Imaging Pearls ❯ Contrast ❯ Oral Contrast
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- “Neutral oral contrasts include water or water-attenuated contrast agents such as mannitol and polyethylene glycol. These contrast agents aid in visualizing luminal content and the bowel wall. Neutral oral contrast is widely used when evaluating inflammatory bowel disease (IBD), intraluminal filling defects including neoplasms, causes of recurrent gastrointestinal (GI) bleeds, and bowel wall calcifications. However, neutral enteric contrasts struggle to visualize extraluminal soft-tissue density lesions and bowel fistulas [7]. Therefore, neutral enteric contrast is preferably used in CT enterography and some indications for CT angiography (CTA) due to the masking of mucosal enhancement and the alteration of three-dimensional (3D) volume-rendered vascular images with positive enteric contrast. With CT enterography replacing small-bowel follow-through as the primary diagnostic modality for small-bowel imaging, neutral oral contrast serves as an essential component of the gold-standard imaging modality for the diagnosis and follow-up of Crohn’s disease.”
Use of oral contrast in 2024: primer for radiologists
Aaroh Patel · Neeraj Lalwani · Ania Kielar
Abdominal Radiology https://doi.org/10.1007/s00261-024-04409-2 - “The use of positive oral contrast in cancer staging and peritoneal carcinomatosis surveillance has been documented in the literature. Staging of tumors that involve the bowel or peritoneum may be facilitated with positive oral contrast to enhance the separation of the bowel from nearby masses. Furthermore, cancer staging is often conducted in a nonurgent outpatient setting, eliminating a key disadvantage of oral contrast use, namely turnaround time. Despite some isolated studies disputing the use of oral contrast in the evaluation of oncologic patients, CT of the AP with administration of oral contrast remains standard practice. Understanding key peritoneal or retroperitoneal pathways for the spread of various malignancies can help radiologists to better evaluateCT images even without oral contrast.”
Use of oral contrast in 2024: primer for radiologists
Aaroh Patel · Neeraj Lalwani · Ania Kielar
Abdominal Radiology https://doi.org/10.1007/s00261-024-04409-2 - “Positive enteric contrast should never be used in acute GI bleeds, as it obscures contrast-enhanced blood within the bowel lumen. In addition, using positive oral contrast in diagnosing acute pain and bowel ischemia is not recommended due to the increased time needed to opacify the bowel with oral contrast and associated challenges in seeing bowel wall density and enhancement compared to the dense intraluminal oral contrast. Positive enteric contrast is also not recommended for the imaging of hepatobiliary, pancreatic, or genitourinary indications as it provides no direct diagnostic benefit.”
Use of oral contrast in 2024: primer for radiologists
Aaroh Patel · Neeraj Lalwani · Ania Kielar
Abdominal Radiology https://doi.org/10.1007/s00261-024-04409-2 - “Restriction of oral contrast use also eliminates potential side effects such as bloating, nausea, and cramping. However, low-osmolar contrast agents such as iohexol may confer better side-effect profiles because they lead to less endoluminalfluid shifts and less resultant nausea, diarrhea, and electrolyte abnormalities. Furthermore, taste, while subjective, differs between contrast media with different contrast agents conferring small but statistically significant differences in the satisfaction levels of patients. Agents such as iohexol may be preferred over agents with worse taste profiles(diatrizoate meglumine) when the diagnostic accuracy remains the same.”
Use of oral contrast in 2024: primer for radiologists
Aaroh Patel · Neeraj Lalwani · Ania Kielar
Abdominal Radiology https://doi.org/10.1007/s00261-024-04409-2 - “The use of oral contrast in patients with low BMI, especially those presenting to the emergency department with abdominal pain, has been shown to be beneficial in certain studies. A multicenter study demonstrated that 83% of patients with a BMI of 21 or lower had inadequate intraabdominal and intrapelvic fat to effectively separate anatomical structures on CT images without oral contrast. This makes oral contrast particularly valuable in improving diagnostic accuracy in this population. Using body fat percentage measurements via bioelectric impedance analysis alongside BMI can help identify patients who would benefit most from oral contrast, thereby enhancing imaging clarity and diagnostic outcomes. Thus, BMI and body-fat percentages may be considered algorithmically to streamline oral-contrast use in the ED.”
Use of oral contrast in 2024: primer for radiologists
Aaroh Patel · Neeraj Lalwani · Ania Kielar
Abdominal Radiology https://doi.org/10.1007/s00261-024-04409-2 - “A separate avenue for advancing the use of oral contrast involves the development of novel drinking protocols that lessen small but pertinent deterrents to the use of oral contrast, such as taste profiles. A flavored beverage (Breeza; Beekley Medical, Bristol, Conn.) containing thickening agents (sorbitol, mannitol, and xanthan gum) was compared to the most common commercially available agent for enterography protocols, a low-Hounsfield barium suspension. The flavored beverage offers similar sideeffect profiles but scored significantly higher in taste and patients’ willingness to repeat the drinking protocol. As previously mentioned, while subjective, taste confers statistically significant differences in patient satisfaction between contrast media.”
Use of oral contrast in 2024: primer for radiologists
Aaroh Patel · Neeraj Lalwani · Ania Kielar
Abdominal Radiology https://doi.org/10.1007/s00261-024-04409-2 - “Despite advancements in imaging technology that have reduced the reliance on oral contrast, there are still clinical scenarios where its judicious use is critical. The development of standardized protocols for oral contrast administration, as well as ongoing research into novel contrast agents and imaging techniques, is essential for optimizing patient outcomes. Adherence to evidence-based guidelines, such as those provided by the ACR, can improve diagnostic accuracy, patient satisfaction, and resource utilization. In summary, while the use of oral contrast in CT imaging remains contentious, it is clear that its strategic application can significantly enhance diagnostic precision in select cases. Future research and the establishment of universal guidelines will be critical in resolving existing controversies and advancing the field of radiologic imaging.”
Use of oral contrast in 2024: primer for radiologists
Aaroh Patel · Neeraj Lalwani · Ania Kielar
Abdominal Radiology https://doi.org/10.1007/s00261-024-04409-2
- BACKGROUND. Extrinsic warming of iodinated CT contrast media to body temperature reduces viscosity and injection pressures. However, studies examining the effect of extrinsic warming on clinical adverse events are limited in number and provide conflict- ing results. Therefore, consensus practice recommendations have been sparse.
OBJECTIVE. The purpose of this study is to compare rates of extravasation, allergic and allergiclike reactions, and physiologic reactions between iohexol 350 mg I/mL warmed to body temperature (37°C) versus this agent maintained at room temperature.
CONCLUSION. The data suggest that maintaining iohexol 350 at room temperature is noninferior to warming the agent to body temperature before injection.
CLINICAL IMPACT. The resources involved to prewarm iohexol 350 before injection may not be warranted.
Effect of Extrinsic Warming of Low-Osmolality CT Contrast Media (Iohexol 350) on Extravasations and Patient Reaction Rates: A Retrospective Study
Noor F. Basharat et al.
AJR 2022; 218:174–179 - Key Finding
- Among 3939 patients who underwent CT using iohexol 350 prewarmed to body temperature, adverse reaction rate was 0.28%, which was not significantly different (p = .69) from the reaction rate of 0.43% among 3933 patients who received iohexol 350 maintained at room temperature; further analyses showed noninferiority at 0.6% margin.
Importance
- The resources required to warm iohexol 350 to body temperature before injection for CT may not be warranted given the lack of observed practical benefit.
Effect of Extrinsic Warming of Low-Osmolality CT Contrast Media (Iohexol 350) on Extravasations and Patient Reaction Rates: A Retrospective Study
Noor F. Basharat et al.
AJR 2022; 218:174–179 - “This study compared the rate of adverse reactions between patients who received iohexol 350 that had been extrinsically warmed to body temperature and patients who received this agent maintained at room temperature. The two groups showed no significant difference in the overall adverse event rate, extravasation rate, or rate of allergic and allergiclike reactions. No physiologic reaction occurred in either group. Our findings question the utility of prewarming contrast media, which can be a resource-intensive process.”
Effect of Extrinsic Warming of Low-Osmolality CT Contrast Media (Iohexol 350) on Extravasations and Patient Reaction Rates: A Retrospective Study
Noor F. Basharat et al.
AJR 2022; 218:174–179 - "Our study has additional limitations. First, we solely assessed adverse reaction rates. We did not explore any potential impact of extrinsic warming on other end points, such as image quality or patient comfort. In addition, the body temperature group had a higher percentage of male patients, whereas the room temperature group had a larger needle gauge. The latter factor may have contributed to a potential decrease in adverse reaction rates in the room temperature group. Additionally, we noted a higher percentage of patients in the room temperature group who underwent CTA, which may also have had an impact on the data.”
Effect of Extrinsic Warming of Low-Osmolality CT Contrast Media (Iohexol 350) on Extravasations and Patient Reaction Rates: A Retrospective Study
Noor F. Basharat et al.
AJR 2022; 218:174–179 - Purpose: To evaluate the incidence and risk factors of late adverse reactions (ARs) to non-ionic low-osmolar contrast media (LOCM).
Methods: The occurrence of late AR was monitored on day 1 and from day 7 to day 28 in all patients who received enhanced computed tomography using LOCM during a 5-week study period in a single tertiary hospital. Patients who experienced late AR were followed up for three years.
Conclusions: Late ARs to LOCM occurred mostly within one week. The use of premedication may be helpful in reducing the recurrence of late ARs.
Incidence and risk factors of late adverse reactions to low-osmolar contrast media: A prospective observational study of 10,540 exposures
Dong Yoon Kang et al.
European Journal of Radiology 146 (2022) 110101 - Results: Among the total 10,540 LOCM exposures, 315 ARs (3.0%) were reported; acute ARs occurred in 108 LOCM exposures (1.0%) and late ARs occurred in 207 LOCM exposures (2.0%) (90.9% within one week, 9.1% developed afterwards by day 20). Previous history of drug allergy (odds ratio [OR] = 4.59; 95% confidence interval [CI] 2.17–9.71) and allergic diseases (OR = 2.54; 95% CI 1.32–4.91) were risk factors of late ARs to LOCM. Although the recurrence rate was lowered with premedication from 8.5% to 1.7% (8/94 vs. 3/178; p = 0.016), LOCM change did not make difference compared to reuse of the culprit LOCM (2/38 vs. 9/234; p = 0.655). In patients with a history of late AR to LOCM, the risk of recurrent reactions decreased with longer time intervals between exposures (OR = 0.86; 95% CI: 0.77–0.97; p = 0.025) and with the use of antihistamine premedication (OR = 0.27; 95% CI: 0.06–0.99; p = 0.049.
Incidence and risk factors of late adverse reactions to low-osmolar contrast media: A prospective observational study of 10,540 exposures
Dong Yoon Kang et al.
European Journal of Radiology 146 (2022) 110101 - “A late AR is defined as an AR that occurs after one hour and up to one week following exposure to a contrast medium and has a peak incidence from 3 h to two days after exposure. Common symptoms of late ARs include allergic-like ARs (maculopapular rashes, erythema, swelling, pruritus) and non-allergic-like ARs (nausea, vomiting, headache, musculoskeletal pain, and fever). Unlike acute ARs which appear to be associated with histamine release, late ARs are caused by a T cell- mediated reaction. Although symptoms of late ARs are usually mild, they can rarely manifest as severe reactions such as Stevens- Johnson syndrome or toxic epidermal necrosis.”
Incidence and risk factors of late adverse reactions to low-osmolar contrast media: A prospective observational study of 10,540 exposures
Dong Yoon Kang et al.
European Journal of Radiology 146 (2022) 110101 - "In conclusion, the incidence of late ARs following LOCM exposure was twice that of acute ARs, and symptoms in most cases developed within one week. A history of drug allergy and other allergic diseases was a significant risk factor in the occurrence of late ARs. In patients with a history of AR to LOCM, the risk of recurrent reactions decreases with longer time intervals between exposures. Premedication with antihistamines may also be effective in reducing the recurrence of patients with late AR.”
Incidence and risk factors of late adverse reactions to low-osmolar contrast media: A prospective observational study of 10,540 exposures
Dong Yoon Kang et al.
European Journal of Radiology 146 (2022) 110101
- OBJECTIVE: The objective of our study was to compare the quality of bowel opacification from three different positive oral contrast agents-barium sulfate, diatrizoate, and iohexol-at abdominopelvic CT.
CONCLUSION: The frequency of inhomogeneous bowel opacification was lower for iohexol than for diatrizoate or barium sulfate. Barium showed the highest frequency of bowel lumen heterogeneity. The iodinated agents showed greater increases in mean CT attenuation from the proximal bowel segments to the distal bowel segments than barium sulfate.
Comparison of Positive Oral Contrast Agents for Abdominopelvic CT.
Winklhofer S, Lin WC, Wang ZJ, Behr SC, Westphalen AC, Yeh BM.
AJR Am J Roentgenol. 2019 Mar 5:1-7. - RESULTS: Fewer artifacts were detected with iohexol (4.3%) as the oral contrast agent than with diatrizoate (13.0%) and barium sulfate (14.3%) (each, p < 0.05). Barium showed a greater frequency of bowel lumen heterogeneity (388/831 segments, 47%) than iohexol (155/679, 23%) and diatrizoate (185/763, 24% segments) (p < 0.001). Barium showed higher CT attenuation than iohexol and diatrizoate in the stomach but lower CT attenuation in the ileum (each, p < 0.05).
Comparison of Positive Oral Contrast Agents for Abdominopelvic CT.
Winklhofer S, Lin WC, Wang ZJ, Behr SC, Westphalen AC, Yeh BM.
AJR Am J Roentgenol. 2019 Mar 5:1-7. - “We found that the frequency of nonuni- form opacification of bowel was higher with oral diatrizoate and barium sulfate than with iohexol at CT. The CT attenuation of all three types of positive oral contrast agents is lowest in the stomach and highest in the ileum, and the increase in CT attenuation from proximal to distal bowel is greater for diatrizoate and iohexol than for barium sulfate.”
Comparison of Positive Oral Contrast Agents for Abdominopelvic CT.
Winklhofer S, Lin WC, Wang ZJ, Behr SC, Westphalen AC, Yeh BM.
AJR Am J Roentgenol. 2019 Mar 5:1-7. - “There is a surprising paucity of published data on the comparative value of positive oral contrast material versus neutral or no oral contrast material for most general indications for abdominal CT. Nevertheless, in a consensus expert statement by the American College of Radiology and Society for Pediatric Radiology, positive oral contrast material is recognized to improve the delineation of bowel disease, such as abscesses or hypovascular tumors, from nonbowel disease and is also recognized to improve the delineation of bowel leaks.”
Comparison of Positive Oral Contrast Agents for Abdominopelvic CT.
Winklhofer S, Lin WC, Wang ZJ, Behr SC, Westphalen AC, Yeh BM.
AJR Am J Roentgenol. 2019 Mar 5:1-7. - “Although multiple studies of emergency department patients with relatively small sample sizes suggest that avoidance of oral contrast material may improve cost efficiency in that niche scenario, extrapolation of these narrowly staged studies to broader patient populations is not founded on solid evidence. Larger prospective multiinstitution studies that compare the value of positive, neutral, and no oral contrast material for the speed, accuracy, and confidence in diag- nosis of critical abdominal disease diagnoses in outpatients, oncology patients, and patients undergoing postoperative evaluations and in other scenarios are clearly needed.”
Comparison of Positive Oral Contrast Agents for Abdominopelvic CT.
Winklhofer S, Lin WC, Wang ZJ, Behr SC, Westphalen AC, Yeh BM.
AJR Am J Roentgenol. 2019 Mar 5:1-7. - "In conclusion, we found that inhomogeneous opacification of the bowel lumen was more frequently seen with oral diatrizoate or barium sulfate than with oral iohexol at CT of the abdomen and pelvis. The iodinated agents showed a greater progressive increase in CT attenuation in more distal bowel segments than the more proximal bowel segments than was seen with barium sulfate. Further study is warranted to assess for the effects of these differences in bowel opacification on disease detection.”
Comparison of Positive Oral Contrast Agents for Abdominopelvic CT.
Winklhofer S, Lin WC, Wang ZJ, Behr SC, Westphalen AC, Yeh BM.
AJR Am J Roentgenol. 2019 Mar 5:1-7. - Objectives: To determine whether positive oral contrast agents improve accuracy of abdominopelvic CT compared 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, utilizing neutral or negative oral contrast agent saves time, costs and decreases risk of aspiration.
Use of Positive Oral Contrast Agents in Abdominopelvic Computed Tomography for Blunt Abdominal Injury: Meta-Analysis and Systematic Review
Chau Hung Lee 1, Benjamin Haaland, Arul Earnest, Cher Heng Tan
Eur Radiol, 23(9), 2513-21 - Introduction: Positive oral contrast is no longer deemed necessary for abdominopelvic computed tomography (CT) scans. Studies have shown water to be an equally effective oral contrast agent. However, to our knowledge no study has compared effectiveness between gastrografin and water in the same patient, which will provide a more objective evaluation of the two oral contrast agents. We aim to make a head-to-head comparison of water as neutral oral contrast (OC) against gastrografin as positive OC for abdominopelvic CT scans in the same patient.
Conclusions: Water can be used in place of gastrografin as oral contrast in abdominopelvic CT without compromising visualization of abdominopelvic organs.
Water as Neutral Oral Contrast Agent in Abdominopelvic CT: Comparing Effectiveness With Gastrografin in the Same Patient
C H Lee 1, H Z Gu 2, B A Vellayappan 3, C H Tan
J Malaysia, 71 (6), 322-327 Dec 2016 - Methods: A retrospective review of 206 abdominopelvic CT scans of 103 patients was performed. The scans were reviewed in consensus by two blinded radiologists. The ability to visualise each abdominopelvic organ, contrast- associated artefacts and small bowel wall delineation, was qualitatively scored on a 5-point scale. Each patient had two sets of scores, one with water and another with gastrografin as OC. Paired scores from the two OCs were evaluated by Wilcoxon signed rank test to determine any significant difference in performance between the two OCs for visualisation of abdominopelvic anatomy on CT.
Water as Neutral Oral Contrast Agent in Abdominopelvic CT: Comparing Effectiveness With Gastrografin in the Same Patient
C H Lee 1, H Z Gu 2, B A Vellayappan 3, C H Tan
J Malaysia, 71 (6), 322-327 Dec 2016 - “There are several limitations of our study. First, detection of abdominopelvic pathology was not directly assessed. However, it can be extrapolated that optimal visualization of normal anatomical structures with water as OC would generally translate into similar diagnostic confidence in detecting pathology.”
Water as Neutral Oral Contrast Agent in Abdominopelvic CT: Comparing Effectiveness With Gastrografin in the Same Patient
C H Lee 1, H Z Gu 2, B A Vellayappan 3, H Tan
J Malaysia, 71 (6), 322-327 Dec 2016 - "Our study confirms that water as a neutral OC is comparable to gastrografin in terms of enabling visualisation of abdominopelvic organs. This is in agreement with evidence in the literature. Moreover, comparing performance of the two OC agents in the same patient in our study gives a more accurate assessment. We suggest that water can be used in place of gastrografin as oral contrast in abdominopelvic CT without compromising scan interpretation.”
Water as Neutral Oral Contrast Agent in Abdominopelvic CT: Comparing Effectiveness With Gastrografin in the Same Patient
C H Lee 1, H Z Gu 2, B A Vellayappan 3, C H Tan
J Malaysia, 71 (6), 322-327 Dec 2016 - OBJECTIVE. The use of positive oral contrast material for abdominal CT is a frequent protocol issue. Confusion abounds regarding its use, and practice patterns often appear arbitrary. Turning to the existing literature for answers is unrewarding, because most studies are underpowered or not designed to address key endpoints. Even worse, many decisions are now being driven by nonradiologists for throughput gains rather than patient-specific consid- erations. Herein, the current indications for positive oral contrast material are discussed, including areas of controversy.
CONCLUSION. As radiologists, we owe it to our patients to drive the appropriate use of positive oral contrast material. At the very least, we should not allow nonradiologists to restrict its use solely on the basis of throughput concerns; rather, we should allow considerations of image quality and diagnostic confidence to enter into the decision process. Based on differences in prior training and practice patterns, some radiologists will prefer to limit the use of positive oral contrast material more than others. However, for those who believe (as I do) that it can genuinely increase diagnostic confidence and can sometimes (rather unpredictably) make a major impact on diagnosis, it behooves us to keep fighting for its use.
Positive Oral Contrast Material for Abdominal CT: Current Clinical Indications and Areas of Controversy
Perry J. Pickhardt
AJR 2020; 215:1–10 - OBJECTIVE. The use of positive oral contrast material for abdominal CT is a frequent protocol issue. Confusion abounds regarding its use, and practice patterns often appear arbitrary. Turning to the existing literature for answers is unrewarding, because most studies are underpowered or not designed to address key endpoints. Even worse, many decisions are now being driven by nonradiologists for throughput gains rather than patient-specific consid- erations. Herein, the current indications for positive oral contrast material are discussed, including areas of controversy. , it behooves us to keep fighting for its use.
Positive Oral Contrast Material for Abdominal CT: Current Clinical Indications and Areas of Controversy
Perry J. Pickhardt
AJR 2020; 215:1–10 - CONCLUSION. As radiologists, we owe it to our patients to drive the appropriate use of positive oral contrast material. At the very least, we should not allow nonradiologists to restrict its use solely on the basis of throughput concerns; rather, we should allow considerations of image quality and diagnostic confidence to enter into the decision process. Based on differences in prior training and practice patterns, some radiologists will prefer to limit the use of positive oral contrast material more than others. However, for those who believe (as I do) that it can genuinely increase diagnostic confidence and can sometimes (rather unpredictably) make a major impact on diagnosis, it behooves us to keep fighting for its use.
Positive Oral Contrast Material for Abdominal CT: Current Clinical Indications and Areas of Controversy
Perry J. Pickhardt
AJR 2020; 215:1–10 - “A disturbing recent trend, however, is the increasing decision to forego positive oral contrast material largely (or solely) for increased patient throughput, typically driven by nonradiologists such as emergency department (ED) physicians, surgeons, and even health system administrators. As radiologists, we need to ensure that such financially driven nonmedical justifications are in the best interest of our patients.”
Positive Oral Contrast Material for Abdominal CT: Current Clinical Indications and Areas of Controversy
Perry J. Pickhardt
AJR 2020; 215:1–10 
Positive Oral Contrast Material for Abdominal CT: Current Clinical Indications and Areas of Controversy
Perry J. Pickhardt
AJR 2020; 215:1–10- Indications for Positive Oral Contrast
- Suspected postoperative bowel leak
- Suspected gastrointestinal fistula
- Suspected interloop abscess or other fluid collection
- Oncologic staging and surveillance
- Nonspecific abdominal pain or other symptoms (subacute) - "I believe that there is definitely still a role for positive oral contrast material in modern state-of-the-art abdominal CT. As radiologists, we owe it to our patients to drive the appropriate use of positive oral contrast material. At the very least, we should not allow nonradiologists to restrict its use solely on the basis of throughput concerns; rather, we should allow considerations of image quality and diagnostic confidence to enter into the decision process.”
Positive Oral Contrast Material for Abdominal CT: Current Clinical Indications and Areas of Controversy
Perry J. Pickhardt
AJR 2020; 215:1–10 - “Our Emergency physicians do not see that oral contrast administration for CT hampers operational efficiency; in fact, they have expressed gratitude to our department for care in diagnosis. They have stated that delays in patient turnaround are more frequently related to overall demand on the scanner and not to the oral contrast consumption period. They are all acutely aware of the serious consequences of missed or incorrect diagnoses (either leading to inappropriate hospital admission or discharge), and will always choose good medical care over time slashing, corner cutting methods that impress the dashboard monitors perhaps at the expense of excellence in patient care.”
Oral contrast utilization for abdominal/pelvic CT scanning in today’s emergency room setting
Megibow A.J.
Abdom Radiol (2017) 42: 781. doi:10.1007/s00261-016-0941-2 - “In summary, the Radiology department at NYU-Langone Medical Center has, through dialogue with our Emergency Medicine section, reaffirmed the benefits of oral contrast utilization for CT scanning of ED patients. We have found that stocking the oral contrast in the ED and allowing a 45-min period for oral contrast administration coordinated with obtaining clinical and laboratory information facilitate radiologic diagnosis with a high level of confidence and accuracy. As stated by JRD Tata, it is insistence on relentless attention to detail and insistence on highest standards of quality and performance that are the keys to productivity and efficiency, most certainly not through cutting corners.”
Oral contrast utilization for abdominal/pelvic CT scanning in today’s emergency room setting
Megibow A.J.
Abdom Radiol (2017) 42: 781. doi:10.1007/s00261-016-0941-2
- OBJECTIVE. The objective of this study was to determine whether body fat percentage, measured using a portable handheld bioelectric impedance analysis (BIA) device, and body mass index (BMI, weight in kilograms divided by the square of height in meters) can estimate the amount of intraabdominal and intrapelvic fat and thereby predict the need for oral contrast material before abdominopelvic CT.
CONCLUSION. Using BIA in addition to BMI accurately predicts amount of intraabdominal and intrapelvic fat. This information may help guide the decision to use oral contrast material in patients presenting for abdominopelvic CT.
Using Body Mass Index and Bioelectric Impedance Analysis to Assess the Need for Positive Oral Contrast Agents Before Abdominopelvic CT
Wu Y et al.
AJR 2018; 211:340–346 - "We also did not directly examine whether the use of oral contrast material would alter clinical diagnosis. Thus, we cannot conclusively state that patients with a fat score of 3 or more could forgo oral contrast material without compromising diagnostic accuracy. In some circumstances, oral contrast material can aid in the diagnostic process regardless of the amount of intraabdominal and intrapelvic fat.”
Using Body Mass Index and Bioelectric Impedance Analysis to Assess the Need for Positive Oral Contrast Agents Before Abdominopelvic CT
Wu Y et al.
AJR 2018; 211:340–346 - “Despite these limitations, our results show that using BMI with the addition of BIA-determined body fat percentage in appropriate cases provides a rapid and refined approach for estimating the amount of intraabdominal and intrapelvic fat in patients presenting to the ED with nontraumatic abdominal pain. Using these criteria may help optimize use of oral contrast material, which would improve workflow and reduce wait times in the ED.”
Using Body Mass Index and Bioelectric Impedance Analysis to Assess the Need for Positive Oral Contrast Agents Before Abdominopelvic CT
Wu Y et al.
AJR 2018; 211:340–346 - “There were no statistically significant differences in sensitivity or specificity for CT scans performed in groups A and B. In patients with a BMI of less than 25, an intravenous contrast-enhanced CT protocol without oral contrast demonstrates similar accuracy to an intravenous contrast-enhanced protocol with oral contrast for diagnosing acute appendicitis.”
Diagnosing acute appendicitis using a nonoral contrast CT protocol in patients with a BMI of less than 25
Ramalingam V et al.
Emerg Radiol (2016) 23:455–462 - "A consideration in the use of oral contrast material is the rate of bowel opacification; notably, even with a standard 2-h preparatory time, in nearly a third of patients in this study, the oral contrast material did not opacify any portion of the colon. This finding is sim- ilar to our prior results, which reported an absence of colonic opacification in 32 % of patients.”
Diagnosing acute appendicitis using a nonoral contrast CT protocol in patients with a BMI of less than 25
Ramalingam V et al.
Emerg Radiol (2016) 23:455–462 - “In the assessment of Crohn’s disease, neutral or low attenuation agents provide the benefit of increasing conspicuity of diseased segments due to the striking contrast between the lower luminal density and the mucosal/mural hyperenhancement and stratification that is produced following intravenous contrast media administration. Also, hypervascular bowel lesions and active bleeding can be detected much more easily on studies performed with neutral oral contrast media as well, since the high attenuation of enhancing lesions or active extravasation of contrast material into bowel lumen stands out when surrounded by the lower attenuation distended bowel lumen. Positive oral contrast media, including both dilute barium and dilute water soluble iodinated contrast media can obscure such abnormalities and is problematic for creating three- dimensional images.”
ACR Manual On Contrast Media
Version 10.3 (2018) - Rationale and Objectives: This study aims to compare the diagnostic performance of abdominal computed tomography (CT) performed with and without oral contrast in patients presenting to the emergency department (ED) with acute nontraumatic abdominal pain.
Conclusions: Our study shows that oral contrast is noncontributory to radiological diagnosis in most patients presenting to the ED with acute nontraumatic abdominal pain. These patients can therefore undergo abdominal CT scanning without oral contrast, with no effect on radiological diagnostic performance.
CT for Acute Nontraumatic Abdominal Pain—Is Oral Contrast Really Required?
Kessner R et al.
Acad Radiol 2017; 24:840–845 - Conclusions: Our study shows that oral contrast is noncontributory to radiological diagnosis in most patients presenting to the ED with acute nontraumatic abdominal pain. These patients can therefore undergo abdominal CT scanning without oral contrast, with no effect on radiological diagnostic performance.
CT for Acute Nontraumatic Abdominal Pain—Is Oral Contrast Really Required?
Kessner R et al.
Acad Radiol 2017; 24:840–845 - “In conclusion, patients presenting to the ED with acute nontraumatic abdominal pain can be evaluated with abdominal CT with IV contrast material and without oral contrast material. Oral contrast material should be considered in very thin patients and in patients with history of inflammatory bowel disease or recent operation. We hope that the results of our study, along with other large studies, will pave the way to the formulation of new medical guidelines.”
CT for Acute Nontraumatic Abdominal Pain—Is Oral Contrast Really Required?
Kessner R et al.
Acad Radiol 2017; 24:840–845 - "A major disadvantage of administration of oral contrast material for abdominal CT in the ED is prolonged stay and delay in diagnosis and treatment. Levenson et al. showed that eliminating routine oral contrast use for abdominal CT in the ED may result in reducing both the mean ED length of stay and the turnaround time from CT request to completion, without compromise of patients’ diagnosis. Razavi et al. showed that when oral contrast was not used, there was a statistically significant decrease in the time from CT order to examination completion, the time from CT order to final in- terpretation, and also in the ED length of stay.”
CT for Acute Nontraumatic Abdominal Pain—Is Oral Contrast Really Required?
Kessner R et al.
Acad Radiol 2017; 24:840–845 - What do you do now?
- Focus on what has not been addressed-What about gastric pathology?
- Focus on positioning the oral contrast in areas to prevent delay in administrating the oral contrast
- Rethink the process from the perspective of the “Reading Physician (the radiologist)” - “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.”
Routine use of positive oral contrast material is not required for oncology patients undergoing follow-up multidetector CT.
Harieaswar S et al.
Radiology. 2009 Jan;250(1):246-53 - "The standard contrast material was barium sulfate suspension (4.9% wt/vol in 225 mL, E-Z-CAT; E-Z-Em, Lake Success, NY) diluted in 1000 mL of water, making a suspension of 1.1% wt/vol. In a previous study, this contrast agent was found to be tolerated similarly to Gastromiro (Bracco, Milan, Italy) and better than Gastrografin (Bayer Schering Pharma, Berlin, Germany).”
Routine use of positive oral contrast material is not required for oncology patients undergoing follow-up multidetector CT.
Harieaswar S et al.
Radiology. 2009 Jan;250(1):246-53 - "In our study, difficulties were encountered with thin patients (although not formally measured), peritoneal disease close to bowel loops, and in patients examined without the use of intravenous contrast material. Oral contrast material may be justified in some of these situations, although we do not routinely use oral contrast material in any of these groups. During the study, we also found positive oral contrast material may mask certain findings such as subtle mucosal deposits seen in carcinoid or melanoma and calcified peritoneal deposits, although a direct comparison of bowel delineation with and that without oral contrast material was not tested in this study.”
Routine use of positive oral contrast material is not required for oncology patients undergoing follow-up multidetector CT.
Harieaswar S et al.
Radiology. 2009 Jan;250(1):246-53 - "On the basis of our findings, we suggest that if multidetector CT is available, positive oral contrast material should not be a routine requirement for follow-up abdominal pelvic scans in oncology patients. The requirement for routine positive oral contrast material should also be removed from research protocols (such as RECIST protocols) in these patients unless there is a specific indication for their use, such as known peritoneal disease or stage 3 ovarian tumors. This recommendation should not preclude using positive oral contrast material in certain situations, such as in patients who are very thin or are unable to have intravenous contrast material.”
Routine use of positive oral contrast material is not required for oncology patients undergoing follow-up multidetector CT.
Harieaswar S et al.
Radiology. 2009 Jan;250(1):246-53 - 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. 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.
Routine use of positive oral contrast material is not required for oncology patients undergoing follow-up multidetector CT.
Harieaswar S et al.
Radiology. 2009 Jan;250(1):246-53 - 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.
Routine use of positive oral contrast material is not required for oncology patients undergoing follow-up multidetector CT.
Harieaswar S et al.
Radiology. 2009 Jan;250(1):246-53
- “Length of stay (LOS) is considered one of the important indicators of quality of care in Emergency departments in the US. Emergency departments are under scrutiny for long ED stays. Many factors have been recognized in association with longer ED stays. One that has received special attention among abdominal imagers is the administration of oral contrast to ED patients in need of abdominal/pelvic CT scan. While the mean duration of an ED visit is reported slightly more than 3 h, the extra 1–2 h of wait time for oral preparation seems quite significant.”
Oral contrast administration for abdominal and pelvic CT scan in emergency setting: is there a happy medium?
Sokhandon F
Abdom Radiol (2017) 42:784–785 - “In the short trial period, the rate of repeat abdominal CT scans began to rise. Disclaimers such as ‘‘evaluation of bowel is limited due to lack of oral contrast’’ were appearing in radiology reports, thus warranting repeat examinations, specifically in a subgroup of patients who remained symptomatic or would present with recurrent symptoms shortly after being discharged from ED.”
Oral contrast administration for abdominal and pelvic CT scan in emergency setting: is there a happy medium?
Sokhandon F
Abdom Radiol (2017) 42:784–785 - "Soon we came to the conclusion that eliminating oral contrast in ED adult abdominal and pelvic CT scans would be a drastic change, and if extrapolated to all our centers, with a group of more than one hundred radiologists with different levels of expertise and opinion, accustomed to looking at opacified bowel for their entire career and who are committed to offering the best quality exams possible, the change would not be received well. We needed to prioritize, and find a rule to help with choosing the right patients for elimination of oral contrast.”
Oral contrast administration for abdominal and pelvic CT scan in emergency setting: is there a happy medium?
Sokhandon F
Abdom Radiol (2017) 42:784–785 - "Utilizing a BMI threshold of 25 for adult men, and 30 for adult women, to administer oral contrast for abdominal and pelvic CT scan in ED patients appears to be a reasonable solution to facilitate shorter ED stays, while maintaining the diagnostic quality of CT scans, and reducing the need for repeat examination. While ED time constraints have cer- tainly modified our current practice, taking action based on priorities has provided a reasonable approach based on demographics of our patient population.”
Oral contrast administration for abdominal and pelvic CT scan in emergency setting: is there a happy medium?
Sokhandon F
Abdom Radiol (2017) 42:784–785 - “According to the National Health and Nutrition Examination Survey (NHANES), 74% of adult men, older than 20 years of age in the United States, have BMI of greater than 25, and 38.3% of women have BMI greater than 30. Although unfortunate, these data are in favor of using the BMI protocol. Based on these data, the majority of our adult patients, specifically men, fall in the category in which we would not administer oral contrast.”
Oral contrast administration for abdominal and pelvic CT scan in emergency setting: is there a happy medium?
Sokhandon F
Abdom Radiol (2017) 42:784–785 - Oral Contrast in the ER in the Patient with Abdominal Pain
- Oral contrast with Omnipaque-350
- Oral contrast with water
- No oral contrast administered
- The deciding factor to most ERs if patient throughput not study accuracy - What are the consequences of lack of oral contrast?
- Missed diagnosis
- Indeterminate diagnosis which may lead to repeat CT or other studies
- Delay in diagnosis
- Radiologist dissatisfaction or stress - Can you administer oral contrast and not delay patient turnaround?
Where is the oral contrast and who gives it?
- Pharmacy
- Nurses station
- CT scanning area
- Other? - Purpose—To compare studies with and without oral contrast on performance of multidetector computed tomography (CT) and the order to CT examination turnaround time in cancer patients presenting to the emergency department (ED). To our knowledge, oral contrast utility has not previously been specifically assessed in cancer patients presenting to the emergency department.
Conclusion—On the basis of our findings and prior studies, targeted rather than default use of oral contrast shows acceptable diagnostic ability in the emergency setting for oncology patients. Benefit from oral contrast use is suggested in scenarios such as suspected fistula/bowel leak/ abscess, hypoattenuating peritoneal disease, prior bowel surgery such as gastric bypass, and the absence of intravenous contrast administration. Improvement through the use of targeted oral contrast administration also supports the emergency department need for prompt diagnosis and disposition.
Utility of CT Oral Contrast Administration in the Emergency Department of a Quaternary Oncology Hospital: diagnostic implications, turnaround times and assessment of ED physician ordering
Jensen CT et al.
Abdom Radiol 2017 November ; 42(11): 2760–2768. - “The administration of oral contrast typically requires a 60- to 90-minute delay before imaging to allow for distal bowel opacification. Huynh et al. reported a difference in order- to-scan times of 68 minutes between CT protocols performed with and without oral contrast. Studies have shown that eliminating oral contrast can increase patient throughput and improved overall patient experience, while maintaining diagnostic accuracy.”
Utility of CT Oral Contrast Administration in the Emergency Department of a Quaternary Oncology Hospital: diagnostic implications, turnaround times and assessment of ED physician ordering
Jensen CT et al.
Abdom Radiol 2017 November ; 42(11): 2760–2768. - "Our study evaluated an oncologic population presenting to the emergency department who underwent CT of the abdomen for abdominal complaints; no statistical difference in reader confidence or diagnosis was identified related to whether or not patients received oral contrast and there was a significant reduction in turnaround time for patients without oral contrast. This is in agreement with prior studies that have evaluated other patient populations.”
Utility of CT Oral Contrast Administration in the Emergency Department of a Quaternary Oncology Hospital: diagnostic implications, turnaround times and assessment of ED physician ordering
Jensen CT et al.
Abdom Radiol 2017 November ; 42(11): 2760–2768. - "On the basis of our findings and prior studies, targeted rather than default use of oral contrast shows acceptable diagnostic ability in the emergency setting for oncology patients. Benefit from oral contrast use is suggested in scenarios such as suspected fistula/bowel leak/abscess, hypo-attenuating peritoneal disease, prior bowel surgery such as gastric bypass, and the absence of intravenous contrast administration. Improvement through the use of targeted oral contrast administration also supports the emergency department need for prompt diagnosis and disposition.”
Utility of CT Oral Contrast Administration in the Emergency Department of a Quaternary Oncology Hospital: diagnostic implications, turnaround times and assessment of ED physician ordering
Jensen CT et al.
Abdom Radiol 2017 November ; 42(11): 2760–2768. - “While some of the above conditions that may benefit from positive oral contrast may not always be suspected clinically during ordering and thus may not receive such contrast, it appears that more cases will benefit from discriminant oral contrast use. Certainly other nuances of protocols can be considered, such as shorter administration time of oral contrast. Further prospective evaluations of oral contrast protocols are needed.”
Utility of CT Oral Contrast Administration in the Emergency Department of a Quaternary Oncology Hospital: diagnostic implications, turnaround times and assessment of ED physician ordering
Jensen CT et al.
Abdom Radiol 2017 November ; 42(11): 2760–2768. - When should oral contrast be used in the ER?
- If IV contrast can not be given
- thin patients with a paucity of intraabdominal fat
- Evaluations for possible anastomotic leak, fistula, extramural hematoma or abscess should typically include positive oral contrast - When should oral contrast be used in the ER?
- Hypoattenuating peritoneal disease adjacent to bowel loops can also be difficult to evaluate without oral contrast
- If the referring clinician requests it
- “Length of stay (LOS) is considered one of the important indicators of quality of care in Emergency departments in the US. Emergency departments are under scrutiny for long ED stays. Many factors have been recognized in association with longer ED stays. One that has received special attention among abdominal imagers is the administration of oral contrast to ED patients in need of abdominal/pelvic CT scan. While the mean duration of an ED visit is reported slightly more than 3 h, the extra 1–2 h of wait time for oral preparation seems quite significant.”
Oral contrast administration for abdominal and pelvic CT scan in emergency setting: is there a happy medium?
Sokhandon F
Abdom Radiol (2017) 42:784–785 - “In the short trial period, the rate of repeat abdominal CT scans began to rise. Disclaimers such as ‘‘evaluation of bowel is limited due to lack of oral contrast’’ were appearing in radiology reports, thus warranting repeat examinations, specifically in a subgroup of patients who remained symptomatic or would present with recurrent symptoms shortly after being discharged from ED.”
Oral contrast administration for abdominal and pelvic CT scan in emergency setting: is there a happy medium?
Sokhandon F
Abdom Radiol (2017) 42:784–785 - "Soon we came to the conclusion that eliminating oral contrast in ED adult abdominal and pelvic CT scans would be a drastic change, and if extrapolated to all our centers, with a group of more than one hundred radiologists with different levels of expertise and opinion, accustomed to looking at opacified bowel for their entire career and who are committed to offering the best quality exams possible, the change would not be received well. We needed to prioritize, and find a rule to help with choosing the right patients for elimination of oral contrast.”
Oral contrast administration for abdominal and pelvic CT scan in emergency setting: is there a happy medium?
Sokhandon F
Abdom Radiol (2017) 42:784–785 - "Utilizing a BMI threshold of 25 for adult men, and 30 for adult women, to administer oral contrast for abdominal and pelvic CT scan in ED patients appears to be a reasonable solution to facilitate shorter ED stays, while maintaining the diagnostic quality of CT scans, and reducing the need for repeat examination. While ED time constraints have cer- tainly modified our current practice, taking action based on priorities has provided a reasonable approach based on demographics of our patient population.”
Oral contrast administration for abdominal and pelvic CT scan in emergency setting: is there a happy medium?
Sokhandon F
Abdom Radiol (2017) 42:784–785 - “According to the National Health and Nutrition Examination Survey (NHANES), 74% of adult men, older than 20 years of age in the United States, have BMI of greater than 25, and 38.3% of women have BMI greater than 30. Although unfortunate, these data are in favor of using the BMI protocol. Based on these data, the majority of our adult patients, specifically men, fall in the category in which we would not administer oral contrast.”
Oral contrast administration for abdominal and pelvic CT scan in emergency setting: is there a happy medium?
Sokhandon F
Abdom Radiol (2017) 42:784–785 - Oral Contrast in the ER in the Patient with Abdominal Pain
- Oral contrast with Omnipaque-350
- Oral contrast with water
- No oral contrast administered
- The deciding factor to most ERs if patient throughput not study accuracy - What are the consequences of lack of oral contrast?
- Missed diagnosis
- Indeterminate diagnosis which may lead to repeat CT or other studies
- Delay in diagnosis
- Radiologist dissatisfaction or stress - Can you administer oral contrast and not delay patient turnaround?
Where is the oral contrast and who gives it?
- Pharmacy
- Nurses station
- CT scanning area
- Other? - Purpose—To compare studies with and without oral contrast on performance of multidetector computed tomography (CT) and the order to CT examination turnaround time in cancer patients presenting to the emergency department (ED). To our knowledge, oral contrast utility has not previously been specifically assessed in cancer patients presenting to the emergency department.
Conclusion—On the basis of our findings and prior studies, targeted rather than default use of oral contrast shows acceptable diagnostic ability in the emergency setting for oncology patients. Benefit from oral contrast use is suggested in scenarios such as suspected fistula/bowel leak/ abscess, hypoattenuating peritoneal disease, prior bowel surgery such as gastric bypass, and the absence of intravenous contrast administration. Improvement through the use of targeted oral contrast administration also supports the emergency department need for prompt diagnosis and disposition.
Utility of CT Oral Contrast Administration in the Emergency Department of a Quaternary Oncology Hospital: diagnostic implications, turnaround times and assessment of ED physician ordering
Jensen CT et al.
Abdom Radiol 2017 November ; 42(11): 2760–2768. - “The administration of oral contrast typically requires a 60- to 90-minute delay before imaging to allow for distal bowel opacification. Huynh et al. reported a difference in order- to-scan times of 68 minutes between CT protocols performed with and without oral contrast. Studies have shown that eliminating oral contrast can increase patient throughput and improved overall patient experience, while maintaining diagnostic accuracy.”
Utility of CT Oral Contrast Administration in the Emergency Department of a Quaternary Oncology Hospital: diagnostic implications, turnaround times and assessment of ED physician ordering
Jensen CT et al.
Abdom Radiol 2017 November ; 42(11): 2760–2768. - "Our study evaluated an oncologic population presenting to the emergency department who underwent CT of the abdomen for abdominal complaints; no statistical difference in reader confidence or diagnosis was identified related to whether or not patients received oral contrast and there was a significant reduction in turnaround time for patients without oral contrast. This is in agreement with prior studies that have evaluated other patient populations.”
Utility of CT Oral Contrast Administration in the Emergency Department of a Quaternary Oncology Hospital: diagnostic implications, turnaround times and assessment of ED physician ordering
Jensen CT et al.
Abdom Radiol 2017 November ; 42(11): 2760–2768. - "On the basis of our findings and prior studies, targeted rather than default use of oral contrast shows acceptable diagnostic ability in the emergency setting for oncology patients. Benefit from oral contrast use is suggested in scenarios such as suspected fistula/bowel leak/abscess, hypo-attenuating peritoneal disease, prior bowel surgery such as gastric bypass, and the absence of intravenous contrast administration. Improvement through the use of targeted oral contrast administration also supports the emergency department need for prompt diagnosis and disposition.”
Utility of CT Oral Contrast Administration in the Emergency Department of a Quaternary Oncology Hospital: diagnostic implications, turnaround times and assessment of ED physician ordering
Jensen CT et al.
Abdom Radiol 2017 November ; 42(11): 2760–2768. - “While some of the above conditions that may benefit from positive oral contrast may not always be suspected clinically during ordering and thus may not receive such contrast, it appears that more cases will benefit from discriminant oral contrast use. Certainly other nuances of protocols can be considered, such as shorter administration time of oral contrast. Further prospective evaluations of oral contrast protocols are needed.”
Utility of CT Oral Contrast Administration in the Emergency Department of a Quaternary Oncology Hospital: diagnostic implications, turnaround times and assessment of ED physician ordering
Jensen CT et al.
Abdom Radiol 2017 November ; 42(11): 2760–2768. - When should oral contrast be used in the ER?
- If IV contrast can not be given
- thin patients with a paucity of intraabdominal fat
- Evaluations for possible anastomotic leak, fistula, extramural hematoma or abscess should typically include positive oral contrast - When should oral contrast be used in the ER?
- Hypoattenuating peritoneal disease adjacent to bowel loops can also be difficult to evaluate without oral contrast
- If the referring clinician requests it
- “Recently, a novel 3-dimensional visualization methodology for volumetric computed tomography data has become available. This method, known as cinematic rendering, uses an advanced lighting model to create photorealistic images from standard computed tomography acquisition data composed of isotropic voxels. We have observed that cinematic rendering visualizations in which patients have been administered dense, positive oral contrast do not have any substantive visual artifacts and can be used to demonstrate bowel pathology to advantage (ie, “virtual fluoroscopy”). In this technical note, we describe our acquisition and visualization parameters, and we also include demonstrative examples.”
Cinematic Rendering With Positive Oral Contrast: Virtual Fluoroscopy
Steven P. Rowe, Linda C. Chu, MD, Elliot K. Fishman,
J Comput Assist Tomogr 2019;43: 718–720 - “In this article, we describe our observation that CR can effectively display bowel anatomy and pathology after the administration of positive oral contrast with no perceptible visual artifacts. Indeed, the presence of positive oral contrast in CR images allows for highly detailed displays of the bowel mucosal fold pattern and might be considered a type of “virtual fluoroscopy.”
Cinematic Rendering With Positive Oral Contrast: Virtual Fluoroscopy
Steven P. Rowe, Linda C. Chu, MD, Elliot K. Fishman,
J Comput Assist Tomogr 2019;43: 718–720 
Cinematic Rendering With Positive Oral Contrast: Virtual Fluoroscopy
Steven P. Rowe, Linda C. Chu, MD, Elliot K. Fishman,
J Comput Assist Tomogr 2019;43: 718–720- “As demonstrated in this article, CR can produce photorealistic images of the oral contrast–opacified bowel without significant vi- sual artifact. The intrinsic advantages of CR, including high levels of surface detail and realistic shadowing, contribute to the visualization of the bowel in a manner analogous to fluoroscopic studies. In- deed, the quality of the visualizations would suggest that CR may have the ability to replace fluoroscopy in certain contexts, while preserving the anatomic and pathologic information that would normally be obtained from a fluoroscopic examination, with the exception that real-time imaging of motion of the bowel and compression maneuvers are not possible. The preset parameters included in this article may be helpful as a starting point for further evaluation of the utility of CR in this context.”
Cinematic Rendering With Positive Oral Contrast: Virtual Fluoroscopy
Steven P. Rowe, Linda C. Chu, MD, Elliot K. Fishman,
J Comput Assist Tomogr 2019;43: 718–720 - “Photorealistic CR images of the bowel after administration of positive oral contrast demonstrate detailed anatomy and pathology without evidence of visual artifacts. We postulate that CR of the bowel with positive contrast may be able to function as a “virtual fluoroscopy” in some contexts, although this will require significantly more studies to validate.”
Cinematic Rendering With Positive Oral Contrast: Virtual Fluoroscopy
Steven P. Rowe, Linda C. Chu, MD, Elliot K. Fishman,
J Comput Assist Tomogr 2019;43: 718–720
- “Recently, a novel 3-dimensional visualization methodology for volumetric computed tomography data has become available. This method, known as cinematic rendering, uses an advanced lighting model to create photorealistic images from standard computed tomography acquisition data composed of isotropic voxels. We have observed that cinematic rendering visualizations in which patients have been administered dense, positive oral contrast do not have any substantive visual artifacts and can be used to demonstrate bowel pathology to advantage (ie, “virtual fluoroscopy”). In this technical note, we describe our acquisition and visualization parameters, and we also include demonstrative examples.”
Cinematic Rendering With Positive Oral Contrast: Virtual Fluoroscopy
Steven P. Rowe, Linda C. Chu, MD, Elliot K. Fishman,
J Comput Assist Tomogr 2019;43: 718–720 - “In this article, we describe our observation that CR can effectively display bowel anatomy and pathology after the administration of positive oral contrast with no perceptible visual artifacts. Indeed, the presence of positive oral contrast in CR images allows for highly detailed displays of the bowel mucosal fold pattern and might be considered a type of “virtual fluoroscopy.”
Cinematic Rendering With Positive Oral Contrast: Virtual Fluoroscopy
Steven P. Rowe, Linda C. Chu, MD, Elliot K. Fishman,
J Comput Assist Tomogr 2019;43: 718–720
Cinematic Rendering With Positive Oral Contrast: Virtual Fluoroscopy
Steven P. Rowe, Linda C. Chu, MD, Elliot K. Fishman,
J Comput Assist Tomogr 2019;43: 718–720- “As demonstrated in this article, CR can produce photorealistic images of the oral contrast–opacified bowel without significant vi- sual artifact. The intrinsic advantages of CR, including high levels of surface detail and realistic shadowing, contribute to the visualization of the bowel in a manner analogous to fluoroscopic studies. In- deed, the quality of the visualizations would suggest that CR may have the ability to replace fluoroscopy in certain contexts, while preserving the anatomic and pathologic information that would normally be obtained from a fluoroscopic examination, with the exception that real-time imaging of motion of the bowel and compression maneuvers are not possible. The preset parameters included in this article may be helpful as a starting point for further evaluation of the utility of CR in this context.”
Cinematic Rendering With Positive Oral Contrast: Virtual Fluoroscopy
Steven P. Rowe, Linda C. Chu, MD, Elliot K. Fishman,
J Comput Assist Tomogr 2019;43: 718–720 - “Photorealistic CR images of the bowel after administration of positive oral contrast demonstrate detailed anatomy and pathology without evidence of visual artifacts. We postulate that CR of the bowel with positive contrast may be able to function as a “virtual fluoroscopy” in some contexts, although this will require significantly more studies to validate.”
Cinematic Rendering With Positive Oral Contrast: Virtual Fluoroscopy
Steven P. Rowe, Linda C. Chu, MD, Elliot K. Fishman,
J Comput Assist Tomogr 2019;43: 718–720
- OBJECTIVE. The objective of our study was to evaluate the diagnostic performance of CT in the identification of anastomotic leaks.
ONCLUSION. Diagnostic performance of CT was highest when an intraluminal contrast agent was used. Meticulous and careful use of an intraluminal contrast agent is therefore important in this patient population.
Anastomotic Leaks After Small- and Large-Bowel Surgery: Diagnostic Performance of CT and the Importance of Intraluminal Contrast Administration Samji KB et al. AJR 2018; 210:1259–1265 -
RESULTS. The most sensitive imaging predictor was intraabdominal free fluid (95.3%). Leakage of intraluminal contrast agent was also a highly specific imaging predictor (96.6%). Substantial interobserver agreement was shown for intraabdominal free gas (κ = 0.76) and leakage of intraluminal contrast agent (κ = 0.76). Overall diagnostic performance in correctly identifying surgically confirmed leaks, as assessed by the area under the ROC curve, ranged from 0.76 to 0.86. Diagnostic performance was higher for all readers when intraluminal contrast agent was used and reached the anastomosis, with the exception of one reader, whose di- agnostic performance remained unchanged.
Anastomotic Leaks After Small- and Large-Bowel Surgery: Diagnostic Performance of CT and the Importance of Intraluminal Contrast Administration Samji KB et al. AJR 2018; 210:1259–1265
- “A study involving 1223 patients reported an incidence rate of 2.7%. Although leaks usually present within days of the surgery, they can present more than 30 days after surgery. Timely and accurate diagnosis of these leaks is essential for the management of these patients; mortality of patients with an anastomotic leak after bowel surgery can range between 7.5% and 39%.”
Anastomotic Leaks After Small- and Large-Bowel Surgery: Diagnostic Performance of CT and the Importance of Intraluminal Contrast Administration Samji KB et al. AJR 2018; 210:1259–1265 -
“The most sensitive findings associated with surgically proven leaks were disseminated intraabdominal free fluid (95.3%) and gas (84.3%). Perianastomotic inflammatory stranding, fluid, and gas were also highly sensitive findings (81.8%, 71.2%, and 67.2%, re- spectively). Reduced bowel wall enhancement and bowel obstruction at the anastomosis were the least sensitive findings (6.7% and 4.7%) but were highly specific (96.1% and 99.5%); however, these findings were rarely present.”
Anastomotic Leaks After Small- and Large-Bowel Surgery: Diagnostic Performance of CT and the Importance of Intraluminal Contrast Administration Samji KB et al. AJR 2018; 210:1259–1265 - “In conclusion, although there is some over- lap of CT findings in patients with and in those without anastomotic leaks, the identification of certain highly sensitive and specific findings—including leakage of intraluminal contrast agent outside the bowel lumen—should assist the radiologist in correctly identifying these leaks. Although the overall sensitivity of CT for the detection of anastomotic leakage remains low, diagnostic performance was improved by using an intraluminal contrast agent and ensuring that it reaches the anastomosis. This study strongly suggests that meticulous and careful use of intraluminal contrast agents (orally or rectally administered) is important in this patient population.”
Anastomotic Leaks After Small- and Large-Bowel Surgery: Diagnostic Performance of CT and the Importance of Intraluminal Contrast Administration Samji KB et al. AJR 2018; 210:1259–1265 - “This study strongly suggests that meticulous and careful use of intraluminal contrast agents (orally or rectally administered) is important in this patient population.”
Anastomotic Leaks After Small- and Large-Bowel Surgery: Diagnostic Performance of CT and the Importance of Intraluminal Contrast Administration Samji KB et al. AJR 2018; 210:1259–1265
- 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.
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.
Preparative Fasting for Contrast- Enhanced CT in a Cancer Center: A New Approach Paula N. V. P. Barbosa et al. AJR 2018; 210:941–947 - “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.”
Preparative Fasting for Contrast- Enhanced CT in a Cancer Center: A New Approach Paula N. V. P. Barbosa et al. AJR 2018; 210:941–947 - “The historical basis for preparative fasting for contrast-enhanced CT is the concern over pulmonary aspiration of gastric contents and aspiration pneumonia after vomiting. Though this may have been a significant clinical issue for first-generation hyperosmolar contrast agents, which caused nausea and vomiting in 4.58% and 1.84% of cases, respectively, the introduction of nonionic low-osmolarity contrast agents has decreased the frequency of vomiting to approximately 0.3%.”
Preparative Fasting for Contrast- Enhanced CT in a Cancer Center: A New Approach Paula N. V. P. Barbosa et al. AJR 2018; 210:941–947 - “Most diagnostic imaging centers ask patients to fast for 4–6 hours before contrast- enhanced examinations. However, patients who abstain from food and liquids for prolonged periods also tend to be more anxious and less cooperative during the examination, in addition to being more susceptible to adverse reactions to the IV contrast medium.”
Preparative Fasting for Contrast- Enhanced CT in a Cancer Center: A New Approach Paula N. V. P. Barbosa et al. AJR 2018; 210:941–947 - “The present findings revealed no clinical- ly and statistically significant differences in the frequency of adverse reactions in outpatients with cancer undergoing contrast-enhanced CT with or without preparative fasting. These findings, together with our clinical experience at an imaging center, support the guidelines provided by the French Radiology Society, which do not recommend fasting before contrast-enhanced CT scans, because the absence of adequate nutrition and hydration may increase the likelihood of adverse reactions to contrast agent administration.”
Preparative Fasting for Contrast- Enhanced CT in a Cancer Center: A New Approach Paula N. V. P. Barbosa et al. AJR 2018; 210:941–947 - “In the present investigation, patients also reported unexpected symptoms after contrast agent administration, such as flushing, dizziness, ear pruritus, tingling, tremor, pain at the injection site, tachycardia, and headaches. These manifestations, referred to as “other unexpected symptoms,” were significantly associated with fasting. Though infrequent, these symptoms are likely to contribute to patient irritability and uncooperativeness.”
Preparative Fasting for Contrast- Enhanced CT in a Cancer Center: A New Approach Paula N. V. P. Barbosa et al. AJR 2018; 210:941–947
- “Our Emergency physicians do not see that oral contrast administration for CT hampers operational efficiency; in fact, they have expressed gratitude to our department for care in diagnosis. They have stated that delays in patient turnaround are more frequently related to overall demand on the scanner and not to the oral contrast consumption period. They are all acutely aware of the serious consequences of missed or incorrect diagnoses (either leading to inappropriate hospital admission or discharge), and will always choose good medical care over time slashing, corner cutting methods that impress the dashboard monitors perhaps at the expense of excellence in patient care.”
Oral contrast utilization for abdominal/pelvic CT scanning in today’s emergency room setting Megibow A.J. Abdom Radiol (2017) 42: 781. doi:10.1007/s00261-016-0941-2 - “In summary, the Radiology department at NYU-Langone Medical Center has, through dialogue with our Emergency Medicine section, reaffirmed the benefits of oral contrast utilization for CT scanning of ED patients. We have found that stocking the oral contrast in the ED and allowing a 45-min period for oral contrast administration coordinated with obtaining clinical and laboratory information facilitate radiologic diagnosis with a high level of confidence and accuracy. As stated by JRD Tata, it is insistence on relentless attention to detail and insistence on highest standards of quality and performance that are the keys to productivity and efficiency, most certainly not through cutting corners.”
Oral contrast utilization for abdominal/pelvic CT scanning in today’s emergency room setting Megibow A.J. Abdom Radiol (2017) 42: 781. doi:10.1007/s00261-016-0941-2 - ”Utilizing a BMI threshold of 25 for adult men, and 30 for adult women, to administer oral contrast for abdominal and pelvic CT scan in ED patients appears to be a reasonable solution to facilitate shorter ED stays, while maintaining the diagnostic quality of CT scans, and reducing the need for repeat examination. While ED time constraints have certainly modified our current practice, taking action based on priorities has provided a reasonable approach based on demographics of our patient population.”
Oral contrast administration for abdominal and pelvic CT scan in emergency setting: is there a happy medium? Sokhandon, F. Abdom Radiol (2017) 42: 784. doi:10.1007/s00261-016-0969-3
- OBJECTIVE. The purpose of this study is to objectively and subjectively compare nonionic iohexol and ionic diatrizoate iodinated oral contrast agents as part of a cathartic bowel regimen within the same CT colonography (CTC) cohort, with otherwise identical preparations.
CONCLUSION. On the basis of this direct intrapatient comparison, we found that oral iohexol is a suitable alternative to diatrizoate for fluid tagging as part of a cathartic bowel preparation at CTC. Because this nonionic tagging agent is more palatable, less expensive, and likely safer than ionic diatrizoate, our CTC program now uses iohexol as the standard recommended regimen.
Objective and Subjective Intrapatient Comparison of Iohexol Versus Diatrizoate for Bowel Preparation Quality at CT Colonography
Johnson B et al. AJR 2016; 206:1202–1207 - CONCLUSION. On the basis of this direct intrapatient comparison, we found that oral iohexol is a suitable alternative to diatrizoate for fluid tagging as part of a cathartic bowel preparation at CTC. Because this nonionic tagging agent is more palatable, less expensive, and likely safer than ionic diatrizoate, our CTC program now uses iohexol as the standard recommended regimen.
Objective and Subjective Intrapatient Comparison of Iohexol Versus Diatrizoate for Bowel Preparation Quality at CT Colonography
Johnson B et al. AJR 2016; 206:1202–1207 - “One important feature of high-quality CTC is adequate bowel preparation before the examination to ensure both removal of bulk stool and contrast tagging of any residual material remaining in the colon. Tagging of solid residual stool can be accomplished with dilute (2% weight/volume [w/v]) barium sulfate, whereas uniform tagging of residual luminal fluid requires iodinated water-soluble agents.”
Objective and Subjective Intrapatient Comparison of Iohexol Versus Diatrizoate for Bowel Preparation Quality at CT Colonography
Johnson B et al. AJR 2016; 206:1202–1207 - “In conclusion, our initial experience with iohexol at CTC shows that it represents a suitable alternative to diatrizoate for fluid tagging as part of a cathartic bowel prepa- ration. On the basis of these results, in con- junction with iohexol being more palatable, less expensive, and presumably safer than diatrizoate, we think that iohexol can replace diatrizoate in routine clinical practice and have implemented this change in our program.”
Objective and Subjective Intrapatient Comparison of Iohexol Versus Diatrizoate for Bowel Preparation Quality at CT Colonography
Johnson B et al. AJR 2016; 206:1202–1207
- 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.”
Abdominal and pelvic CT: is positive enteric contrast still necessary? Results of a retrospective observational study. Kammerer S et al. Eur Radiol. 2015 Mar;25(3):669-78. - “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.”
Abdominal and pelvic CT: is positive enteric contrast still necessary? Results of a retrospective observational study. Kammerer S et al. Eur Radiol. 2015 Mar;25(3):669-78. - “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..”
Abdominal and pelvic CT: is positive enteric contrast still necessary? Results of a retrospective observational study. Kammerer S et al. Eur Radiol. 2015 Mar;25(3):669-78. - “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.”
Abdominal and pelvic CT: is positive enteric contrast still necessary? Results of a retrospective observational study. Kammerer S et al. Eur Radiol. 2015 Mar;25(3):669-78.
- In the ER setting do we need to use contrast agents?
- Oral contrast
- IV contrast
- Rectal contrast
- Any combination of the above
- No contrast needed - “Omitting oral contrast for imaging patients with BMI >25 presenting with acute abdominal pain resulted in no delayed or missed diagnoses, in our retrospective study. The benefits of prompt imaging diagnosis outweigh the unlikely need for repeat imaging.”
Is Oral Contrast Necessary for Multidetector Computed Tomography Imaging of Patients With Acute Abdominal Pain? Alabousi A, Patlas MN, Sne N, Katz DS Can Assoc Radiol J. 2015 Jul 9. pii: S0846-5371(15)00038-8. [Epub ahead of print] - “We conducted a retrospective study to assess the effect of discontinuing oral contrast use for MDCT scans of the abdomen and pelvis for patients presenting with acute abdominal pain and body mass index (BMI) >25. Patients with BMI <25 continued to receive oral contrast. The medical records were reviewed to determine the rate of repeat imaging within 7 days from the initial CT scan, as well as delayed or missed diagnoses related to the absence of oral contrast. The study was approved by the research ethics board at our institution.”
Is Oral Contrast Necessary for Multidetector Computed Tomography Imaging of Patients With Acute Abdominal Pain? Alabousi A, Patlas MN, Sne N, Katz DS Can Assoc Radiol J. 2015 Jul 9. [Epub ahead of print] - “A total of 1378 patients had an MDCT examination of the abdomen and pelvis between November 1, 2012, and October 31, 2013. 375 patients met the inclusion criteria (174 males and 201 females; mean age 57 years; range 18-97 years). Seven of 375 (1.9%) patients had a repeat CT examination with oral contrast within 7 days. Of these 7 patients, none had a change in the course of their management due to the utilization of oral contrast. No delayed or missed diagnoses related to the absence of oral contrast were identified.”
Is Oral Contrast Necessary for Multidetector Computed Tomography Imaging of Patients With Acute Abdominal Pain? Alabousi A, Patlas MN, Sne N, Katz DS Can Assoc Radiol J. 2015 Jul 9. [Epub ahead of print] - “PURPOSE: The purpose of our study was to validate the hypothesis that eliminating the use of oral contrast for multidetector computed tomography (MDCT) would not affect the detection of acute abdominal abnormalities in emergency room patients
CONCLUSION: Omitting oral contrast for imaging patients with BMI >25 presenting with acute abdominal pain resulted in no delayed or missed diagnoses, in our retrospective study. The benefits of prompt imaging diagnosis outweigh the unlikely need for repeat imaging..”
Is Oral Contrast Necessary for Multidetector Computed Tomography Imaging of Patients With Acute Abdominal Pain? Alabousi A, Patlas MN, Sne N, Katz DS Can Assoc Radiol J. 2015 Jul 9. [Epub ahead of print] - “In patients with body mass index greater than 25 presenting to the ED with acute abdominal pain, CT examinations can be acquired without oral contrast without compromising the clinical efficacy of CT.”
Evaluation of Acute Abdominal Pain in the Emergency Setting Using Computed Tomography Without Oral Contrast in Patients With Body Mass Index Greater Than 25. Uyeda JW et al. J Comput Assist Tomogr. 2015 Aug 5. [Epub ahead of print] - “Of the 1992 patients included in this study, 4 patients (0.2%) underwent repeat CT studies directly related to the absence of oral contrast on the original examination. Of the 1992 CT scans, 1193(59.8%) were interpreted as negative, none of which required surgery or direct intervention. In patients with acute appendicitis, there was a sensitivity of CT in this patient population of 100% with a specificity of 99.5%.”
Evaluation of Acute Abdominal Pain in the Emergency Setting Using Computed Tomography Without Oral Contrast in Patients With Body Mass Index Greater Than 25. Uyeda JW et al. J Comput Assist Tomogr. 2015 Aug 5. [Epub ahead of print] - “PURPOSE: To evaluate the rate of delayed or missed diagnoses and need for additional computed tomography (CT) imaging in emergency department patients with abdominal pain who are imaged without oral contrast.
CONCLUSIONS: In patients with body mass index greater than 25 presenting to the ED with acute abdominal pain, CT examinations can be acquired without oral contrast without compromising the clinical efficacy of CT.”
Evaluation of Acute Abdominal Pain in the Emergency Setting Using Computed Tomography Without Oral Contrast in Patients With Body Mass Index Greater Than 25. Uyeda JW et al. J Comput Assist Tomogr. 2015 Aug 5. [Epub ahead of print] - “Abdominal CT scan without the use of oral contrast is accurate to allow for appropriate decision making by emergency physicians and general surgeons. In our series, no patients required repeat scanning. Further assessment by larger studies is appropriate.”
Emergency department experience with nonoral contrast computed tomography in the evaluation of patients for appendicitis. Glauser J, Siff J, Emerman C J Patient Saf. 2014 Sep;10(3):154-8. - “STUDY OBJECTIVES: The American College of Radiology lists oral contrast as an institution-specific option in the evaluation of right lower quadrant pain. Previous literature indicates that an accurate assessment for appendicitis can be made by CT using IV contrast alone, with significant time savings from withholding oral contrast. Before 2010, the protocol for CT use in the evaluation of possible appendicitis or undifferentiated abdominal pain routinely included oral contrast. The purpose of this study was to determine the incidence of repeat CT scans with oral contrast for the purpose of arriving at a final disposition in patients undergoing evaluation for abdominal pain. This analysis was also to determine if the general surgery service was willing and able to make accurate clinical determinations to operate without the use of oral contrast..”
Emergency department experience with nonoral contrast computed tomography in the evaluation of patients for appendicitis. Glauser J, Siff J, Emerman C J Patient Saf. 2014 Sep;10(3):154-8. - “RESULTS: A total of 311 CT scans met the study criteria. No cases of appendicitis were missed. Two patients were operated on based upon inflammatory findings in the right lower quadrant, one with typhlitis, the second with possible inflammatory bowel disease versus typhlitis. In each case, the diagnosis was made by CT, but the surgery service chose to operate based on clinical findings. Sixteen (5.14%; 95% CI, 3.2%-8.2%) cases of acute appendicitis were accurately identified. A normal appendix was visualized in 125 (40.2 %; 95% CI, 34.9-45.7) patients. No patients (0%; 95% CI, 0%-1.2%) required a repeat CT scan with oral contrast as part of the workup. On 30-day follow-up by chart review, no (0%; 95% CI, 0%-1.2%) significant surgical problems were identified, and no cases of missed appendicitis were identified.”
Emergency department experience with nonoral contrast computed tomography in the evaluation of patients for appendicitis. Glauser J, Siff J, Emerman C J Patient Saf. 2014 Sep;10(3):154-8.
- “ Eliminating routine oral contrast use for AP CT in the ED may be successful in decreasing LOS and time from order to CT without demonstrated compromise in acute patient diagnosis.”
Eliminating routine oral contrast use for CT in the emergency department: impact on patient throughput and diagnosis
Levenson RB et al.
Emerg Radiol (2012) 19:513-517
- Do you need to be NPO for contrast enhanced CT scans?
- Overnight fasting
- 4-6 hours prior to the study
- 2-3 hours prior to the study
- Not needed at all - “ There is little evidence that ingestion of clear inert flluid prior to contrast enhanced CT is a cause of aspiration pneumonia; the length of fasting is variable in any country, being much long in some hospitals than in others.”
Preparative Fasting for Contrast-Enhanced CT: Reconsideration
Lee BY et al.
Radiology 2012;263:444-450 - “ The literature provides no direct evidence suggesting that ingestion of inert fluids prior to CT with intravenous contrast adminiastration causes aspiration pneumonia.”
Preparative Fasting for Contrast-Enhanced CT: Reconsideration
Lee BY et al.
Radiology 2012;263:444-450 - JHU Policy 2012
- Do not eat 3 hours before the study
- Drink lots of fluids though try to avoid coffee especially if you are scheduled for a cardiac CT scan
- Drink lots of fluid for the 24 hours after the CT scan is completed
"Of 287 subjects who expressed a preference, 233 patients (81%) preferred dilute iohexol compared with 54 patients (19%) who preferred dilute diatrizoate sodium.ten patients had no preference and 3 did not complete the taste comparison study."
Oral Contrast Media for Body CT: Comparison of Diatrizoate Sodium and Iohexol for Patient Acceptance and Bowel Opacification
McNamara MM et al.
AJR 2010;195:1137-11411"Patients preferred dilute iohexol over dilute diatrizoate sodium for oral contrast for abdominal-pelvic CT. There was no significant difference in bowel opacification or adverse effect profile."
Oral Contrast Media for Body CT: Comparison of Diatrizoate Sodium and Iohexol for Patient Acceptance and Bowel Opacification
McNamara MM et al.
AJR 2010;195:1137-11411- "We have recently switched completely to LOCM for our oral contrast during CT scanning. Iohexol is the only LOCM with Food and Drug Administration approval for use as an oral contrast at this time."
The Use of Iohexol as Oral Contrast for Computed Tomography of the Abdomen and Pelvis
Horton KM, Fishman EK, Gayler B
J Comput Assist Tomogr 2008; 32:207-209 - "Whole milk is comparable to VoLumen with respect to bowel distension 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."
Cost Effectiveness and Patient Tolerance of Low-Attenuation Oral Contrast Material: Milk Versus VoLumen
Koo CW et al.
AJR 2008; 190:1307-1313 - Milk contains 4% fat and slows peristalsis and gives good distension of small bowel.
Cost Effectiveness and Patient Tolerance of Low-Attenuation Oral Contrast Material: Milk Versus VoLumen
Koo CW et al.
AJR 2008; 190:1307-1313