Gastrografin can be detected in ex vivo biological specimens by dual-energy CT scanning.

BACKGROUND: Dual-energy CT is able to distinguish between materials based on differences in X-ray absorption at different X-ray beam energies. The strong k-edge photoelectric effect of materials with a high atomic number makes this modality ideal for identifying iodine-containing compounds. We aim to evaluate dual-energy CT for the detection of Gastrografin (GG) (diatrizoate, Bayer PLC, Reading, UK) enteric contrast medium and validate the conditions for the measurement in ex vivo samples. METHODS: Dual-energy CT acquisitions were performed to detect Gastrografin in serial dilutions of water, saline and body fluids. We also evaluated the stability of Gastrografin solutions over time at room temperature. Stool specimens were examined to validate the proposed study protocol for clinical applications. RESULTS: Concentrations as low as 0.2% of Gastrografin were reproducibly detected in vitro and ex vivo samples by DECT, with linear readings ranging from 0.2% to 25% Gastrografin. Gastrografin was shown to be stable in ex vivo biological samples, and there was no difference in detection over time. Gastrografin was detected in stool specimens when administered orally. The detection curves followed the expected saturation effect at high concentrations of iodine. CONCLUSIONS: Dual-energy CT offers a convenient, quick, reliable and reproducible method for detecting and quantifying the presence of Gastrografin in ex vivo clinical specimens. Biological solutions containing Gastrografin are stable over time. A minimum dilution level of 25% is suggested to avoid beam saturation and inaccurate results.

Contrast media (meglumine diatrizoate) aggravates renal inflammation, oxidative DNA damage and apoptosis in diabetic rats which is restored by sulforaphane through Nrf2/HO-1 reactivation.

Diabetes mellitus is an independent risk factor for renal impairment in patients exposed to contrast media. It doubles the risk and decreases survival rate of contrast induced nephropathy (CIN). Sulforaphane has antioxidant properties via Nrf2 activation. The interaction of diabetes and/or sulforaphane with contrast media on Nrf2 regulation is not yet understood. Herein, diabetes was induced by a single intra-peritoneal injection of streptozotocin. Animals were then divided into five groups; control non-diabetic group; diabetic group; diabetic/sulforaphane group; diabetic/CIN group; diabetic/CIN/sulforaphane group. Animals were assessed 24 h after CIN induction. Sulforaphane improved the impaired nephrotoxicity parameters, histopathological features, and oxidative stress markers induced by contrast media (meglumine diatrizoate) in diabetic rats. Immunofluorescence detection revealed increased Nrf2 expression in kidney sections after sulforaphane pretreatment. Moreover, gene expression of Nrf2 and HO-1 were up-regulated, while IL-6 and caspase3 were down-regulated in kidney tissues of animals pretreated with sulforaphane. In NRK-52E cells, sulforaphane pretreatment significantly ameliorated the cytotoxicity of meglumine diatrizoate. However, silencing Nrf2 using small interfering RNA (siRNA) abolished the cytoprotective effects of sulforaphane. Collectively, the results of this study suggest that Nrf2/HO-1 pathway has a protective role against CIN and support the clinical implication of Nrf2 activators, such as sulforaphane, in CIN particularly in diabetic patients.

An Incidental Discovery of Morgagni Hernia in an Elderly Patient Presented with Chronic Dyspepsia.

A Morgagni hernia was first described in 1761 by Giovanni Morgagni. In adults, it is accompanied by gastrointestinal- or respiratory-type symptoms. Herein, we report an 84-year-old woman presented to our hospital with nausea and vomiting. After hospitalization, an X-ray revealed a right diaphragmatic hernia. Based on the results of abdominal computed tomography, duodenoscopy, and upper gastrointestinography (gastrografin), we concluded that her symptoms were caused by Morgagni hernia. Our patient underwent laparoscopic surgery, and shortly thereafter, her symptoms resolved.

Composite silica coated gold nanosphere and quantum dots nanoparticles for X-ray CT and fluorescence bimodal imaging.

In this study, silica coated Au nanospheres (Au@SiO2) were prepared by a reverse microemulsion method; subsequently, a layer of fluorescent quantum dots (QDs) were adsorbed onto it and then it was coated with silica again. After modifying with PVP, the composite silica coated gold nanosphere and quantum dots nanoparticle (Au@SiO2-QDs/SiO2-PVP) was obtained. This composite structure contained Au and QDs, and it could be used for contrast-enhanced X-ray CT imaging and fluorescence imaging. Characterization showed that the composite nanoparticle had good dispersity, a high fluorescence intensity and a good effect of X-ray absorption, and it was suitable for using as a bimodal imaging probe.

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.

Matching the rheological properties of videofluoroscopic contrast agents and thickened liquid prescriptions.

In the treatment of oropharyngeal dysphagia, the link between diagnosis and prescription of thickened liquids that are safe to swallow is not always straightforward. Frequently, the capacity to objectively assess and quantify the rheological properties of diagnostic test fluids and to select "rheologically equivalent" dietary products is missing. Perhaps sometimes the importance of an objective comparison is not fully appreciated because two liquids seem reasonably similar in a subjective comparison (e.g., flow from a spoon). The present study deals with some of these issues. Shear viscosity measurements were used to characterize the flow behavior of videofluoroscopic contrast agents and of thickened fluids prepared with commercial thickening agents. Effects of time and composition of the different fluids were analyzed regarding shear-rate-dependent viscosity. Nearly all materials tested showed a pronounced dependence of viscosity with shear rate ("shear thinning"). Results confirm that it is feasible (but not always straightforward) to "match" the viscosities of diagnostic fluids and thickened beverages if certain precautions are taken. For example, the time required to reach final viscosity levels can be significant for some thickeners, particularly when used with liquids containing contrast agents. It is recommend to use only diagnostic materials and thickening agents for which reliable viscosity data are available.

Dry powdered aerosols of diatrizoic acid nanoparticle agglomerates as a lung contrast agent.

Aerosolized contrast agents may improve the resolution of biomedical imaging modalities and enable more accurate diagnosis of lung diseases. Many iodinated compounds, such as diatrizoic acid, have been shown to be safe and useful for radiographic examination of the airways. Formulations of such compounds must be improved in order to allow imaging of the smallest airways. Here, diatrizoic acid nanoparticle agglomerates were created by assembling nanoparticles into inhalable microparticles that may augment deposition in the lung periphery. Nanoparticle agglomerates were fully characterized and safety was determined in vivo. After dry powder insufflation to rats, no acute alveolar tissue damage was observed 2h post-dose. Diatrizoic acid nanoparticle agglomerates possess the characteristics of an efficient and safe inhalable lung contrast agent.

Osmolarity: a decisive parameter of bowel agents in intestinal magnetic resonance imaging.

The aim was to evaluate the importance of the osmolarity of different oral agents for bowel distension and the level of related adverse events. The longitudinal design included the exposition of different oral MR agents on two separate occasions. Four groups of volunteers were randomly given 350 ml gastrografin of three different concentrations and water. On the second occasion they received mannitol, iohexol or iodixanol with equivalent osmolarities, but the control group (water) received mannitol. We recorded the outcomes as the degree of bowel distension determined as the mean bowel section area and the total level of discomfort recorded from a visual analogue scale (VAS). The statistical analysis included scatter plots with the best-fitted line with linear regression to study the association between osmolarity and section area and the association between osmolarity and adverse events. A dose-response association was found between increasing osmolarity levels and bowel area in square centimeters (P = 0.00001). A similar dose-response association existed between increasing levels of osmolarity and adverse events (P = 0.001). Osmolarity appears to be more important for bowel distension than the physico-chemical characteristics of the nonabsorbable oral agents. The optimum osmolarity level is determined by the patient's tolerance of the adverse events.

Effect of water-soluble contrast in colorectal surgery: a prospective randomized trial.

AIM: Postoperative gastrointestinal-tract motility is normally delayed. Early feeding after colorectal surgery has been reported recently, but late feeding is common. Gastrografin not only enhances bowel peristalsis, but also decreases bowel-wall edema. Whether contrast medium allows early oral feeding and reduces the duration of hospitalization requires clarification. METHODS: Fifty patients underwent elective colorectal surgery in a regional medical center. Patients were prospectively randomized into a Gastrografin group or control group (n = 25 each). Patients in the Gastrografin group began their feeding schedule with 100 mL of 5% dextrose water with 100 mL of Gastrografin on postoperative d 3 and were advanced to a full liquid diet when the contrast reached the colon in 4 h. Patients in the control group began their feeding schedule with 200 mL of 5% dextrose water on postoperative d 3 and were advanced to a full liquid diet after the passage of flatus and stool. Nasogastric tubes were inserted for persistent postoperative vomiting. Fullness, nausea, vomiting, complications, time of anesthesia, time of operation, time of mobilization, time of oral feeding, and duration of hospital stay were recorded and analyzed with Student's t-test. RESULTS: In the Gastrografin group, one patient had aspiration pneumonia and one patient had anastomotic leakage resulting in sepsis and eventual death. This mortality was excluded from the subsequent statistical analysis. In the control group, two patients had wound infections. There was no significant difference between the two groups at the time of anesthesia, time of operation, or time of mobilization. There were significant differences between the two groups in the time of oral feeding (3.3+/-0.3 d in the Gastrografin group vs 4.8+/-0.4 d in the control group; P = odds ratio--, 95%CI [-0.5 to +0.7 d]) and in the length of hospital stay (7.6+/-1.1 d in the Gastrografin group vs 10.2+/-1.3 d in the control group; P = odds ratio--, 95% CI [-1.2 to +1.4 d]). CONCLUSION: Gastrografin not only allowed early oral feeding but also reduced the duration of hospitalization after elective colorectal surgery.

Permeability of iodinated and MR contrast media through two types of hemodialysis membrane.

The clearance of three iodinated contrast media (CM) and three MR-CM through two kinds of hemodialysis (HD) membranes were investigated in vitro. All three MR-CM are not only injected intravenously and mainly secreted through the kidney, but also now commercially available. Each of the six CM showed significantly higher clearance with one kind of HD membrane, with a larger pore size, than that with the other. There were also large differences in clearance between the three iodinated CM with both kinds of HD membranes, but not between the three MR-CM with either kind of membrane. Thus, in order that iodinated CM be removed from the body as soon as possible in HD patients, it is important to consider the choice not only among the iodinated CM, but also between the type of HD membrane that is used. Concerning MR-CM, only the choice of HD membrane is important.

Oral contrast agents for CT: a taste test survey.

PURPOSE: Our goal was to evaluate the palatability of the currently available oral contrast agents for CT. METHOD: We surveyed 202 adults (92 women and 110 men) with a mean age of 59 years. Each participant sampled five or eight products. The participants ingested 1 oz. of each product and recorded an overall score, taking into account the factors of palatability that were important to them. Scores were marked on a visual analog rating scale with 0 representing "dislike a lot" and 10 representing "like a lot." RESULTS: The following mean palatability scores were obtained: Gastrografin mixed with Tropical Punch Kool-Aid 8.2; Scan C 5.7; Cheetah 4.7; Readi-Cat 4.4; E-Z-Cat 4.0; Tomo-Cat 3.6, Prep-Cat 3.5; Baro-Cat 3.2; Lipomul mixed with water 3.1. CONCLUSION: Statistical cluster analysis suggested the following groupings of the products (i.e., products with statistically similar scores grouped together): Cluster 1-Kool-Aid with Gastrografin; Cluster 2-Scan C, Cheetah, Readi-Cat: Cluster 3-E-Z-Cat, Tomo-Cat, Prep-Cat, Baro-Cat, Lipomul.

Adverse effects of calcium binding contrast agents in diagnostic cardiac angiography. A comparison between formulations with and without calcium binding additives.

RATIONALE AND OBJECTIVES: The authors compared complications and hemodynamic and electrophysiologic effects of two formulations of diatrizoate, one with additives that bind calcium and one without, in diagnostic cardiac angiography. METHODS: Two hundred twenty-three consecutive low-risk patients alternately received Hypaque 76 (group 1, little calcium binding effect), and MD 76 (group 2, significant calcium binding). Electrocardiographic and hemodynamic changes related to coronary angiography and left ventriculography were measured, and complications requiring treatment were recorded. RESULTS: There were more complications in patients in group 2 than in group 1 (18 versus 8, P = 0.04). Arterial pressure fell more, the QT interval increased more, and the heart rate fell more in group 2 after coronary angiography. CONCLUSIONS: Formulations of diatrizoate that minimize calcium binding are advocated for cardiac angiography when using high osmolality contrast media. The more detrimental effects that calcium binding has on myocardial function and cardiac conduction may lead to the higher incidence of complications.

Local and systemic effects of water-soluble contrast media and barium in rats with chronic small bowel obstruction.

RATIONALE AND OBJECTIVES: The local effects on the small intestine and systemic changes produced by different contrast media in small bowel obstruction, with time courses of 4 days, were evaluated. MATERIALS AND METHODS: Four groups, each with 10 normal rats and another four groups (also each with 10 rats) that had ligation of the terminal ileum (obstructed rats) for 4 days were given 3 mL of barium, meglumine sodium diatrizoate, iohexol, or saline (control animals). Radiographs were taken immediately, 1 and 4 hours after administration of contrast media. Immediately before sacrifice, blood samples were taken to determine the hematocrit (Hct), hemoglobin (Hb), white blood cell count (WBC), red blood cell count (RBC), and serum sodium, and potassium and chloride concentrations. Specimens of small bowel were taken for histologic and morphometric analysis. RESULTS: In obstructed rats, the image quality with iohexol improved on final radiographs despite being diluted in the great intestinal contents. There was an improvement in the serum electrolyte concentrations in the obstructed animals that were given any one of the contrast media, the best improvement being in the iohexol groups. A shortening of the length of epithelial cells when any one of the contrast media was administered was observed, as was an increase in the lymphatic space area in the diatrizoate group in normal rats. In the bowel proximal to the obstruction, the lymphatic space area was increased in the diatrizoate group and the size of the epithelial cells was higher in the diatrizoate and iohexol groups compared to the barium and saline groups. CONCLUSION: Our results suggest that iohexol offers good radiologic efficacy and excellent systemic and local tolerance in small bowel obstruction.

Effect of static pressure on the disappearance rate of specific echocardiographic contrast agents.

Contrast echocardiography has been applied to identify cardiac structures, shunts, and perfusion territories. Most recently, quantification of flow has been proposed based on disappearance of contrast intensity. This requires that contrast agents are stable and produce a predictable effect. To assess the possible effect of pressure on their stability, the rates of backscatter decay of four echocardiographic contrast agents (Albunex, Levovist, agitated Angiovist, and agitated saline solution) exposed to constant pressures (0, 50, 100, 150, and 200 mm Hg) were quantitated. Contrast was recorded by echocardiography and measured to construct time-intensity curves. The peak decay rate for each agent at each pressure was determined. For all four agents, contrast intensity (I) decreased over time and could be described by the sigmoid function: I = a [e-lambda(t-ts)/1 + e-lambda(t-ts)] + C. Peak decay rate was significantly affected by pressure (p < 0.005) in a proportionate fashion. At pressures of 0, 100, and 200 mm Hg, the rates increased for each agent in the following fashion: Albunex, 0.144 +/- 0.109 to 0.410 +/- 0.142 to 1.442 +/- 0.309; Levovist, 0.060 +/- 0.023 to 0.162 +/- 0.049 to 0.495 +/- 0.142; Angiovist, 0.089 +/- 0.028 to 0.166 +/- 0.057 to 0.224 +/- 0.027; and saline solution, 0.068 +/- 0.039 to 0.110 +/- 0.036 to 0.154 +/- 0.057. The effect of pressure on the peak rate of contrast disappearance (lambda) was significantly different among agents (p < 0.001). Thus attempts to quantitate blood flow with contrast agents must take into account the influence of pressure.

Laser angioplasty: enough to make your blood boil!

Some of the effects on blood and contrast agents of a laser angioplasty device of the "hot tip" variety have been studied. This device liberates iodine from contrast agents both in the form of soluble free iodide and in the form of solid elemental iodine debris. Some of the solid iodine does not adhere to the probe but remains free and, in vivo, would be available to embolize distal vessels. The liberation of iodine occurs more readily with dimeric agents than with monomeric contrast agents regardless of whether they are ionic or non-ionic. Blood and blood/contrast agent mixtures exhibit local boiling in the vicinity of the hot tip laser probe. Blood so treated exhibits markedly accelerated clotting as indicated by measurements of whole blood clotting times. Untreated blood to which aliquots of blood treated as described above are added also exhibits accelerated clotting. The laser tip, operating in blood/iodine mixtures, becomes coated with a friable black/brown deposit which analysis reveals to be a mixture of carbon and iodine. Again, some of this particulate debris fails to adhere to the probe and is available as free embolic material. The possible practical clinical implications of these observations are discussed.