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

CT Enterography Using Four Different Endoluminal Contrast Agents: A Comparative Study

Objectives To determine the most preferable endoluminal contrast agent among mannitol, polyethylene glycol (PEG), iohexol, and water by comparing various qualitative (distension, fold visibility, and homogeneity) and quantitative parameters (distension) along with artifacts and patient feedback for computed tomography enterography (CTE).

Methods This was a prospective study including 120 patients of age more than or equal to 18 years who were randomized equally into four groups. Group 1 was given 1500 mL of 3% mannitol solution, group 2 was given 1500 mL of PEG, group 3 was given 20 mL of iohexol dissolved in 1500 mL of water, and group 4 was given 1500 mL of plain water. CTE was done and images were evaluated in axial and coronal planes. Various quantitative and qualitative parameters were taken at the level of second part of duodenum, jejunum, ileum and ileocecal junction (ICJ). Artifacts and patient feedback were also taken into consideration.

Results The quantitative distension and grading, qualitative distension, fold visibility, and homogeneity of the second part of duodenum, jejunum at the level of superior mesenteric artery, inferior mesenteric artery and renal artery on both sides of abdomen, ileum at the level of aortic bifurcation, common iliac bifurcation, and deep pelvis on both sides of abdomen and ICJ were significantly more in PEG group as compared with mannitol group, followed by iohexol and water group. The results were calculated by ANOVA test using p-value. In terms of patient feedback and artifacts, water was the best agent.

Conclusions PEG is the most suitable contrast agent to carry out CTE. Distension, fold visibility, and homogeneity are the essential features for a better diagnostic outcome of CTE, which was better with PEG.

Duodeno-pancreatic and extrahepatic biliary tree trauma: WSES-AAST guidelines

Duodeno-pancreatic and extrahepatic biliary tree injuries are rare in both adult and pediatric trauma patients, and due to their anatomical location, associated injuries are very common. Mortality is primarily related to associated injuries, but morbidity remains high even in isolated injuries. Optimal management of duodeno-bilio-pancreatic injuries is dictated primarily by hemodynamic stability, clinical presentation, and grade of injury. Endoscopic and percutaneous interventions have increased the ability to non-operatively manage these injuries. Late diagnosis and treatment are both associated to increased morbidity and mortality. Sequelae of late presentations of pancreatic injury and complications of severe pancreatic trauma are also increasingly addressed endoscopically and with interventional radiology procedures. However, for moderate and severe extrahepatic biliary and severe duodeno-pancreatic injuries, immediate operative intervention is preferred as associated injuries are frequent and commonly present with hemodynamic instability or peritonitis. The aim of this paper is to present the World Society of Emergency Surgery (WSES) and American Association for the Surgery of Trauma (AAST) duodenal, pancreatic, and extrahepatic biliary tree trauma management guidelines.

Evaluation of neutral oral contrast agents for assessment of the small bowel at abdominal staging CT

Background

Although neutral oral contrast agents are widely in use, a consensus regarding a standardized protocol in abdominal staging CT does not exist.

Purpose

To test the null hypothesis that there is no quantitative or qualitative difference between water and mannitol for evaluation of the small bowel at abdominal staging CT.

Material and methods

180 patients prospectively underwent abdominal staging CT with oral administration of either 1 liter mannitol solution (n = 88) or water (n = 92). Intestinal distension was measured in 6 different segments of the small intestine. In addition, two radiologists separately evaluated diagnostic image quality with regards to luminal distension (three-point scale) in each segment and the possibility to rule out a possible underlying pathology. Quantitative and qualitative results were compared (Mann-Whitney test).

Results

Quantitatively, intestinal distension was comparable in all segments (p>0.05), except for the horizontal duodenum (p = 0.019). The mean luminal diameter over all intestinal segments was 19.0 mm (18.1–19.9 mm) for the water group and 18.4 mm (17.5–19.2 mm) for the mannitol group, respectively. Qualitatively, ratings were comparable for the first three segments, while distal segments were rated better using mannitol. Side effects were only observed using mannitol (n = 26; 29.5%).

Conclusions

Orally administered water and mannitol solution for evaluation of the small bowel at abdominal staging CT in clinical routine resulted in comparable results for the quantitative, but not for the qualitative analysis. Looking more differentiated at the overall performance, water has advantages in terms of patient comfort, side effects and costs, and can therefore be regarded as noninferior to mannitol in this specific patient group.

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.

A Comparative Study of Four Oral Contrast Agents for Small Bowel Distension with Computed Tomography Enterography

PURPOSE

To assess the efficacy of a variety of oral contrast agents in obtaining small bowel distention for computed tomography (CT) enterography examinations.

METHODS

A retrospective study was developed to quantitatively assess small bowel luminal distension during CT enterography by using 4 contrast agents, which included water, Metamucil, polyethylene glycol, and lactulose. A total of 256 patients were enrolled in the study and included 64 individuals for each oral regimen. The widest loop of small bowel in each of 4 quadrants on representative coronal images was separately measured for luminal distension. Overall distension and the greatest number of "useful" quadrants were evaluated. Overall distension was calculated by summing the 4 quadrant values into an overall luminal diameter distention score (cm). A "useful" quadrant was defined as having a measurement of ≥2 cm. Each "useful" quadrant was assigned a score of 1, with values that ranged from 0-4.

RESULTS

For overall distension, multivariable liner regression analysis showed that the lactulose group had a significantly higher overall distension value than Metamucil, polyethylene glycol, and water by 0.88, 0.92, and 1.63 cm, respectively, with 95% confidence interval. The categorical multivariable logistic regression analysis showed that the lactulose group had greater odds of having more "useful" quadrants than the Metamucil, polyethylene glycol, and water groups, with odds ratios of 3.51, 2.68, and 9.19, respectively.

CONCLUSION

Lactulose achieves better small bowel distension for CT enterography studies than the other 3 agents and, therefore, is the preferred oral regimen at our institution.

Improvement of distension and mural visualization of bowel loops using neutral oral contrasts in abdominal computed tomography

AIM: To assess and compare the image quality of 4% sorbitol and diluted iodine 2% (positive oral contrast agent) in abdomino-pelvic multi-detector computed tomography.

METHODS: Two-hundred patients, referred to the Radiology Department of a central educational hospital for multi-detector row abdominal-pelvic computed tomography, were randomly divided into two groups: the first group received 1500 mL of 4% sorbitol solution as a neutral contrast agent, while in the second group 1500 mL of meglumin solution as a positive contrast agent was administered in a one-way randomized prospective study. The results were independently reviewed by two radiologists. Luminal distension and mural thickness and mucosal enhancement were compared between the two groups. Statistical analysis of the results was performed by Statistical Package for the Social Sciences software version 16 and the Mann-Whitney test at a confidence level of 95%.

RESULTS: Use of neutral oral contrast agent significantly improved visualization of the small bowel wall thickness and mural appearance in comparison with administration of positive contrast agent (P < 0.01). In patients who received sorbitol, the small bowel showed better distention compared with those who received iodine solution as a positive contrast agent (P < 0.05).

CONCLUSION: The results of the study demonstrated that oral administration of sorbitol solution allows better luminal distention and visualization of mural features than iodine solution as a positive contrast agent.

Abdominal and pelvic CT: is positive enteric contrast still necessary? Results of a retrospective observational study

PURPOSE

Evaluation of diagnostic accuracy of abdominal CT depending on the type of enteric contrast agent.

METHODS AND MATERIALS

Multislice CTs of 2,008 patients with different types of oral preparation (positive with barium, n = 576; neutral with water, n = 716; and no enteric contrast, n = 716) were retrospectively evaluated by two radiologists including delineation of intestinal segments and influence on diagnosis and diagnostic reliability exerted by the enteric contrast, using a three-point scale. Furthermore, diagnostic reliability of the delineation of selected enteric pathologies was noted. CT data were assigned into groups: oncology, inflammation, vascular, pathology, trauma and gastrointestinal pathology.

RESULTS

Delineation of the bowel was clearly practicable across all segments irrespective of the type of enteric contrast, though a slight impairment was observed without enteric contrast. Although delineation of intestinal pathologies was mostly classified "clearly delimitable" more difficulties occurred without oral contrast (neutral/positive/no contrast, 0.8 %/3.8 %/6.5 %). Compared to examinations without enteric contrast, there was a significant improvement in diagnosis that was even increased regarding the reader's diagnostic reliability. Positive opacification impaired detection of mucosal enhancement or intestinal bleeding.

CONCLUSION

Water can replace positive enteric contrast agents in abdominal CTs. However, selected clinical questions require individual enteric contrast preparations. Pathology detection is noticeably impaired without any enteric contrast.

An evaluation of the use of oral contrast media in abdominopelvic CT

OBJECTIVES

To evaluate the diagnostic efficacy of different oral contrast media (OCM) for abdominopelvic CT examinations performed for follow-up general oncological indications. The objectives were to establish anatomical image quality criteria for abdominopelvic CT; use these criteria to evaluate and compare image quality using positive OCM, neutral OCM and no OCM; and evaluate possible benefits for the medical imaging department.

METHODS

Forty-six adult patients attending a follow-up abdominopelvic CT for general oncological indications and who had a previous abdominopelvic CT with positive OCM (n = 46) were recruited and prospectively placed into either the water (n = 25) or no OCM (n = 21) group. Three radiologists performed absolute visual grading analysis (VGA) to assess image quality by grading the fulfilment of 24 anatomical image quality criteria.

RESULTS

Visual grading characteristics (VGC) analysis of the data showed comparable image quality with regards to reproduction of abdominal structures, bowel discrimination, presence of artefacts, and visualization of the amount of intra-abdominal fat for the three OCM protocols.

CONCLUSION

All three OCM protocols provided similar image quality for follow-up abdominopelvic CT for general oncological indications.

KEY POINTS

• Positive oral contrast media are routinely used for abdominopelvic multidetector computed tomography • Experimental study comparing image quality using three different oral contrast materials • Three different oral contrast materials result in comparable CT image quality • Benefits for patients and medical imaging department.

Quantitative and qualitative bowel analysis using mannitol, water and iodine-based endoluminal contrast agent on 64-row detector CT

OBJECTIVE

To assess the performance of mannitol as a luminal contrast as compared to water and positive contrast in evaluation of bowel on multidetector computed tomography (MDCT).

MATERIALS AND METHODS

Three hundred patients were randomly selected for this study and were divided equally into three groups. Each subject received 1500 ml of oral contrast. Group 1 received 3% mannitol in water, group 2 received diluted iodinated positive contrast, and group 3 received plain water without additives. Qualitative and quantitative analysis for distension, fold visibility, and overall image quality were analyzed by actual diameter measurement and point scale system at different bowel levels. One-way analysis of variance (ANOVA) followed by Tukey's HSD Post-hoc test and Pearson's Chi-square (exact test) test were applied.

RESULTS

Group 1 showed better results for small bowel distension, intraluminal homogeneity, and visibility of mucosal folds on quantitative and qualitative analysis with statistically significant P value (P<0.001). The ileo-caecal junction distension and mural feature visibility was better with mannitol (P < 0.001). No significant difference in distension of stomach and duodenum was found between the three groups.

CONCLUSION

Mannitol as endoluminal contrast increases the diagnostic accuracy of the investigative studies in comparison to water and iodine-based contrast by producing significantly better bowel distension and visibility of mural features with improved image quality without additional adverse effects.

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.

Small intestinal tumors: diagnostic accuracy of enhanced multi-detector CT virtual endoscopy

OBJECTIVE

To study the diagnostic accuracy of enhanced multi-detector CT virtual endoscopy (MDCT-VE) for small intestinal tumors.

MATERIALS AND METHODS

125 patients were examined by multi-detector CT (MDCT: 54 on 4-slice; 71 on 64-slice) following standard gastrointestinal tract cleansing, oral double contrast aerogenesis agent, and rectal gas administration. Unenhanced CT was performed, followed by enhanced CT in supine (30 and 80s delay after 100 mL standard intravenous contrast medium) and prone positions (180s delay). Supplementary CT in the lateral position was performed if small bowel was not well-filled. Images were reviewed on post-processing workstations with Virtual Endoscopy software.

RESULTS

33/125 patients had proven small intestinal tumors: ten stromal tumors, nine lymphoma, eight adenocarcinomas, three hemangiomas, one each lipoma, Brunner gland adenoma, and hamartoma. 92 were nontumors. MDCT-VE correctly identified 30/33 cases with one false-positive diagnosis: sensitivity 90.9%, specificity 98.9% and accuracy 96.8%.

CONCLUSION

Small intestinal MDCT-VE technique has high diagnostic accuracy for the detection of intestinal tumors. Contrast enhancement and adequate intestinal tract gas-filling can improve the detection rate for small intestinal tumors.

Enterografia por tomografia computadorizada: uma avaliação de diferentes contrastes orais neutros

OBJETIVO: O objetivo deste estudo foi avaliar o desempenho de contrastes orais neutros, comparando a capacidade de distensão intestinal, a distinção da parede intestinal, a aceitação e os efeitos colaterais. MATERIAIS E MÉTODOS: Estudo prospectivo, randomizado e duplo-cego em 30 pacientes submetidos a tomografia computadorizada de abdome e pelve com administração de contraste oral neutro, divididos em três grupos: leite, água e polietilenoglicol. Os exames foram analisados quanto ao grau de distensão intestinal e distinção da parede intestinal por dois examinadores em consenso. Os pacientes responderam a um questionário referente ao sabor da solução ingerida e efeitos colaterais. Foram utilizados os testes Kruskal-Wallis e qui-quadrado para as análises estatísticas. RESULTADOS: Distensão intestinal adequada (calibre da alça maior que 2 cm) foi observada em 14 segmentos dos 40 estudados (35%) no grupo leite, em 10 segmentos (25%) no grupo água e em 23 segmentos (57%) no grupo polietilenoglicol (p = 0,01). O preparo com polietilenoglicol resultou na melhor distensão intestinal, porém apresentou o pior sabor e maior incidência de diarreia, referidos pelos pacientes. CONCLUSÃO: O preparo oral com polietilenoglicol promove maior grau de distensão intestinal do que quando se utiliza água ou leite, mas tem pior aceitação, relacionada ao seu sabor e frequência de diarreia.

Propeller-based wireless device for active capsular endoscopy in the gastric district

An innovative approach to active locomotion for capsular endoscopy in the gastric district is reported in this paper. Taking advantage of the ingestion of 500 ml of transparent liquid by the patient, an effective distension of the stomach is safely achieved for a timeframe of approximately 30 minutes. Given such a scenario, an active swallowable capsule able to navigate inside the stomach thanks to a four propeller system has been developed. The capsule is 15 mm in diameter and 30 mm in length, and it is composed of a supporting shell containing a wireless microcontroller, a battery and four motors. The motors enable the rotation of propellers located in the rear side of the device, thus obtaining a reliable locomotion and steering of the capsule in all directions in a liquid. The power consumption has been properly optimized in order to achieve an operative lifetime consistent with the time of the diagnostic inspection of the gastric district, assumed to be no more than 30 minutes. The capsule can be easily remotely controlled by the endoscopist using a joystick together with a purposely developed graphical user interface. The capsule design, prototyping, in vitro, ex vivo and preliminary in vivo tests are described in this work.

Multidetector CT in children: current concepts and dose reduction strategies

The recent technical development of multidetector CT (MDCT) has contributed to a substantial increase in its diagnostic applications and accuracy in children. A major drawback of MDCT is the use of ionising radiation with the risk of inducing secondary cancer. Therefore, justification and optimisation of paediatric MDCT is of great importance in order to minimise these risks ("as low as reasonably achievable" principle). This review will focus on all technical and non-technical aspects relevant for paediatric MDCT optimisation and includes guidelines for radiation dose level-based CT protocols.

CT enterography of Crohn's disease

CT enterography (CTE) is a technique using neutral oral contrast, intravenous contrast and thin cut, multiplanar CT acquisitions to optimize small bowel imaging. One of the primary indications for CTE is the detection and evaluation of Crohn's disease. This article summarizes the advantages/disadvantages, scanning technique, imaging findings, performance and pitfalls of CTE for the evaluation of Crohn's disease.

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.

Vascular contact with soft tissue: a sign of mesenteric masses at computed tomography

PURPOSE

To evaluate prevalence of mesenteric vascular contact at routine computed tomography (CT) and evaluate its value for distinguishing missed mesenteric masses from adjacent bowel.

MATERIALS AND METHODS

We identified 18 abdominopelvic CT scans of 9 patients in whom mesenteric masses were missed on the prospective CT reports. We recorded the long-axis diameter of the masses, time interval to eventual detection, and presence of vascular contact (fat plane obscuration) with a mesenteric vessel greater than 1 mm in diameter. We also retrospectively identified 129 consecutive abdominopelvic CT scans of nononcology patients and recorded all locations of vascular contact between a mesenteric vessel greater than 1 mm in diameter and adjacent bowel.

RESULTS

In the 18 CT examinations where mesenteric masses were missed, the mean long-axis diameter was 2.9 cm, and time between the initial CT scan and first discovery was 12 months. Mesenteric vessels contacted the masses in 17 (94%) of 18 scans. In the 129 nononcology patients, vascular contact was rarely seen with bowel distal to the proximal jejunum (6 had vascular contact with distal jejunum, 5 with ileum, and 0 with colon). However, the third and fourth duodenal portions showed vascular contact with the superior mesenteric vessels in 36 (28%) and 12 patients (9.4%), respectively, and with the inferior mesenteric vessels in 58 patients (48%).

CONCLUSIONS

At CT, mesenteric vessels greater than 1 mm in diameter rarely contact bowel other than the duodenum and proximal jejunum; however, they often contact mesenteric masses. At CT scan review, inspection of the mesenteric vessels may facilitate mesenteric mass identification.

Noninvasive quantification of tumor volume in preclinical liver metastasis models using contrast-enhanced x-ray computed tomography

OBJECTIVES

To determine a timepoint after contrast injection that yields equal liver parenchymal and vascular enhancement in micro-computed tomography images. To evaluate the utility of images acquired during this time period for the noninvasive measurement of liver-tumor volume.

MATERIALS AND METHODS

The imaging timepoint was determined by quantifying the enhancement kinetics of Fenestra VC (0.015 mL/g) in NIH III mice. In respiratory-gated images of tumor bearing mice, the ability to measure tumor volume was evaluated with a measurement variability study, and by comparing in vivo and histologically measured tumor volume.

RESULTS

Eight hours after contrast injection the liver parenchyma and vasculature were equally enhanced allowing for clear delineation of the unenhanced tumors. The smallest tumor detected in this study was 1.1 mm in diameter. The coefficient of variation for tumor-volume measurement ranged from 3.6% to 12.9% and from 6.3% to 25.8% for intra and interobserver variability, respectively. In vivo and histologic tumor-volume measurements were closely correlated (r = 0.98, P < 0.0001).

CONCLUSIONS

Imaging at a time period of equal liver parenchyma and vascular enhancement after contrast injection allows for clear delineation of liver-tumor borders, thereby enabling quantitative tumor-volume monitoring.

Comparison of 2 different protocols for ingestion of low-attenuating oral contrast agent for multidetector computed tomography of the abdomen

OBJECTIVE

To evaluate 2 different oral contrast application protocols concerning degree of intestinal contrast filling and distension in multidetector computed tomography.

METHODS

Examinations of 260 patients were retrospectively analyzed. Group 1 (n = 205) was prepared with 1000 mL of water with 28 g of dissolved mannitol which was ingested for 1 hour; group 2 (n = 55) was prepared with 2000 mL of water containing 56 g of mannitol which was ingested for 2 hours. Small intestine was divided into 4 quadrants; colon was divided into 4 segments. Contrast filling and distension of bowel loops were graded with a 3-point scale and compared using chi2 testing.

RESULTS

Besides the right upper quadrant, no significant differences in contrast filling and distention were found for small bowel segments. Colonic segments were significantly better contrast filled and distended in group 2 (0.001 < P < 0.025).

CONCLUSIONS

A higher amount of water with 28 g/L of mannitol and a prolonged ingestion of oral contrast media result in significantly better contrast filling and bowel distension in the ileocecal region, the colon, and the rectum.

Comparison of Colonic Transit Between Polyethylene Glycol and Water as Oral Contrast Vehicles in the CT Evaluation of Acute Appendicitis

OBJECTIVE

The objective of our study was to assess the efficacy of a new positive oral contrast agent's ability to reach the colon during CT evaluation of acute appendicitis.

SUBJECTS AND METHODS

Eighty adult emergency department patients who underwent abdominal CT to evaluate for appendicitis were studied. Forty patients received the department's standard dose of 1,600 mL of a water-iodinated contrast mixture (ratio of 2 mL of iodinated contrast material to 100 mL of water) with a standard delay time of 2-2.5 hours from the beginning of contrast medium ingestion. Forty patients were given a new oral contrast mixture of 1,000 mL of polyethylene glycol (PEG) mixed with 30 mL of iodinated contrast agent, and the examination was conducted only 1 hour from inception of contrast administration. Examinations were reviewed for the presence of contrast medium in the cecum and the presence of appendicitis or other abdominal abnormality.

RESULTS

Thirty-eight of 40 patients in the PEG group had contrast medium in the colon at 1 hour after contrast administration, 20 of whom had surgically confirmed cases of appendicitis. In five other patients in that group, another cause to explain the patient's complaints was identified on imaging. Only 18 of the 40 patients who received the standard oral preparation had contrast material present in the cecum. Eleven patients in that group had confirmed appendicitis, and four others had another abnormal finding detected at CT. There was a significant difference in the success of contrast medium transit to the colon with these two agents (p < 0.0001).

CONCLUSION

The use of an oral contrast agent composed of PEG and iodinated contrast material provided a marked improvement in oral agent transit to the colon even in patients with intraabdominal inflammation.