water was 17.50 mm, whereas that for PEG was 21.88 mm (p < 0.05); (2) average bowel diameter in the pelvis for water was 14.79 mm, that for fiber was 15.67 mm, and that for PEG was 18.48 mm (p < 0.05); (3) wall visualization was better with PEG than with fiber (p < 0.05); (4) successful transit of contrast to the colon occurred in every subject who received PEG compared with only 20% of those received water and 39% of those who received fiber (p < 0.05). Similar trends for the superiority of PEG over DI were noted, although many of these did not reach statistical significance.

CONCLUSION

PEG solution has imaging characteristics related to bowel wall visualization, luminal distention, and colonic transit that make it an effective oral agent for abdominal pelvic CT examination.

Multidetector row CT of the small bowel

Multidetector row CT (MDCT) has become an imaging technique of choice to study routinely the small bowel. Thin collimation and fast scanning allow coverage of the entire abdomen within a single suspended respiration phase allowing the use of multiple enhancement phases after intravenous contrast administration. MDCT of the small bowel can identify and stage most of the common diseases of the small bowel. MDCT is changing the paradigm for diagnosing small bowel disease by becoming the first diagnostic line for almost all small bowel diseases. MDCT has the needed sensitivity and specificity, the availability, and the safety for a front-line diagnostic method.

Evaluation of bowel distention and bowel wall appearance by using neutral oral contrast agent for multi-detector row CT

PURPOSE

To prospectively evaluate the performance of an orally administered 0.1% barium suspension, Volumen, as a bowel-marking agent for multi-detector row computed tomography (CT).

MATERIALS AND METHODS

This HIPAA-compliant study was approved by the Institutional Review Board and conformed to the institutional standards for research funded by a commercial sponsor. A total of 60 patients (33 women, 27 men; average age, 58.2 years) who were referred for multi-detector row CT of the pancreas were randomized into two groups. Prior to examination, group 1 consumed 1200 mL of Volumen over a 30-minute period and group 2 consumed 1200 mL of a solution containing three parts water and one part methylcellulose over a 30-minute period. Results were independently reviewed by two radiologists who were unaware of the contrast agent used. The degree of distention and the visualization of mural detail were qualitatively scored on a five-point scale. Differences were evaluated by using the Mann-Whitney test at a confidence level of 95%.

RESULTS

There was significantly better distention in the stomach (P = .013), duodenum (P = .006), jejunum (P = .029), and ileum (P = .014) [corrected] in group 1 compared with group 2. Significant distention was also evident by comparing the products of the widest cross-sectional diameters in duodenum (P = .143), jejunum (P < .001), and ileum (P < .001). Group 1 also demonstrated significantly better visualization of mural features in the duodenum (P = .003), jejunum (P = .024), and ileum (P = .01) and a trend toward better visualization of mural features in the stomach (P = .092).

CONCLUSION

Oral administration of Volumen provided excellent distention and excellent visualization of mural features in the gastrointestinal tract.

"Pancreatic lesion" outside the pancreas: value of endoscopic ultrasound

Tumors of the small intestine are rare as compared to malignant tumors of the pancreas. Here we report on the case of a 61-year-old man suffering from chronic pancreatitis presenting with a lesion projecting into the pancreatic head shown by both computed tomography and transabdominal ultrasound. Pancreatic cancer was suspected, but endoscopic ultrasound revealed this lesion to be situated in the submucosal layer of the duodenal wall. Surgery was performed since biopsy of this lesion was not diagnostic and a malignant leiomyosarcoma could therefore not be excluded. Limited surgery comprised resection of the duodenal lesion, whereas based on computed tomography alone, exploration of the pancreas would have been performed. Thus, in the present case endoscopic ultrasound leads to a more appropriate, less invasive therapeutic measure.

Multislice CT of the abdomen

Major advances have been made in CT technology since its introduction 30 years ago. Examination time has been markedly reduced and it is possible to cover considerably larger scan ranges. Multidetector technology now allows near isotopic imaging with the ability to perform high quality multiplanar reconstructions. It is also now possible to image in well defined vascular phases. In this article we share our experience in the use of multislice CT and detail protocols used in imaging of the abdomen.

Oral contrast agents for CT of abdominal trauma in pediatric patients: a comparison of dilute hypaque and water

OBJECTIVE

Dilute Hypaque Sodium is generally well accepted as an oral contrast agent for CT of pediatric patients who have experienced recent blunt abdominal trauma. However, Hypaque can cause complications. Using water as a substitute contrast agent eliminates these potential complications. The purpose of our study was to compare the performance of water with that of dilute Hypaque as an oral contrast agent. Our hypothesis was that we would find no significant difference in performance between the two agents in defining anatomic details of the hollow gastrointestinal tract.

MATERIALS AND METHODS

We performed a retrospective review of 74 CT scans obtained in infants and children who had received blunt abdominal trauma, scoring the quality of visualization of bowel structures, the presence of non-bowel-related findings, and the confidence level in making each assessment. The date range of the scans reviewed overlapped with the period in which the oral contrast material used for scanning such patients was switched from dilute Hypaque to water. Of the 74 CT scans that we reviewed, 53 were obtained with dilute Hypaque and 21 were obtained with water. The sex distribution between the two groups was compared using a chi-square test, whereas the mean age was compared using a two-sample two-sided Student's t test. A two-sample one-sided Student's t test of equivalence was used to analyze the data.

RESULTS

Sex distribution for the two groups of patients was not significantly different (69.81% of the group who received dilute Hypaque were boys; 68.18% of the group who received water were boys). Furthermore, the difference in the mean age for the two groups was not statistically significantly (dilute Hypaque group, 8.86 years; water group, 10.18 years). No statistically significant difference in performance of the contrast agents was found with respect to the detection of intraabdominal abnormality. As an oral contrast material, water performed as well as dilute Hypaque in facilitating visualization of all intraabdominal anatomic structures.

CONCLUSION

In defining anatomic details of the hollow gastrointestinal tract, water is as effective as dilute Hypaque as an oral contrast agent for CT in the setting of acute blunt abdominal trauma in pediatric patients.

Organes critiques et irradiation externe des cancers gynécologiques : l'eau peut-elle être utilisée comme produit de contraste pour faciliter la délinéation de l'intestin grêle ?

PURPOSE

To validate the use of water as contrast agent for the delineation of the small intestine on the planning CT of external beam in patients treated with conformal radiotherapy for gynaecological tumours.

PATIENTS AND METHODS

From March to September 2003, 20 patients received an external irradiation for a gynaecological carcinoma (13 with cervix carcinoma, seven with endometrial carcinoma) in the radiotherapy department of the Centre G.F. Leclerc of Dijon. The protocol of opacification of the small intestine consisted in administration of a "negative" contrast agent: water. The protocol commonly used for the bladder filling, i.e. absorption of 500 cm(3) of water from 60 to 30 min before the CT-scan, was applied for the evaluation of the visualisation of the small intestine in the 12 first patients (group I). For the last eight patients (group II), the absorption of the same amount of water was fractionated, every 10 min within half an hour before the start of the examination.

RESULTS

The small bowel identification was possible in 100% of cases without any need of administration of a "positive" contrast agent. In overall, the identification of the small intestine was considered as easy in 14 patients (70%) and as difficult in two patients (10%). In group I, the delineation was considered as easy in 50% of cases, moderately easy in 33% of cases and none easy in 17% of cases. Conversely, no difficulty was encountered for the definition of the small bowel in all patients of group II.

CONCLUSIONS

Water is an efficient "negative" contrast agent for the differentiation of the small bowel from the colon on the planning abdomino-pelvic CT. Nevertheless, the delineation was really made easier only when the fractionated protocol of water absorption within half an hour before CT was used.

Multidetector-row computed tomography and 3-dimensional computed tomography imaging of small bowel neoplasms: current concept in diagnosis

The diagnosis of small bowel neoplasms can present a difficult challenge to the radiologist because the tumors are uncommon, often small, and may be difficult to detect radiographically. The most common small bowel neoplasms include adenocarcinoma, carcinoid, lymphoma, and gastrointestinal stromal tumors. The location and computed tomography (CT) appearance of the small bowel tumors may aid in the diagnosis. For instance, small bowel adenocarcinoma occurs more frequently in the duodenum and may result in obstruction. Carcinoid tumors are more common in the ileum and are typically hypervascular submucosal masses that produce a characteristic mesenteric mass when they spread to the mesenteric nodes. Lymphoma can occur anywhere along the gastrointestinal tract and have a variable CT appearance. It may appear as a single mass, multiple masses, an infiltrating lesion resulting in aneurysmal dilatation of the bowel, or as an exophytic mass. Gastrointestinal stromal tumors are more common in the jejunum and ileum and usually appear exophytic and bulky often with ulceration. Traditionally, small bowel series and enteroclysis have been used for imaging patients with suspected small bowel tumors. More recently, CT is beginning to play a more important role for this clinical indication. The thinner collimation possible with multidetector CT (MDCT) along with water as oral contrast and a good intravenous contrast bolus may improve the sensitivity of CT for detecting small bowel tumors. In addition, MDCT scanners improve the quality of the 3-dimensional CT (3D CT) images that are valuable to the clinicians and surgeons for surgical planning. It is important for the radiologist to be familiar with the CT appearance of these neoplasms and the potential role of MDCT and 3D imaging in their diagnosis and surgical planning.

State-of-the-art imaging of pancreatic neoplasms

Pancreatic imaging with multidetector CT allows multiphase acquisition of thin slices in a single breath-hold and is especially valuable in obtaining isotropic three-dimensional reformations that improves our ability to provide accurate pre-operative vascular mapping. Advanced MR technology allows faster imaging of pancreas, thus facilitating MR cholangiopancreatography. Use of tissue-specific MR contrast agents, endoscopic ultrasound and PET in pancreatic imaging has evolved considerably. This review article discusses the role of CT, MR, endoscopic ultrasound and PET imaging in pancreas.

Acute small bowel ischemia: CT imaging findings

Small bowel ischemia is a disorder related to a variety of conditions resulting in interruption or reduction of the blood supply of the small intestine. It may present with various clinical and radiologic manifestations, and ranges pathologically from localized transient ischemia to catastrophic necrosis of the intestinal tract. The primary causes of insufficient blood flow to the small intestine are various and include thromboembolism (50% of cases), nonocclusive causes, bowel obstruction, neoplasms, vasculitis, abdominal inflammatory conditions, trauma, chemotherapy, radiation, and corrosive injury. Computed tomography (CT) can demonstrate changes because of ischemic bowel accurately, may be helpful in determining the primary cause of ischemia, and can demonstrate important coexistent findings or complications. However, common CT findings in acute small bowel ischemia are not specific and, therefore, it is often a combination of clinical, laboratory and radiologic signs that may lead to a correct diagnosis. Understanding the pathogenesis of various conditions leading to mesenteric ischemia and being familiar with the spectrum of diagnostic CT signs may help the radiologist recognize ischemic small bowel disease and avoid delayed diagnosis. The aim of this article is to provide a review of the pathogenesis and various causes of acute small bowel ischemia and to demonstrate the contribution of CT in the diagnosis of this complex disease.

Evaluation of simethicone-coated cellulose as a negative oral contrast agent for abdominal CT

RATIONALE AND OBJECTIVES

Because of the increased clinical use of computed tomography (CT) for imaging the abdominal vasculature and urinary tract, there is a need for negative contrast agents. The authors undertook this study to assess the suitability of simethicone-coated cellulose (SCC), which is approved for use as an oral contrast agent in sonography, for use as a negative oral contrast agent in abdominal CT.

MATERIALS AND METHODS

This prospective study involved 40 adult patients scheduled to undergo abdominal CT for the evaluation of hematuria. Prior to scanning, 20 subjects received 800 mL of SCC and 20 received 800 mL of water as an oral contrast agent. Imaging was performed with a multi-detector row helical scanner in two phases, according to the abdominal CT protocol used for hematuria evaluation at the authors' institution. The first, "early" phase began an average of 15 minutes after the ingestion of contrast material; the second, "late" phase began an average of 45 minutes after the ingestion of contrast material. Blinded analysis was performed by three abdominal radiologists separately, using a three-point scale (0 = poor, 1 = acceptable, 2 = excellent) to assess the effectiveness of SCC for marking the proximal, middle, and distal small bowel. Average scores for enhancement with SCC and with water were obtained and compared. Statistical analysis was performed with a Wilcoxon signed-rank test.

RESULTS

SCC was assigned higher mean scores than water for enhancement in each segment of the bowel, both on early-phase images (0.8-1.35 for SCC vs 0.6-1.1 for water) and on late-phase images (1.1-1.4 vs 0.81-0.96). Bowel marking with SCC, particularly in the jejunum and ileum, also was rated better than that with water in a high percentage of patients. The differences between the scores for water and for SCC, however, were not statistically significant (P > .05).

CONCLUSION

SCC is effective as a negative oral contrast agent for small bowel marking at CT.

CT in acute mesenteric ischaemia

Enhanced computed tomography (CT) is frequently performed for possible bowel ischaemia. It has the distinct advantage of possible detection of the causes of ischaemia. Radiologists therefore need to be familiar with the spectrum of diagnostic CT signs. We present the CT imaging findings in surgically proven cases of small bowel ischaemia. In addition to signs pertaining to the underlying aetiological pathology, bowel dilatation, bowel wall thickening, mural gas, occlusion of mesenteric vessels, ascites and infarct of other abdominal organs were observed.