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Sample records for standard contrast medium

  1. Ioversol contrast medium in canine neuroradiology

    International Nuclear Information System (INIS)

    Tudury, E.A.; Arias, M.V.B.; Camargo, P.L. de; Faria, M. de L.E.; Machado, C.E.G.

    1997-01-01

    Ioversol, a non-ionic, hydrosoluble iodine contrast medium at a concentration of 320mg I/ml was used to perform 26 contrast neuroradiographic studies (myelography, epidurography and cerebral ventriculography) in 22 dogs. Since this contrast medium is rapidly absorbed, proper radiographs were obtained within 30 minutes of injection. The product showed adequate radio-opacity, retention time, diffusion and liquor miscibility. Minimal side effects both during and after the radiographic procedures were observed. Not one patient developed seizures, in spite of the use of anesthetic protocols that included either zolarepan-tiletamine or levomepromazin- zilazine- or diazepam-sodium thiopental. The presentation of the contrast medium in a multiple dose vial was considered an advantage, since it decreases losses and allows repeated sterilization in autoclave [pt

  2. Effects of computed tomography contrast medium factors on contrast enhancement

    International Nuclear Information System (INIS)

    Terasawa, Kazuaki; Hatcho, Atsushi; Okuda, Itsuko

    2011-01-01

    The various nonionic iodinated contrast media used in contrast computed tomography (CT) studies differ in terms of their composition, characteristics, and iodine concentration (mgI/ml), as well as the volume injected (ml). Compared with ionic iodinated contrast media, nonionic iodinated contrast media are low-osmolar agents, with different agents having different osmotic pressures. Using a custom-made phantom incorporating a semipermeable membrane, the osmotic flow rate (hounsfield unit (HU)/s) could easily be measured based on the observed increase in CT numbers, and the relationship between the osmotic pressure and the osmotic flow rate could be obtained (r 2 =0.84). In addition, taking the effects of patient size into consideration, the levels of contrast enhancement in the abdominal aorta (AA) and inferior vena cava (IVC) were compared among four types of CT contrast medium. The results showed differences in contrast enhancement in the IVC during the equilibrium phase depending on the type of contrast medium used. It was found that the factors responsible for the differences observed in enhancement in the IVC were the osmotic flow rate and the volume of the blood flow pathways in the circulatory system. It is therefore considered that the reproducibility of contrast enhancement is likely to be reduced in the examination of parenchymal organs, in which scanning must be performed during the equilibrium phase, even if the amount of iodine injected per unit body weight (mgI/kg) is maintained at a specified level. (author)

  3. Radiculography with reduced amounts of contrast medium

    International Nuclear Information System (INIS)

    Signorini, E.; Caputo, N.; Chiurulla, C.; Ciorba, E.; Pelliccioli, G.P.; Cianciulli, E.

    1984-01-01

    Because of the frequency and seriousness of side effects observed after radiculography, due to, among the other things, the amount of contrast medium, the authors describe a method that gives diagnostically satisfactory results using a low dose of contrast and a tangent-beam technique. Among 106 patients undergoing radiculography with a tangent-beam technique and Iopamidol, only 4 developed mild side effects, namely headache in three cases and headache with nausea in one. (Author)

  4. Radiculography with water-soluble contraste medium

    International Nuclear Information System (INIS)

    Araujo Pinheiro, R.S. de

    1987-01-01

    The etiologic diagnosis of the lumbar pain is discussed. The radiculography with water-soluble contrast medium is used and 250 cases are studied. Some practical criteria of indication executation and interpretation of the examination are reported. (M.A.C.) [pt

  5. Contrast medium extravasation in intravenous urography

    Energy Technology Data Exchange (ETDEWEB)

    Tosch, U.; Becker-Gaab, C.; Hahn, D.

    1984-09-01

    Aetiology and diagnostic procedure of calyceal fornix rupture during intravenous urography are discussed. In the literature the fornix rupture is discribed as a spontaneous event - not so in the four cases presented. In two cases a sudden increase in intrapelvic pressure was due to an ureteric calculus, in the other cases an obstruction of the ureter was secondary to neoplasm. It is recommended to perform a CT as soon as a contrast medium extravasation in intravenous urography is diagnosed.

  6. Contrast medium-induced nephropathy: the pathophysiology

    DEFF Research Database (Denmark)

    Persson, P B; Tepel, Martin

    2006-01-01

    A widespread, rather general, definition of contrast-induced nephropathy (CIN) is an impairment in renal function occurring within 3 days following the intravascular administration of contrast media (CM) and the absence of an alternative aetiology. In spite of the vast clinical importance of CIN...... the current knowledge of the mechanisms causing CIN, it is not possible to recommend a certain class of contrast media, except to avoid large doses of CM of the first generation. From a pathophysiological perspective, volume expansion is effective in avoiding CIN, since water permeability of the collecting...

  7. Histamine release and endothelial leakage from an intravascular contrast medium

    Energy Technology Data Exchange (ETDEWEB)

    Raininko, R.

    1981-04-01

    The endothelial injury produced by meglumine iodamide was studied in the rat aorta. A mixture of blood and contrast medium was more toxic to the endothelium than the pure contrast agent. This difference disappeared after premedication with antihistamine, which did not affect the injury produced by the pure contrast agent. Meglumine iodamide appears to cause a release of histamine from blood but not from the aortic endothelium nor from surrounding tissues in amounts demonstrable by this method. Leucocytes are a source of histamine after intravascular contrast medium administration.

  8. Renal clearance of an ionic high-osmolar and a nonionic low-osmolar contrast medium

    International Nuclear Information System (INIS)

    Thomsen, H.S.; Vestergaard, A.; Nielsen, S.L.; Fogh-Andersen, N.; Golman, K.; Dorph, S.

    1991-01-01

    One hundred patients with normal serum creatinine concentration underwent intravenous urography with either an ionic high-osmolar (diatrizoate) or a nonionic low-osmolar (iopamidol) contrast medium after randomization. Before injection of the contrast medium, a blood sample was drawn for determinating serum creatinine concentration, and a urine sample for measurement of urine osmolality. Using x-ray fluorescence, the plasma concentration of iodine (contrast medium) was determined on blood samples drawn approximately 3 and 4 hours after injection of the contrast medium. The glomerular filtration rate was calculated by two different formulas: one requiring only a single sample and one requiring at least two samples (standard). There were poor correlations between the standard contrast medium clearance and the serum creatinine concentration, the estimated creatinine clearance (calculated from a nomogram), as well as the urine osmolality. The 3-hour and the 4-hour single-sample values correlated well with the two-sample values for both contrast media. In patients with normal serum creatinine, the glomerular filtration rate determined by measuring the contrast medium concentration in a single plasma sample obtained at 3 hours, is almost identical to the value determined from two samples. Consequently, two samples are unnecessary

  9. Potential mechanisms behind contrast medium-induced nephropathy

    African Journals Online (AJOL)

    How contrast medium-induced nephropathy (CIN) comes about is poorly understood, although CIN is a common cause of acute renal failure. Hitherto, the various studies performed have led to different interpretations and partially contradictory conclusions. This article aimed to review the mechanisms underlying CIN and to ...

  10. Extravasation of contrast medium during CT examination: An ...

    African Journals Online (AJOL)

    Introduction: extravasation is an adverse reaction to intravenous injection of contrast medium (CM) during CT examination. The objectives of this study are to determine the frequency, management and outcomes of extravasations and to assess risk factors for extravasation. Methods: every incident of extravasation which ...

  11. An Individually Optimized Protocol of Contrast Medium Injection in Enhanced CT Scan for Liver Imaging

    Directory of Open Access Journals (Sweden)

    Shi-Ting Feng

    2017-01-01

    Full Text Available Objective. To investigate the effectiveness of a new individualized contrast medium injection protocol for enhanced liver CT scan. Methods. 324 patients who underwent plain and dual phase enhanced liver CT were randomly assigned to 2 groups: G1 (n=224, individualized contrast medium injection protocol; G2 (n=100, standard contrast medium injection with a dose of 1.5 ml/kg. CT values and ΔHU (CT values difference between plain and enhanced CT of liver parenchyma and tumor-liver contrast (TLC during hepatic arterial phase (HAP and portal venous phase (PVP and contrast medium dose were measured. The tumor conspicuity of hepatocellular carcinoma (HCC between two groups was independently evaluated by two radiologists. Results. The mean contrast medium dose of G1 was statistically lower than that of G2. There were no significantly statistical differences in CT values and ΔHU of liver parenchyma during HAP, TLC values during HAP, and PVP between two groups. The CT values and ΔHU of liver parenchyma during PVP of G2 were significantly higher than those of G1. Two independent radiologists were both in substantial conformity in grading tumor conspicuity. Conclusion. Using the individually optimized injection protocol might reduce contrast medium dose without impacting on the imaging quality in enhanced liver CT.

  12. Contrast enhancement technique in brain 3D-CTA studies. Optimizing the amount of contrast medium according to scan time based on TDC

    International Nuclear Information System (INIS)

    Terasawa, Kazuaki; Hatcho, Atsushi

    2008-01-01

    In three-dimensional CT angiography (3D-CTA), good reproducibility can be obtained by maintaining the maximum CT numbers (HU) at a specified level. However, the correlation between the scan time and the injection time showed that the maximum CT numbers increased and varied due to the additional contrast enhancement effect from recirculation of the injected contrast medium for longer injection times when the dose of iodinated contrast medium per unit time (mgI/s) was maintained at a specified level based on the time-density curve (TDC) of the phantom. The amount of contrast medium employed at our hospital has been optimized based on an iodinated contrast medium dose per unit time providing a contrast enhancement effect of 300 HU in the middle cerebral artery. Using this standard, a TDC phantom was employed to obtain an iodinated contrast medium dose per unit time, permitting equivalent maximum CT values (used as standard values) to be obtained by changing the injection time. A contrast-enhancement technique that accounts for the variation in the scan time was evaluated. Strong correlations were observed between the scan time and the injection time (R 2 =0.969) and between the injection time and the dose of iodinated contrast medium per unit body weight (R 2 =0.994). We conclude that adjusting the dose of iodinated contrast medium per unit body weight per unit time according to the scan time permits optimization of the contrast-enhancement technique. (author)

  13. Post-contrast acute kidney injury - Part 1: Definition, clinical features, incidence, role of contrast medium and risk factors : Recommendations for updated ESUR Contrast Medium Safety Committee guidelines.

    Science.gov (United States)

    van der Molen, Aart J; Reimer, Peter; Dekkers, Ilona A; Bongartz, Georg; Bellin, Marie-France; Bertolotto, Michele; Clement, Olivier; Heinz-Peer, Gertraud; Stacul, Fulvio; Webb, Judith A W; Thomsen, Henrik S

    2018-02-09

    The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 2011 guidelines on the prevention of post-contrast acute kidney injury (PC-AKI). The results of the literature review and the recommendations based on it, which were used to prepare the new guidelines, are presented in two papers. AREAS COVERED IN PART 1: Topics reviewed include the terminology used, the best way to measure eGFR, the definition of PC-AKI, and the risk factors for PC-AKI, including whether the risk with intravenous and intra-arterial contrast medium differs. • PC-AKI is the preferred term for renal function deterioration after contrast medium. • PC-AKI has many possible causes. • The risk of AKI caused by intravascular contrast medium has been overstated. • Important patient risk factors for PC-AKI are CKD and dehydration.

  14. Contrast medium enhancement of soft tissues and brain in CT examinations of dogs

    CERN Document Server

    Pavlicek, M

    2000-01-01

    CT is a x-ray based method which shows less contrast for soft tissue as has been known from radiography. Therefore, it is necessary to use intravenously administered iodine contrast media to detect and localize tumors, fistulas or other pathologic lesions. Usually contrast medium is administered manually which yields random patterns of media distribution due to varying application pressure during varying administration time, therefore enhancement of parenchymous organs could not be used to the optimum extent. The use of an automatic injection pump guarantees the necessary constancy during the examination procedure to undoubtedly detect pathologic enhancement of organs in the CT-image as known from human medicine. The standards which are expected of the injection pump and the contrast media are: a good contrast enhancement, a good accumulation in the examined organs, an accumulation, which lasts long enough during the diagnostic phase, and a rapid excretion without side effects. Because of the short scan time ...

  15. Hypersensitivity reactions and contrast medium injection: Are they always related?

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    Boehm, Ingrid, E-mail: i.boehm@uni-bonn.de [Department of Radiology, Philipps University of Marburg, Baldingerstrasse, 35039 Marburg (Germany); Alfke, Heiko [Department of Radiology, Klinikum Luedenscheid, Luedenscheid (Germany); Klose, Klaus Jochen [Department of Radiology, Philipps University of Marburg, Baldingerstrasse, 35039 Marburg (Germany)

    2011-11-15

    Background: Hypersensitivity (allergic or non-allergic) reactions that occur after contrast medium (CM) injection are usually related to the CM. Recent studies, and case reports lack the analysis of alternate causes that could be also responsible in individual cases. Patients and methods: We investigated the individual relevant factor/causative agent of adult patients with hypersensitivity reactions that occurred in radiological units during CM-enhanced procedures (CT, angiography, urography, or MR-examinations). Both immediate and non-immediate (delayed) reactions were included. To find out the relevant agent a detailed patients' history was carefully analyzed. In addition, the records were retrospectively reviewed, and if indicated and possible laboratory (e.g. basophil activation test) and skin tests (e.g. prick) and/or provocations with CM-injections under routine conditions were performed. Results: 38 patients (men n = 21) suspected for CM-hypersensitivity reactions were identified. These reactions were in most cases mild (n = 21), moderate reactions occurred in 13 cases, and four patients had severe reactions. In 28 patients the reactions were induced by the CM (iodinated CM in 25 cases). Four patients had reactions that were not CM-related (latex allergy, adenosine reaction, vasovagal reaction, unknown cause) and in six cases the reaction was partly CM-related (immunological activation was present due to the patients' diseases). Conclusion: Our data support the hypothesis that in CM-enhanced procedures not only contrast materials but also a broad range of other factors may also induce hypersensitivity reactions. Therefore, the number of CM-induced hypersensitivity is smaller than initially suspected. The knowledge of the cause of a reaction is essential to effectively prevent its recurrence and to improve safety aspects in patients undergoing CM-injection. Larger trials should be performed to more specifically assess alternate causes in patients

  16. Patient radiation dose during fluoroscopy testes with contrast medium

    International Nuclear Information System (INIS)

    Darsalih, Abir Abdelrady El noor

    2016-09-01

    The purpose of this study was to assess the patient radiation dose received in fluoroscopy examinations during contrast medium. The cumulative air kerma (Ck), kerma area product (KAP) and fluoroscopy time were measured for sixty ( male and female ) patients undergoing five fluoroscopy examinations KAP metre which was installed for the purpose of this study. The mean kerma area product were found to be 2.681, 5.1561, 9.85529. 5.7974 and 13.09 Gy.cm 2 for HSG, A.S and D.S, GI Track and sonogram tests, respectively. The obtained mean cumulative dose was were 6.31, 13.88, 24.61, 22.56 and 32.14 mGy for HSG, A.S, A.S and D.S , GI Track, respectively, the mean fluoroscopy time were. 0.18, 0.51,0.89,1.57 and 1.75 min, for HSG, A.S, A.S, and D.S, G1 Track and sonogram test respectively. Patient dose is mainly dependent on the patient size, procedure, equipment used exposure factor and user experience. As KV and mA were controlled by the AEC and it was found to be well calibrated, possible optimization could be achieved by radiologist by decreasing the exposure time if possible. (Author)

  17. Improve identification of details in double-contrast examination of the stomach by means of a new contrast medium mixture

    International Nuclear Information System (INIS)

    Tenner, R.

    1984-01-01

    In a contrast medium study, 100 patients were employed for a comparison between the contrast medium Mikropaque liquid and a mixture of Mikropaque HD and Mikropaque liquid in double-contrast examination of the stomach. The special feature of this method was that one and the same stomach was examined in each case with both contrast media. The new contrast media mixture with Mikropaque HD represents a step forward; the contrast could be enhanced in 80% of the cases, and the finely contoured relief became visible in two-thirds of the cases, compared with one-third of the examined patients before this method was introduced. (orig.) [de

  18. Magnetic Resonance Imaging in degenerative disease of the lumbar spine: Fat Saturation technique and contrast medium.

    Science.gov (United States)

    D'Aprile, Paola; Nasuto, Michelangelo; Tarantino, Alfredo; Cornacchia, Samantha; Guglielmi, Giuseppe; Jinkins, J Randy

    2018-01-19

    To examine both anterior and posterior elements of the lumbar spine in patients with low back pain using MRI T2-weighted sequences with Fat Saturation (FS) and contrast enhanced T1-weighted sequences with FS. Two thousand eight hundred and twenty (2820) patients (1628 male, 1192 female, mean age 54) presenting low back pain underwent MRI standard examination (Sagittal T1w TSE and T2w TSE, axial T1 SE) with the addition of sagittal and axial T2w Fat Sat (FS) sequences. Among all the patients, 987 (35%) have been studied adding Contrast Enhanced (CE) T1w FS sequences after administration of contrast medium. Among 987 patients studied with contrast medium, we found: active-inflammatory intervertebral osteochondrosis in 646 (65%) patients; degenerative-inflammatory changes in facet joints (facet joint effusion, synovitis, synovial cysts) in 462 (47%); spondylolysis in 69 (7%); degenerative-inflammatory changes of the flava, interspinous and supraspinous ligaments in 245 (25%); inflammatory changes of posterior perispinal muscles in 84 (8%) patients. In patients with suspected no-disc-related low back pain, the implementation of T2w FS and CE T1w FS sequences to the standard MR protocol could allow a better identification of degenerative-inflammatory changes more likely associated to the pain.

  19. Contrast medium enhancement of soft tissues and brain in CT examinations of dogs

    International Nuclear Information System (INIS)

    Pavlicek, M.

    2000-11-01

    CT is an x-ray based method which shows less contrast for soft tissue as has been known from radiography. Therefore, it is necessary to use intravenously administered iodine contrast media to detect and localize tumors, fistulas or other pathologic lesions. Usually contrast medium is administered manually which yields random patterns of media distribution due to varying application pressure during varying administration time, therefore enhancement of parenchymous organs could not be used to the optimum extent. The use of an automatic injection pump guarantees the necessary constancy during the examination procedure to undoubtedly detect pathologic enhancement of organs in the CT-image as known from human medicine. The standards which are expected of the injection pump and the contrast media are: a good contrast enhancement, a good accumulation in the examined organs, an accumulation, which lasts long enough during the diagnostic phase, and a rapid excretion without side effects. Because of the short scan time of the modern CT-scanner, the best contrast enhancement can be administered by a short bolus injection, which can be applied by the automatic injection pump with a defined flow and a defined quantity of contrast media. This guarantees a good enhancement in the chosen region for the duration of the scan. The main aim of this study is to find a standardized flow and quantity of contrast media for defined regions and organs considering the speed of the scanner. In a subsequent step, the existing scan-protocols are then updated using the newly found information. This study showed, that CT examination of the head and brain in middle-sized dogs can be administered with a flow of 0.5 ml/s and a dose of 2 ml of contrast medium per kg weight. The contrast enhancement of the brain is caused by the enhancement of the vessels, the parenchym is free of contrast media - brain shows a low increase of density. Only if the blood-brain-barrier is destroyed, it is possible that

  20. Contrast medium enhancement of soft tissues and brain in CT examinations of dogs

    International Nuclear Information System (INIS)

    Pavlicek, M.

    2000-11-01

    CT is a x-ray based method which shows less contrast for soft tissue as has been known from radiography. Therefore, it is necessary to use intravenously administered iodine contrast media to detect and localize tumors, fistulas or other pathologic lesions. Usually contrast medium is administered manually which yields random patterns of media distribution due to varying application pressure during varying administration time, therefore enhancement of parenchymous organs could not be used to the optimum extent. The use of an automatic injection pump guarantees the necessary constancy during the examination procedure to undoubtedly detect pathologic enhancement of organs in the CT-image as known from human medicine. The standards which are expected of the injection pump and the contrast media are: a good contrast enhancement, a good accumulation in the examined organs, an accumulation, which lasts long enough during the diagnostic phase, and a rapid excretion without side effects. Because of the short scan time of the modern CT-scanner, the best contrast enhancement can be administered by a short bolus injection, which can be applied by the automatic injection pump with a defined flow and a defined quantity of contrast media. This guarantees a good enhancement in the chosen region for the duration of the scan. The main aim of this study is to find a standardized flow and quantity of contrast media for defined regions and organs considering the speed of the scanner. In a subsequent step, the existing scan-protocols are then updated using the newly found information. This study showed, that CT examination of the head and brain in middle-sized dogs can be administered with a flow of 0.5 ml/s and a dose of 2 ml of contrast medium per kg weight. The contrast enhancement of the brain is caused by the enhancement of the vessels, the parenchym is free of contrast media - brain shows a low increase of density. Only if the blood-brain-barrier is destroyed, it is possible that

  1. Contrast medium-induced nephropathy: Aspects on incidence ...

    African Journals Online (AJOL)

    Contrast media-induced nephropathy (CIN) is a well-known complication of radiological examinations employing iodine contrast media (I-CM). The rapid development and frequent use of coronary interventions and multi-channel detector computed tomography with concomitant administration of relatively large doses of ...

  2. Allergic reaction to contrast medium following gastric band adjustment.

    Science.gov (United States)

    Dewachter, Pascale; Mouton-Faivre, Claudie

    2007-10-01

    Bariatric surgery is increasingly performed for effective weight loss. A morbidly obese 27-year-old woman underwent laparoscopoic adjustable gastric banding. After a postoperative adjustment of the stomal diameter of the band with ioxaglate, she presented an immediate hypersensitivity reaction. With the patient's consent, cutaneous tests to contrast agents used during the procedure and to latex were performed. Allergy to ioxaglate was confirmed by skin-test positivity. This case suggests the need for allergological investigation of drugs/substances administered during the perioperative period, in case of hypersensitivity reaction.

  3. Contrast of Korean industrial standard and overseas standard

    International Nuclear Information System (INIS)

    Kim, Jong Deuk

    2006-12-01

    This book introduces Korean Industrial Standard and Overseas Standard, which deals with furniture, plasticizers, valcaning agents, gaskets, steel pipes and tubes. It covers wooden furniture for offices, washing dresser, children crib, chairs and desks for students, chairs and desks made from synthetic resins, tricresyl phosphate, dibutyl phthalate, dioctyl phthalate, phtalic acid dieptil, V packing, vulcanization accelerator CBS(CZ), vulcanization accelerator MBT(M), vulcanization accelerator Zn BDC, steel pipe for heating furnace and carbon steel pope for high voltage piping.

  4. The affects of contrast medium on renal function in selective coronary angiography and intervention

    International Nuclear Information System (INIS)

    Chen Yueguang; Lv Baojing

    2006-01-01

    Selective coronary angiography and intervention with injection of contrast medium into the coronary arteries has become very common in dealing with coronary cardiac diseases. The excretion of contrast medium through kidneys may lead to acute renal functional insufficiency, especially for those suffering from chronic nephropathy, diabetes and cardiac functional disorder to form the so called 'contrast medium nephropathy' which is considered as the number second drug induced acute renal functional failure. Although routine preventive measure including low osmotic contrast medium and fine hydrotherapy have been taken, 14% incidences still occur with renal functional damage. The majority could be reversible but the minority needs emergent hemodialysis or even with persistent renal functional damage in a few ones. (authors)

  5. Contrast-medium-induced nephropathy: is there a new consensus? A review of published guidelines

    International Nuclear Information System (INIS)

    Thomsen, Henrik S.; Morcos, Sameh K.

    2006-01-01

    The interest in contrast-medium-induced nephropathy has increased considerably during the last few years. Various guidelines regarding identifying patients at risk and measures to reduce the incidence of this complication have been proposed. The aim of this review was to analyse whether there is some consistency amongst these guidelines. A Medline search for the keyword ''contrast medium induced nephropathy'' during the period from the beginning of 2003 through the end of September 2005 was carried out. Only papers in English were reviewed. Thirteen guidelines were identified. Inconsistency was observed regarding advise on the prophylactic use of drugs and the isoosmolar dimer to reduce the incidence of contrast-medium-induced nephropathy. Consistency was found in relation to the importance of hydration, cessation of intake of nephrotoxic drugs and administration of the lowest possible dose of contrast medium. No new consensus has been observed in comparison to the European Society for Urogenital Radiology (ESUR) guidelines, which were published in 1999. (orig.)

  6. Aspiration of barium contrast medium in an elderly man with disordered swallowing

    OpenAIRE

    Bağcı Ceyhan, B.; Çelikel, T.; Koç, M.; Ahıskalı, R.; Biren, T.; Ataizi Çelikel, Ç.

    1995-01-01

    The aspiration of contrast medium during the investigation of gastrointestinal diseases is a well recognized hazard, particularly in patients with swallowing disorders. A case is reported in which accidental aspiration of contrast barium occurred owing to disordered swallowing in an elderly man. The infiltration on chest x-ray persisted 2 years after barium contrast aspiration. Inflammatory reaction and retractile, granular material observed in lung biopsy specimens suggested barium-induced p...

  7. Recommendation to use iso-osmotic contrast medium in interventional treatment

    International Nuclear Information System (INIS)

    Zhou Bing; Cheng Yongde

    2012-01-01

    With the rapid development of imaging diagnostic and interventional therapeutic techniques, the contrast medium (CM) has been used more and more common in clinical practice, and meanwhile more and more attention has been paid to the CM-related adverse events. Contrast induced nephropathy (CN) is the most common CM-related adverse event, and CM-related neurotoxicity has already attracted the physicians' attention. The osmotic pressure of the iso-osmotic contrast medium (IOCM) is quite the same as that of the plasma, and therefore its safety is higher than that of low-osmotic contrast medium (LOCM), the patient's tolerance to IOCM is better than that to LOCM. For this reason, the use of IOCM should be strongly recommended in interventional procedures, which is of great significance to the reduction of the occurrence of CM-related adverse events. (authors)

  8. CT contrasting theory. Effects of the concentration, volume and infusion rate of iodine contrast medium on TDC

    International Nuclear Information System (INIS)

    Yamachi, Jun

    2007-01-01

    This study was performed to evaluate the effects in the title on TDC (time-density curve) using a phantom. CT machine used was Toshiba Aquilion Multi 64, TDC phantom was the product of Nemoto-Kyorindo Co., and the contrast medium was Eisai iomeprol, in syringe-sealed formulations of 300 and 350 mg I/mL. The medium was infused at 1-5 mL/sec in the phantom equivalent to body weight of 78 kg (total water volume=1 min circulation=6,000 mL, 800 mL/heart) to obtain 30 TDCs. Evaluated were the relationships of the infusion rate (mL/sec), volume (mL) or time (sec) with TDC parameters of the detection time of the medium, slope, time to reach the maximum CT value, the maximum CT value, time to keep the CT concentration and its actual concentration. Results revealed that, regardless to the difference of formulations of the contrast medium, TDC with high reproducibility can be obtainable by making the infusion rate of I per unit time and body weight (mgI/sec/kg) constant when the infusion time is made identical for CT of the same diagnostic purpose. (R.T.)

  9. Contrast medium-enhanced MRI findings and changes over time in stage I tuberculous meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Oztoprak, I. [Department of Radiology Cumhuriyet University Faculty of Medicine, 58140 Sivas (Turkey)], E-mail: oztoprak@cumhuriyet.edu.tr; Guemues, C.; Oztoprak, B. [Department of Radiology Cumhuriyet University Faculty of Medicine, 58140 Sivas (Turkey); Engin, A. [Department of Infectious Diseases, Cumhuriyet University Faculty of Medicine, Sivas (Turkey)

    2007-12-15

    Aim: To demonstrate the detailed imaging characteristics of early tuberculous meningitis (TBM) and changes over time on standard gadolinium-enhanced, T1-weighted magnetic resonance imaging (MRI) images. Materials and methods: Contrast-enhanced, T1-weighted, spin-echo MRI images of 26 patients with early TBM were evaluated retrospectively. Meningeal enhancement characteristics were categorized according to distribution and pattern as diffuse, focal, linear, nodular, and mixed. Results: We found that 35% of patients had diffuse meningeal enhancement and 65% of cases had focal meningeal enhancement. There was a predilection for focal meningeal enhancement in basal pial areas, the interpeduncular fossa being the most common. In six patients with diffuse meningeal enhancement admitted to hospital relatively early after the onset of symptoms, the type of meningeal enhancement later changed to the focal form. Conclusion: Reactive diffuse meningeal enhancement occurs in the early period of TBM on contrast medium-enhanced T1-weighted MR images, but later becomes limited to basal areas.

  10. Contrast medium-enhanced MRI findings and changes over time in stage I tuberculous meningitis

    International Nuclear Information System (INIS)

    Oztoprak, I.; Guemues, C.; Oztoprak, B.; Engin, A.

    2007-01-01

    Aim: To demonstrate the detailed imaging characteristics of early tuberculous meningitis (TBM) and changes over time on standard gadolinium-enhanced, T1-weighted magnetic resonance imaging (MRI) images. Materials and methods: Contrast-enhanced, T1-weighted, spin-echo MRI images of 26 patients with early TBM were evaluated retrospectively. Meningeal enhancement characteristics were categorized according to distribution and pattern as diffuse, focal, linear, nodular, and mixed. Results: We found that 35% of patients had diffuse meningeal enhancement and 65% of cases had focal meningeal enhancement. There was a predilection for focal meningeal enhancement in basal pial areas, the interpeduncular fossa being the most common. In six patients with diffuse meningeal enhancement admitted to hospital relatively early after the onset of symptoms, the type of meningeal enhancement later changed to the focal form. Conclusion: Reactive diffuse meningeal enhancement occurs in the early period of TBM on contrast medium-enhanced T1-weighted MR images, but later becomes limited to basal areas

  11. Evaluation of changes in vertebral body density following administration of contrast medium during routine CT examination

    International Nuclear Information System (INIS)

    Janicek, M.; Bruna, J.; Stenhova, H.

    1984-01-01

    The possibility is discussed of depicting changes in the density of spongiosis of the vertebral body in normal patients after intravenous administration of a bolus of 40 ml 60% Diazetrizoate in the course of a routine CT examination. The average increase in density immediately after the administration of the contrast medium is 12 H (8%), in the course of 10 minutes is reduced to 5 H (4%) against the initial values in native examination. These average changes are statistically significant, in individual patients, however, the increase in density following the administration of a contrast medium fluctuates considerably (from 0.7% to 10%). Only systematic comparison with various pathological conditions will make it possible to assess the possibilities of the evaluation of the structure of the vertebral body in routine CT with the administration of a contrast medium into the blood flow. (author)

  12. Effects of use of the lodine contrast medium on gamma camera imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pyo, Sung Jae; Cho, Yun Ho [Dept. of Nuclear Medicine, Inha University hospital, Incheon (Korea, Republic of); Choi, Jae Ho [Dept. of Radiological Technology, Ansan College, Ansan (Korea, Republic of)

    2016-12-15

    Effects of Gamma camera imaging on gamma ray counting rates as a function of use and density of the iodine contrast medium currently in primary use for clinics, and changes in gamma ray counting rates as a function of the contrast medium status upon attenuation correction using a CT absorption coefficientin an SPECT/CT attenuation correction will be considered herein. For experimental materials used 99mTcO4 370 MBq and Pamiray 370 mg, Iomeron 350 mg, Visipaque 320 mg, Bonorex 300 mg of iodine contrast medium. For image acquisition, planar imaging was consecutively filmed for 1, 2, 3, 4, 5 min, respectively, 30 min after administration of 99mTcO4. while 60 views were filmed per frame for 20 min at 55 min for the SPECT/CT imaging. In planar imaging, the gamma ray counting rates as a function of filming time were reduced showing a statistically significant difference when mixed according to the type of contrast medium density rather than when the radioactive isotope 99mTcO4 and the saline solution were mixed. In the tomography for mixing of the radioactive isotope 99mTcO4 and saline solution, the mean counting rate without correction by the CT absorption coefficient is 182±26 counts, while the counting rate with correction by the CT absorption coefficient is 531.3±34 counts. In the tomography for mixing of the radioactive isotope 99mTcO4 and the saline solution with the contrast medium, the mean values before attenuation correction by CT absorption coefficient were 166±29, 158.3±17, 154±36, and 150±33 counts depending on the densities of the contrast medium, while the mean values after attenuation correction were 515±03, 503±10, 496±31, and 488.7±33 counts, showing significant differences in both cases when comparatively evaluated with the imaging for no mixing of the contrast medium. Iodine contrast medium affects the rate of gamma ray. Therefore, You should always be preceded before another test on the day of diagnosis.

  13. Acute Severe Thrombocytopenia Following Non-Ionic Low-Osmolarity Intravenous Contrast Medium Injection

    Energy Technology Data Exchange (ETDEWEB)

    Bata Pal; Domonkos, Adam; Tamoki, David Laszio; Horvath, Evelin; Berczi, Viktor; Szalay, Ferenc [Semmelweis University, Budapest (Hungary)

    2012-07-15

    Intravenous contrast medium (ICM) rarely induces anaphylactic reactions, including urticaria, hypotension and respiratory failure. Even the most modern ICM may cause such adverse events. Thrombocytopenia has been reported as an extreme rare consequence of ICM. Here we report on a case of a 72-year-old male patient with a self-limiting severe acute thrombocytopenia following administration of intravenous non-ionic low-osmolarity contrast medium. No such low platelet count has ever been reported. We also present a review of the literature.

  14. Use of iohexol as a gastrointestinal contrast medium in the dog

    International Nuclear Information System (INIS)

    Agut, A.; Sanchez-Valverde, M.A.; Lasaosa, J.M.; Murciano, J.; Molina, F.

    1993-01-01

    Iohexol was administered orally in five dogs. The dose, gastrointestinal (GI) transit time, appearance of mucosal patterns and side effects were studied. Three different doses (525, 700, 875 mgI/kg) were used in each dog at 1-week intervals. GI transit time was rapid. In each dose, gastric emptying commenced immediately after administration of the contrast medium, and was completed within 30–60 min with doses of 525–700 mgI/kg and 90–120 min with 875 mgI/kg. Large intestinal filling was observed within 60-90 min. In the majority of studies, the mucosal border appeared as a thin homogeneous halo of lucency surrounding the more opaque bowel lumen contents. The contrast intensity was not adequate with the lowest dose. The image quality did not deteriorate along the GI tract. No adverse reactions were found. Iohexol is an alternative GI contrast medium in the dog when contrast media are contraindicated

  15. Battery Ownership Model - Medium Duty HEV Battery Leasing & Standardization

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Ken; Smith, Kandler; Cosgrove, Jon; Prohaska, Robert; Pesaran, Ahmad; Paul, James; Wiseman, Marc

    2015-12-01

    Prepared for the U.S. Department of Energy, this milestone report focuses on the economics of leasing versus owning batteries for medium-duty hybrid electric vehicles as well as various battery standardization scenarios. The work described in this report was performed by members of the Energy Storage Team and the Vehicle Simulation Team in NREL's Transportation and Hydrogen Systems Center along with members of the Vehicles Analysis Team at Ricardo.

  16. MRI of the liver with the new contrast medium Gd-BOPTA

    International Nuclear Information System (INIS)

    Vogl, T.J.; Pegios, W.; Balzer, J.; Lissner, J.; Pirovano, G.

    1992-01-01

    A phase 1 study on 8 normals has been carried out to determine the effectiveness and safety during MRI of a new hepatobiliary contrast medium Gd-BOPTA for causing enhancement of the upper abdominal organs. Gradient echo sequences (flash), T 1 and T 2 -weighted spin echo sequences and turbo-flash sequences were used. The contrast medium was given as a single infusion in various concentrations (0.005, 0.05, 0.1 and 0.2 mmol/kg body weight). Optimal contrast of liver parenchyma was obtained with a dose of 0.05-0.1 mmol/kg body weight, resulting in contrast increase of 149.1% during gradient echo sequences and 107.8% during T 1 spin echo sequences. In general, the increased contrast lasted for about two hours. Because of the biliary and renal excretion there was an enormous increase in signal intensity of the bile ducts and a significant increase in the kidneys and ureters. The results of the first in-vivo-trial of Gd-BOPTA encourages the performance of further clinical studies of this new hepatobiliary contrast medium. (orig.) [de

  17. CO{sub 2} as a contrast medium in endoluminal treatment of high flow vascular malformations

    Energy Technology Data Exchange (ETDEWEB)

    Gorriz, Elias; Carreira, Jose M.; Reyes, Ricardo; Gallardo, Laura; Pulido, Juan M.; Romero, Alejandro; Maynar, Manuel

    1999-09-01

    Purpose: To evaluate the diagnostic usefulness of CO{sub 2} as a radiologic contrast medium in pre and post-embolization of hemodynamically active vascular malformations. Material and methods: Eight pre and post-embolization angiographies were performed on five patients with hemodynamically active vascular malformations. In all cases sequentially iodinated contrast medium and CO{sub 2} were used. Procedures were performed using Philips Integris V equipped with specific software to process images obtained with CO{sub 2} as contrast medium and with a purpose-built gas injector pump. The images were assessed by three interventional radiologists who evaluated the findings by consensus. They were asked whether uptake of the malformations were better, worse or the same with iodinated contrast and CO{sub 2}. The images were judged according to the following characteristics; quality, the filling in of the contrast in afferent artery of the HAVM, caliber and number of vessels and existence of pathologic communications in HAVM. These characteristics were assessed in all the patients of the study, both before and after embolization. Results: The CO{sub 2} angiographic results were compared to those obtained using iodinated contrast material. Iodinated contrast provided superior image quality in all performed studies. The filling of arterial afference of HAVM was well defined with both contrast media. In all performed cases with CO{sub 2}, the malformations showed more vessels. No immediate nor subsequent complications developed with CO{sub 2} injections, except in one female patient, who presented an intense sensation of cramps in the lower limbs. Conclusion: CO{sub 2} is a useful diagnostic and assessment tool before and especially during the embolization of hemodynamically active vascular malformations. It improves quantification and uptake of the malformation's vascular architecture, detecting collateral circulation and arteriovenous shunts. It also detects residual

  18. Oral contrast medium in PET/CT: should you or shouldn't you?

    International Nuclear Information System (INIS)

    Groves, Ashley M.; Kayani, Irfan; Dickson, John C.; Townsend, Caroline; Croasdale, Ian; Syed, Rizwan; Nagabushan, Nagesh; Hain, Sharon F.; Ell, Peter J.; Bomanji, Jamshed B.

    2005-01-01

    It has been suggested that the use of computed tomography (CT) positive contrast agents has led to attenuation-induced artefacts on 18 F-fluorodeoxyglucose positron emission tomography ( 18 F-FDG PET/CT) systems. Consequently, centres may withhold the use of such agents. Whilst there is theoretical evidence to support the aforementioned claim, the clinical relevance of the induced artefacts has not been widely established. Moreover, the potential benefits of bowel enhancement on PET/CT have yet to be formally evaluated. We therefore prospectively examined PET/CT studies to assess whether the use of oral contrast medium induces clinically relevant artefacts and whether the use of these agents is diagnostically helpful. Over a 2-month period, 18 F-FDG PET/CT images were prospectively reviewed from 200 patients following Gastrografin administration 2 h prior to examination. Both a radiologist and a nuclear medicine physician reviewed the images for contrast medium-mediated clinically relevant artefacts. Artefacts were sought on the CT attenuation-corrected images and were compared with the appearance on non-attenuated-corrected images. The number of examinations in which the oral contrast aided image interpretation was also noted. There were no oral contrast medium-induced clinically significant artefacts. In 38 of the 200 patients, oral contrast aided image interpretation (owing to differentiation of mass/node from bowel, discrimination of intestinal wall from lumen or definition of the anatomy of a relevant site). In 33 of these 38 patients, the anatomical site of interest was the abdomen/pelvis. The use of oral contrast medium in 18 F-FDG PET studies should not be withheld as it improves image interpretation and does not produce clinically significant artefacts. (orig.)

  19. Digital subtraction angiography and intraarterial contrast medium injection for coronary examinations

    Energy Technology Data Exchange (ETDEWEB)

    Tobio, R.; Kallmeyer, C.; Castello, J.

    1985-01-01

    Digital subtraction angiography (DSA) is an established method of vasography, most extensively used as i.v. DSA. Intraarterial injection, however, applying selective or non-selective contrast medium injection, seems to be at least as important a technique although it has not yet met with corresponding interest. The article explains advantages of the technique for angiographic examinations, in particular of coronary angiography.

  20. Comparison between two positive and one negative oral contrast medium for abdominal CT diagnosis

    International Nuclear Information System (INIS)

    Zwaan, M.; Gmelin, E.

    1989-01-01

    In a prospective randomised study three groups of 30 patients each were subjected to CT of the entire abdomen. The oral intestinal contrast media used were iodine solution (2%), barium suspension (1.5%) and paraffin emulsion (25%). The results were evaluated according to imaging, artifacts, assessability of the intestinal wall, taste and side effects. All three contrast media are suitable for marking the gastrointestinal tract; paraffin shows advantages in the upper part of the tract and is the only medium that enables assessment of the wall, while causing the lowest rate of artifacts. Barium has a high acceptance and the best tolerance of all contrast agents. (orig.) [de

  1. Transient partial amnesia complicating cardiac and peripheral arteriography with nonionic contrast medium

    International Nuclear Information System (INIS)

    Yildiz, A.; Yencilek, E.; Apaydin, F.D.; Duce, M.N.; Oezer, C.; Atalay, A.

    2003-01-01

    The aim of this study was to present a case of disruption of the blood-brain barrier during the coronary and lower extremity angiographies with radiological and clinical findings. This condition was secondary to intraarterial use of a nonionic, monomeric contrast medium. A total of 450 cc contrast media was used. Computed tomography examination showed contrast enhancement of the right occipital and frontoparietal cortical regions, which returned to normal one day after. The patient also fully recovered from the neurological symptoms within 24 h. We discussed the possible mechanism for blood-brain barrier disruption in this case. (orig.)

  2. Transient partial amnesia complicating cardiac and peripheral arteriography with nonionic contrast medium

    Energy Technology Data Exchange (ETDEWEB)

    Yildiz, A.; Yencilek, E.; Apaydin, F.D.; Duce, M.N.; Oezer, C. [Dept. of Radiology, Mersin Ueniv. Tip Fakueltesi Sokak Mersin (Turkey); Atalay, A. [Dept. of Cardiology, Mersin Ueniv. Tip Fakueltesi Sokak Mersin (Turkey)

    2003-12-01

    The aim of this study was to present a case of disruption of the blood-brain barrier during the coronary and lower extremity angiographies with radiological and clinical findings. This condition was secondary to intraarterial use of a nonionic, monomeric contrast medium. A total of 450 cc contrast media was used. Computed tomography examination showed contrast enhancement of the right occipital and frontoparietal cortical regions, which returned to normal one day after. The patient also fully recovered from the neurological symptoms within 24 h. We discussed the possible mechanism for blood-brain barrier disruption in this case. (orig.)

  3. Estimating standardized linear contrasts of means with desired precision.

    Science.gov (United States)

    Bonett, Douglas G

    2009-03-01

    L. Wilkinson and the Task Force on Statistical Inference (1999) recommended reporting confidence intervals for measures of effect sizes. If the sample size is too small, the confidence interval may be too wide to provide meaningful information. Recently, K. Kelley and J. R. Rausch (2006) used an iterative approach to computer-generate tables of sample size requirements for a standardized difference between 2 means in between-subjects designs. Sample size formulas are derived here for general standardized linear contrasts of k > or = 2 means for both between-subjects designs and within-subjects designs. Special sample size formulas also are derived for the standardizer proposed by G. V. Glass (1976).

  4. Clinical experience with a commercially available negative oral contrast medium in PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Hausegger, K.; Reinprecht, P. [Roentgendiagnostisches Zentralinstitut, LKH Klagenfurt (Austria); Kau, T. [Roentgendiagnostisches Zentral Inst., Klagenfurt (Austria); Igerc, I.; Lind, P. [Abt. fuer Nuklearmedizin und Spezielle Endokrinologie, LKH Klagenfurt (Austria)

    2005-06-01

    Purpose: to evaluate a commercially available negative oral contrast material for PET/CT. Material and methods: in a prospective series of 49 patients, Mukofalk {sup registered}, which is a vegetarian-based substance, was used as a negative oral contrast medium in whole body PET/CT studies. Mukofalk was administered during a time period of 1.5 hours before the examination. Quality of small bowl distension and eventual pathological tracer uptake in the intestine were evaluated. Results: distension of the small bowel was excellent or good in 41 (85%) and poor in 8 (15%) patients. Mild tracer uptake in the small bowel was observed in 5 patients (10.2%) and moderate uptake in another 2 patients (4%). In none of these patients did the F-18 FDG uptake interfere with image interpretation. Conclusion: Mukofalk {sup registered} can be used as a negative oral contrast medium in PET/CT studies. (orig.)

  5. Intravenous contrast medium application in elderly patients - evaluation of Iopentol (Imagopaque trademark 300)

    International Nuclear Information System (INIS)

    Rathsmann, P.; Jacobs, G.F.; Mueller, R.D.

    2004-01-01

    Purpose: We examined the subjective compatibility of elderly patients who received the intravenous contrast medium Iopentol (Imagopaque trademark 300). In addition, objective data were acquired to show possible interactions between contrast media and organ systems in old patients. Methods and materials: A CT scan with intravenous application of contrast media was performed on 132 patients ranging in age from 75 to 96 years. The patients were questioned about their individual sensations. In addition, blood pressure, creatinine and CT-densitometry were acquired as objective date. Results: The patients' individual sensations and clinical data show a very low rate of complications. Mild allergic reactions were noticed in two patients. No severe anaphylactic reactions were encountered. Statistically significant changes in blood pressure before and after administration of the contrast medium were not observed. The serum creatinine concentration was unchanged after application of contrast media. For CT-densitometry, the patients were divided into two groups, one group with patients 75-84 years and the other group with patients 85-96 years of age. CT-densitometry showed no age-related differences. The protocol of contrast administration resulted in excellent opacification of the examined regions, only the liver did not enhance in some cases before the opacification of the portal vein. Conclusion: It is shown that old age alone is no reason to withhold contrast media containing iodine when performing CT. For the evaluation of the liver, however, the peculiarities of old age have to be taken into account and the interval between injection of the contrast medium and beginning of the spiral-CT has to be extended. (orig.)

  6. Effect of barium sulfate contrast medium on rheology and sensory texture attributes in a model food.

    Science.gov (United States)

    Ekberg, O; Bulow, M; Ekman, S; Hall, G; Stading, M; Wendin, K

    2009-03-01

    The swallowing process can be visualized using videoradiography, by mixing food with contrast medium, e.g., barium sulfate (BaSO(4)), making it radiopaque. The sensory properties of foods may be affected by adding this medium. To evaluate if and to what extent sensory and rheological characteristics of mango purée were altered by adding barium sulfate to the food. This study evaluated four food samples based on mango purée, with no or added barium sulfate contrast medium (0%, 12.5%, 25.0%, and 37.5%), by a radiographic method, and measured sensory texture properties and rheological characteristics. The sensory evaluation was performed by an external trained panel using quantitative descriptive analysis. The ease of swallowing the foods was also evaluated. The sensory texture properties of mango purée were significantly affected by the added barium in all evaluated attributes, as was the perception of particles. Moreover, ease of swallowing was significantly higher in the sample without added contrast medium. All samples decreased in extensional viscosity with increasing extension rate, i.e., all samples were tension thinning. Shear viscosity was not as dependent on the concentration of BaSO(4) as extensional viscosity. Addition of barium sulfate to a model food of mango purée has a major impact on perceived sensory texture attributes as well as on rheological parameters.

  7. Water as a contrast medium: a re-evaluation using the multidetector-row computed tomography.

    Science.gov (United States)

    Makarawo, Tafadzwa P; Negussie, Edsa; Malde, Sachit; Tilak, Jacqueline; Gayagoy, Jennifer; Watson, Jenna; Francis, Faiz; Lincoln, Denis; Jacobs, Michael J

    2013-07-01

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

  8. Computed tomography of the cervical spine with iv injection of contrast medium

    International Nuclear Information System (INIS)

    Magnaldi, S.; Pozzi-Mucelli, R.S.; Cova, M.A.; De Morpurgo, P.

    1989-01-01

    Computed Tomography (CT) without contrast medium is largely applied to the study of intervertebral disk pathology in the lumbar spine, but has not been widely accepted in cervical spine, due to technical and anatomical limitations. For these reasons many neuroradiologists still prefer myelography or myelo-CT. CT may yield better results if combined with iv contrast medium injection, which allows a better visualization of disk herniation. This technique is aimed at enhancing the density of the venous plexus which is located close to the intervertebral disk the vertebral bodies and the neural foramina. A better contrast enhancement is thus obtained between the disk and the spinal cord. The authors' experience is based on 61 patients who underwent contrast enhanced CT; in 22 cases myelography and myelo-CT were also performed. The authors describe their technique and the most frequent CT findings of disk hernation: the typical finding includes a focal hypodensity surrounded by a linear blush, due to a posteriorly dislocated epidural vein. The posterior linear blush alone may be present in few cases. Contrast enhanced CT is very useful in the study of disk pathology of the cervical spine, even when compared with myelography and myelo-CT, due the increase in the density of epidural plexus it allows. However, the technique must be very accurate if the same results as those of myelo-CT are to be obtained

  9. Diagnostic capabilities of the contrast medium verografin in liposomes (animal experiments)

    International Nuclear Information System (INIS)

    Rozenberg, O.A.; Khason, K.P.; Aliyakparov, M.T.; Davidenkova, E.F.; Zherbin, E.A.; Akademiya Meditsinskikh Nauk SSSR, Leningrad. Inst. Ehksperimental'noj Meditsiny)

    1985-01-01

    Some examples for the diagnosis of various diseases of liver and spleen after intravenous (cats, dogs) or intraportal (rodents) injection of lecithin-cholesterol liposomes containing the water soluble contrast medium verografin are described. Tumors of 1 mm were found in the spleen of mice with lymphogranulomatosis, hepatomas of 3-5 mm in rats and lesions of 10 mm in cats with turpentine abscesses. The application of liposomes containing radiographic contrast media offers good possibilities for the diagnosis of liver and spleen. (author)

  10. Image contrast enhancement based on a local standard deviation model

    International Nuclear Information System (INIS)

    Chang, Dah-Chung; Wu, Wen-Rong

    1996-01-01

    The adaptive contrast enhancement (ACE) algorithm is a widely used image enhancement method, which needs a contrast gain to adjust high frequency components of an image. In the literature, the gain is usually inversely proportional to the local standard deviation (LSD) or is a constant. But these cause two problems in practical applications, i.e., noise overenhancement and ringing artifact. In this paper a new gain is developed based on Hunt's Gaussian image model to prevent the two defects. The new gain is a nonlinear function of LSD and has the desired characteristic emphasizing the LSD regions in which details are concentrated. We have applied the new ACE algorithm to chest x-ray images and the simulations show the effectiveness of the proposed algorithm

  11. Right arm injection of contrast medium reduces venous artifacts in head and neck multislice spiral computed tomography angiography.

    Science.gov (United States)

    Fang, H; Song, Y-L; Li, X-S; Bi, Y-M; Wang, P; Fan, H-X; Meng, L M; Hu, H-X

    2015-12-01

    We tested whether injection of contrast medium via right or left arm would affect venous artifacts on head and neck multislice spiral computed tomography (CT) angiography. 326 patients were enrolled. Each patient was injected with 10 ml of contrast medium at 5 ml/sec. Time of peak contrast value plus an additional 1 sec was defined as delay time. Another 40 ml of contrast medium were injected with the same injection speed. The scanning area ranged from the aortic arch to the top of the head. Left and right forearms were used for intravenous injections of contrast medium in, respectively, 151 and 175 patients. Comparative analyses of image quality included determining contrast medium residues remaining in the superior vena cava, brachiocephalic vein, or subclavian vein, and comparisons of quality of three-dimensional CT angiography. In 75% of head and neck angiographies, the delay time of the common carotid artery ranged from 16 to 22 sec. In 60% of the images, the quality was graded as excellent, with the left arm injection resulting in delay time of > 23 sec and the right arm delay time of > 18 sec. The CT imaging quality after contrast injections via left or right arms was statistically significant (p arm injection was better than after left arm injection. Intravenous injection of contrast medium via right arm reduces artifacts from contrast medium residues and improves the image quality of head and neck CT angiography.

  12. In vitro experiments for the development of a high density (HD) barium sulfate contrast medium

    International Nuclear Information System (INIS)

    Klein, J.

    1986-01-01

    In vitro experiments with the high-density (HD) barium meal Falibaryt HD are described. Several charges of BaSO 4 were tested together with certain additives influencing dispersion, stability of the suspension, flowability, surface tension etc. Particle size spectra were measured by the manufacturer, VEB Fahlberg-List. With a simple PVC test plate containing several grooves simulating small details (areae gastricae) the diagnostic capabilities of the HD contrast medium were evaluated in an in vitro test. The developed barium meal Falibaryt HD is in its physical and chemical parameters comparable with Prontobario-HD, one of the best HD barium meals. (author)

  13. MR imaging distinction between occlusive and reperfused myocardial infarctions with a myocardial persistent contrast medium

    International Nuclear Information System (INIS)

    Saeed, M.; Wagner, S.; Wendland, M.; Derugin, N.; Pomeroy, O.; Higgins, C.B.

    1988-01-01

    Paramagnetic contrast agents have limitations for myocardial enhancement of the area at risk after acute occlusion and for differentiating occlusive and reperfused infarctions. A new contrast medium was used in an attempt to discriminate occlusive and reperfused infarctions. The pattern of enhancement was compared in occlusive (6-hour occlusion, 13 rats) and reperfused (2-hour occlusion and 4-hour reperfusion, ten rats) infarctions with electrocardiogram-gated MR imaging. MR imaging of infarcted areas was histologically and histochemically documented. Rats received 100-mM Mn-DPDP. The reperfused infarct showed transmural enhancement early after Mn-DPDP administration. However, occlusive infarcts showed no early enhancement. The difference in the pattern was significant. Mn-DPDP has the potential to distinguish between the occlusive and reperfused infarctions

  14. In which patients should serum creatinine be measured before iodinated contrast medium administration?

    International Nuclear Information System (INIS)

    Thomsen, Henrik S.

    2005-01-01

    Routine measurement of serum creatinine before injection of intravascular iodinated contrast material in all patients would be cumbersome and have an associated cost. There is doubt about whether serum creatinine should be measured routinely in all patients or selectively. The Contrast Media Safety Committee of the European Society of Urogenital Radiology decided to review the literature and draw up guidelines on this important practical issue. A literature search was carried out and summarized in a report. Based on the available information and discussions amongst the members of the Committee, guidelines were produced. The report and guidelines were discussed at the 11th European Symposium on Urogenital Radiology in Santiago de Compostela, Spain. The practice for identifying patients at risk of contrast medium induced nephropathy varies considerably from one institution to another. Patients at risk constitute only a small percentage of all cases referred for contrast enhanced imaging examination. However, it is important to identify them and take the necessary precautions. Recent serum creatinine level should be available in patients with an increased probability of a raised serum creatinine level (renal disease, renal surgery, proteinuria, diabetes mellitus, hypertension, gout, current intake of nephrotoxic drugs). A simple guideline has been produced. (orig.)

  15. Does MRI with oral contrast medium allow single-study depiction of inflammatory bowel disease enteritis and colitis?

    Energy Technology Data Exchange (ETDEWEB)

    Cronin, Carmel G.; Lohan, Derek G.; Browne, Ann Michelle; Roche, Clare; Murphy, Joseph M. [University College Hospital, Department of Radiology, Galway (Ireland)

    2010-07-15

    To assess the feasibility and utility of magnetic resonance (MR) imaging of the bowel in concurrent small- and large-bowel evaluation for the presence of inflammatory bowel disease (IBD). Over a 5-year period, 62 MR examinations performed on 53 patients demonstrated evidence of IBD. Sixteen of these 53 (30.1%) patients had imaging findings of colonic disease and underwent 19 formal MR small bowel examinations. These were further evaluated for bowel distention and image quality. The sensitivity and specificity of the technique compared with colonoscopy as the 'gold standard' was evaluated. Simultaneous imaging of the colon is feasible at MR small bowel follow-through with moderate-to-excellent colonic visibility and colon distention obtained when the contrast medium is present in the colon at the time of image acquisition. MR imaging had a sensitivity of 80% (0.56-0.93), specificity of 100% (0.77-1.00), positive predictive value (PPV) of 1 and a negative predictive value (NPV) of 0.8 for the identification of colitis (based on available concurrent correlation of 38/62 examinations with colonoscopy). Small and large bowel MR imaging with orally consumed contrast medium represents a promising, feasible, non-invasive, non-radiating single mode of assessment of the entire gastrointestinal tract, performed at a single sitting. (orig.)

  16. Does MRI with oral contrast medium allow single-study depiction of inflammatory bowel disease enteritis and colitis?

    International Nuclear Information System (INIS)

    Cronin, Carmel G.; Lohan, Derek G.; Browne, Ann Michelle; Roche, Clare; Murphy, Joseph M.

    2010-01-01

    To assess the feasibility and utility of magnetic resonance (MR) imaging of the bowel in concurrent small- and large-bowel evaluation for the presence of inflammatory bowel disease (IBD). Over a 5-year period, 62 MR examinations performed on 53 patients demonstrated evidence of IBD. Sixteen of these 53 (30.1%) patients had imaging findings of colonic disease and underwent 19 formal MR small bowel examinations. These were further evaluated for bowel distention and image quality. The sensitivity and specificity of the technique compared with colonoscopy as the 'gold standard' was evaluated. Simultaneous imaging of the colon is feasible at MR small bowel follow-through with moderate-to-excellent colonic visibility and colon distention obtained when the contrast medium is present in the colon at the time of image acquisition. MR imaging had a sensitivity of 80% (0.56-0.93), specificity of 100% (0.77-1.00), positive predictive value (PPV) of 1 and a negative predictive value (NPV) of 0.8 for the identification of colitis (based on available concurrent correlation of 38/62 examinations with colonoscopy). Small and large bowel MR imaging with orally consumed contrast medium represents a promising, feasible, non-invasive, non-radiating single mode of assessment of the entire gastrointestinal tract, performed at a single sitting. (orig.)

  17. Intravenous contrast ultrasound examination using contrast-tuned imaging (CnTI) and the contrast medium SonoVue for discrimination between benign and malignant adnexal masses with solid components.

    Science.gov (United States)

    Testa, A C; Timmerman, D; Van Belle, V; Fruscella, E; Van Holsbeke, C; Savelli, L; Ferrazzi, E; Leone, F P G; Marret, H; Tranquart, F; Exacoustos, C; Nazzaro, G; Bokor, D; Magri, F; Van Huffel, S; Ferrandina, G; Valentin, L

    2009-12-01

    To determine whether intravenous contrast ultrasound examination is superior to gray-scale or power Doppler ultrasound for discrimination between benign and malignant adnexal masses with complex ultrasound morphology. In an international multicenter study, 134 patients with an ovarian mass with solid components or a multilocular cyst with more than 10 cyst locules, underwent a standardized transvaginal ultrasound examination followed by contrast examination using the contrast-tuned imaging technique and intravenous injection of the contrast medium SonoVue(R). Time intensity curves were constructed, and peak intensity, area under the intensity curve, time to peak, sharpness and half wash-out time were calculated. The sensitivity and specificity with regard to malignancy were calculated and receiver-operating characteristics (ROC) curves were drawn for gray-scale, power Doppler and contrast variables and for pattern recognition (subjective assignment of a certainly benign, probably benign, uncertain or malignant diagnosis, using gray-scale and power Doppler ultrasound findings). The gold standard was the histological diagnosis of the surgically removed tumors. After exclusions (surgical removal of the mass > 3 months after the ultrasound examination, technical problems), 72 adnexal masses with solid components were used in our statistical analyses. The values for peak contrast signal intensity and area under the contrast signal intensity curve in malignant tumors were significantly higher than those in borderline tumors and benign tumors, while those for the benign and borderline tumors were similar. The area under the ROC curve of the best contrast variable with regard to diagnosing borderline or invasive malignancy (0.84) was larger than that of the best gray-scale (0.75) and power Doppler ultrasound variable (0.79) but smaller than that of pattern recognition (0.93). Findings on ultrasound contrast examination differed between benign and malignant tumors but there

  18. A case of pulmonary edema developed after intraarterial injection of iodinated contrast medium

    International Nuclear Information System (INIS)

    Min, Byoung Chol; Chun, Kang Woo; Koh, Jae Hyu; Yoon, Jong Sup

    1982-01-01

    Pulmonary edema is a rare adverse reaction to the iodinated contrast medium. Complaining of huge abdominal mass, a 52 years old female was admitted to the Hangang Sungsim Hospital. On physical examination, the patient appeared to be healthy. She had stable vital signs, i.e. BP: 120/80 mmHg, pulse rate: 80/min.etc. An adult head sized mass was palpated in the left mid and lower abdomen. Otherwise nonspecific. On laboratory studies the positive findings were 8-10 WBC/HPF in urine, 25.6 mg/dl for BUN and PVC in EKG. It was negative for urine protein, serum creatinline and liver function test. We injected 100 ml and 30 ml of Urografin 60 through the abdominal aorta dividing 3 times and major branches of the abdominal aorta, respectively. Immediately after complicating angiography, interstitial pulmonary edema was found, showing blurring of the vascular margins, perivascular haziness and thickening of the interlobular septal lines in the both lower lung fields. The blood pressure was dropped to 80/60 mmHg, but pulse rate was normal. She did not complain of dyspnea, and cyanosis was not developed. The urine volume was normally maintained. She was treated for pulmonary edema, which was completely absorbed after 20 hours. And the blood pressure was also normalized. We have experienced a case of pulmonary edema developed after intraarterial injection of the iodinated contrast medium without underlying cardiac, renal and hepatic problems, and reviewed the literatures on mechanisms of pulmonary edema caused by intravascular injection of the iodinated contrast materials

  19. The influence of different contrast medium concentrations and injection protocols on quantitative and clinical assessment of FDG–PET/CT in lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Verburg, Frederik A., E-mail: fverburg@ukaachen.de [RWTH Aachen University Hospital, Department of Nuclear Medicine, Pauwelsstraße 30, 52074 Aachen (Germany); Maastricht University Medical Center, Department of Nuclear Medicine, P. Debyelaan 25, 6229 HX Maastricht (Netherlands); Kuhl, Christiane K. [RWTH Aachen University Hospital, Department of Diagnostic and Interventional Radiology, Pauwelsstraße 30, 52074 Aachen (Germany); Pietsch, Hubertus [Bayer Pharma AG, Berlin, Müllerstrasse 178, 13353 Berlin (Germany); Palmowski, Moritz [RWTH Aachen University Hospital, Department of Nuclear Medicine, Pauwelsstraße 30, 52074 Aachen (Germany); Mottaghy, Felix M. [RWTH Aachen University Hospital, Department of Nuclear Medicine, Pauwelsstraße 30, 52074 Aachen (Germany); Maastricht University Medical Center, Department of Nuclear Medicine, P. Debyelaan 25, 6229 HX Maastricht (Netherlands); Behrendt, Florian F. [RWTH Aachen University Hospital, Department of Nuclear Medicine, Pauwelsstraße 30, 52074 Aachen (Germany)

    2013-10-01

    Objectives: To compare the effects of two different contrast medium concentrations for use in computed X-ray tomography (CT) employing two different injection protocols on positron emission tomography (PET) reconstruction in combined 2-{sup 18}F-desoxyglucose (FDG) PET/CT in patients with a suspicion of lung cancer. Methods: 120 patients with a suspicion of lung cancer were enrolled prospectively. PET images were reconstructed with the non-enhanced and venous phase contrast CT obtained after injection of iopromide 300 mg/ml or 370 mg/ml using either a fixed-dose or a body surface area adapted injection protocol. Maximum and mean standardized uptake values (SUVmax and SUVmean) and contrast enhancement (HU) were determined in the subclavian vein, ascending aorta, abdominal aorta, inferior vena cava, portal vein, liver and kidney and in the suspicious lung lesion. PET data were evaluated visually for the presence of malignancy and image quality. Results: At none of the sites a significant difference in the extent of the contrast enhancement between the four different protocols was found. However, the variability of the contrast enhancement at several anatomical sites was significantly greater in the fixed dose groups than in the BSA groups for both contrast medium concentrations. At none of the sites a significant difference was found in the extent of the SUVmax and SUVmean increase as a result of the use of the venous phase contrast enhanced CT for attenuation. Visual clinical evaluation of lesions showed no differences between contrast and non-contrast PET/CT (P = 0.32). Conclusions: Contrast enhanced CT for attenuation correction in combined PET/CT in lung cancer affects neither the clinical assessment nor image quality of the PET-images. A body surface adapted contrast medium protocol reduces the interpatient variability in contrast enhancement.

  20. Magnesium sulfate as an oral contrast medium in magnetic resonance imaging of the small intestine.

    Science.gov (United States)

    Shi, Hao; Liu, Cun; Ding, Hong Yu; Li, Chun Wei

    2012-03-01

    To explore the use of magnesium sulfate (MgSO4) as an oral contrast medium (CM) in MRI of the small intestine. By comparing MgSO4 SNRs at different concentrations, we determined that 2.5% MgSO4 is the ideal concentration for small bowel MRI. Twenty volunteers underwent MRI after drinking 2.5% MgSO4. Thirty-one patients with clinical suspicion of small intestinal pathology underwent both MRI and the air-barium contrast examination. The patient's tolerance, side effects and complications were noted. 2.5% MgSO4 can decrease the absorption of water and fully fill the enteric cavity, thereby increasing the contrast between the intestinal wall and lumen and facilitating radiographic examination of the small bowel. The mean diameter of the small intestine was 19.8±1.21 mm in the 20 volunteers consuming 2.5% MgSO4 and 12.7±0.84 mm in the 20 volunteers given water. There was a significant difference (P0.05) in side effects between MgSO4 and water groups. Small intestinal MRI was successfully performed in all 31 patients, who were also examined by the double contrast barium, which gave almost identical diagnoses to MRI in all cases except for 1 patient with small intestinal hemorrhage. MRI with 2.5% MgSO4 can demonstrate intestinal abnormalities. Therefore, 2.5% MgSO4 solution is an ideal oral CM for small bowel MRI. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  1. Nanoparticles generated by laser in liquids as contrast medium and radiotherapy intensifiers

    Science.gov (United States)

    Restuccia, Nancy; Torrisi, Lorenzo

    2018-01-01

    The synthesis of Au and Ag nanoparticles (NP) though laser ablation in liquids as a function the laser parameters is presented. Spherical NPs with diameter distribution within 1 and 100 nm were prepared by laser ablation in water. The nanoparticles characterization was performed using optical spectroscopy and electronic microscopy (SEM and TEM) measurements. Studies of the possible use of metallic nanoparticles as intensifier of diagnostics imaging contrast medium and absorbing dose from ionizing radiations in traditional radiotherapy and protontherapy are presented. Examples of in vitro (in tissue equivalent materials) and in vivo (in mice), were conducted thank to simulation programs permitting to evaluate the enhancement of efficiency in imaging and therapy as a function of the NPs concentrations and irradiation conditions.

  2. Nanoparticles generated by laser in liquids as contrast medium and radiotherapy intensifiers

    Directory of Open Access Journals (Sweden)

    Restuccia Nancy

    2018-01-01

    Full Text Available The synthesis of Au and Ag nanoparticles (NP though laser ablation in liquids as a function the laser parameters is presented. Spherical NPs with diameter distribution within 1 and 100 nm were prepared by laser ablation in water. The nanoparticles characterization was performed using optical spectroscopy and electronic microscopy (SEM and TEM measurements. Studies of the possible use of metallic nanoparticles as intensifier of diagnostics imaging contrast medium and absorbing dose from ionizing radiations in traditional radiotherapy and protontherapy are presented. Examples of in vitro (in tissue equivalent materials and in vivo (in mice, were conducted thank to simulation programs permitting to evaluate the enhancement of efficiency in imaging and therapy as a function of the NPs concentrations and irradiation conditions.

  3. Effects of barium sulfate as a contrast medium to enterocutaneous fistulas

    International Nuclear Information System (INIS)

    Pelster, F.W.; Reichelt, S.; Arndt, M.; Eising, E.G.

    1989-01-01

    Fistulation following thoracic and epigastric interventions are conservatively treated, as a rule, because of the high rate of complications expected from reoperation. With properly functioning anastomotic transit, insufficiencies usually undergo spontaneous healing, within four to six weeks. Enterocutaneous fistulae developed in 29 of 271 patients with intrathoracic oesophagastric or oesophagojejunal anastomosis. Syringeal ramification into pleural or abdominal cavities were eliminated by means of an absorbable contrast medium, before barium sulphate was orally administered to all patients. Thoracic fistulae were closed after 21.8 days on average, while 20.3 days was the average period required for closure of epigastric fistulae. Barium sulphate was found to stimulate fistular tissue granulation, so that obliteration of the fistular system occurred much sooner, as compared to conservative treatment. The patient's quality of life can thus be improved, and hospitalisation can be shortened. Neither locally delimited nor systemic complications were observed in any of the cases described. (author)

  4. Iomeprol: results of clinical trials in children with a new nonionic contrast medium

    International Nuclear Information System (INIS)

    Gessel, R. van; Moeller, A.; Schmiedel, E.

    1994-01-01

    A total of 438 patients (1 day - 17 years) were enrolled in open-label phase III studies with Iomeprol in the most important radiologic, urologic, and cardiologic indications. Iomeprol was tested in five concentrations ranging from isotonic solutions of 150 mg iodine/ml up to 400 mg iodine/ml. Half of the patients were younger than 3 years. Apart from the mostly slight sensations of heat, pain, and taste, the following adverse events were observed independently of a causal relationship to the test compound: vomiting (1.8%), rise in blood pressure (1.8%), and restlessness (1.1%). The respective incidence of all other adverse events was below 1%. Iomeprol is a suitable and well-tolerated nonionic contrast medium for use in pediatric examinations. (orig./MG) [de

  5. Bilateral Renal Fornix Rupture Following Intraarterial Contrast Medium Application for Infrarenal Aortic Stent Placement

    International Nuclear Information System (INIS)

    Niggemann, Pascal; Brehmer, Bernhard; Schuermann, Karl

    2006-01-01

    A 74-year-old male claudicant who had a significant abdominal aortic stenosis was hydrated before aortic stent placement because of an elevated creatinine level. During the intervention the patient experienced acute abdominal pain with vomiting. No vascular cause was detected. Due to persistant pain, plain radiography and an abdominal CT scan were performed a few hours after the procedure. Images revealed a bilateral renal fornix rupture with a large retroperitoneal fluid collection. The patient was treated conservatively with ureteral double-J placement and percutaneous nephrostomy. The further course was uneventful and the patient was discharged 2 weeks later free of symptoms. Renal fornix rupture is a very rare complication after contrast medium application that can be treated without surgery

  6. Arterial and venous blood pressure and blood flow following femoral angiography with a new non-ionic contrast medium

    International Nuclear Information System (INIS)

    Nyman, U.; Almen, T.

    1978-01-01

    At femoral angiography in dogs the effects of a new non-ionic contrast medium (C29) were compared with those of one non-ionic medium (metrizamide) and one ionic medium (meglumine/sodium diatrizoate) in current use. In the leg subjected to angiography the pressure gradient over the peripheral vessels decreased and the femoral blood flow increased. The changes induced by the ionic medium were significantly greater than those induced by metrizamide and C29, whereas no significant difference between the two non-ionic media was recorded. (Auth.)

  7. Analysis on the entrance surface dose and contrast medium dose at computed tomography and angiography in cardiovascular examination

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Young Hyun [Dept. of Cardiovascular Center, Yeocheon Jeonnam Hospital, Yeosu (Korea, Republic of); Han, Jae Bok; Choi, Nam Gil; Song, Jong Nam [Dept. of Radiological Science, Dongshin University, Naju (Korea, Republic of)

    2016-12-15

    This study aimed to identify dose reduction measures by retrospectively analyzing the entrance surface dose at computed tomography and angiography in cardiovascular examination and to contribute the patients with renal impairmend and a high probability of side effects to determine the inspection's direction by measuring the contrast usages actually to active actions for the dose by actually measuring the contrast medium dose. The CTDIvol value and air kerma value, which are the entrance surface doses of the two examinations, and the contrast medium dose depending on the number of slides were compared and analyzed. This study was conducted in 21 subjects (11 males; 10 females) who underwent Cardiac Computed Tomographic Angiography (CCTA) and Coronary Angiography (CAG) in this hospital during the period from May 2014 to May 2016. The subject's age was 48-85 years old (mean 65±10 years old), and the weight was 37.6~83.3 kg (mean 63±6 kg). Dose reduction could be expected in the cardiovascular examination using CCTA rather than in the examination using CAG. In terms of contrast medium dose, CAG used a smaller dose than CCTA. In particular, as the number of slides increases at CAG, the contrast medium dose increases. Therefore, in order to reduce the contrast medium dose, the number of slides suitable for the scan range must be selected.

  8. Intravenous Contrast Medium Administration for Computed Tomography Scan in Emergency: A Possible Cause of Contrast-Induced Nephropathy

    International Nuclear Information System (INIS)

    Sonhaye, Lantam; Kolou, Bérésa; Tchaou, Mazamaesso; Amadou, Abdoulatif; Assih, Kouméabalo; N'Timon, Bidamin; Adambounou, Kokou; Agoda-Koussema, Lama; Adjenou, Komlavi; N'Dakena, Koffi

    2015-01-01

    The goal of this study was to assess risk for CIN after CT Scan during an emergency and to identify risk factors for the patient. Prospective review of all patients admitted to the emergency room (ER) of the Teaching Hospital of Lomé (Togo) during a 2-year period. CIN was defined as an increase in serum creatinine by 0.5 mg/dL from admission after undergoing CT Scan with intravenous contrast. A total of 620 patients underwent a CT Scan in the emergency room using intravenous contrast and 672 patients took the CT Scan without intravenous contrast. Out of the patients who received intravenous contrast for CT Scan, three percent of them developed CIN during their admission. Moreover, upon discharge no patient had continued renal impairment. No patient required dialysis during their admission. The multivariate analysis of all patients who had serial creatinine levels (including those who did not receive any contrast load) shows no increased risk for acute kidney injury associated intravenous contrast (odds ratio = 0.619, p value = 0.886); only diabetes remains independent risk factor of acute kidney injury (odds ratio = 6.26, p value = 0.031)

  9. High-pitch dual-source CT coronary angiography with low volumes of contrast medium

    International Nuclear Information System (INIS)

    Lembcke, Alexander; Hein, Patrick A.; Knobloch, Gesine; Durmus, Tahir; Hamm, Bernd; Schwenke, Carsten; Huppertz, Alexander

    2014-01-01

    To assess the effect of lower volumes of contrast medium (CM) on image quality in high-pitch dual-source computed tomography coronary angiography (CTCA). One-hundred consecutive patients (body weight 65-85 kg, stable heart rate ≤65 bpm, cardiac index ≥2.5 L/min/m 2 ) referred for CTCA were prospectively enrolled. Patients were randomly assigned to one of five groups of different CM volumes (G 30 , 30 mL; G 40 , 40 mL; G 50 , 50 mL; G 60 , 60 mL; G 70 , 70 mL; flow rate 5 mL/s each, iodine content 370 mg/mL). Attenuation within the proximal and distal coronary artery segments was analysed. Mean attenuation for men and women ranged from 345.0 and 399.1 HU in G 30 to 478.2 and 571.8 HU in G 70 . Mean attenuation values were higher in groups with higher CM volumes (P 30 , G 40 , G 50 , G 60 and G 70 were 89 %, 95 %, 98 %, 98 % and 99 %. CM volume of 30 mL in women and 40 mL in men proved to be sufficient to guarantee attenuation of at least 300 HU. In selected patients high-pitch dual-source CTCA can be performed with CM volumes of 40 mL in men or 30 mL in women. (orig.)

  10. Computed tomography of kidney with diuretics. A method for avoiding artifact due to nonionic contrast medium

    Energy Technology Data Exchange (ETDEWEB)

    Hiromura, Tadao; Terae, Satoshi; Takamura, Akio; Mizoe, Junetsu (Obihiro Kosei Hospital, Hokkaido (Japan)); Morita, Yutaka; Irie, Goro

    1989-07-01

    We devised a method for avoiding beam-hardening artifacts, which interfere with enhanced CT images of kidney due to nonionic contrast medium. The radiographic effect and the frequency of beam-hardening artifacts on enhanced CT of kidney were studied by prospective comparison among three groups: a group of 20 patients examined with furosemide (f-d.CT), a group of 20 patients examined without diuretics (non-d.CT) and a group of 20 patients examined after water intake (w-d.CT). In all patients of f-d.CT group, the renal parenchyma from the cortex to the papilla was almost evently enhanced, free from artifacts. The density of the renal papilla and pelvis in non-d.CT and w-d.CT groups was significantly higher than that in f-d.CT group, and artifacts were also observed in 14 (70%) of non-d.CT group and 12 (60%) of w.d.CT group, respectively. Satisfactory CT of kidney free from artifacts was obtained by f-d.CT, providing easy evaluation of renal pelvic or peripelvic lesions. In conclusion, this technique can be used in those pathologic cases of renal pelvis or peripelvic region, that are not clear on routine CT because of artifacts. (author).

  11. Hydration for the prevention of contrast medium-induced nephropathy. An update

    International Nuclear Information System (INIS)

    Heinrich, M.; Uder, M.

    2006-01-01

    Contrast medium-induced nephropathy (CIN) continues to be one of the most common causes of hospital-acquired acute renal failure. Since most of the clinical studies on the prophylactic use of different drugs to prevent CIN produced disappointing results, hydration remains the mainstay of prophylaxis. A number of recent prospective randomized trials provided further evidence of the effectiveness of hydration and relevant information regarding the optimization of hydration protocols. It was shown that a bolus hydration solely during examination is not sufficient to prevent CIN. In addition, isotonic 0.9% saline was superior to the commonly used halfisotonic 0.45% saline in another trial. An outpatient hydration protocol including oral hydration before the examination followed by forced intravenous hydration over 6 hrs. beginning 30 to 60 min. prior to examination seems to be comparable to the usual hydration over 24 hrs. Another hydration protocol, which could also be very attractive especially for outpatients, included the infusion of sodium bicarbonate. In a recent trial, hydration with sodium bicarbonate, given as a bolus for 1 hr. prior to examination followed by an infusion for 6 hrs. after examination, was more effective than hydration with sodium chloride for the prophylaxis of CIN. However, there is still a lack of large-scale, multi-center trials comparing different hydration protocols and investigating their influence on clinically relevant endpoints such as mortality or the need for dialysis. (orig.)

  12. Feasibility study of using air as a contrast medium in MR colonography

    International Nuclear Information System (INIS)

    So, N.M.C.; Lam, W.W.M.; Mann, D.; Leung, K.L.; Metreweli, C.

    2003-01-01

    AIM: To evaluate the feasibility of using air as intraluminal contrast medium in magnetic resonance (MR) colonography. MATERIALS AND METHODS: Twenty-two patients underwent MR colonography (MRC) using air before colonoscopy. All patients were imaged in prone and supine positions. Each colon was divided into five segments. Two radiologists reviewed the images for the degree of colonic distension, image quality and colonic lesions. The colonic lesions identified using MR were compared with those identified on colonoscopy. RESULTS: Eight men and 14 women with mean age of 55.5 years were studied. All patients completed the MR examination. One hundred and five out of 110 (95.5%) colonic segments were well distended in both prone and supine positions. Image quality was good in all cases. Colonoscopy detected 16 lesions: three ≥1 cm, one 7 mm lesion and 12 lesions ≤5 mm. All lesions 1 cm or larger were detected by MRC. CONCLUSION: MRC using air and the single-shot half-Fourier rapid acquisition with refocused echos (RARE) technique is feasible. But in this small pilot study, it had low sensitivity for the detection of polyps less than 1 cm in diameter

  13. Duplex-assisted carotid artery stenting without administration of contrast medium for patients with chronic kidney disease or allergic reaction.

    Science.gov (United States)

    Mizowaki, Takashi; Fujita, Atsushi; Imahori, Taichiro; Uyama, Atsushi; Inoue, Satoshi; Kohta, Masaaki; Hamaguchi, Hirotoshi; Sasayama, Takashi; Hosoda, Kohkichi; Kohmura, Eiji

    2016-07-01

    We aimed to investigate the safety and feasibility of duplex-assisted carotid artery stenting (CAS) without administration of contrast medium for the prevention of adverse reactions. Fifteen patients (9 % of all CASs) with severe carotid stenosis (≥70 %) associated with chronic kidney disease (CKD) (stage ≥3) or allergy to contrast medium underwent duplex-assisted CAS without administration of contrast medium over 4 years. The procedural success rate and perioperative complication rates were compared between the duplex-assisted CAS (n = 15) and conventional CAS (n = 153) groups. The technical success rate was 100 % in both groups. Combined stroke or death rates during the post-procedural period did not differ significantly between the duplex-assisted CAS group (0/15, 0 %) and conventional CAS group (4/153, 2.6 %). None of the 14 patients with CKD in the duplex-assisted CAS group experienced further deterioration of renal function. The mean surface radiation dose of participants in the duplex-assisted CAS group (n = 13, 312 ± 131 mGy) was significantly lower than that of the conventional CAS group (n = 31, 1036 ± 571 mGy) (p < 0.001). The mean duration of CAS procedure was not significantly different between the duplex-assisted CAS group (156 ± 39.7 min) and the conventional CAS group (156 ± 37.4 min). Duplex-assisted CAS without administration of contrast medium could be an alternative option in selected patients deemed to be at high risk for renal failure from nephrotoxic contrast medium or who have an allergy to contrast medium.

  14. Enhancement effects of test injection with a small amount of MR contrast medium in the oral and maxillofacial region

    International Nuclear Information System (INIS)

    Yanagi, Yoshinobu; Asaumi, Jun-ichi; Konouchi, Hironobu; Hisatomi, Miki; Matsuzaki, Hidenobu; Murakami, Jun; Maki, Yuu; Unetsubo, Teruhisa; Kishi, Kanji

    2006-01-01

    Purpose: To examine whether the signal intensity of dynamic contrast-enhanced MRI (DCE-MRI) is altered by test injection of 1 ml of contrast medium, and if so, whether this change affects the DCE-MRI analysis. Materials and methods: Six healthy volunteers were examined by DCE-MRI using a Magnevist syringe and/or an Omniscan syringe for the injection of contrast medium. Each scan was performed 10 times using steady-state free precession (3D-FISP), a sequence for DCE-MRI, before and after intravenous injection of 1 ml of the contrast medium. The internal pterygoid muscle, masseter muscle, tongue, parotid gland, submandibular gland, bone marrow of the mandible, subcutaneous adipose tissue, and common carotid artery were determined to be regions of interest (ROI), and the ROI internal average signal intensity was measured. The 10 data sets obtained before or after contrast medium administration for each ROI were evaluated using the paired t-test. Results: The test injection increased the signal intensities of six of eight ROIs, with all 20 experiments in the submandibular gland showing significant differences. There was no significant difference in the two ROIs corresponding to the carotid artery and subcutaneous adipose tissue of the cheek. Conclusions: The enhanced signal intensity in the tissue might have been caused by the small amount of contrast medium in the test injection. To eliminate this discrepancy caused by the test injection, a pre-contrast scan should be performed when the average signal intensity of an ROI is measured. We therefore believe that the data obtained before a test injection may be important in the analysis of DCE-MRI

  15. Medium term water deficit elicits distinct transcriptome responses in Eucalyptus species of contrasting environmental origin.

    Science.gov (United States)

    Spokevicius, Antanas V; Tibbits, Josquin; Rigault, Philippe; Nolin, Marc-Alexandre; Müller, Caroline; Merchant, Andrew

    2017-04-07

    Climatic and edaphic conditions over geological timescales have generated enormous diversity of adaptive traits and high speciation within the genus Eucalyptus (L. Hér.). Eucalypt species occur from high rainfall to semi-arid zones and from the tropics to latitudes as high as 43°S. Despite several morphological and metabolomic characterizations, little is known regarding gene expression differences that underpin differences in tolerance to environmental change. Using species of contrasting taxonomy, morphology and physiology (E. globulus and E. cladocalyx), this study combines physiological characterizations with 'second-generation' sequencing to identify key genes involved in eucalypt responses to medium-term water limitation. One hundred twenty Million high-quality HiSeq reads were created from 14 tissue samples in plants that had been successfully subjected to a water deficit treatment or a well-watered control. Alignment to the E. grandis genome saw 23,623 genes of which 468 exhibited differential expression (FDR species-specific response of which 74 were linked to the 'dry' species E. cladocalyx where 23 of these genes were uncharacterised. The majority (approximately 80%) of these differentially expressed genes, were expressed in stem tissue. Key genes that differentiated species responses were linked to photoprotection/redox balance, phytohormone/signalling, primary photosynthesis/cellular metabolism and secondary metabolism based on plant metabolic pathway network analysis. These results highlight a more definitive response to water deficit by a 'dry' climate eucalypt, particularly in stem tissue, identifying key pathways and associated genes that are responsible for the differences between 'wet' and 'dry' climate eucalypts. This knowledge provides the opportunity to further investigate and understand the mechanisms and genetic variation linked to this important environmental response that will assist with genomic efforts in managing native populations

  16. The incidence of contrast medium-induced nephropathy following endovascular aortic aneurysm repair: assessment of risk factors.

    Science.gov (United States)

    Guneyli, Serkan; Bozkaya, Halil; Cinar, Celal; Korkmaz, Mehmet; Duman, Soner; Acar, Turker; Akin, Yigit; Parildar, Mustafa; Oran, Ismail

    2015-05-01

    The aim of the study was to investigate the incidence of contrast medium-induced nephropathy (CIN) and risk factors for CIN following endovascular abdominal aortic aneurysm repair or thoracic endovascular aortic aneurysm repair. After exclusion criteria, 139 (121 males, 18 females) patients aged 20-86 (median 65.5) years who underwent endovascular aortic aneurysm repair between January 2002 and September 2013 were included in this retrospective study. CIN, with ≥25% increase in serum creatinine levels within 3 days after contrast medium administration, was compared to the patients' demographics, risk factors, type and complexity of the endovascular operation, parameters regarding to the contrast medium, preoperative estimated glomerular filtration rate (eGFR), and preoperative and early postoperative serum parameters. Statistical analyses were performed with Kolmogorov-Smirnov, χ (2) and Student's t tests. CIN, detected in 39 of 139 patients (28%), was correlated with preoperative eGFR <60 ml/min/1.73 m(2) (P = 0.04) and high preoperative and postoperative serum urea and creatinine levels. Postoperative serum urea levels (P < 0.001) were significant in multivariate analysis. In patients undergoing endovascular aortic aneurysm repair, CIN was correlated with preoperative and postoperative renal impairment, while it was not correlated with the contrast medium dose.

  17. Study of the safety of a new non-ionic contrast medium, iopromide 370 in patients with chronic renal failure

    International Nuclear Information System (INIS)

    Meyrier, A.; Fernet, M.; Rainfray, M.

    1989-01-01

    Intravenous injection of iodinated contrast media usually induces modifications of renal function. Adverse effects of contrast media on renal function may affect diuresis, blood flow or glomerular filtration rate. These modifications are mainly related to osmolality but also chemotoxicity. This open study showed that after i.v. injection of a bolus of iopromide 370, a new non-ionic contrast medium, there was no untoward effect on renal function in patients with renal insufficiency. This justifies comparative studies in patients with renal impairment including elderly subjects, to confirm the tolerance of this product in high risk groups [fr

  18. Potentials and limitations of low-concentration contrast medium (150 mg iodine/ml) in CT pulmonary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Radon, M.R., E-mail: mark.radon@gmail.co [Department of diagnostic Imaging, Northern General Hospital, Sheffield (United Kingdom); Kaduthodil, M.J.; Jagdish, J.; Matthews, S.; Hill, C.; Bull, M.J.; Morcos, S.K. [Department of diagnostic Imaging, Northern General Hospital, Sheffield (United Kingdom)

    2011-01-15

    Aim: To assess the feasibility of producing diagnostic multidetector computed tomography (MDCT) pulmonary angiography with low iodine concentration contrast media (150 mg iodine/ml) in patients with suspected acute pulmonary embolism. Materials and methods: Ninety-five randomized patients underwent MDCT (64 row) pulmonary angiography with 100 ml iopromide either at low concentration (LC) of 150 mg iodine/ml (n = 45) or high concentration (HC) of 300 mg iodine/ml (n = 50), delivered at the rate of 5 ml/s via a power injector. Two experienced radiologists, blinded to the concentration used, subjectively assessed the diagnostic quality and confidence using a four-point scale [1 = poor (not diagnostic), 2 = satisfactory, 3 = good, 4 = excellent]. Attenuation values (in HU) were measured in the main proximal branches of the pulmonary arteries. Results: The median diagnostic quality score for both observers was 3.5 (interquartile range 3-4) in the HC group and 2.5 (interquartile range 1.5-3) in the LC group (p < 0.01). The median diagnostic confidence score for both observers was 4 (interquartile range 3-4) in the HC group and 3 (interquartile range 1.5-4) in the LC group (p < 0.01). Both observers rated examinations as diagnostic in 69% of cases in the LC group, compared with 96% of cases in the HC group. Good interobserver agreement was found in both groups (K value 0.72 in the LC group and 0.73 in the HC). Obesity, poor scan timing, and dilution by venous return of non-opacified blood were the main reasons for a reduction in diagnostic quality of examinations in the LC group. Conclusion: Despite a 50% reduction of contrast medium dose in comparison to the standard technique, 150 mg iodine/ml can produce diagnostic MDCT pulmonary angiogram studies in the absence of obesity or high cardiac output and hyper-dynamic pulmonary circulation. Reducing the dose of contrast media would minimize the risk of contrast nephropathy in patients at risk of this complication

  19. Potentials and limitations of low-concentration contrast medium (150 mg iodine/ml) in CT pulmonary angiography

    International Nuclear Information System (INIS)

    Radon, M.R.; Kaduthodil, M.J.; Jagdish, J.; Matthews, S.; Hill, C.; Bull, M.J.; Morcos, S.K.

    2011-01-01

    Aim: To assess the feasibility of producing diagnostic multidetector computed tomography (MDCT) pulmonary angiography with low iodine concentration contrast media (150 mg iodine/ml) in patients with suspected acute pulmonary embolism. Materials and methods: Ninety-five randomized patients underwent MDCT (64 row) pulmonary angiography with 100 ml iopromide either at low concentration (LC) of 150 mg iodine/ml (n = 45) or high concentration (HC) of 300 mg iodine/ml (n = 50), delivered at the rate of 5 ml/s via a power injector. Two experienced radiologists, blinded to the concentration used, subjectively assessed the diagnostic quality and confidence using a four-point scale [1 = poor (not diagnostic), 2 = satisfactory, 3 = good, 4 = excellent]. Attenuation values (in HU) were measured in the main proximal branches of the pulmonary arteries. Results: The median diagnostic quality score for both observers was 3.5 (interquartile range 3-4) in the HC group and 2.5 (interquartile range 1.5-3) in the LC group (p < 0.01). The median diagnostic confidence score for both observers was 4 (interquartile range 3-4) in the HC group and 3 (interquartile range 1.5-4) in the LC group (p < 0.01). Both observers rated examinations as diagnostic in 69% of cases in the LC group, compared with 96% of cases in the HC group. Good interobserver agreement was found in both groups (K value 0.72 in the LC group and 0.73 in the HC). Obesity, poor scan timing, and dilution by venous return of non-opacified blood were the main reasons for a reduction in diagnostic quality of examinations in the LC group. Conclusion: Despite a 50% reduction of contrast medium dose in comparison to the standard technique, 150 mg iodine/ml can produce diagnostic MDCT pulmonary angiogram studies in the absence of obesity or high cardiac output and hyper-dynamic pulmonary circulation. Reducing the dose of contrast media would minimize the risk of contrast nephropathy in patients at risk of this complication

  20. 75 FR 81952 - Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty...

    Science.gov (United States)

    2010-12-29

    ... Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and...-Duty National Program that will increase fuel efficiency and reduce greenhouse gas emissions for on... a comprehensive Heavy-Duty National Program that will increase fuel efficiency and reduce greenhouse...

  1. Magnetic resonance tomography for focal lesions in the liver using the para-magnetic contrast medium gadolinium DTPA

    International Nuclear Information System (INIS)

    Hamm, B.; Roemer, T.; Felix, R.; Wolf, K.J.; Klinikum Charlottenburg, Berlin

    1986-01-01

    The use of the para-magnetic contrast medium gadolinium DTPA for magnetic resonance tomography of focal lesions in the liver was investigated in 31 patients. Two dosage schedules of the contrast medium (0.1 and 0.2 mmol/kg body weight) were used with field strengths of 0.35 and 0.5 Tesla. Using T 1 sequences, gadolinium DTPA showed increased signal intensity in the liver and in tumours, but this was significantly more marked in the tumour. On T 1 spin-echo sequences, previously iso-intense lesions became visible after administration of contrast. On the other hand, contrast-enhanced lesions were less well seen on inversion recovery sequences because of a reduction in the contrast between tumour and liver tissue. The contrast between tumour and liver tissue was not improved by gadolinium DTPA in comparison with precontrast inversion recovery sequences and T 2 spin-echo sequences. The perfusion of intra-hepatic tumours could be elucidated by magnetic resonance tomography after the administration of gadolinium DTPA. (orig.) [de

  2. Effects of high iodine doses given parenterally as contrast medium on parameter of the pro/antioxidative balance

    International Nuclear Information System (INIS)

    Winkler, R.; Griebenow, S.; Scheidleder, B.; Bailer, H.

    2002-01-01

    The aim of this study was to investigate effects of high iodine doses given parenterally as contrast medium on parameters of lipid status and thyroid hormone status as well as on parameters of the pro/antioxidative balance of spa patients. 29 patients with a comparable indication who had to undergo an angiography were chosen. The blood parameters of these patients were determined before and after the angiographic treatment. No provable changes of the thyroid parameters f-T 3 , f-T 4 and TSH were found after the angiography. In case of enzyme activities, the protective enzymes SOD and GSHPX showed no changes, while the concentrations of peroxides and MDA were increased significantly. Corresponding to this, the total antioxidative status and the vitamin E level decreased significantly. Altogether these results stand for a moderate deterioration of the antioxidative protective potential by the highly iodine containing contrast medium. (author)

  3. CONTRAST

    DEFF Research Database (Denmark)

    Kristensen, Thomas Krogsgaard

    2007-01-01

    Dette er en afrapportering fra den årlige CONTRAST workshop, der i 2007 blev afholdt i Yaoundé, Cameroon.......Dette er en afrapportering fra den årlige CONTRAST workshop, der i 2007 blev afholdt i Yaoundé, Cameroon....

  4. Reduction of contrast medium volume in abdominal aorta CTA: Multiphasic injection technique versus a test bolus volume

    Energy Technology Data Exchange (ETDEWEB)

    Nijhof, Wouter H., E-mail: w.h.nijhof@student.utwente.nl [University of Twente, MIRA-Institute for Biomedical Technology and Technical Medicine, P.O. Box 21, 7500 AE Enschede (Netherlands); Vos, Charlotte S. van der, E-mail: c.s.vandervos@student.utwente.nl [University of Twente, MIRA-Institute for Biomedical Technology and Technical Medicine, P.O. Box 21, 7500 AE Enschede (Netherlands); Anninga, Bauke, E-mail: b.anninga@student.utwente.nl [University of Twente, MIRA-Institute for Biomedical Technology and Technical Medicine, P.O. Box 21, 7500 AE Enschede (Netherlands); Jager, Gerrit J., E-mail: g.jager@JBZ.nl [Department of Radiology, Jeroen Bosch Hospital, Henri Dunantstraat 1, 5223 GZ ’s-Hertogenbosch (Netherlands); Rutten, Matthieu J.C.M., E-mail: mj.rutten@online.nl [Department of Radiology, Jeroen Bosch Hospital, Henri Dunantstraat 1, 5223 GZ ’s-Hertogenbosch (Netherlands)

    2013-09-15

    Objective: The purpose of this study is to reduce the administered contrast medium volume in abdominal CTA by using a test bolus injection, with the preservation of adequate quantitative and qualitative vessel enhancement. Study design: For this technical efficacy study 30 patients, who were referred for a CTA examination of the abdominal aorta, were included. Randomly 15 patients were assigned to undergo a multiphasic injection protocol and received 89 mL of contrast medium (Optiray 350) (protocol I). Fifteen patients were assigned to the test bolus injection protocol (protocol II), which implies injection of a 10 mL test bolus of Optiray 350 prior to performing CTA with a 40 mL of contrast medium. Quantitative assessment of vascular enhancement was performed by measuring the amount of Hounsfield Units in the aorta at 30 positions from the celiac trunk to the iliac arteries in both groups. Qualitative assessment was performed by three radiologists who scored the images at a 5-point scale. Results: Quantitative assessment showed that there was no significant difference in vascular enhancement for patients between the two protocols, with mean attenuation values of 280.9 ± 50.84 HU and 258.60 ± 39.28 HU, respectively. The image quality of protocol I was rated 4.31 (range: 3.67/5.00) and of protocol II 4.11 (range: 2.67/5.00). These differences were not statistically significant. Conclusion: This study showed that by using a test bolus injection and the administration of 50 mL of contrast medium overall, CTA of the abdominal aorta can reliably be performed, with regard to quantitative and qualitative adequate vessel enhancement.

  5. Estimation of shear velocity contrast for dipping or anisotropic medium from transmitted Ps amplitude variation with ray-parameter

    Science.gov (United States)

    Kumar, Prakash

    2015-12-01

    Amplitude versus offset analysis of P to P reflection is often used in exploration seismology for hydrocarbon exploration. In the present work, the feasibility to estimate crustal velocity structure from transmitted P to S wave amplitude variation with ray-parameter has been investigated separately for dipping layer and anisotropy medium. First, for horizontal and isotropic medium, the approximation of P-to-s conversion is used that is expressed as a linear form in terms of slowness. Next, the intercept of the linear regression has been used to estimate the shear wave velocity contrast (δβ) across an interface. The formulation holds good for isotropic and horizontal layer medium. Application of such formula to anisotropic medium or dipping layer data may lead to erroneous estimation of δβ. In order to overcome this problem, a method has been proposed to compensate the SV-amplitude using shifted version of SH-amplitude, and subsequently transforming SV amplitudes equivalent to that from isotropic or horizontal layer medium as the case may be. Once this transformation has been done, δβ can be estimated using isotropic horizontal layer formula. The shifts required in SH for the compensation are π/2 and π/4 for dipping layer and anisotropic medium, respectively. The effectiveness of the approach has been reported using various synthetic data sets. The methodology is also tested on real data from HI-CLIMB network in Himalaya, where the presence of dipping Moho has already been reported. The result reveals that the average shear wave velocity contrast across the Moho is larger towards the Indian side compared to the higher Himalayan and Tibetan regions.

  6. Long-term results with a nonionic contrast medium - a clinical experience report

    International Nuclear Information System (INIS)

    Hruby, W.; Stellamor, K.

    1987-01-01

    Between January 1982 and May 1986 more than 50 000 patients were examined radioligically with water-soluble (ionic and nonionic) contrast media at the Department of Radiology Rudolfstiftung, Vienna. 1983 only 2,2% of the contrast agents used were nonionic, in 1985 the share had increased to 53,3%. During this period the rate of drug-related side effects (DRSE) decreased from 6,9% (1983) to 3,3% (1985). From 1983 to 1985 DRSE were observed with 1952 patients after administration of ionic agents, whereas after application of nonionic media adverse reactions occurred in only 6 cases, so that DRSE rates of 6,98% respectively 0,07% resulted for ionic respectively nonionic contrast media. These results are discussed with regard to the physicochemical properties and physiological actions of ionic and nonionic contrast agents. (orig.) [de

  7. Transient global amnesia following cerebral angiography with non-ionic contrast medium

    International Nuclear Information System (INIS)

    Schamschula, R.G.; Soo, M.Y.S.

    1994-01-01

    Transit global amnesia (TGA) is an uncommon syndrome of recent memory deficit and inability to learn new data, usually resolving within 24 hours. Two cases following use of non-ionic contrast media in cerebral angiography are presented. The neuroanatomy of memory is reviewed. Possible aetiologies of TGA in relation to cerebral angiography include ischemia (embolic, arterial spasm), epilepsy that may be primary or tumour-related and direct toxic effects of contrast media. 19 refs., 1 fig

  8. The standard biphasic-contrast examination of the stomach and duodenum

    International Nuclear Information System (INIS)

    Op den Orth, J.O.

    1979-01-01

    A standard examination has been developed, called biphasic, because it combines the advantages of positive-contrast and double-contrast techniques. The theoretical background and technique of this examination are described and the basic interpretation of double-contrast studies stated. General remarks on the results and on the complementary role of radiological examination and endoscopy are included. A quantitative study of standard biphasic-contrast examinations in patients over a period of 3 years is presented. Finally a radiological atlas of common lesions of the stomach and duodenum is given. (C.F.)

  9. Transient angioedema of small bowel secondary to intravenous iodinated contrast medium

    Directory of Open Access Journals (Sweden)

    Kirankumar N Kulkarni

    2014-01-01

    Full Text Available We report the clinical details and imaging findings of a case of transient angioedema of the small bowel following intravenous administration of non-ionic iodinated contrast material in a 17 year old female with no predisposing risk factors. Findings included long segment, symmetric, circumferential, low-density, bowel wall thickening involving the duodenum, jejunum, and most of the ileum on computed tomography scan obtained at 7 min following intravenous contrast material injection. This entity is self-limiting with a favourable clinical outcome and requires no specific treatment but only aggressive clinical monitoring.

  10. 76 FR 59922 - Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty...

    Science.gov (United States)

    2011-09-28

    ...) * * * (4) * * * (ii) Calculate the equivalent fuel consumption test group results as follows for spark... (gallons per 100 mile). * * * * * (c) * * * (4) * * * (ii) Calculate equivalent fuel consumption FCL values... standards for medium- and heavy-duty engines and vehicles, as prescribed under the Energy Independence and...

  11. An evaluation of ultravist - a contrast medium by Schering in angiography

    International Nuclear Information System (INIS)

    Twarkowski, P.; Woynarowski, M.

    1993-01-01

    An angiography with ''uropolina'' (Polfa), ''hexabrix'' (Byk) and ''ultravist'' (Schering) was performed in 30 patients with various vascular disorders. It has appeared, that low-osmolality contrast media (''hexabrix'') and nonionic ones (''ultravist'') less frequently caused the complications than ''uropolina'', widely used by us. (author)

  12. Submillisievert standard-pitch CT pulmonary angiography with ultra-low dose contrast media administration: A comparison to standard CT imaging.

    Science.gov (United States)

    Suntharalingam, Saravanabavaan; Mikat, Christian; Stenzel, Elena; Erfanian, Youssef; Wetter, Axel; Schlosser, Thomas; Forsting, Michael; Nassenstein, Kai

    2017-01-01

    To evaluate the image quality and radiation dose of submillisievert standard-pitch CT pulmonary angiography (CTPA) with ultra-low dose contrast media administration in comparison to standard CTPA. Hundred patients (56 females, 44 males, mean age 69.6±15.4 years; median BMI: 26.6, IQR: 5.9) with suspected pulmonary embolism were examined with two different protocols (n = 50 each, group A: 80 kVp, ref. mAs 115, 25 ml of contrast medium; group B: 100 kVp, ref. mAs 150, 60 ml of contrast medium) using a dual-source CT equipped with automated exposure control. Objective and subjective image qualities, radiation exposure as well as the frequency of pulmonary embolism were evaluated. There was no significant difference in subjective image quality scores between two groups regarding pulmonary arteries (p = 0.776), whereby the interobserver agreement was excellent (group A: k = 0.9; group B k = 1.0). Objective image analysis revealed that signal intensities (SI), signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the pulmonary arteries were equal or significantly higher in group B. There was no significant difference in the frequency of pulmonary embolism (p = 0.65). Using the low dose and low contrast media protocol resulted in a radiation dose reduction by 71.8% (2.4 vs. 0.7 mSv; pcontrast agent volume can obtain sufficient image quality to exclude or diagnose pulmonary emboli while reducing radiation dose by approximately 71%.

  13. Indirect MR venography: contrast medium protocols, postprocessing and combination in diagnosing pulmonary emboli with MRI

    International Nuclear Information System (INIS)

    Kluge, A.; Bachmann, G.; Rominger, M.; Schoenburg, M.

    2004-01-01

    Purpose: Integration of MR venography in a comprehensive MR imaging protocol in patients with suspected pulmonary embolism (PE) and evaluation of contrast media dosage, timing and postprocessing for diagnostic accuracy. Materials and Methods: Fortyeight consecutive inpatients with suspected PE or deep vein thrombosis were examined by MR venography according to one of the following protocols: protocol I: MR venography only, 0.25 mmol/kg bodyweight (BW) Gadopentate dimeglumine(Gd-DTPA) as single dose, bolus timing; protocol II: MR angiography of pulmonary arteries with a cumulative dosage of 0.25 mmol/kg contrast media, modification of coil setting for MR venography without further contrast media application; protocol III: as protocol II but with 0.125 mmol/kg BW, followed by MR venography. Signal-to-noise ratio, contrast-to-noise ratio, number of definable vascular segments and image quality were evaluated. The results were compared to conventional bilateral venography. Results: All MR venography examinations were of diagnostic quality and the examination time was below 10 min. MR venography could be performed in all 48 patients comparted to 43 of 48 patients for conventional venography. Significantly more superficial and deep veins of the leg could be visualized by MR venography (94% compared to 83% for conventional venography). Sensitivity and specificity were 100% and 92%, respectively. Quality differed significantly between 0.125 mmol/kg (protocol III) and 0.25 mmol/kg Gd-DTPA (protocols I and II) while timing did not influence quality (protocol I vs. II). (orig.) [de

  14. Characterisation of urinary stones in the presence of iodinated contrast medium using dual-energy CT: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jia; Qu, Mingliang; Duan, Xinhui; Takahashi, Naoki; Kawashima, Akira; Leng, Shuai; McCollough, Cynthia H. [Mayo Clinic, Department of Radiology, Rochester, MN (United States)

    2012-12-15

    To develop a dual-energy CT (DECT) method for differentiating uric acid (UA) from non-UA stones in the presence of iodinated contrast medium. Thirty UA and 45 non-UA stones were selected after infra-red spectroscopic analysis and independently placed in a 1.5-ml vial, which was filled first with saline and then with increasing concentrations of iodine. For each condition, tubes were put in a 35-cm water phantom and examined using a dual-source CT system at 100 and 140 kV. Virtual unenhanced images created from CT data sets of the stones in iodine-containing solutions provided position and volume information. This map was used to calculate a CT number ratio to differentiate stone type. A region-growing method was developed to improve the ability to differentiate between UA and non-UA stones with iodinated contrast medium. The sensitivity for detecting UA stones was 100 % for unenhanced images but fell to 18 % with 20 mgI/ml iodine solution and 0 % for higher concentrations. With region growing, the sensitivity for detecting UA stones was increased to 100 %, 82 %, 57 %, 50 % and 21 % for iodine solutions of 20, 40, 60, 80 and 100 mgI/ml. The region-growing method improves differentiation of UA from non-UA stones on contrast-enhanced DECT urograms. (orig.)

  15. Nanotoxic Profiling of Novel Iron Oxide Nanoparticles Functionalized with Perchloric Acid and SiPEG as a Radiographic Contrast Medium

    Directory of Open Access Journals (Sweden)

    Muhamad Idham Mohamed

    2015-01-01

    Full Text Available Emerging syntheses and findings of new metallic nanoparticles (MNPs have become an important aspect in various fields including diagnostic imaging. To date, iodine has been utilized as a radiographic contrast medium. However, the raise concern of iodine threats on iodine-intolerance patient has led to search of new contrast media with lower toxic level. In this animal modeling study, 14 nm iron oxide nanoparticles (IONPs with silane-polyethylene glycol (SiPEG and perchloric acid have been assessed for toxicity level as compared to conventional iodine. The nanotoxicity of IONPs was evaluated in liver biochemistry, reactive oxygen species production (ROS, lipid peroxidation mechanism, and ultrastructural evaluation using transmission electron microscope (TEM. The hematological analysis and liver function test (LFT revealed that most of the liver enzymes were significantly higher in iodine-administered group as compared to those in normal and IONPs groups P<0.05. ROS production assay and lipid peroxidation indicator, malondialdehyde (MDA, also showed significant reductions in comparison with iodine group P<0.05. TEM evaluation yielded the aberration of nucleus structure of iodine-administered group as compared to those in control and IONPs groups. This study has demonstrated the less toxic properties of IONPs and it may postulate that IONPs are safe to be applied as radiographic contrast medium.

  16. Characterisation of urinary stones in the presence of iodinated contrast medium using dual-energy CT: a phantom study

    International Nuclear Information System (INIS)

    Wang, Jia; Qu, Mingliang; Duan, Xinhui; Takahashi, Naoki; Kawashima, Akira; Leng, Shuai; McCollough, Cynthia H.

    2012-01-01

    To develop a dual-energy CT (DECT) method for differentiating uric acid (UA) from non-UA stones in the presence of iodinated contrast medium. Thirty UA and 45 non-UA stones were selected after infra-red spectroscopic analysis and independently placed in a 1.5-ml vial, which was filled first with saline and then with increasing concentrations of iodine. For each condition, tubes were put in a 35-cm water phantom and examined using a dual-source CT system at 100 and 140 kV. Virtual unenhanced images created from CT data sets of the stones in iodine-containing solutions provided position and volume information. This map was used to calculate a CT number ratio to differentiate stone type. A region-growing method was developed to improve the ability to differentiate between UA and non-UA stones with iodinated contrast medium. The sensitivity for detecting UA stones was 100 % for unenhanced images but fell to 18 % with 20 mgI/ml iodine solution and 0 % for higher concentrations. With region growing, the sensitivity for detecting UA stones was increased to 100 %, 82 %, 57 %, 50 % and 21 % for iodine solutions of 20, 40, 60, 80 and 100 mgI/ml. The region-growing method improves differentiation of UA from non-UA stones on contrast-enhanced DECT urograms. (orig.)

  17. Pulmonary edema following intravenous injection of nonionic low-osmolar contrast medium - appearance on HRCT. A case report

    International Nuclear Information System (INIS)

    Bristedt, P.; Tylen, U.

    1998-01-01

    Pulmonary edema following i.v. contrast medium injection is a rare adverse reaction. We report on a 71-year-old woman who developed pulmonary edema following i.v. injection of iohexol during spiral CT of the thorax. She developed shortness of breath during the injection, and the first radiographic signs of pulmonary edema were visible on CT images 25 s after the onset of injection. On HRCT images 15 min later, marked edema was demonstrated in both lungs in a mosaic pattern of distribution. After appropriate therapy, the patient recovered without sequelae. A repeat CT 6 days later showed complete normalization. (orig.)

  18. MRI with intrathecal MRI gadolinium contrast medium administration: a possible method to assess glymphatic function in human brain

    International Nuclear Information System (INIS)

    Eide, Per Kristian; Ringstad, Geir

    2015-01-01

    Recently, the “glymphatic system” of the brain has been discovered in rodents, which is a paravascular, transparenchymal route for clearance of excess brain metabolites and distribution of compounds in the cerebrospinal fluid. It has already been demonstrated that intrathecally administered gadolinium (Gd) contrast medium distributes along this route in rats, but so far not in humans. A 27-year-old woman underwent magnetic resonance imaging (MRI) with intrathecal administration of gadobutrol, which distributed throughout her entire brain after 1 and 4.5 h. MRI with intrathecal Gd may become a tool to study glymphatic function in the human brain

  19. Cytogenetic analysis of peripheral blood lymphocytes after arteriography (exposure to x-rays and contrast medium)

    International Nuclear Information System (INIS)

    Popova, L.; Hadjidekova, V.; Karadjov, G.; Agova, S.; Traskov, D.; Hadjidekov, V.

    2005-01-01

    Backgrounds. The purpose of our study is to investigate the cytogenetic analysis findings in peripheral blood lymphocytes of 29 patients who had undergone diagnostic radiography. Methods. Peripheral blood samples were taken from 22 patients submitted to renal arteriography and 7 patients submitted to cerebral arteriography (17 male and 12 female, aged between 13-68 years). Cytogenetic analyses of peripheral lymphocytes were performed before the procedure, immediately after and 24 hours later. The entrance skin dose obtained during the whole diagnostic X-ray exposure was measured by thermoluminescent dosimeters and varied between 0.03-0.30 Gy. Both low and high osmolarity contrast media were used. Chromosomal aberrations and micronuclei frequency were used as biomarkers of genotoxicity. Results. The estimated frequency of chromosomal aberrations and micronuclei in the peripheral blood lymphocytes of patients after arteriography examination was significantly higher than the level before the diagnostic exposure. The mean frequency of cells with chromosomal aberrations was nearly double after examination and proved to be constant in the analysis after 24 hours. Conclusions. Radiological diagnostic procedures involving iodinated contrast media as arteriography may cause a significant increase in cytogenetic damage in peripheral blood lymphocytes. (author)

  20. MRI for local staging of endometrial carcinoma: Is endovenous contrast medium administration still needed?

    Energy Technology Data Exchange (ETDEWEB)

    Bonatti, Matteo, E-mail: matteobonatti@hotmail.com [Department of Radiology of Bolzano Central Hospital, 5 Böhler St., 39100 Bolzano (Italy); Stuefer, Josef [Department of Radiology of Bolzano Central Hospital, 5 Böhler St., 39100 Bolzano (Italy); Oberhofer, Nadia [Department of Physics of Bolzano Central Hospital, 5 Böhler St., 39100 Bolzano (Italy); Negri, Giovanni [Department of Pathology of Bolzano Central Hospital, 5 Böhler St., 39100 Bolzano (Italy); Tagliaferri, Tiziana [Department of Gynecology of Bolzano Central Hospital, 5 Böhler St., 39100 Bolzano (Italy); Schifferle, Günther [Department of Radiology of Bolzano Central Hospital, 5 Böhler St., 39100 Bolzano (Italy); Messini, Sergio [Department of Gynecology of Bolzano Central Hospital, 5 Böhler St., 39100 Bolzano (Italy); Manfredi, Riccardo [Department of Radiology of the University of Verona, Piazzale L.A. Scuro 10, 37134 Verona (Italy); Bonatti, Giampietro [Department of Radiology of Bolzano Central Hospital, 5 Böhler St., 39100 Bolzano (Italy)

    2015-02-15

    Highlights: • Intravenous contrast material administration is not routinely indicated for MRI local staging of endometrial carcinoma. • The combination of T2-weighted images with diffusion-weighted images warrants at least the same accuracy as the combination of T2-weighted images with contrast-enhanced T1-weighted images in recognizing deep myometrial invasion and cervical stromal infiltration by endometrial carcinoma. - Abstract: Purpose: To compare the diagnostic performance of T2-weighted images (T2-WI) + contrast-enhanced T1-weighted images (CE T1-WI) with the one of T2-WI + diffusion-weighted images (DWI) in the assessment of myometrial and cervical stromal infiltration by endometrial carcinoma (EC). Materials and methods: Institutional review board approved our retrospective study; requirement for informed consent was waived. 56 patients with histologically proven EC who underwent preoperative MRI and surgery at our Institution over a 34 months period were included. Two radiologists independently evaluated T2-WI + CE T1-WI and T2-WI + DWI of each patient. Confidence in imaging evaluation (0–3), depth of myometrial invasion ( 0.05) whereas both imaging sequences combinations showed the same diagnostic performance in recognizing cervical stromal infiltration (accuracy, sensitivity and specificity of 0.95, 0.98 and 0.80, p > 0.05). Conclusion: T2-WI + DWI can reliably replace the “classical” combination T2-WI + CE T1-WI for local staging of endometrial carcinoma.

  1. [Dynamic MR mammography. Multidimensional visualization of contrast medium enhancement in virtual reality].

    Science.gov (United States)

    Englmeier, K H; Griebel, J; Lucht, R; Knopp, M; Siebert, M; Brix, G

    2000-03-01

    The purpose of this study was the development of a method for fast and efficient analysis of dynamic MR images of the female breast. The image data sets were acquired with a saturation-recovery turbo-FLASH sequence which enables the detection of the kinetics of the contrast agent concentration in the whole breast with a high temporal and spatial resolution. In addition, a morphologic 3D-FLASH data set was acquired. The dynamic image datasets were analyzed by a pharmacokinetic model which enables the representation of the relevant functional tissue information by two parameters. In order to display simultaneously morphologic and functional tissue information, we developed a multidimensional visualization system, which enables a practical and intuitive human-computer interface in virtual reality. The developed system allows the fast and efficient analysis of dynamic MR data sets. An important clinical application is the localization and definition of multiple lesions of the female breast.

  2. Utility of vaginal and rectal contrast medium in MRI for the detection of deep pelvic endometriosis

    Energy Technology Data Exchange (ETDEWEB)

    Chassang, M.; Novellas, S.; Bloch-Marcotte, C.; Chevallier, P. [Hopital Archet 2, Service d' Imagerie Diagnostique et Interventionnelle, Centre Hospitalier Regional et Universitaire de Nice, 151 route de Saint Antoine de Ginestiere, B.P. 3079, Nice Cedex 3 (France); Delotte, J.; Bongain, A. [Hopital Archet 2, Service de Gynecologie-Obstetrique, Centre Hospitalier Regional et Universitaire de Nice, 151 route de Saint Antoine de Ginestiere, B.P. 3079, Nice Cedex 3 (France); Toullalan, O. [Hopital de Cannes, Service de Gynecologie, 15 avenue des Broussailles, B.P. 264, Cannes Cedex (France)

    2010-04-15

    To study the sensitivity of MRI performed utilising vaginal and rectal opacification with ultrasound gel in the detection of deep pelvic endometriosis. This was a prospective monocentric study. All patients evaluated by the gynaecologist for pelvic pain, endometriosis or infertility were included. Axial and sagittal T2-weighted images were performed both with and without vaginal and rectal opacification with ultrasound gel. Three radiologists, all blinded, interpreted the images with a minimum of 15 days between the two readings. MRI performance with and without vaginal and rectal opacification was evaluated by calculating sensitivity, specificity and both positive and negative predictive values. Seventy-eight patients were included. Among these, 31 patients had deep pelvic endometriosis of which 24 were confirmed by laparoscopy. Seventy-six locations of deep pelvic endometriosis were discovered on MRI. For the three reviewers there was a significant improvement in sensitivity between pre- and post-contrast MRI (p < 0.0002). Opacification of the vagina and rectum significantly improved the sensitivity of MRI for the detection of deep pelvic endometriosis by expanding the vagina and rectum, thus allowing better delineation of the pelvic organs. This was especially apparent for lesions localised to the vagina and rectovaginal septum. (orig.)

  3. Utility of vaginal and rectal contrast medium in MRI for the detection of deep pelvic endometriosis

    International Nuclear Information System (INIS)

    Chassang, M.; Novellas, S.; Bloch-Marcotte, C.; Chevallier, P.; Delotte, J.; Bongain, A.; Toullalan, O.

    2010-01-01

    To study the sensitivity of MRI performed utilising vaginal and rectal opacification with ultrasound gel in the detection of deep pelvic endometriosis. This was a prospective monocentric study. All patients evaluated by the gynaecologist for pelvic pain, endometriosis or infertility were included. Axial and sagittal T2-weighted images were performed both with and without vaginal and rectal opacification with ultrasound gel. Three radiologists, all blinded, interpreted the images with a minimum of 15 days between the two readings. MRI performance with and without vaginal and rectal opacification was evaluated by calculating sensitivity, specificity and both positive and negative predictive values. Seventy-eight patients were included. Among these, 31 patients had deep pelvic endometriosis of which 24 were confirmed by laparoscopy. Seventy-six locations of deep pelvic endometriosis were discovered on MRI. For the three reviewers there was a significant improvement in sensitivity between pre- and post-contrast MRI (p < 0.0002). Opacification of the vagina and rectum significantly improved the sensitivity of MRI for the detection of deep pelvic endometriosis by expanding the vagina and rectum, thus allowing better delineation of the pelvic organs. This was especially apparent for lesions localised to the vagina and rectovaginal septum. (orig.)

  4. Systemic Hypotension Following Intravenous Administration of Nonionic Contrast Medium During Computed Tomography: Iopromide Versus Iodixanol.

    Science.gov (United States)

    Widmann, Gerlig; Bale, Reto; Ulmer, Hanno; Putzer, Daniel; Schullian, Peter; Wiedermann, Franz-Josef; Lederer, Wolfgang

    2018-03-01

    In light of the increasing number of radiologic interventions performed under general anesthesia, the effects of contrast media (CM) on circulation and organ perfusion are of paramount importance. The objectives of this study were to systematically quantify effects on blood pressure, heart rate, and kidney function following intravenous administration of nonionic CM with normal and low osmolality. In this controlled, double-blinded phase IV clinical trial, 40 consecutive patients were randomly assigned to receive repeated measures of either low-osmolar iopromide or iso-osmolar iodixanol. Normal saline solution (NSS) served as control. Blood pressure and heart rate were measured continuously from 1 minute before until 3 minutes after administration of CM and NSS. Urine output was recorded hourly. Administration of iopromide resulted in systemic hypotension lasting up to 300 seconds (105 ± 61 seconds) with the lowest mean arterial pressure of 39 mm Hg (56.7 ± 12.2 mm Hg). Iopromide caused a systolic/diastolic decrease of 31/26 mm Hg (P .640). Administration of low-osmolar iopromide was followed by a significant transient decrease in blood pressure and a rise in heart rate. Anesthetists and radiologists should be aware of these effects in patients in whom short episodes of disturbed tissue microcirculation may pose a clinical risk.

  5. Contrasting medium and genre on Wikipedia to open up the dominating definition and classification of geoengineering

    Directory of Open Access Journals (Sweden)

    Nils Markusson

    2016-08-01

    Full Text Available Geoengineering is typically defined as a techno-scientific response to climate change that differs from mitigation and adaptation, and that includes diverse individual technologies, which can be classified as either solar radiation management or carbon dioxide removal. We analyse the representation of geoengineering on Wikipedia as a way of opening up this dominating, if contested, model for further debate. We achieve this by contrasting the dominating model as presented in the encyclopaedic article texts with the patterns of hyper-link associations between the articles. Two datasets were created tracing the geoengineering construct on Wikipedia, shedding light on its boundary with its context, as well as on its internal structure. The analysis shows that the geoengineering category tends to be associated on Wikipedia primarily with atmospheric solar radiation management rather than land-based carbon dioxide removal type technologies. The results support the notion that the dominant model of defining and classifying geoengineering technology has been beneficial for solar radiation management type technologies more than for land-based carbon dioxide removal ones. The article also demonstrates that controversy mapping with Wikipedia data affords analysis that can open up dominating definitions and classifications of technologies, and offer resistance to their frequent naturalising and decontextualising tendencies. This work is in line with recent work on digital sociology, but the article contributes a new methodology and reports on the first empirical application of controversy mapping using Wikipedia data to a technology.

  6. International Financial Reporting standard for Small and Medium-sized entities

    Directory of Open Access Journals (Sweden)

    Z Koppeschaar

    2012-12-01

    Full Text Available The International Financial Reporting Standard for Small and Medium-sized entities (IFRS for SMEs was published as a standard by the International Accounting Standards Board (IASB during July 2009. During 2007 South Africa became one of the first countries and the first country in Africa to early accept the proposed accounting standard (exposure draft of an IFRS for SMEs. The accounting standard will probably also be accepted by numerous other countries. The aim of this article is to investigate the applicability of this accounting standard. The results indicated that the IFRS for SMEs remains too comprehensive for the majority of small companies. The IFRS for SMEs does not satisfy the needs of South African users of small company financial statements, and as a result the accounting requirements should be simplified. KEYWORDS: Financial accounting; Financial reporting requirements; IFRS for SMEs; Small companies; Users of financial statements; Small company financial statements.

  7. Carbon dioxide is a cost-effective contrast medium to guide revascularization of TASC A and TASC B femoropopliteal occlusive disease.

    Science.gov (United States)

    de Almeida Mendes, Cynthia; de Arruda Martins, Alexandre; Teivelis, Marcelo Passos; Kuzniec, Sergio; Nishinari, Kenji; Krutman, Mariana; Halpern, Helio; Wolosker, Nelson

    2014-08-01

    Iodine contrast medium (ICM) is considered gold standard in endovascular revascularization procedures. However, nephrotoxicity and hypersensitivity to ICM are causes that limit its indiscriminate use. Carbon dioxide (CO2) contrast angiography has been used as an alternative in patients with formal contraindication to ICM. However, no studies to the present date have compared in a randomized and prospective way, outcomes of revascularization procedures performed with either ICM or CO2 in patients eligible for use of both contrasts. Between April 2012 and April 2013, 35 patients with peripheral arterial disease with arterial lesions classified as Trans-Atlantic Inter-Society Consensus A or B (identified on preoperative angio computed tomography scan) and adequate runoff underwent femoropopliteal revascularization by endovascular technique in a prospective, randomized, and controlled study. Patients were randomized into 2 groups: CO2 group and ICM group, according to the contrast media selected of the procedure. We evaluated the following outcomes in both groups: feasibility of the procedures, complications, surgical outcomes (ankle-brachial index [ABI]), glomerular filtration rate using the Cockcroft-Gault formula, relationship between the volume of injected iodine and postoperative creatinine clearance, quality of the angiographic images obtained with CO2, costs of the endovascular materials, and finally, cost of contrast agents. We were able to perform the proposed procedures in all patients treated in this series (ICM group and CO2). There were no CO2-related complications. No procedures required conversion to open surgery. Clinical results were satisfactory, with regression of ischemia and increased levels of ABI in both groups. Variations in creatinine clearance levels showed a numerical increase in the CO2 group and a decrease in ICM group, however, with no statistically significant difference between the delta clearance in each group. All CO2 arteriograms of

  8. Contrast Medium Induced Nephropathy after Endovascular Stent Graft Placement: An Examination of Its Prevalence and Risk Factors

    International Nuclear Information System (INIS)

    Kawatani, Yohei; Nakamura, Yoshitsugu; Mochida, Yoshihiko; Yamauchi, Naoya; Hayashi, Yujiro; Taneichi, Tetsuyoshi; Ito, Yujiro; Kurobe, Hirotsugu; Suda, Yuji; Hori, Takaki

    2016-01-01

    Endovascular stent graft placement has become a major treatment for thoracic and abdominal aneurysms. While endovascular therapy is less invasive than open surgery, it involves the use of a contrast medium. Contrast media can cause renal impairment, a condition termed as contrast-induced nephropathy (CIN). This study sought to evaluate the incidence and risk factors of CIN following endovascular stent graft placement for aortic aneurysm repair. The study included 167 consecutive patients who underwent endovascular stent graft placement in our hospital from October 2013 to June 2014. CIN was diagnosed using the European Society of Urogenital Radiology criteria. Patients with and without CIN were compared. Chi-squared tests, t-tests, and multivariate logistic regression analyses were performed. Thirteen patients (7.8%) developed CIN. Left ventricular dysfunction and intraoperative blood transfusion were significantly more frequent in the CIN group (P = 0.017 and P = 0.032, resp.). Multivariate analysis showed that left ventricular dysfunction had the strongest influence on CIN development (odds ratio 9.34, P = 0.018, and 95% CI = 1.46–59.7). Patients with CIN also experienced longer ICU and hospital stays. Measures to improve renal perfusion flow should be considered for patients with left ventricular dysfunction who are undergoing endovascular stent graft placement

  9. Dry preparation for virtual CT colonography with fecal tagging using water-soluble contrast medium: initial results

    International Nuclear Information System (INIS)

    Bielen, Didier; Thomeer, Maarten; Vanbeckevoort, Dirk; Marchal, Guy; Kiss, Gabriel; Maes, Frederik; Rutgeerts, Paul

    2003-01-01

    The purpose of this study was to evaluate the feasibility of a dry bowel preparation, i.e. without laxative fluids, for virtual CT colonography (VCTC), and its impact on patient acceptance compared with conventional colonoscopy (CC). A randomly chosen patient population scheduled for CC (n=11) was first submitted to VCTC after a dry preparation, consisting of low-residue meals combined with a small amount of a iodinated water-soluble contrast medium during each meal 3 days before VCTC. In different colon segments and between different persons, the degree of tagging in VCTC was evaluated and graded. Patient acceptance and future preference were assessed for both preparations as well as for both investigations. The mixing of the contrast with the intestinal content results in contrast impregnated stool, the tagged feces. The degree of fecal tagging was good in the majority of the patients and the colonic segments, especially in the descending colon and sigmoid. Furthermore, patient acceptance and preference were clearly in favour of VCTC compared with CC merely because of the non-invasiveness of the dry preparation. Dry bowel preparation and VCTC is a promising approach towards a patient-friendly colon cancer-screening setup. (orig.)

  10. Ultralow contrast medium doses at CT to diagnose pulmonary embolism in patients with moderate to severe renal impairment: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Kristiansson, Mattias; Nyman, Ulf [Lasarettet Trelleborg, University of Lund, Department of Diagnostic Radiology, Trelleborg (Sweden); Holmquist, Fredrik [Malmoe University Hospital, University of Lund, Department of Diagnostic Radiology, Malmoe (Sweden)

    2010-06-15

    To analyse 80-kVp 16-MDCT in patients with clinically suspected pulmonary embolism (PE) and diminished renal function after a reduction in dose of contrast medium (CM) from 200 to 150 mg I/kg. Fifty patients with suspected PE and glomerular filtration rate (GFR) less than 50 mL/min underwent 80-kVp 16-MDCT with 150 mg I/kg. Mean density/image noise (1 standard deviation) was measured in a region of interest in the left pulmonary artery (LPA) and a lower lobe segmental artery (LLSA), and the contrast-to-noise ratio (CNR) was calculated. The values of LPA and LLSA were averaged. Median values/2.5-97.5 percentiles were: age 84/67-96 years, weight 65/43-84 kg, GFR 36/21-45 mL/min, CM dose 9.6/6.4-12 g of iodine, PA density 353/164-495 HU and CNR 11/4.4-20. PE incidence was 16%, and 8% and 12% of the examinations were regarded suboptimal by observer 1 and 2, respectively. Density/CNR values were within ranges reported for common 120-kVp MDCT protocols. None of 32 patients with plasma-creatinine follow-up within 1 week experienced a rise of more than 44.2 {mu}mol/L and none of 50 patients had oliguria/anuria or dialysis. None of 40 patients with a negative CT/no anticoagulation had thromboembolism during follow-up. 80-kVp MDCT combined with individualised ultralow CM doses may provide satisfactory diagnostic quality, which should be to the benefit of patients at risk of contrast medium-induced nephropathy. (orig.)

  11. 2D and 3D parameter images for analysis of contrast medium enhancement based on dynamic CT and MR

    International Nuclear Information System (INIS)

    Beier, J.; Stroszczynski, C.; Oellinger, H.; Felix, R.; Buege, T.; Fleck, E.

    1998-01-01

    Aim: For dynamic contrast medium (CM) studies, parameter images exploit specific features of the time/intensity curve (TIC) of each pixel and represent these values in a new image. Existing concepts of two-dimensional CM analysis are extended for three-dimensional applications using adequate computer graphic visualization. Results: In first-pass analyses, TMIP and TG allowed the simultaneous or separted presentation of different temporal phases of the CM bolus. Correlation images emphasized regions with similarities to given TIC patterns. Three-dimensional computer graphic techniques enabled (1) anatomical/function mapping of original image and CM accumulation and (2) fused display of both spatial CM enhancement and color-encoded time of TIC peak in one common image. Conclusions: The quantifiction of presence, magnitude, and time-of-peak of CM accumulation in local image regions supports the assessment of vascularization and of ischemic or necrotic areas. (orig./AJ) [de

  12. The effect of contrast medium SonoVue® on the electric charge density of blood cells.

    Science.gov (United States)

    Petelska, Aneta D; Janica, Jacek R; Kotynska, Joanna; Łebkowska, Urszula; Figaszewski, Zbigniew A

    2012-01-01

    The effect of contrast medium SonoVue® on the electric charge density of blood cells (erythrocytes and thrombocytes) was measured using a microelectrophoretic method. We examined the effect of adsorbed H⁺ and OH⁻ ions on the surface charge of erythrocytes or thrombocytes. Surface charge density values were determined from electrophoretic mobility measurements of blood cells performed at various pH levels. The interaction between solution ions and the erythrocyte's or thrombocyte's surface was described by a four-component equilibrium model. The agreement between the experimental and theoretical charge variation curves of the erythrocytes and thrombocytes was good at pH 2-9. The deviation observed at a higher pH may be caused by disregarding interactions between the functional groups of blood cells.

  13. Kinetics of intravenous radiographic contrast medium injections as used on CT: simulation with time delay differential equations in a basic human cardiovascular multicompartment model.

    Science.gov (United States)

    Violon, D

    2012-12-01

    To develop a multicompartment model of only essential human body components that predicts the contrast medium concentration vs time curve in a chosen compartment after an intravenous injection. Also to show that the model can be used to time adequately contrast-enhanced CT series. A system of linked time delay instead of ordinary differential equations described the model and was solved with a Matlab program (Matlab v. 6.5; The Mathworks, Inc., Natick, MA). All the injection and physiological parameters were modified to cope with normal or pathological situations. In vivo time-concentration curves from the literature were recalculated to validate the model. The recalculated contrast medium time-concentration curves and parameters are given. The results of the statistical analysis of the study findings are expressed as the median prediction error and the median absolute prediction error values for both the time delay and ordinary differential equation systems; these are situated well below the generally accepted maximum 20% limit. The presented program correctly predicts the time-concentration curve of an intravenous contrast medium injection and, consequently, allows an individually tailored approach of CT examinations with optimised use of the injected contrast medium volume, as long as time delay instead of ordinary differential equations are used. The presented program offers good preliminary knowledge of the time-contrast medium concentration curve after any intravenous injection, allowing adequate timing of a CT examination, required by the short scan time of present-day scanners. The injected volume of contrast medium can be tailored to the individual patient with no more contrast medium than is strictly needed.

  14. Risk of contrast-medium-induced nephropathy in high-risk patients undergoing MDCT--a pooled analysis of two randomized trials

    DEFF Research Database (Denmark)

    Thomsen, Henrik S; Morcos, Sameh K

    2009-01-01

    The incidence of contrast-medium-induced nephropathy (CIN) following intravenous (IV) CM administration of contrast media to renally impaired patients undergoing multidetector computed tomography (MDCT) is not well characterized. Our objective was to investigate the incidence of CIN in patients...... with glomerular filtration rate (GFR) contrast-enhanced MDCT examinations and to compare the rates of CIN following the IV administration of low-osmolar contrast media (LOCM, iopamidol and iomeprol) and an iso-osmolar contrast medium (IOCM, iodixanol). A total of 301 adult patients...... with moderate-to-severe renal failure received a similar IV contrast dose (40 gI). Serum creatinine (SCr) was measured at screening, baseline and 48-72 +/- 6 h after the MDCT examination. Primary CIN outcome was an increase in SCr >or=0.5 mg/dl (>or=44.2 micromol/l) from baseline. The CIN rates were 2...

  15. Assessment of errors caused by X-ray scatter and use of contrast medium when using CT-based attenuation correction in PET

    Energy Technology Data Exchange (ETDEWEB)

    Ay, Mohammad R. [Geneva University Hospital, Division of Nuclear Medicine, Geneva (Switzerland); Zaidi, Habib

    2006-11-15

    Quantitative image reconstruction in positron emission tomography (PET) requires an accurate attenuation map of the object under study for the purpose of attenuation correction. Current dual-modality PET/CT systems offer significant advantages over stand-alone PET, including decreased overall scanning time and increased accuracy in lesion localisation and detectability. However, the contamination of CT data with scattered radiation and misclassification of contrast medium with high-density bone in CT-based attenuation correction (CTAC) are known to generate artefacts in the attenuation map and thus the resulting PET images. The purpose of this work was to quantitatively measure the impact of scattered radiation and contrast medium on the accuracy of CTAC. Our recently developed MCNP4C-based Monte Carlo X-ray CT simulator for modelling both fan- and cone-beam CT scanners and the Eidolon dedicated 3D PET Monte Carlo simulator were used to generate realigned PET/CT data sets. The impact of X-ray scattered radiation on the accuracy of CTAC was investigated through simulation of a uniform cylindrical water phantom for both a commercial fan-beam multi-slice and a prototype cone-beam flat panel detector-based CT scanner. The influence of contrast medium was studied by simulation of a cylindrical phantom containing different concentrations of contrast medium. Moreover, an experimental study using an anthropomorphic striatal phantom was conducted for quantitative evaluation of errors arising from the presence of contrast medium by calculating the apparent recovery coefficient (ARC) in the presence of different concentrations of contrast medium. The analysis of attenuation correction factors (ACFs) for the simulated cylindrical water phantom in both fan- and cone-beam CT scanners showed that the contamination of CT data with scattered radiation in the absence of scatter removal causes underestimation of the true ACFs, namely by 7.3% and 28.2% in the centre for the two

  16. Deficiency of Standard Effective-Medium Approximation for Ellipsometry of Layers of Nanoparticles

    International Nuclear Information System (INIS)

    Bortchagovsky, E. G.; Bortchagovsky, E. G.; Lozovski, V. Z.; Mishakova, T. O.; Jastrabik, L.

    2015-01-01

    Correct description of optical properties of layers of disordered interacting nanoparticles is the problem. Contrary to volumes of nano composites, when standard models of effective-medium approximations (EMA) work well, two-dimensional case of layers has intrinsic anisotropy, which influences interparticle interactions. The deficiency of standard Maxwell-Garnett model in the application to the ellipsometry of layers of gold nanoparticles is demonstrated. It demands the modification of EMA models and one way of this is considered in this paper. Contrary to existing 2D models with phenomenological parameters, the proposed Green function approach uses the same number of parameters as standard 3D EMA models for explicit calculations of effective parameters of layers of disordered nanoparticles

  17. Deficiency of Standard Effective-Medium Approximation for Ellipsometry of Layers of Nanoparticles

    Directory of Open Access Journals (Sweden)

    E. G. Bortchagovsky

    2015-01-01

    Full Text Available Correct description of optical properties of layers of disordered interacting nanoparticles is the problem. Contrary to volumes of nanocomposites, when standard models of effective-medium approximations (EMA work well, two-dimensional case of layers has intrinsic anisotropy, which influences interparticle interactions. The deficiency of standard Maxwell-Garnett model in the application to the ellipsometry of layers of gold nanoparticles is demonstrated. It demands the modification of EMA models and one way of this is considered in this paper. Contrary to existing 2D models with phenomenological parameters, the proposed Green function approach uses the same number of parameters as standard 3D EMA models for explicit calculations of effective parameters of layers of disordered nanoparticles.

  18. Luminosity and contrast normalization in color retinal images based on standard reference image

    Science.gov (United States)

    S. Varnousfaderani, Ehsan; Yousefi, Siamak; Belghith, Akram; Goldbaum, Michael H.

    2016-03-01

    Color retinal images are used manually or automatically for diagnosis and monitoring progression of a retinal diseases. Color retinal images have large luminosity and contrast variability within and across images due to the large natural variations in retinal pigmentation and complex imaging setups. The quality of retinal images may affect the performance of automatic screening tools therefore different normalization methods are developed to uniform data before applying any further analysis or processing. In this paper we propose a new reliable method to remove non-uniform illumination in retinal images and improve their contrast based on contrast of the reference image. The non-uniform illumination is removed by normalizing luminance image using local mean and standard deviation. Then the contrast is enhanced by shifting histograms of uniform illuminated retinal image toward histograms of the reference image to have similar histogram peaks. This process improve the contrast without changing inter correlation of pixels in different color channels. In compliance with the way humans perceive color, the uniform color space of LUV is used for normalization. The proposed method is widely tested on large dataset of retinal images with present of different pathologies such as Exudate, Lesion, Hemorrhages and Cotton-Wool and in different illumination conditions and imaging setups. Results shows that proposed method successfully equalize illumination and enhances contrast of retinal images without adding any extra artifacts.

  19. Body surface area adapted iopromide 300 mg/ml versus 370 mg/ml contrast medium injection protocol: Influence on quantitative and clinical assessment in combined PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Verburg, Frederik A., E-mail: fverburg@ukaachen.de [RWTH Aachen University Hospital, Department of Nuclear Medicine, Pauwelsstraße 30, 52074 Aachen (Germany); Maastricht University Medical Center, Department of Nuclear Medicine, P. Debyelaan 25, 6229 HX Maastricht (Netherlands); Apitzsch, Jonas [RWTH Aachen University Hospital, Department of Diagnostic and Interventional Radiology, Pauwelsstraße 30, 52074 Aachen (Germany); Lensing, Carina [RWTH Aachen University Hospital, Department of Nuclear Medicine, Pauwelsstraße 30, 52074 Aachen (Germany); Kuhl, Christiane K. [RWTH Aachen University Hospital, Department of Diagnostic and Interventional Radiology, Pauwelsstraße 30, 52074 Aachen (Germany); Pietsch, Hubertus [Bayer Pharma AG, Müllerstrasse 178, 13353 Berlin (Germany); Mottaghy, Felix M. [RWTH Aachen University Hospital, Department of Nuclear Medicine, Pauwelsstraße 30, 52074 Aachen (Germany); Maastricht University Medical Center, Department of Nuclear Medicine, P. Debyelaan 25, 6229 HX Maastricht (Netherlands); Behrendt, Florian F. [RWTH Aachen University Hospital, Department of Nuclear Medicine, Pauwelsstraße 30, 52074 Aachen (Germany)

    2013-12-01

    Purpose: To investigate the quantitative and qualitative differences between combined positron emission tomography and computed X-ray tomography (PET/CT) enhanced with contrast medium with either an iodine concentration 300 mg/ml or 370 mg/ml. Materials and methods: 120 consecutive patients scheduled for F-18-Fluorodeoxyglucose (FDG) PET/CT were included. The first (second) 60 patients received contrast medium with 300 (370) mg iodine/ml. Intravenous injection protocols were adapted for an identical iodine delivery rate (1.3 mg/s) and body surface area (BSA) adapted iodine dose (22.26 g I/m{sup 2}). Maximum and mean standardized uptake values (SUV{sub max}; SUV{sub mean}) and contrast enhancement (HU) were determined in the ascending aorta, the abdominal aorta, the inferior vena cava, the portal vein, the liver and the right kidney in the venous contrast medium phase. PET data were evaluated visually for the presence of malignancy and image quality. Results: Both media caused significantly higher values for HU, SUV{sub mean} and SUV{sub max} for the enhanced PET/CT than the non-enhanced one (all p < 0.01). There were no significant differences in the degree of increase of HU, SUV{sub mean} and SUV{sub max} between the two contrast media at any anatomic site (all p > 0.05). Visual evaluation of lesions showed no differences between contrast and non-contrast PET/CT or between the two different contrast media (p = 0.77). Conclusion: When using a constant iodine delivery rate and total iodine dose in a BSA adapted injection protocol, there are no quantitative or qualitative differences in either CT or PET between contrast media with an iodine concentration of 300 mg/ml and 370 mg/ml, respectively.

  20. Follow-up of breast lesions detected by MRI not biopsied due to absent enhancement of contrast medium

    Energy Technology Data Exchange (ETDEWEB)

    Hefler, L.; Koelbl, H. [Department of Obstetrics and Gynecology, Martin Luther University Halle-Wittenberg, Magdeburger Strasse 16, 06112 Halle (Germany); Casselman, J. [Department of Radiology, A.Z. St. Jan, Brugge (Belgium); Amaya, B.; Heinig, A.; Alberich, T.; Heywang-Koebrunner, S.H. [Department of Diagnostic Radiology, Martin Luther University Halle-Wittenberg, Magdeburger Strasse 16, 06112 Halle (Germany)

    2003-02-01

    Our objective was to follow-up patients in whom scheduled MR-guided vacuum biopsies for suspicious lesions were aborted due to absent enhancement of contrast medium. Thirty-seven of 291 scheduled MR-guided vacuum biopsies were aborted. Six cases were lost to follow-up. Two could be unequivocally identified and were nevertheless biopsied. In 25 of 29 patients absent enhancement was confirmed on subsequent studies without compression. Varying hormonal or inflammatory changes between initial MRI and MR-guided vacuum biopsy most probably explain the findings. Enhancement re-appeared on short-term follow-up <6 months without compression in 4 of the 29 patients. Too strong compression during MR-guided vacuum biopsy explains the absence of enhancement in these patients. Of note, on histology, three of these cases proved malignant. We conclude that short-term follow-up without compression is necessary and recommended for all lesions not visible during scheduled MR-guided vacuum biopsy. (orig.)

  1. Contrast-enhanced MR angiography of the arterial and portovenous system of the liver with varying concentrations of contrast medium; Kontrastmittel-gestuetzte 3D-MR-Angiographie des arteriellen und portalvenoesen Gefaesssysteme der Leber mit unterschiedlicher KM-Konzentration

    Energy Technology Data Exchange (ETDEWEB)

    Vosshenrich, R.; Engeroff, B.; Obenauer, S.; Grabbe, E. [Klinikum der Georg-August-Universitaet, Goettingen (Germany). Abt. Diagnostische Radiologie

    2003-09-01

    Purpose: To evaluate the diagnostic value of a higher concentrated contrast medium (gadobutrol) for contrast-enhanced MRA of the hepatic arteries and portovenous system. Materials and methods: The examinations were performed on a 1.5-Tesla whole body imaging system (Magnetom Symphony Quantum, Siemens) with a 30-mTesla/m gradient field strength using a phased-array body coil. A 3D FLASH sequence (TR/TE/FA 3.88 ms/1.44 ms/25 ) was used imaging the hepatic arteries and portovenous system after determination of the circulation time. The study included 50 patients, with 25 patients (group 1) injected with 0.2 mmol Gd-GTPA/kg body weight and 25 patients (group 2) injected with 0.1 mmol gadobutrol/kg body weight. The signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) were calculated for both groups. The image quality was graded by three radiologists on a 5-point scale. Results: The highest SNR was measured in group 1, with no statistically significant differences of the SNR in the abdominal aortal, coeliac trunk and common hepatic artery. CNR was also similar in both groups. Likewise, portal, superior mesenteric and splenic veins showed no statistically significant differences. All cases were found to have a good image quality. Conclusion: For MRA of the hepatic arteries and the portal veins, the higher concentrated Gd-DTPA contrast medium gadobutrol can be used at half the dosage recommended for the standard Gd-DTPA contrast medium. (orig.) [German] Ziel: Die vorliegende Studie soll den Stellenwert eines hoeher konzentrierten Kontrastmittels (KM) fuer die 3D-MR-Angiographie (MRA) der arteriellen und portalvenoesen Lebergefaesse evaluieren. Methoden: Die Durchfuehrung der Untersuchungen erfolgte an einem Magnetom Symphony/Quantum mit einer Feldstaerke von 1.5 T und einer Gradientenstaerke von 30 mT/m unter Verwendung einer Koerper-Array-Spule. Zur Anwendung kam eine 3D-FLASH-Sequenz (TR/TE/FA 3,88 ms/1,44 ms/25 ). Untersucht wurde das arterielle und

  2. Effects of changes in analytic variables and contrast medium on estimation of glomerular filtration rates by computed tomography in healthy dogs.

    Science.gov (United States)

    Matsuda, Yuri; Kishimoto, Miori; Kushida, Kazuya; Yamada, Kazutaka; Shimizu, Miki; Itoh, Hiroshi

    2017-09-01

    OBJECTIVE To investigate effects of changes in analytic variables and contrast medium osmolality on glomerular filtration rate estimated by CT (CT-GFR) in dogs. ANIMALS 4 healthy anesthetized Beagles. PROCEDURES GFR was estimated by inulin clearance, and dogs underwent CT-GFR with iodinated contrast medium (iohexol or iodixanol) in a crossover-design study. Dynamic renal CT scanning was performed. Patlak plot analysis was used to calculate GFR with the renal cortex or whole kidney selected as the region of interest. The renal cortex was analyzed just prior to time of the second cortical attenuation peak. The whole kidney was analyzed 60, 80, 100, and 120 seconds after the appearance of contrast medium. Automated GFR calculations were performed with preinstalled perfusion software including 2 noise reduction levels (medium and strong). The CT-GFRs were compared with GFR estimated by inulin clearance. RESULTS There was no significant difference in CT-GFR with iohexol versus iodixanol in any analyses. The CT-GFR at the renal cortex, CT-GFR for the whole kidney 60 seconds after appearance of contrast medium, and CT-GFR calculated by perfusion software with medium noise reduction did not differ significantly from GFR estimated by inulin clearance. The CT-GFR was underestimated at ≥ 80 seconds after contrast medium appearance (whole kidney) and when strong noise reduction was used with perfusion CT software. CONCLUSIONS AND CLINICAL RELEVANCE Selection of the renal cortex as region of interest or use of the 60-second time point for whole-kidney evaluation yielded the best CT-GFR results. The perfusion software used produced good results with appropriate noise reduction. IMPACT FOR HUMAN MEDICINE The finding that excessive noise reduction caused underestimation of CT-GFR suggests that this factor should also be considered in CT-GFR examination of human patients.

  3. Body surface area adapted iopromide 300 mg/ml versus 370 mg/ml contrast medium injection protocol: influence on quantitative and clinical assessment in combined PET/CT.

    Science.gov (United States)

    Verburg, Frederik A; Apitzsch, Jonas; Lensing, Carina; Kuhl, Christiane K; Pietsch, Hubertus; Mottaghy, Felix M; Behrendt, Florian F

    2013-12-01

    To investigate the quantitative and qualitative differences between combined positron emission tomography and computed X-ray tomography (PET/CT) enhanced with contrast medium with either an iodine concentration 300 mg/ml or 370 mg/ml. 120 consecutive patients scheduled for F-18-Fluorodeoxyglucose (FDG) PET/CT were included. The first (second) 60 patients received contrast medium with 300 (370) mg iodine/ml. Intravenous injection protocols were adapted for an identical iodine delivery rate (1.3mg/s) and body surface area (BSA) adapted iodine dose (22.26 gI/m(2)). Maximum and mean standardized uptake values (SUV(max); SUV(mean)) and contrast enhancement (HU) were determined in the ascending aorta, the abdominal aorta, the inferior vena cava, the portal vein, the liver and the right kidney in the venous contrast medium phase. PET data were evaluated visually for the presence of malignancy and image quality. Both media caused significantly higher values for HU, SUV(mean) and SUV(max) for the enhanced PET/CT than the non-enhanced one (all pmedia at any anatomic site (all p>0.05). Visual evaluation of lesions showed no differences between contrast and non-contrast PET/CT or between the two different contrast media (p=0.77). When using a constant iodine delivery rate and total iodine dose in a BSA adapted injection protocol, there are no quantitative or qualitative differences in either CT or PET between contrast media with an iodine concentration of 300 mg/ml and 370 mg/ml, respectively. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  4. Polysorbate 80 and low-osmolality water-soluble contrast medium enema in diagnosis and treatment of faecal obstruction in malignant phaeochromocytoma. Report of a case

    Energy Technology Data Exchange (ETDEWEB)

    Ratcliffe, J.F.

    Stercoral obstruction in a young woman with disseminated phaeochromocytoma was diagnosed and treated successfully using an enema of isosmolar iohexol (Omnipaque) and 1% polysorbate 80 (Tween 80) without complication. Surgical intervention was thus avoided. A low osmolality water-soluble contrast medium (iohexol 150 mg I/ml) with a wetting agent (1% Tween 80) was used because a barium suspension would have inspissated, exacerbating the constipation and a hyperosmolar contrast medium might have precipitated a hypertensive crisis and destablished her critical salt and water balance.

  5. Polysorbate 80 and low-osmolality water-soluble contrast medium enema in diagnosis and treatment of faecal obstruction in malignant phaeochromocytoma

    International Nuclear Information System (INIS)

    Ratcliffe, J.F.

    1986-01-01

    Stercoral obstruction in a young woman with disseminated phaeochromocytoma was diagnosed and treated successfully using an enema of isosmolar iohexol (Omnipaque) and 1% polysorbate 80 (Tween 80) without complication. Surgical intervention was thus avoided. A low osmolality water-soluble contrast medium (iohexol 150 mg I/ml) with a wetting agent (1% Tween 80) was used because a barium suspension would have inspissated, exacerbating the constipation and a hyperosmolar contrast medium might have precipitated a hypertensive crisis and destablished her critical salt and water balance. (orig.)

  6. Multi-detector CT urography: effect of oral hydration and contrast medium volume on renal parenchymal enhancement and urinary tract opacification - a quantitative and qualitative analysis

    Energy Technology Data Exchange (ETDEWEB)

    Szolar, Dieter H.; Tillich, Manfred; Preidler, Klaus W. [Diagnostikum Graz-Suedwest, Graz (Austria)

    2010-09-15

    To assess the effect of oral hydration and contrast-medium volume on renal enhancement and urinary tract opacification in multi-detector CT urography. A total of 192 patients were assigned to different protocols with varying doses of contrast agent with and without oral hydration. The attenuation was measured in the renal parenchyma in the unenhanced, nephrographic and excretory phase, and in the urinary tract in excretory phase imaging, respectively. Opacification of the urinary tract was graded on volume rendered images. Oral hydration did not significantly alter renal parenchymal enhancement in both the nephrographic and the excretory phase (p > 0.001), but significantly decreased mean attenuation of the urinary tract in the excretory phase (p {<=} 0.001), and improved continuous opacification of all ureter segments (p < 0.01). Higher volumes of contrast medium improved renal parenchymal enhancement (p {<=} 0.001) and continuous opacification of the urinary tract (p {<=} 0.01). Oral hydration leads to lower attenuation values in the urinary tract but improves the continuous opacification of the tract. Increase in contrast medium volume leads to higher renal parenchymal enhancement as well as to an increased continuous opacification of the urinary tract. Decrease in contrast medium volume cannot be compensated for by oral hydration in terms of parenchymal enhancement. (orig.)

  7. Minimizing Contrast Medium Doses to Diagnose Pulmonary Embolism with 80-kVp Multidetector Computed Tomography in Azotemic Patients

    Energy Technology Data Exchange (ETDEWEB)

    Holmquist, F. (Dept. of Diagnostic Radiology, Malmoe Univ. Hospital, Univ. of Lund, Malmoe (Sweden)); Hansson, K.; Pasquariello, F. (Dept. of Internal Medicine, Lasarettet Trelleborg, Univ. of Lund, Trelleborg (Sweden)); Bjoerk, J. (Competence Center for Clinical Research, Univ. Hospital, Univ. of Lund, Lund (Sweden)); Nyman, U. (Dept. of Radiology, Lasarettet Trelleborg, Univ. of Lund, Trelleborg (Sweden))

    2009-02-15

    Background: In diagnosing acute pulmonary embolism (PE) in azotemic patients, scintigraphy and magnetic resonance imaging are frequently inconclusive or not available in many hospitals. Computed tomography is readily available, but relatively high doses (30-50 g I) of potentially nephrotoxic iodine contrast media (CM) are used. Purpose: To report on the diagnostic quality and possible contrast-induced nephropathy (CIN) after substantially reduced CM doses to diagnose PE in azotemic patients using 80-peak kilovoltage (kVp) 16-row multidetector computed tomography (MDCT) combined with CM doses tailored to body weight, fixed injection duration adapted to scan time, automatic bolus tracking, and saline chaser. Material and Methods: Patients with estimated glomerular filtration rate (eGFR) <50 ml/min were scheduled to undergo 80-kVp MDCT using 200 mg I/kg, and those with eGFR =50 ml/min, 120-kVp MDCT with 320 mg I/kg. Both protocols used an 80-kg maximum dose weight and a fixed 15-s injection time. Pulmonary artery density and contrast-to-noise ratio were measured assuming 70 Hounsfield units (HU) for a fresh clot. CIN was defined as a plasma creatinine rise >44.2 mumol/l from baseline. Results: 89/148 patients (63/68 females) underwent 80-/120-kVp protocols, respectively, with 95% of the examinations being subjectively excellent or adequate. Mean values in the 80-/120-kVp cohorts regarding age were 82/65 years, body weight 66/78 kg, effective mAs 277/117, CM dose 13/23 g I, pulmonary artery density 359/345 HU, image noise (1 standard deviation) 24/21 HU, contrast-to-noise ratio 13/13, and dose-length product 173/258 mGycm. Only 1/65 and 2/119 patients in the 80- and 120-kVp cohorts, respectively, with negative CT and no anticoagulation suffered non-fatal thromboembolism during 3-month follow-up. No patient developed CIN. Conclusion: 80-kVp 16-row MDCT with optimization of injection parameters may be performed with preserved diagnostic quality, using markedly reduced CM

  8. A New Standard for Assessing the Performance of High Contrast Imaging Systems

    Science.gov (United States)

    Jensen-Clem, Rebecca; Mawet, Dimitri; Gomez Gonzalez, Carlos A.; Absil, Olivier; Belikov, Ruslan; Currie, Thayne; Kenworthy, Matthew A.; Marois, Christian; Mazoyer, Johan; Ruane, Garreth; Tanner, Angelle; Cantalloube, Faustine

    2018-01-01

    As planning for the next generation of high contrast imaging instruments (e.g., WFIRST, HabEx, and LUVOIR, TMT-PFI, EELT-EPICS) matures and second-generation ground-based extreme adaptive optics facilities (e.g., VLT-SPHERE, Gemini-GPI) finish their principal surveys, it is imperative that the performance of different designs, post-processing algorithms, observing strategies, and survey results be compared in a consistent, statistically robust framework. In this paper, we argue that the current industry standard for such comparisons—the contrast curve—falls short of this mandate. We propose a new figure of merit, the “performance map,” that incorporates three fundamental concepts in signal detection theory: the true positive fraction, the false positive fraction, and the detection threshold. By supplying a theoretical basis and recipe for generating the performance map, we hope to encourage the widespread adoption of this new metric across subfields in exoplanet imaging.

  9. Functional cardiac MR imaging with true fast imaging with steady-state free precession before and after intravenous injection of contrast medium: comparison of image quality and accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Krombach, Gabriele A. [University Hospital, RWTH Aachen, Department of Diagnostic Radiology, Aachen (Germany); University Hospital Giessen, Department of Radiology, Justus-Liebig University Giessen, Giessen (Germany); Plum, Thorsten; Kraemer, Nils A.; Guenther, Rolf W.; Schoth, Felix [University Hospital, RWTH Aachen, Department of Diagnostic Radiology, Aachen (Germany); Koos, Ralf; Hoffmann, Rainer; Altiok, Ertunc [University Hospital, RWTH Aachen, Department of Cardiology, Aachen (Germany)

    2011-04-15

    To compare image quality and accuracy of left ventricular function of cine SSFP (steady-state free precession) images before and after injection of Gd-DTPA. In 30 patients T1 times of LV blood and myocardium were measured before and after injection of 0.2 mmol/kg body weight Gd-DTPA. Signal intensity of myocardium and left ventricular blood were measured on SSFP images and the contrast calculated. In 20 additional patients short axis images completely covering the left ventricle were acquired before and after injection of Gd-DTPA and parameters of left ventricular function compared. Image quality and regional function were assessed using the 17-segment model. Image quality after injection of contrast medium did not significantly change compared with unenhanced images. Contrast between myocardium and LV blood decreased from 0.6 {+-} 0.01 to 0.4 {+-} 0.03 after injection while the T1 value of myocardium decreased from 1121 {+-} 21 ms to 389 {+-} 14 ms (blood 1413 {+-} 48 ms to 222 {+-} 8 ms). Assessment of regional and global left ventricular function revealed similar results before and after the injection of contrast medium. Cine SSFP can be obtained after injection of contrast medium without loss of accuracy for regional and global LV ventricular function. This protocol can be used to decrease imaging time for thorough cardiac examination. (orig.)

  10. The use of dilute calogen[reg] as a fat density oral contrast medium in upper abdominal computed tomography, compared with the use of water and positive oral contrast media

    International Nuclear Information System (INIS)

    Ramsay, Duncan W.; Markham, Derrian H.; Morgan, Bruno; Rodgers, Peter M.; Liddicoat, Amanda J.

    2001-01-01

    AIM: Oral contrast media are commonly given prior to computed tomography (CT) examination of the upper abdomen. Although positive oral contrast media are normally used, there is increasing interest in using negative agents such as water and less commonly fat density products. The aim of this study was to compare a positive oral contrast medium, water, and a diluted emulsion of arachis oil (Calogen[reg], a fat density food supplement) for assessment of the upper abdomen. MATERIALS AND METHODS: Seventy-one patients referred for upper abdominal CT were randomized to receive either 500 ml water, 2% sodium diatrizoate or a dilute suspension of Calogen[reg]. The CT images were scored independently by three radiologists. Distension and anatomical identification was assessed for the stomach, duodenum and jejunum; with anatomical identification recorded for the pancreas, retroperitoneum, liver, gallbladder and spleen. RESULTS: Dilute Calogen[reg] produced a significant improvement (P < 0.01) in distension and anatomical visualization of the stomach and proximal duodenum. Only minimal differences were demonstrated between the three contrast media for visualization of more distal small bowel or identification of the other upper abdominal viscera. Significantly more artifacts were caused by positive contrast media than with the Calogen[reg] mixture. CONCLUSION: A dilute suspension of Calogen[reg] as an oral contrast medium is recommended when disease is suspected within the stomach or proximal duodenum. Ramsay, D.W. et al. (2001)

  11. Systematic review of current guidelines, and their evidence base, on risk of lactic acidosis after administration of contrast medium for patients receiving metformin.

    Science.gov (United States)

    Goergen, Stacy K; Rumbold, Gregory; Compton, Gregory; Harris, Claire

    2010-01-01

    To systematically review evidence about the relationship between metformin administration and the use of iodinated contrast medium and risk of lactic acidosis (LA) and to assess the quality of five current guidelines for use of contrast medium in patients who are taking metformin. A search strategy was developed by using search termsrelated to metformin, contrast media, and LA. Searches were conducted in MEDLINE (Ovid), all Evidence-based Medicine Reviews (Ovid), EMBASE, and Cochrane library databases and were augmented with searches for evidence-based guidelines on radiology and evidence-based medicine Web sites by using the Google Internet search engine. Guidelines were appraised by two independent reviewers by using the Appraisal of Guidelines Research and Evaluation Collaboration Instrument. Other studies were appraised by using structured appraisal checklists. Five guidelines were identified and five empirical studies met inclusion criteria. All guidelines had poor scores on some Appraisal of Guidelines for Research and Evaluation (AGREE) Collaboration criteria; poorer scores tended to occur in relation to objective assessment of rigor of guideline development, editorial independence, and applicability of the guideline to clinical practice. Lack of agreement was observed among guidelines about the need to stop taking metformin after contrast medium is administered, risk of LA in patients with normal renal function before contrast medium injection, recommended method of measuring renal function, and values used to define abnormal function. The evidence that was used as a basis for determining the guidelines for metformin administration, use of contrast medium, and risk of LA consisted of a limited number of observational studies, including case reports, summaries of case reports, and case series (National Health and Medical Research Council of Australia level IV-V evidence). More important, it was not apparent that a systematic search strategy had been used to

  12. Evaluation of the nephrotoxicity of iodixanol in patients with predisposing factors to contrast medium induced nephropathy referred for contrast enhanced computed tomography

    International Nuclear Information System (INIS)

    Sandstede, Joern J.W.; Roth, Anne; Machann, Wolfram; Kaupert, Christine; Hahn, Dietbert

    2007-01-01

    To determine the risk of developing contrast induced nephropathy (CIN) in intermediate-risk patients receiving iodixanol, an iso-osmolar, dimeric non-ionic contrast agent, for CT in a clinical setting. Hundred consecutive patients referred for a contrast enhanced CT with a serum creatinine concentration > 1.1 mg/dl and/or a glomerular filtration rate (GFR) 2.0 mg/dl and a GFR 25% above baseline within 72 h after contrast administration. Serum creatinine concentration and GFR were 1.40 ± 0.22, 1.29 ± 0.29, and 1.26 ± 0.29 mg/dl and 52.2 ± 13.9, 51.3 ± 21.1, and 51.5 ± 15.1 ml/min on days 0, 3, and 7, respectively. Three out of 99 (3%) patients who received 90-110 ml iodixanol revealed a CIN on day 3 without persistence on day 7. No specific therapy was needed. One out of 99 patients reported an exanthema on days 3 and 7. With the use of iodixanol in intermediate-risk patients, 3% of the patients develop CIN on day 3 without need for a specific therapy or persistence on day 7

  13. The International Standards for Solar Thermal Collectors and Components as a Medium of Quality Assurance

    International Nuclear Information System (INIS)

    Alkishriwi, Nouri; Schorn, Christian A.; Theis, Danjana

    2014-01-01

    regarding a product are fulfilled. In a certification process based on specified certification rules an authorized certification body is confirming that a solar thermal product has passed performance tests, reliability tests and further requirements according to the standards. In Europe a certification body holds an accreditation according to EN45011. At international level the standard ISO/IEC17065 is in force. Test results as a basis for product certification are determined by solar thermal test laboratories. The implementation and the business operation of such a solar thermal test laboratory is an important element within the national/regional solar thermal market. To ensure the quality of the products and to attend the role of an observer on the market, the test facility has to fulfill a number of requirements. Besides the necessary technical equipment and the implementation of tests in accordance with the various national and international standards, the laboratory shall realize a quality management system to guarantee the quality of tests and services. Based on the technical equipment, the testing scope and an implemented Quality Management System (QMS), the test laboratory can achieve an accreditation according to ISO/IEC17025 as basis for independent third party testing. Independent testing and evaluation of solar thermal collectors and components like hot water stores and controllers offers an important medium for quality assurance. To guarantee a high degree of product quality and consumer protection a quality system for the solar thermal market is necessary. Core of the quality assurance of a functioning solar thermal market are the national standards body, which is developing standards and regulations as a working basis ill technical committees, the national metrology institute that guarantees the traceability of measurements on fundamental and natural constants, and finally the national accreditation body which ensures the conformity of the various actors to a

  14. Why a standard contrast-enhanced MRI might be useful in intracranial internal carotid artery stenosis.

    Science.gov (United States)

    Oeinck, Maximilian; Rozeik, Christoph; Wattchow, Jens; Meckel, Stephan; Schlageter, Manuel; Beeskow, Christel; Reinhard, Matthias

    2016-06-01

    In patients with ischemic stroke of unknown cause cerebral vasculitis is a rare but relevant differential diagnosis, especially when signs of intracranial artery stenosis are found and laboratory findings show systemic inflammation. In such cases, high-resolution T1w vessel wall magnetic resonance imaging (MRI; 'black blood' technique) at 3 T is preferentially performed, but may not be available in every hospital. We report a case of an 84-year-old man with right hemispheric transient ischemic attack and signs of distal occlusion in the right internal carotid artery (ICA) in duplex sonography. Standard MRI with contrast agent pointed the way to the correct diagnosis since it showed an intramural contrast uptake in the right ICA and both vertebral arteries. Temporal artery biopsy confirmed the suspected diagnosis of a giant cell arteritis and dedicated vessel wall MRI performed later supported the suspected intracranial large artery inflammation. Our case also shows that early diagnosis and immunosuppressive therapy may not always prevent disease progression, as our patient suffered several infarcts in the left middle cerebral artery (MCA) territory with consecutive high-grade hemiparesis of the right side within the following four months. © The Author(s) 2016.

  15. A High Throughput Medium Access Control Implementation Based on IEEE 802.11e Standard

    Science.gov (United States)

    Huang, Min Li; Lee, Jin; Setiawan, Hendra; Ochi, Hiroshi; Park, Sin-Chong

    With the growing demand for high-performance multimedia applications over wireless channels, we need to develop a Medium Access Control (MAC) system that supports high throughput and quality of service enhancements. This paper presents the standard analysis, design architecture and design issues leading to the implementation of an IEEE 802.11e based MAC system that supports MAC throughput of over 100Mbps. In order to meet the MAC layer timing constraints, a hardware/software co-design approach is adopted. The proposed MAC architecture is implemented on the Xilinx Virtex-II Pro Field-Programmable Gate Array (FPGA) (XC2VP70-5FF1704C) prototype, and connected to a host computer through an external Universal Serial Bus (USB) interface. The total FPGA resource utilization is 11, 508 out of 33, 088 (34%) available slices. The measured MAC throughput is 100.7Mbps and 109.2Mbps for voice and video access categories, transmitted at a data rate of 260Mbps based on IEEE 802.11n Physical Layer (PHY), using the contention-based hybrid coordination function channel access mechanism.

  16. Risk of contrast-medium-induced nephropathy in high-risk patients undergoing MDCT - A pooled analysis of two randomized trials

    Energy Technology Data Exchange (ETDEWEB)

    Thomsen, Henrik S. [University of Copenhagen, Department of Diagnostic Radiology, Copenhagen University Hospital Herlev, and Department of Diagnostic Sciences, Faculty of Health Sciences, Herlev (Denmark); Morcos, Sameh K. [University of Sheffield, Department of Diagnostic Imaging, Northern General Hospital, Sheffield (United Kingdom)

    2009-04-15

    The incidence of contrast-medium-induced nephropathy (CIN) following intravenous (IV) CM administration of contrast media to renally impaired patients undergoing multidetector computed tomography (MDCT) is not well characterized. Our objective was to investigate the incidence of CIN in patients with glomerular filtration rate (GFR) <60 ml/min undergoing contrast-enhanced MDCT examinations and to compare the rates of CIN following the IV administration of low-osmolar contrast media (LOCM, iopamidol and iomeprol) and an iso-osmolar contrast medium (IOCM, iodixanol). A total of 301 adult patients with moderate-to-severe renal failure received a similar IV contrast dose (40 gI). Serum creatinine (SCr) was measured at screening, baseline and 48-72 {+-} 6 h after the MDCT examination. Primary CIN outcome was an increase in SCr {>=}0.5 mg/dl ({>=}44.2 {mu}mol/l) from baseline. The CIN rates were 2.3% in the total population, 0.6% when GFR >40 ml/min, 4.6% when GFR <40 ml/min and 7.8% in patients with GFR <30 ml/min. The incidence of CIN was significantly higher after iodixanol than after LOCM (seven patients, 4.7% following IOCM, no CIN cases following the LOCM; p = 0.007). Significant differences in favor of the LOCM were also observed in patients with GFR <40 ml/min and GFR <30 ml/min. Following the IV administration of nonionic contrast agents in patients with moderate-to-severe renal insufficiency, the risk of significant CIN seems to be low. The IOCM iodixanol caused a higher rate of CIN than the LOCM iopamidol and iomeprol, especially in high-risk patients. Differences in osmolality between these LOCM and iodixanol do not play a role in the genesis of CIN. (orig.)

  17. Nonlinear image blending for dual-energy MDCT of the abdomen: can image quality be preserved if the contrast medium dose is reduced?

    Science.gov (United States)

    Mileto, Achille; Ramirez-Giraldo, Juan Carlos; Marin, Daniele; Alfaro-Cordoba, Marcela; Eusemann, Christian D; Scribano, Emanuele; Blandino, Alfredo; Mazziotti, Silvio; Ascenti, Giorgio

    2014-10-01

    The objective of this study was to compare the image quality of a dual-energy nonlinear image blending technique at reduced load of contrast medium with a simulated 120-kVp linear blending technique at a full dose during portal venous phase MDCT of the abdomen. Forty-five patients (25 men, 20 women; mean age, 65.6 ± 9.7 [SD] years; mean body weight, 74.9 ± 12.4 kg) underwent contrast-enhanced single-phase dual-energy CT of the abdomen by a random assignment to one of three different contrast medium (iomeprol 400) dose injection protocols: 1.3, 1.0, or 0.65 mL/kg of body weight. The contrast-to-noise ratio (CNR) and noise at the portal vein, liver, aorta, and kidney were compared among the different datasets using the ANOVA. Three readers qualitatively assessed all datasets in a blinded and independent fashion. Nonlinear blended images at a 25% reduced dose allowed a significant improvement in CNR (p < 0.05 for all comparisons), compared with simulated 120-kVp linear blended images at a full dose. No statistically significant difference existed in CNR and noise between the nonlinear blended images at a 50% reduced dose and the simulated 120-kVp linear blended images at a full dose. Nonlinear blended images at a 50% reduced dose were considered in all cases to have acceptable image quality. The dual-energy nonlinear image blending technique allows reducing the dose of contrast medium up to 50% during portal venous phase imaging of the abdomen while preserving image quality.

  18. Influence of osmolarity of contrast medium and saline flush on computed tomography angiography: Comparison of monomeric and dimeric iodinated contrast media with different iodine concentrations at an identical iodine delivery rate

    International Nuclear Information System (INIS)

    Kishimoto, Miori; Doi, Shoko; Shimizu, Junichiro; Lee, Ki-Ja; Iwasaki, Toshiroh; Miyake, Yoh-Ichi; Yamada, Kazutaka

    2010-01-01

    Purpose: To evaluate the influence of osmolarity of iodinated contrast media and saline flush on the contrast effect in thoracic computed tomography angiography (CTA) at an identical iodine delivery rate (IDR). Materials and methods: Seven beagles were used in a cross-over experiment. The contrast media used were iohexol 350 mgI/ml (IOH350; osmolarity 844 mmol/kg) and iodixanol 320 mgI/ml (IDX320; osmolarity 290 mmol/kg). Each contrast medium was administered to groups with and without saline flush at 40.0 mgI/kg/s for all experiments. Dynamic CT scanning was performed at the ninth thoracic vertebra level. The peak value, area under the curve (AUC), and time to peak (TTP) were calculated from the time attenuation curves of the pulmonary artery and aorta. Results: There was no significant difference between IOH350 and IDX320 with or without saline flush in the peak values for the pulmonary artery and aorta. AUC was significantly higher in groups with saline flush for both contrast media and arteries (p < 0.05) with no significant difference between contrast media. TTP was significantly longer in groups with saline flush than without saline flush for both contrast media and arteries (p < 0.05), with no significant difference between contrast media. Conclusions: There were no significant differences in the contrast effects of monomeric IOH350 and dimeric IDX320 in thoracic CTA when used at an identical IDR. Moreover, saline flush prolonged the peak duration at 600 mgI/kg.

  19. Influence of osmolarity of contrast medium and saline flush on computed tomography angiography: Comparison of monomeric and dimeric iodinated contrast media with different iodine concentrations at an identical iodine delivery rate

    Energy Technology Data Exchange (ETDEWEB)

    Kishimoto, Miori, E-mail: miori@mx6.et.tiki.ne.j [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Doi, Shoko, E-mail: s16024@st.obihiro.ac.j [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Shimizu, Junichiro, E-mail: s01163@st.obihiro.ac.j [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Lee, Ki-Ja, E-mail: s01173@st.obihiro.ac.j [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Iwasaki, Toshiroh, E-mail: bpag2180@cc.tuat.ac.j [Department of Veterinary Internal Medicine, Tokyo University of Agriculture and Technology, Saiwai-cho, 3-5-8, Fuchu 183-8509 (Japan); Miyake, Yoh-Ichi, E-mail: miyake@obihiro.ac.j [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Yamada, Kazutaka, E-mail: kyamada@obihiro.ac.j [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan)

    2010-10-15

    Purpose: To evaluate the influence of osmolarity of iodinated contrast media and saline flush on the contrast effect in thoracic computed tomography angiography (CTA) at an identical iodine delivery rate (IDR). Materials and methods: Seven beagles were used in a cross-over experiment. The contrast media used were iohexol 350 mgI/ml (IOH350; osmolarity 844 mmol/kg) and iodixanol 320 mgI/ml (IDX320; osmolarity 290 mmol/kg). Each contrast medium was administered to groups with and without saline flush at 40.0 mgI/kg/s for all experiments. Dynamic CT scanning was performed at the ninth thoracic vertebra level. The peak value, area under the curve (AUC), and time to peak (TTP) were calculated from the time attenuation curves of the pulmonary artery and aorta. Results: There was no significant difference between IOH350 and IDX320 with or without saline flush in the peak values for the pulmonary artery and aorta. AUC was significantly higher in groups with saline flush for both contrast media and arteries (p < 0.05) with no significant difference between contrast media. TTP was significantly longer in groups with saline flush than without saline flush for both contrast media and arteries (p < 0.05), with no significant difference between contrast media. Conclusions: There were no significant differences in the contrast effects of monomeric IOH350 and dimeric IDX320 in thoracic CTA when used at an identical IDR. Moreover, saline flush prolonged the peak duration at 600 mgI/kg.

  20. Effects of a dimeric vs a monomeric nonionic contrast medium on renal function in patients with mild to moderate renal insufficiency: a double-blind, randomized clinical trial

    Energy Technology Data Exchange (ETDEWEB)

    Carraro, M.; Malalan, F.; Antonione, R.; Faccini, L. [Institute of Medicina Clinica, Ospedale di Cattinara, University of Trieste, Strada di Fiume 447, I-34 149 Trieste (Italy); Stacul, F.; Cova, M.; Petz, S.; Assante, M.; Dalla Palma, L. [Institute of Radiology, Ospedale di Cattinara, University of Trieste, Strada di Fiume 447, I-34 149 Trieste (Italy); Grynne, B.; Haider, T. [Nycomed Imaging AS, Nycoveien 1-2, N-0401 Oslo (Norway)

    1998-02-01

    The efficacy and safety of nonionic dimeric contrast media in subjects with impaired renal function is largely unknown. The present study was aimed at determining the risk of tubular nephrotoxicity in patients with mild to moderate renal insufficiency who underwent intravenous urography (IVU) with the nonionic dimeric contrast agent iodixanol (Visipaque, Nycomed Imaging, Oslo, Norway). In a double-blind protocol 64 patients (55 males; mean age 68.3 years) with serum creatinine between 135 and 265 {mu}mol/l who were to undergo IVU were randomized to receive iodixanol (a nonionic dimer) or iopromide (a nonionic monomer), 600 mg I/kg b. w. Renal function was evaluated before and 1 h, 6 h, 24 h, 48 h and 7 days after IVU with analysis of serum creatinine, urinary enzymes alanylaminopeptidase and N-acetyl-{beta}-glucosaminidase, and urinary microproteins {alpha}-1-microglobulin and albumin. Renal function remained stable in both contrast medium groups during the follow-up period. No statistically significant differences were observed between the monomer and the dimer in terms of urinary enzyme and microprotein excretion or serum creatinine. Transient radiocontrast-induced nephropathy developed in 1 patient who had received iodixanol. The administration of the nonionic dimeric contrast medium iodixanol, or of the nonionic monomer iopromide, entailed a low nephrotoxic potential in patients with mild to moderate renal insufficiency undergoing excretory urography. (orig.) With 2 figs., 1 tab., 13 refs.

  1. Evaluation of Tumor Angiogenesis with a Second-Generation US Contrast Medium in a Rat Breast Tumor Model

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Eun Young [Samsung Medical Center, Sungkyunkwan University School of Medicine (Korea, Republic of); Lee, Sang Hoon; Kim, Hak Hee; Kim, Sung Moon; Shin, Myung Jin; Kim, Nam Kug; Gong, Gyung Yub [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2008-06-15

    Tumor angiogenesis is an important factor for tumor growth, treatment response and prognosis. Noninvasive imaging methods for the evaluation of tumor angiogenesis have been studied, but a method for the quantification of tumor angiogenesis has not been established. This study was designed to evaluate tumor angiogenesis in a rat breast tumor model by the use of a contrast enhanced ultrasound (US) examination with a second-generation US contrast agent. The alkylating agent 19N-ethyl-N-nitrosourea (ENU) was injected into the intraperitoneal cavity of 30-day-old female Sprague-Dawley rats. Three to four months later, breast tumors were detected along the mammary lines of the rats. A total of 17 breast tumors larger than 1 cm in nine rats were evaluated by gray-scale US, color Doppler US and contrast-enhanced US using SonoVue. The results were recorded as digital video images; time-intensity curves and hemodynamic parameters were analyzed. Pathological breast tumor specimens were obtained just after the US examinations. The tumor specimens were stained with hematoxylin and eosin (H and E) and the expression of CD31, an endothelial cell marker, was determined by immunohistochemical staining. We also evaluated the pathological diagnosis of the tumors and the microvessel density (MVD). Spearman's correlation and the Kruskal-Wallis test were used for the analysis. The pathological diagnoses were 11 invasive ductal carcinomas and six benign intraductal epithelial proliferations. The MVD did not correlate with the pathological diagnosis. However, blood volume (BV) showed a statistically significant correlation with MVD (Spearman's correlation, p < 0.05). Contrast-enhanced US using a second-generation US contrast material was useful for the evaluation of tumor angiogenesis of breast tumors in the rat.

  2. Low contrast medium-volume third-generation dual-source computed tomography angiography for transcatheter aortic valve replacement planning

    Energy Technology Data Exchange (ETDEWEB)

    Felmly, Lloyd M. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiothoracic Surgery, Department of Surgery, Charleston, SC (United States); De Cecco, Carlo N.; Varga-Szemes, Akos; McQuiston, Andrew D. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Schoepf, U.J.; Litwin, Sheldon E.; Bayer, Richard R. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States); Mangold, Stefanie [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University Hospital of Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Vogl, Thomas J. [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Wichmann, Julian L. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany)

    2017-05-15

    To investigate feasibility, image quality and safety of low-tube-voltage, low-contrast-volume comprehensive cardiac and aortoiliac CT angiography (CTA) for planning transcatheter aortic valve replacement (TAVR). Forty consecutive TAVR candidates prospectively underwent combined CTA of the aortic root and vascular access route (270 mgI/ml iodixanol). Patients were assigned to group A (second-generation dual-source CT [DSCT], 100 kV, 60 ml contrast, 4.0 ml/s flow rate) or group B (third-generation DSCT, 70 kV, 40 ml contrast, 2.5 ml/s flow rate). Vascular attenuation, noise, signal-to-noise (SNR) and contrast-to-noise ratios (CNR) were compared. Subjective image quality was assessed by two observers. Estimated glomerular filtration (eGFR) at CTA and follow-up were measured. Besides a higher body-mass-index in group B (24.8±3.8 kg/m{sup 2} vs. 28.1±5.4 kg/m{sup 2}, P=0.0339), patient characteristics between groups were similar (P≥0.0922). Aortoiliac SNR (P=0.0003) was higher in group B. Cardiac SNR (P=0.0003) and CNR (P=0.0181) were higher in group A. Subjective image quality was similar (P≥0.213) except for aortoiliac image noise (4.42 vs. 4.12, P=0.0374). TAVR-planning measurements were successfully obtained in all patients. There were no significant changes in eGFR among and between groups during follow-up (P≥0.302). TAVR candidates can be safely and effectively evaluated by a comprehensive CTA protocol with low contrast volume using low-tube-voltage acquisition. (orig.)

  3. Barium sulfate aspiration: Severe chemical pneumonia induced by a massive reflux of contrast medium during small bowel barium enema.

    Science.gov (United States)

    Zhang, Lin; Yang, Yi; Zhang, Ji; Zhou, Xiaowei; Dong, Hongmei; Zhou, Yiwu

    2015-08-01

    Barium contrast radiography is a conventional procedure aimed at revealing lesions of the alimentary tract using barium sulfate on X-ray irradiation. Although it is widely used in clinics, adverse effects and complications are observed, such as anaphylaxis, granuloma, fecalithes, abdomen-leaking, embolism, bacterial contamination, and aspiration. We report a case of death due to a massive barium sulfate aspiration resulted from an air-barium double contrast enema radiography. A 25-year-old female patient was hospitalized with symptoms of abdominal distention, nausea, vomiting and diarrhea for three days. A progressive respiratory distress presented only 1h after a small bowel air-barium double contrast enema. The patient died 11h later. The result of autopsy revealed the cause of death to be severe chemical pneumonitis induced by gastric fluid which was aspirated into her lungs. Barium sulfate is generally recognized to be chemically inert for the respiratory system, but a mixture of barium sulfate with gastric contents is fatal. Here we intend to suggest that, when determining the potential cause of death, medical examiners should consider a patient's status quo as well as the possible adverse effects and complications caused by the barium sulfate preparation during gastrointestinal radiography. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. Ultrastructural study on the effects of retrograde infusion of water-soluble contrast medium the rabbit submandibular gland

    International Nuclear Information System (INIS)

    Kim, Eun Kyung; Park, Tae Won

    1987-01-01

    The author observed the effects of retrograde infusion of water soluble contrast media (Telebrix 30) on the rabbit submandibular glands and compared the effects of different degrees of filling. 26 rabbit were divided into 2 group of 1 2 each as experimental and 1 group of 2 as normal controls. One experimental group was filed with 0.2 ml and the other with 0.4 ml. Right submandibular gland of each rabbit was infused with contrast media and left one with physiologic saline as a ex perimental control, at a constant rate of 0.12 ml/min. Using an infusion pump via the main excretory duct. Immediately after the inclusion of contrast media, oblique lateral radiographs of the glands were made with occlusal film in order to confirm the glandular filling. The rabbit were sacrificed after varying periods (1, 8, 24 hours and 3, 6, 10 days) and the tissues were prepared for light and electron microscopic examination. The results were as follows: 1. In glands filled with 0.2 ml contrast media, the initial changes were a few vacuole formation in the acini and slight dilation of the intralobular duct. The moderately severe changes such as vacuole formation in the acini, the abnormal substructure within the secretory granule, dilation of acinar and intercalated duct lumen, scalloping of striated duct lumen and inflammatory cell infiltrate were observed at 3 days. The general appearance was successively recovered, so the tissue had a normal appearance at 10 days. 2. In glands filled with 0.4 ml contrast media, the most prominent alterations such as severe acinar atrophy, decreased number of secretory granules, proliferation of connective tissue stroma and pronounced inflammatory cell infiltrates appeared at 6 days. Although the general appearance returned to be almost normal at 10 days, acinar cells showed some atrophy and decreased secretory granules. 3. In glands subjected to 0.4 ml infusion, the alterations were more severe and recovery was slower than those seen in the glands

  5. The role of dual energy CT in differentiating between brain haemorrhage and contrast medium after mechanical revascularisation in acute ischaemic stroke

    International Nuclear Information System (INIS)

    Tijssen, M.P.M.; Stadler, A.A.R.; Zwam, W. van; Graaf, R. de; Postma, A.A.; Hofman, P.A.M.; Oostenbrugge, R.J. van; Klotz, E.; Wildberger, J.E.

    2014-01-01

    To assess the feasibility of dual energy computed tomography (DE-CT) in intra-arterially treated acute ischaemic stroke patients to discriminate between contrast extravasation and intracerebral haemorrhage. Thirty consecutive acute ischaemic stroke patients following intra-arterial treatment were examined with DE-CT. Simultaneous imaging at 80 kV and 140 kV was employed with calculation of mixed images. Virtual unenhanced non-contrast (VNC) images and iodine overlay maps (IOM) were calculated using a dedicated brain haemorrhage algorithm. Mixed images alone, as ''conventional CT'', and DE-CT interpretations were evaluated and compared with follow-up CT. Eight patients were excluded owing to a lack of follow-up or loss of data. Mixed images showed intracerebral hyperdense areas in 19/22 patients. Both haemorrhage and residual contrast material were present in 1/22. IOM suggested contrast extravasation in 18/22 patients; in 16/18 patients this was confirmed at follow-up. The positive predictive value (PPV) of mixed imaging alone was 25 %, with a negative predictive value (NPV) of 91 % and accuracy of 63 %. The PPV for detection of haemorrhage with DE-CT was 100 %, with an NPV of 89 % and accuracy improved to 89 %. Dual energy computed tomography improves accuracy and diagnostic confidence in early differentiation between intracranial haemorrhage and contrast medium extravasation in acute stroke patients following intra-arterial revascularisation. (orig.)

  6. Does the MRI or MRI contrast medium gadopentetate dimeglumine change the oxidant and antioxidant status in humans?

    International Nuclear Information System (INIS)

    Olmaz, Refik; Oguz, Ebru Gok; Kiykim, Ahmet; Turgutalp, Kenan; Horoz, M.; Ozhan, Onur; Muslu, Necati; Sungur, Mehmet

    2013-01-01

    Background: It has become evident that gadolinium-based contrast agents (GBCA) may have nephrotoxic potential. Oxidative stress is one of the most important pathways in the pathogenesis of iodinated contrast-induced nephropathy. Purpose: To investigate the effects of static magnetic fields and gadopentetate dimeglumine (Magnevist) on oxidant/antioxidant status via measurement of total antioxidant capacity (TAC), total oxidant status (TOS), and serum malondialdehide (MDA). Material and Methods: Two age- and sex-matched groups of patients not under oxidative stress conditions that underwent magnetic resonance imaging (MRI) were recruited to this study. While contrast-enhanced (Magnevist, 0.2 mmol/kg) MRI was performed in group 1, MRI without GBCA was performed in group 2. Fasting blood glucose, C-reactive protein, serum creatinine, liver enzymes, uric acid, and lipid parameters were examined in all patients. Peripheral venous blood samples in order to determine TAC, TOS, and MDA were collected before and 6, 24, and 72 h after the MRI procedures. The TOS:TAC ratio was used as the oxidative stress index (OSI). Patients were followed up to 72 h. Results: There were no significant changes in serum TAC, TOS, and MDA levels (Δ s erum T AC, Δ s erum T OS, and Δ M DA) in either group 6, 24, or 72 h after the procedures (P > 0.05). Furthermore, OSI did not change after the procedures in either group (P > 0.05). Conclusion: Magnetic field and gadopentetate dimeglumine (Magnevist) do not change the oxidant or antioxidant status at a dose of 0.2 mmol/kg

  7. Does the MRI or MRI contrast medium gadopentetate dimeglumine change the oxidant and antioxidant status in humans?

    Energy Technology Data Exchange (ETDEWEB)

    Olmaz, Refik; Oguz, Ebru Gok; Kiykim, Ahmet; Turgutalp, Kenan [Dept. of Internal Medicine, Div. of Nephrology, School of Medicine, Mersin Univ., Mersin (Turkey)], e-mail: k.turgutalp@hotmail.com; Horoz, M. [Dept. of Internal Medicine, Div. of Nephrology, School of Medicine, Harran Univ., Sanliurfa (Turkey); Ozhan, Onur [Dept. of Internal Medicine, Div. of Endocrinology and Metabolism, School of Medicine, Mersin Univ., Mersin (Turkey); Muslu, Necati [Dept. of Biochemistry, School of Medicine, Mersin Univ., Mersin (Turkey); Sungur, Mehmet [Dept. of Biostatistics, School of Medicine, Mersin Univ., Mersin (Turkey)

    2013-02-15

    Background: It has become evident that gadolinium-based contrast agents (GBCA) may have nephrotoxic potential. Oxidative stress is one of the most important pathways in the pathogenesis of iodinated contrast-induced nephropathy. Purpose: To investigate the effects of static magnetic fields and gadopentetate dimeglumine (Magnevist) on oxidant/antioxidant status via measurement of total antioxidant capacity (TAC), total oxidant status (TOS), and serum malondialdehide (MDA). Material and Methods: Two age- and sex-matched groups of patients not under oxidative stress conditions that underwent magnetic resonance imaging (MRI) were recruited to this study. While contrast-enhanced (Magnevist, 0.2 mmol/kg) MRI was performed in group 1, MRI without GBCA was performed in group 2. Fasting blood glucose, C-reactive protein, serum creatinine, liver enzymes, uric acid, and lipid parameters were examined in all patients. Peripheral venous blood samples in order to determine TAC, TOS, and MDA were collected before and 6, 24, and 72 h after the MRI procedures. The TOS:TAC ratio was used as the oxidative stress index (OSI). Patients were followed up to 72 h. Results: There were no significant changes in serum TAC, TOS, and MDA levels ({Delta}{sub s}erum{sub T}AC, {Delta}{sub s}erum{sub T}OS, and {Delta}{sub M}DA) in either group 6, 24, or 72 h after the procedures (P > 0.05). Furthermore, OSI did not change after the procedures in either group (P > 0.05). Conclusion: Magnetic field and gadopentetate dimeglumine (Magnevist) do not change the oxidant or antioxidant status at a dose of 0.2 mmol/kg.

  8. Pre-Interventional Kynurenine Predicts Medium-Term Outcome after Contrast Media Exposure Due to Coronary Angiography.

    Science.gov (United States)

    Reichetzeder, Christoph; Heunisch, Fabian; Einem, Gina von; Tsuprykov, Oleg; Kellner, Karl-Heinz; Dschietzig, Thomas; Kretschmer, Axel; Hocher, Berthold

    2017-01-01

    Contrast induced acute kidney injury (CI-AKI) remains a serious complication of contrast media enhanced procedures like coronary angiography. There is still a lack of established biomarkers that help to identify patients at high risk for short and long-term complications. The aim of the current study was to evaluate plasma kynurenine as a predictive biomarker for CI-AKI and long-term complications, measured by the combined endpoint "major adverse kidney events" (MAKE) up to 120 days after CM application. In this prospective cohort study 245 patients undergoing coronary angiography were analyzed. Blood samples were obtained at baseline, 24h and 48h after contrast media (CM) application to diagnose CI-AKI. Patients were followed for 120 days for adverse clinical events including death, the need for dialysis, and a doubling of plasma creatinine. Occurrence of any of these events was summarized in the combined endpoint MAKE. Preinterventional plasma kynurenine was not associated with CI-AKI. Patients who later developed MAKE displayed significantly increased preinterventional plasma kynurenine levels (p<0.0001). ROC analysis revealed that preinterventional kynurenine is highly predictive for MAKE (AUC=0.838; p<0.0001). The optimal cutoff was found at ≥3.5 µmol/L Using this cutoff, the Kaplan-Meier estimator demonstrated that concentrations of plasma kynurenine ≥3.5 µmol/L were significantly associated with a higher prevalence of MAKE until follow up (p<0.0001). This association remained significant in multivariate Cox regression models adjusted for relevant factors of long-term renal outcome. Preinterventional plasma kynurenine might serve as a highly predictive biomarker for MAKE up to 120 days after coronary angiography. © 2017 The Author(s). Published by S. Karger AG, Basel.

  9. Low-dose triple-rule-out using 320-row-detector volume MDCT - less contrast medium and lower radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Durmus, Tahir; Lembcke, Alexander; Muehler, Matthias R.; Hamm, Bernd; Hein, Patrick A. [Charite - University Hospital Berlin, Department of Radiology, Berlin (Germany); Rogalla, Patrik [Universitiy of Toronto, Department of Medical Imaging, Toronto, ON (Canada)

    2011-07-15

    To investigate image quality of triple-rule-out (TRO) computed tomography (CT) using a 320-row-detector CT system with substantially reduced contrast medium volume at 100 kV. Forty-six consecutive patients with noncritical, acute chest pain underwent 320-row-detector CT using a two-step TRO protocol consisting of a non-spiral, non-gated chest CT acquisition (150 mA) followed by a non-spiral, electrocardiography-gated cardiac acquisition (200-500 mA based on body mass index (BMI)). Data were acquired using a biphasic injection protocol with a total iodinated contrast medium volume of 60 ml (370 mg/ml). Vessel attenuation and effective doses were recorded. Image quality was scored independently by two readers. Mean attenuation was 584 {+-} 114 Hounsfield units (HU) in the ascending aorta, 335 {+-} 63HU in the aortic arch, 658 {+-} 136HU in the pulmonary trunk, and 521 {+-} 97HU and 549 {+-} 102HU in the right and left coronary artery, respectively. In all but one patient, attenuation and image quality allowed accurate visualization of the pulmonary arteries, thoracic aorta, and coronary arteries in a single examination. Ninety-six percent of all coronary artery segments were rated diagnostic. Radiation exposure ranged between 2.0 and 3.3 mSv. Using 320-row-detector CT the investigated low-dose TRO protocol resulted in excellent opacification and image quality with substantial reduction of contrast medium volume compared to recently published TRO protocols. (orig.)

  10. Myelography in achondroplasia: value of a lateral C1-2 puncture and non-ionic, water-soluble contrast medium

    Energy Technology Data Exchange (ETDEWEB)

    Suss, R.A.; Udvarhelyi, G.B.; Wang, H.; Kumar, A.J.; Zinreich, S.J.; Rosenbaum, A.E.

    1983-10-01

    Because of technical difficulties and diagnostic limitations encountered with other myelographic techniques in patients with achondroplasia, the authors employed a lateral C1-2 puncture and non-ionic, water-soluble contrast medium in 18 achondroplastic patients with spinal compression (21 procedures). This technique proved most appropriate for identifying the upper limit of degenerative osteophytes causing exacerbation of congenital spinal stenosis, which is crucial in planning decompressive surgery. A potentially important additional finding was the presence of degenerative lower cervical spine disease in the majority of patients. There were no serious complications. The authors recommend this technique as safe and effective in achondroplastic patients with severe congenital spinal stenosis.

  11. Use of postmortem coronary computed tomography angiography with water-insoluble contrast medium to detect stenosis of the left anterior descending artery in a case of sudden death.

    Science.gov (United States)

    Takahashi, Yoichiro; Sano, Rie; Takahashi, Keiko; Kominato, Yoshihiko; Takei, Hiroyuki; Kobayashi, Susumu; Shimada, Takehiro; Tokue, Hiroyuki; Awata, Sachiko; Hirasawa, Satoshi

    2016-03-01

    A 40-year-old man was found dead on a sidewalk in an expressway parking area one hour after he had entered the area on a motorcycle. A medicolegal autopsy was performed to reveal the cause of this sudden and unexpected death. Postmortem coronary CT angiography after introduction of 5% gelatin-barium emulsion as a radiopaque contrast medium into the heart demonstrated a significant arterial luminal filling defect in the left anterior descending (LAD) coronary artery. Macroscopic and microscopic examinations revealed that a thrombus had become deposited on ruptured plaque within the LAD artery, and that a small amount of the contrast medium was present between the thrombus and the vessel endothelium. These histological findings were consistent with incomplete occlusion of the LAD artery in the 3D reconstructed image. The cause of death in this case was definitively determined to be ischemic heart disease. Postmortem angiography played a role in screening of a vascular lesion that was subsequently verified by histology to have been responsible for sudden and unexpected death. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. [Recurrence of drug eruption after renewed injection of iodinated contrast medium in patients with known allergic contraindications].

    Science.gov (United States)

    Amsler, E; Autegarden, J-E; Senet, P; Frances, C; Soria, A

    2016-12-01

    Iodinated contrast media (ICM) are used extensively by both radiologists and cardiologists. Injection of such products can induce immediate hypersensitivity reactions, some of which are IgE-mediated, and delayed hypersensitivity reaction with all types of drug eruptions being reported. Allergy tests, whether patch-tests or intradermal tests, are useful to confirm whether patients are allergic. At the end of these tests, depending on the reaction (chronology and clinical symptoms) and the results of the skin tests, patients are given an allergy card as well as a detailed certificate indicating the various ICM contraindicated and those allowed. We report herein three cases of patients experiencing a confirmed allergic eruption after injection of ICM, and whose recommendations and contraindication were not taken into consideration, leading to recurrence of eruption after renewed ICM injection. The three cases we report herein underscore the lack of knowledge concerning eruptions induced by ICM, particularly among radiologists. Better dissemination of information about the existence of such reactions appears necessary amongst the medical professionals concerned. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. Low concentration contrast medium for dual-source computed tomography coronary angiography by a combination of iterative reconstruction and low-tube-voltage technique: Feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Minwen, E-mail: zhengmw2007@163.com; Liu, Ying, E-mail: yingyinglyly@126.com; Wei, Mengqi, E-mail: weimengqi2008@163.com; Wu, Yongjie, E-mail: wu18291988526@163.com; Zhao, Hongliang, E-mail: zhaohl1980@163.com; Li, Jian, E-mail: xjyylj@yeah.net

    2014-02-15

    Objectives: To assess the impact of low-concentration contrast medium on vascular enhancement, image quality and radiation dose of coronary CT angiography (cCTA) by using a combination of iterative reconstruction (IR) and low-tube-voltage technique. Materials and methods: One hundred patients were prospectively randomized to two types of contrast medium and underwent prospective electrocardiogram-triggering cCTA (Definition Flash, Siemens Healthcare; collimation: 128 mm × 0.6 mm; tube current: 300 mA s). Fifty patients received Iopromide 370 were scanned using the conventional tube setting (100 kVp or 120 kVp if BMI ≥ 25 kg/m{sup 2}) and reconstructed with filtered back projection (FBP). Fifty patients received Iodixanol 270 were scanned using the low-tube-voltage (80 kVp or 100 kVp if BMI ≥ 25 kg/m{sup 2}) technique and reconstructed with IR. CT attenuation was measured in coronary artery and other anatomical regions. Noise, image quality and radiation dose were compared. Results: Compared with two Iopromide 370 subgroups, Iomeprol 270 subgroups showed no significant difference in CT attenuation (576.63 ± 95.50 vs. 569.51 ± 118.93 for BMI < 25 kg/m{sup 2}, p = 0.647 and 394.19 ± 68.09 vs. 383.72 ± 63.11 for BMI ≥ 25 kg/m{sup 2}, p = 0.212), noise (in various anatomical regions of interest) and image quality (3.5 vs. 4.0, p = 0.13), but significantly (0.41 ± 0.17 vs. 0.94 ± 0.45 for BMI < 25 kg/m{sup 2}, p < 0.001 and 1.14 ± 0.24 vs. 2.37 ± 0.69 for BMI ≥ 25 kg/m{sup 2}, p < 0.001) lower radiation dose, which reflects dose saving of 56.4% and 51.9%, respectively. Conclusions: Combined IR with low-tube-voltage technique, a low-concentration contrast medium of 270 mg I/ml can still maintain the contrast enhancement without impairing image quality, as well as significantly lower the radiation dose.

  14. Estimating kinetic parameters from dynamic contrast-enhanced T(1)-weighted MRI of a diffusable tracer: standardized quantities and symbols

    DEFF Research Database (Denmark)

    Tofts, P.S.; Brix, G; Buckley, D.L.

    1999-01-01

    We describe a standard set of quantity names and symbols related to the estimation of kinetic parameters from dynamic contrast-enhanced T(1)-weighted magnetic resonance imaging data, using diffusable agents such as gadopentetate dimeglumine (Gd-DTPA). These include a) the volume transfer constant K...

  15. The legibility of the Clearview typeface system versus standard highway alphabets on negative- and positive-contrast signs.

    Science.gov (United States)

    2015-02-01

    The main objective of this research was to compare the legibility distance of the negative-contrast (i.e., darker letters on a lighter : background) Clearview Typeface System with that of comparable Standard Highway Alphabets on black-on-white signs ...

  16. Non-Native Japanese Listeners' Perception of Vowel Length Contrasts in Japanese and Modern Standard Arabic (MSA)

    Science.gov (United States)

    Tsukada, Kimiko

    2012-01-01

    This study aimed to compare the perception of short vs. long vowel contrasts in Japanese and Modern Standard Arabic (MSA) by four groups of listeners differing in their linguistic backgrounds: native Arabic (NA), native Japanese (NJ), non-native Japanese (NNJ) and Australian English (OZ) speakers. The NNJ and OZ groups shared the first language…

  17. Influence of cardiac insufficiency on acute renal impairment induced by contrast medium in patients with diabetes and renal dysfunction

    Directory of Open Access Journals (Sweden)

    Jing LI

    2015-10-01

    Full Text Available Objective To evaluate the influence of cardiac insufficiency on contrast-induced acute kidney injury (CIAKI after percutaneous coronary intervention (PCI in patients with diabetes mellitus (DM complicated with mild to moderate renal insufficiency (MMRI. Methods From Dec. 2008 to Oct. 2011, 2998 patients, with type 2 DM and concomitant chronic kidney diseases (CKD from 53 hospitals in China, were enrolled in the present study. Out of them, 2533 patients showed normal cardiac function (NYHA=1 and 465 patients suffered from cardiac insufficiency (NYHA>1. The demographic characteristics, preoperative renal function and postoperative incidence of CIAKI in the two groups were monitored. Results No significant difference was found between two groups (P>0.05 in preoperative baseline data (age, sex, high risk factors, etc.. The incidence of CIAKI was significantly higher in NYHA>1 group than in NYHA=1 group (4.7% vs2.8%, P=0.03. During a 30 day follow-up, the incidence of all-cause mortality was not significantly different between two groups (P>0.05. Multiple factors analysis found that rosuvastatin was the protective agent for CIAKI, and acute coronary syndrome, cardiac insufficiency, anemia and renal insufficiency were the risk factors for CIAKI. Conclusion For PCI, the risk of postoperative incidence of CIAKI is higher in patients with preoperative cardiac insufficiency than in those with normal cardiac function. The incidence of CIAKI may be reduced obviously by meticulous preoperative assessment of heart function in high-risk patients, giving effective treatment and performing PCI after cardiac function is improved. DOI: 10.11855/j.issn.0577-7402.2015.09.08

  18. How good is the turbid medium-based approach for accounting for light partitioning in contrasted grass--legume intercropping systems?

    Science.gov (United States)

    Barillot, Romain; Louarn, Gaëtan; Escobar-Gutiérrez, Abraham J; Huynh, Pierre; Combes, Didier

    2011-10-01

    Most studies dealing with light partitioning in intercropping systems have used statistical models based on the turbid medium approach, thus assuming homogeneous canopies. However, these models could not be directly validated although spatial heterogeneities could arise in such canopies. The aim of the present study was to assess the ability of the turbid medium approach to accurately estimate light partitioning within grass-legume mixed canopies. Three contrasted mixtures of wheat-pea, tall fescue-alfalfa and tall fescue-clover were sown according to various patterns and densities. Three-dimensional plant mock-ups were derived from magnetic digitizations carried out at different stages of development. The benchmarks for light interception efficiency (LIE) estimates were provided by the combination of a light projective model and plant mock-ups, which also provided the inputs of a turbid medium model (SIRASCA), i.e. leaf area index and inclination. SIRASCA was set to gradually account for vertical heterogeneity of the foliage, i.e. the canopy was described as one, two or ten horizontal layers of leaves. Mixtures exhibited various and heterogeneous profiles of foliar distribution, leaf inclination and component species height. Nevertheless, most of the LIE was satisfactorily predicted by SIRASCA. Biased estimations were, however, observed for (1) grass species and (2) tall fescue-alfalfa mixtures grown at high density. Most of the discrepancies were due to vertical heterogeneities and were corrected by increasing the vertical description of canopies although, in practice, this would require time-consuming measurements. The turbid medium analogy could be successfully used in a wide range of canopies. However, a more detailed description of the canopy is required for mixtures exhibiting vertical stratifications and inter-/intra-species foliage overlapping. Architectural models remain a relevant tool for studying light partitioning in intercropping systems that exhibit

  19. Visualization of endolymphatic hydrops in meniere's disease after single-dose intravenous gadolinium-based contrast medium. Timing of optimal enhancement

    International Nuclear Information System (INIS)

    Naganawa, Shinji; Yamazaki, Masahiro; Kawai, Hisashi; Bokura, Kiminori; Sone, Michihiko; Nakashima, Tsutomu

    2012-01-01

    Visualization of endolymphatic hydrops (EH) in patients with Meniere's disease (MD) is now possible by heavily T 2 -weighted 3-dimensional fluid-attenuated inversion recovery (h T 2 W-3D-FLAIR) obtained 4 hours after intravenous (IV) administration of single dose gadolinium-based contrast medium (GBCM). Although maximum enhancement has been reported 4 hours after contrast administration in healthy volunteers, the timing of optimal enhancement in patients with MD is not reported. We investigated if that optimal timing is earlier or later than 4 hours. We evaluated 10 consecutive patients with suspected MD whom we randomly divided into 2 groups. We obtained h T 2 W-3D-FLAIR before GBCM administration and 10 min, 3.5 hours, and 4 hours after GBCM administration in Group A and before and 10 min, 4 hours, and 4.5 hours after GBCM administration in Group B. We compared signal intensity ratio (SIR) values of the perilymph and pons between 3.5 and 4 hours in Group A and between 4 and 4.5 hours in Group B and evaluated grades of EH at 3.5 and 4 hours in Group A and at 4 and 4.5 hours in Group B. SIR values did not differ significantly between 3.5 and 4 hours in Group A and between 4 and 4.5 hours in Group B. However, SIR values at 4 hours were significantly higher in Group A than Group B. Grades of EH agreed between 3.5 and 4 hours in Group A and between 4 and 4.5 hours in Group B. The optimal timing of contrast enhancement in patients with suspected MD remains unclear, but evaluation of EH may be possible from 3.5 to 4.5 hours after contrast administration. (author)

  20. The social effectiveness of small and medium-sized entities standard from the view point of Game Theory

    Directory of Open Access Journals (Sweden)

    Alexandre Gonzales

    2013-05-01

    Full Text Available Accounting has been undergoing significant changes, and among these changes is the creation of a standard for the accounting of small and medium enterprises, in line with international accounting standards for companies of this size. This rule arose from the development of a pronouncement by the Accounting Pronouncements Committee – CPC, which subsequently was approved by the Federal Accounting Council - CFC through specific resolutions. The present study aimed to analyze trends of accounting professionals and business managers concerning the adoption of Technical Pronouncement emitted by Accounting Pronouncements Committee for Small and Medium Enterprises. Considering the level of complexity of the operations performed by companies of this size, the lack of oversight by specific entities and the question of enforcement of these pronouncements, it was used the game theory to determine possible strategies adopted by the accountants and business managers regarding to the effective adoption of pronouncement for SMEs. The study was characterized as a descriptive research, using bibliographical and field research. With the use of surveys sought to identify the perceptions of accounting professionals regarding the adoption of the pronouncement. It was found that this statement constitutes a valid legal standard, endowed with legal effectiveness and technical efficiency, but lacking social effectiveness, due to the low level of efforts for its adoption, both by accounting professionals and by firms.

  1. Intercomparison of the medium energy primary standards for X-ray exposure of NPL and ENEA, Italy

    International Nuclear Information System (INIS)

    Moretti, C.J.; Heaton, J.A.; Laitano, R.F.; Toni, M.P.

    1991-04-01

    An intercomparison between the primary standards of exposure for medium energy X-rays held by the National Physical Laboratory (NPL) and ENEA in Italy is described. The intercomparison, using four different transfer chambers, took place at NPL in December 1989 and at ENEA during March 1990. Measurements were made at four therapy-level qualities, with half value layers of 0.15, 0.5, 1.0 and 2.5 mm Cu (nominal generating voltages of 100, 135, 180 and 250 kV respectively). At the 2.5 mm Cu HVL quality the primary standards were found to agree to within about 0.8%; for the other three qualities the chambers differed by no more than 0.3%. (author)

  2. Comparison of the air-kerma standards of the PTB and the BIPM in the medium-energy X-ray range

    International Nuclear Information System (INIS)

    Burns, D.T.; Bueermann, L.; Kramer, H.M.; Lange, B.

    2002-06-01

    An indirect comparison has been made between the air erma standards of the PTB and the BIPM in the medium-energy x-ray range. The results show the standards to be in general agreement at the level of the stated standard uncertainty, although the result for the 100 kV radiation quality differs significantly from that for the other qualities. (authors)

  3. The possible ways to IFRS (International Financial Reporting Standards for SME (Small and Medium sized Entities development

    Directory of Open Access Journals (Sweden)

    Hana Bohušová

    2007-01-01

    Full Text Available The most business entities in Europe are small or medium-sized enterprises (SME, which have a legal obligation to prepare financial statements in accordance with a set of accounting principles accepted in their country. Those statements are available to creditors, suppliers, and national governments but they could be badly understandable to creditors, suppliers and subjects in other countries. This is a great obstacle of their activities in the EU internal market. The existence of 27 different national accounting systems in the EU can be held for the most important obstacle.There are many ways how to develop compatible accounting standards for SMEs but the most significant activity in this field is the research project of IASB (International Accounting Standards Board. IASB has developed IFRS (International Financial Reporting Standards. Even though IFRS are suitable for all enterprises, their application in case of SMEs would be very expensive and could significantly increase compliance costs of taxation. This development has not been finished yet and there are still some problems which need to be solved before the introduction of accounting standards to the public. The research has shown that IFRS for SMEs should be used mainly by the entities which do not have public accountability – i.e. that its equities are not publicly traded and do not hold assets in a fiduciary capacity for a broad group of outsiders. This paper discusses those IFRS modifications, which should be done in case of SMEs.

  4. High-pitch coronary CT angiography at 70 kVp adopting a protocol of low injection speed and low volume of contrast medium

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Ruiqi; Liu, Xiao Fei; Zhao, Yu; Zhang, Liang [Dept. of Radiology, The First Affiliated Hospital of China Medical University, Shenyang (China); Tong, Jia Jie [Dept. of Radiology, Hebei General Hospital, Shijiazhuang(China)

    2017-09-15

    To evaluate the feasibility and image quality (IQ) of prospectively high-pitch coronary CT angiography (CCTA) with low contrast medium injection rate at 70 kVp. One hundred and four patients with suspected coronary artery disease (body mass index < 26 kg/m{sup 2}, sinus rhythm and heart rate < 70 beats/min) were prospectively enrolled and randomly divided into two groups. In group A and group B, 28 mL and 40 mL of 370 mgI/mL iodinated contrast media was administrated at a flow rate of 3.5 and 5 mL/s, respectively. CT values, noise, signal-to-noise ratio, contrast-to-noise ratio (CNR) of the proximal segments of coronary arteries and subjective IQ were evaluated. The CT values and noise in group A were significantly lower than those in group B (434–485 Hounsfield units [HU] vs. 772–851 HU, all p < 0.001; 17.8–22.3 vs. 23.3–26.4, all p < 0.005). The CNRs of the right coronary artery and left main artery showed no statistical difference between the two groups (42.1 ± 13.8 vs. 36.8 ± 16.0, p = 0.074; 38.7 ± 10.6 vs. 38.1 ± 17.0, p = 0.819). No statistical difference was observed between the two groups in IQ scores (3.04 ± 0.75 vs. 3.0 ± 0.79, p = 0.526) and diagnostic ratio (96.1% [50/52] vs. 94.2% [49/52], p = 0.647). Prospective high-pitch CCTA at 70 kVp with 28 mL of contrast media and injection rate of 3.5 mL/s could provide diagnostic IQ for normal-weight patients with heart rate of < 70 beats/min.

  5. INTERNATIONAL FINANCIAL REPORTING STANDARD FOR SMALL AND MEDIUM-SIZED ENTITIES- A NEW CHALLENGE FOR THE EUROPEAN UNION

    Directory of Open Access Journals (Sweden)

    Ana-Maria Pascu

    2011-03-01

    Full Text Available In the context of the global economic crisis, small and medium enterprises are most affected. That is why the problem that arises more frequently is the harmonization of national legislation with the European legislation. The necessity to implement specific standards for SMEs appeared in order to provide them a beneficial framework for better economic and financial market positioning. In this respect, the International Accounting Standards Board issued in 2009 IFRS for SMEs, a referential aiming to the simplification of accounting procedures, reconciliation and increase of confidence of potential investors (stakeholders. The question of compatibility of these standards with the European Accounting Directives appears in situations where they may choose to use IFRS for SMEs. The aim of this paper is to evaluate the incompatibilities between IFRS for SMEs and the European Accounting Directives and to analyze the results concerning the implementation of the IFRS for SMEs in Europe. Through this article we want to contribute to the SME accounting area of knowledge.

  6. Standardized Volume-Rendering of Contrast-Enhanced Renal Magnetic Resonance Angiography

    International Nuclear Information System (INIS)

    Smedby, Oe.; Oeberg, R.; Aasberg, B.; Stenstroem, H.; Eriksson, P.

    2005-01-01

    PURPOSE: To propose a technique for standardizing volume-rendering technique (VRT) protocols and to compare this with maximum intensity projection (MIP) in regard to image quality and diagnostic confidence in stenosis diagnosis with magnetic resonance angiography (MRA). MATERIAL AND METHODS: Twenty patients were examined with MRA under suspicion of renal artery stenosis. Using the histogram function in the volume-rendering software, the 95th and 99th percentiles of the 3D data set were identified and used to define the VRT transfer function. Two radiologists assessed the stenosis pathology and image quality from rotational sequences of MIP and VRT images. RESULTS: Good overall agreement (mean kappa=0.72) was found between MIP and VRT diagnoses. The agreement between MIP and VRT was considerably better than that between observers (mean kappa=0.43). One of the observers judged VRT images as having higher image quality than MIP images. CONCLUSION: Presenting renal MRA images with VRT gave results in good agreement with MIP. With VRT protocols defined from the histogram of the image, the lack of an absolute gray scale in MRI need not be a major problem

  7. Assessment of arterial tumor vascularity in small hepatocellular carcinoma. Comparison between color Doppler ultrasonography and radiographic imagings with contrast medium: dynamic CT, angiography, and CT hepatic arteriography

    International Nuclear Information System (INIS)

    Furuse, Junji; Maru, Yasushi; Yoshino, Masahiro; Mera, Kiyomi; Sumi, Hajime; Sekiguchi, Ryuzo; Satake, Mitsuo; Hasebe, Takahiro; Ochiai, Atsushi

    2000-01-01

    Hepatocellular carcinoma (HCC) is characterized by tumor vascularization from the hepatic artery. The objective of our work was to compare color Doppler ultrasonography (CDU), including power Doppler ultrasonography (PDU) with radiographic imagings with contrast medium in regard to the detection of the arterial tumor vascularity of small hepatocellular carcinomas (HCC). We examined 42 small HCC lesions 2 cm or less in diameter in 37 patients for arterial tumor vascularity by conventional CDU, PDU, dynamic computed tomography (dCT), digital subtraction angiography (DSA), and CT hepatic arteriography (CTA). Color images were detected in 25 (59.5%) and 28 (66.7%) of the 42 lesions with conventional CDU and PDU, respectively, and tumor vascularity was detected in 26 (61.9%) by dCT, 23 (54.8%) by DSA, and 29 (69.0%) by CTA. Tumor vascularity could be detected in 51.9% by PDU and CTA, more than by conventional CDU, dCT, and DSA (44.4, 44.4, and 33.3%, respectively) in well-differentiated HCC, whereas the detection rates by these techniques were almost equal (86.7% by CDU, 93.3% by PDU, dCT, and DSA, 100% by CTA, respectively) in moderately and poorly differentiated HCC. PDU is superior to CDU, dCT and DSA and equal to CTA for the detection of tumor vascularity in small HCC, particularly in well-differentiated HCC

  8. A pre-validation trial - testing genotoxicity of several chemicals using standard, medium- and high-throughput comet formats.

    Directory of Open Access Journals (Sweden)

    Kristine Bjerve Gutzkow

    2015-06-01

    Results obtained with the three systems (standard, medium- and high-throughput were essentially the same. The 96-minigel format was analysed with the fully automated scoring system IMSTAR and comparable results were achieved with the semi-automated scoring system from Perceptives. The known genotoxic chemicals MNU, B(aP, 4-NQO and cyclophosphamide showed little consistent sign of genotoxicity at concentrations causing limited cytotoxicity. D-mannitol and Triton X-100 were, as expected, non-genotoxic (though Triton X-100, at high concentrations, caused DNA breaks as an apparent secondary effect of cytotoxicity. Etoposide and bleomycin gave significant increase in DNA strand break at borderline cytotoxic concentrations. The limitation of the assay to detect damaged bases by known genotoxins may be overcome by incorporating a DNA repair enzyme, such as formamidopyrimidine-DNA-glycosylase (FPG, to convert damaged bases into breaks as shown by Azqueta A et al., Mutagenesis vol. 28 no. 3 pp. 271–277, 2013 .

  9. The dosimetric standards for low and medium energy X-rays; Les references dosimetriques pour les rayons X de basses et moyennes energies

    Energy Technology Data Exchange (ETDEWEB)

    Ksouri, W.; Denoziere, M.; Lecerf, N.; Leroy, E.

    2009-07-01

    The Laboratoire national Henri Becquerel (LNE-LNHB) has developed national dosimetric standards for x-rays of low and medium energies. This article describes these standards which are aimed at applications of radiation protection of workers and patients in the fields of medical diagnosis and industrial x-ray radiation. Developments for contact radiotherapy are also discussed. (author)

  10. F2 slope as a Perceptual Cue for the Front-Back Contrast in Standard Southern British English.

    Science.gov (United States)

    Chládková, Kateřina; Hamann, Silke; Williams, Daniel; Hellmuth, Sam

    2017-09-01

    Acoustic studies of several languages indicate that second-formant (F2) slopes in high vowels have opposing directions (independent of consonantal context): front [iː]-like vowels are produced with a rising F2 slope, whereas back [uː]-like vowels are produced with a falling F2 slope. The present study first reports acoustic measurements that confirm this pattern for the English variety of Standard Southern British English (SSBE), where /uː/ has shifted from the back to the front area of the vowel space and is now realized with higher midpoint F2 values than several decades ago. Subsequently, we test whether the direction of F2 slope also serves as a reliable cue to the /iː/-/uː/ contrast in perception. The findings show that F2 slope direction is used as a cue (additional to midpoint formant values) to distinguish /iː/ from /uː/ by both young and older Standard Southern British English listeners: an otherwise ambiguous token is identified as /iː/ if it has a rising F2 slope and as /uː/ if it has a falling F2 slope. Furthermore, our results indicate that listeners generalize their reliance on F2 slope to other contrasts, namely /ɛ/-/ɒ/ and /æ/-/ɒ/, even though F2 slope is not employed to differentiate these vowels in production. This suggests that in Standard Southern British English, a rising F2 seems to be perceptually associated with an abstract feature such as [+front], whereas a falling F2 with an abstract feature such as [-front].

  11. Brain tumours at 7T MRI compared to 3T - contrast effect after half and full standard contrast agent dose: initial results

    International Nuclear Information System (INIS)

    Noebauer-Huhmann, Iris-Melanie; Weber, M.; Szomolanyi, P.; Juras, V.; Kronnerwetter, C.; Widhalm, G.; Nemec, S.; Prayer, D.; Ladd, M.E.; Trattnig, S.

    2015-01-01

    To compare the contrast agent effect of a full dose and half the dose of gadobenate dimeglumine in brain tumours at 7 Tesla (7T) MR versus 3 Tesla (3T). Ten patients with primary brain tumours or metastases were examined. Signal intensities were assessed in the lesion and normal brain. Tumour-to-brain contrast and lesion enhancement were calculated. Additionally, two independent readers subjectively graded the image quality and artefacts. The enhanced mean tumour-to-brain contrast and lesion enhancement were significantly higher at 7T than at 3T for both half the dose (91.8 ± 45.8 vs. 43.9 ± 25.3 [p = 0.010], 128.1 ± 53.7 vs. 75.5 ± 32.4 [p = 0.004]) and the full dose (129.2 ± 50.9 vs. 66.6 ± 33.1 [p = 0.002], 165.4 ± 54.2 vs. 102.6 ± 45.4 [p = 0.004]). Differences between dosages at each field strength were also significant. Lesion enhancement was higher with half the dose at 7T than with the full dose at 3T (p =.037), while the tumour-to-brain contrast was not significantly different. Subjectively, contrast enhancement, visibility, and lesion delineation were better at 7T and with the full dose. All parameters were rated as good, at the least. Half the routine contrast agent dose at 7T provided higher lesion enhancement than the full dose at 3T which indicates the possibility of dose reduction at 7T. (orig.)

  12. An open source, 3D printed preclinical MRI phantom for repeated measures of contrast agents and reference standards.

    Science.gov (United States)

    Cox, B L; Ludwig, K D; Adamson, E B; Eliceiri, K W; Fain, S B

    2018-03-01

    In medical imaging, clinicians, researchers and technicians have begun to use 3D printing to create specialized phantoms to replace commercial ones due to their customizable and iterative nature. Presented here is the design of a 3D printed open source, reusable magnetic resonance imaging (MRI) phantom, capable of flood-filling, with removable samples for measurements of contrast agent solutions and reference standards, and for use in evaluating acquisition techniques and image reconstruction performance. The phantom was designed using SolidWorks, a computer-aided design software package. The phantom consists of custom and off-the-shelf parts and incorporates an air hole and Luer Lock system to aid in flood filling, a marker for orientation of samples in the filled mode and bolt and tube holes for assembly. The cost of construction for all materials is under $90. All design files are open-source and available for download. To demonstrate utility, B 0 field mapping was performed using a series of gadolinium concentrations in both the unfilled and flood-filled mode. An excellent linear agreement (R 2 >0.998) was observed between measured relaxation rates (R 1 /R 2 ) and gadolinium concentration. The phantom provides a reliable setup to test data acquisition and reconstruction methods and verify physical alignment in alternative nuclei MRI techniques (e.g. carbon-13 and fluorine-19 MRI). A cost-effective, open-source MRI phantom design for repeated quantitative measurement of contrast agents and reference standards in preclinical research is presented. Specifically, the work is an example of how the emerging technology of 3D printing improves flexibility and access for custom phantom design.

  13. Contrast induced nephropathy

    DEFF Research Database (Denmark)

    Stacul, Fulvio; van der Molen, Aart J; Reimer, Peter

    2011-01-01

    PURPOSE: The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 1999 guidelines on contrast medium-induced nephropathy (CIN). AREAS COVERED: Topics reviewed include the definition of CIN, the choice of contrast medium, the prophylactic...... measures used to reduce the incidence of CIN, and the management of patients receiving metformin. Key Points • Definition, risk factors and prevention of contrast medium induced nephropathy are reviewed. • CIN risk is lower with intravenous than intra-arterial iodinated contrast medium. • eGFR of 45 ml....../min/1.73 m (2) is CIN risk threshold for intravenous contrast medium. • Hydration with either saline or sodium bicarbonate reduces CIN incidence. • Patients with eGFR = 60 ml/min/1.73 m (2) receiving contrast medium can continue metformin normally....

  14. Perforations during contrast enema

    International Nuclear Information System (INIS)

    Vogel, H.; Steinkamp, U.; Grabbe, E.; Allgemeines Krankenhaus Ochsenzoll, Hamburg

    1983-01-01

    During contrast enema, perforation into the retroperitoneal space can be differentiated from perforation into the peritoneum and perforation into the intestinal wall associated with formation of barium granulomas or submucosal spreading of the contrast medium. Other special forms are perforation with contrast medium embolism of diverticula; of the processus vermiformis; penetration of contrast medium into fistulous systems and from the operated areas. Risk factors are: balloon catheter, intestinal tubes with a hard tip, preternatural anus, excessive enema pressure, contrast medium additions, preceding manipulations, intestinal diseases, advanced age and delegation of manipulations to assistants and unskilled staff. Children are particularly at risk. (orig.) [de

  15. Contrast induced nephropathy

    DEFF Research Database (Denmark)

    Stacul, Fulvio; van der Molen, Aart J; Reimer, Peter

    2011-01-01

    PURPOSE: The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 1999 guidelines on contrast medium-induced nephropathy (CIN). AREAS COVERED: Topics reviewed include the definition of CIN, the choice of contrast medium, the prophylactic me....../min/1.73 m (2) is CIN risk threshold for intravenous contrast medium. • Hydration with either saline or sodium bicarbonate reduces CIN incidence. • Patients with eGFR = 60 ml/min/1.73 m (2) receiving contrast medium can continue metformin normally....

  16. Contrast induced nephropathy

    DEFF Research Database (Denmark)

    Stacul, Fulvio; van der Molen, Aart J; Reimer, Peter

    2011-01-01

    PURPOSE: The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 1999 guidelines on contrast medium-induced nephropathy (CIN). AREAS COVERED: Topics reviewed include the definition of CIN, the choice of contrast medium, the prophylactic me....../min/1.73 m (2) is CIN risk threshold for intravenous contrast medium. • Hydration with either saline or sodium bicarbonate reduces CIN incidence. • Patients with eGFR ≥ 60 ml/min/1.73 m (2) receiving contrast medium can continue metformin normally....

  17. MR imaging in recurrent pain after back surgery. A comparative study using standard and high doses of gadolinium contrast agents

    International Nuclear Information System (INIS)

    Aakeson, P.; Jonsson, E.; Holtaas, S.

    1996-01-01

    Purpose: To compare the diagnostic results following injection of (a) a high dose (0.3 mmol/kg b.w.) of gadodiamide injection and (b) the standard dose (0.1 mmol/kg b.w.) of Gd-DTPA, in patients with recurrent symptoms after surgery for lumbar disc herniation. Material and Methods: Twenty patients with recurrent or sustained symptoms after surgery for lumbar disc herniations were examined. MR imaging (0.3 T) was first performed before and after Gd-DTPA at 0.1 mmol/kg b.w., and then within one month (17 patients) or within 3 months (3 patients) before and after gadodiamide injection at 0.3 mmol/kg b.w. The examinations were first evaluated by 2 neuroradiologists blinded to dose but not to patient as the images were presented in pairs. Six months later the same investigators evaluated the examinations again, this time blinded to both dose and patient. Results: At the evaluation in pairs (with the investigators blinded to dose only) the high-dose examinations were considered the most informative (p=0.05). However, at the later evaluation (with the investigators blinded both to dose and patient) no significant difference between high and standard dose was found regarding diagnosis or diagnostic certainty. Conclusion: In this study the high-dose contrast enhancement of MR imaging at 0.3 T did not increase the diagnostic information for differentiating between scar and recurrent hernia. The high-dose images were considered more informative when evaluated in pairs, but gave no additional or different information when evaluated separately. The study also indicated that comparisons in pairs should be interpreted with caution. (orig.)

  18. MR imaging in recurrent pain after back surgery. A comparative study using standard and high doses of gadolinium contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Aakeson, P. [Univ. Hospital, Lund (Sweden). Dept. of Radiology; Annertz, M. [Univ. Hospital, Lund (Sweden). Dept. of Radiology; Kristoffersen, D.T. [Nycomed Imaging AS, Oslo (Norway); Jonsson, E. [Nycomed AB, Stockholm (Sweden); Holtaas, S. [Univ. Hospital, Lund (Sweden). Dept. of Radiology

    1996-11-01

    Purpose: To compare the diagnostic results following injection of (a) a high dose (0.3 mmol/kg b.w.) of gadodiamide injection and (b) the standard dose (0.1 mmol/kg b.w.) of Gd-DTPA, in patients with recurrent symptoms after surgery for lumbar disc herniation. Material and Methods: Twenty patients with recurrent or sustained symptoms after surgery for lumbar disc herniations were examined. MR imaging (0.3 T) was first performed before and after Gd-DTPA at 0.1 mmol/kg b.w., and then within one month (17 patients) or within 3 months (3 patients) before and after gadodiamide injection at 0.3 mmol/kg b.w. The examinations were first evaluated by 2 neuroradiologists blinded to dose but not to patient as the images were presented in pairs. Six months later the same investigators evaluated the examinations again, this time blinded to both dose and patient. Results: At the evaluation in pairs (with the investigators blinded to dose only) the high-dose examinations were considered the most informative (p=0.05). However, at the later evaluation (with the investigators blinded both to dose and patient) no significant difference between high and standard dose was found regarding diagnosis or diagnostic certainty. Conclusion: In this study the high-dose contrast enhancement of MR imaging at 0.3 T did not increase the diagnostic information for differentiating between scar and recurrent hernia. The high-dose images were considered more informative when evaluated in pairs, but gave no additional or different information when evaluated separately. The study also indicated that comparisons in pairs should be interpreted with caution. (orig.).

  19. Assessment of the image contrast improvement and dose reduction in mammography with synchrotron radiation compared to standard units

    CERN Document Server

    Moeckli, R; Fiedler, S; Pachoud, M; Hessler, C; Meuli, R; Valley, J F

    2001-01-01

    An objective method was used to evaluate image quality and dose in mammography with synchrotron radiation and to compare them to standard units. It was performed systematically in the energy range of interest for mammography through the evaluation of the contrast and the measurement of the mean glandular dose. Synchrotron radiation measurements were performed at the ESRF and a slit was placed between the test object and the screen-film system in order to reduce scatter. The conventional films were obtained on mammography units with an anti-scatter grid. In a recent paper, it was shown that the use of synchrotron radiation leads to a noticeable improvement of the image quality-dose relationship (Moeckli et al. Phys. Med. Biol. 45(12)3509). The reason of that enhancement is partly due to the monochromaticity of the synchrotron beam and partly due to the use of a slit instead of a grid. The dose reduction with synchrotron radiation can be attributed to a better X-ray total transmission of the slit and the contra...

  20. Standard Review Risk Assessment on Medium-chain and Long-chain Chlorinated paraffin PMN submissions by INEOS Chlor Americas

    Science.gov (United States)

    This assessment was conducted under EPA’s TSCA Section 5 New Chemicals Program. EPA is assessing Medium-chain Chlorinated Paraffin (MCCP) and Long-Chain Chlorinated Paraffin (LCCP) chemicals as part of its New Chemicals Review program.

  1. Standard Review Risk Assessment on Medium-chain and Long-chain Chlorinated paraffin PMN submissions by Dover Chemical

    Science.gov (United States)

    This assessment was conducted under EPA’s TSCA Section 5 New Chemicals Program. EPA is assessing Medium-chain Chlorinated Paraffin (MCCP) and Long-Chain Chlorinated Paraffin (LCCP) chemicals as part of its New Chemicals Review program.

  2. Standard Review Risk Assessment on Medium-chain and Long-chain Chlorinated paraffin PMN submissions by Qualice, LLC

    Science.gov (United States)

    This assessment was conducted under EPA’s TSCA Section 5 New Chemicals Program. EPA is assessing Medium-chain Chlorinated Paraffin (MCCP) and Long-Chain Chlorinated Paraffin (LCCP) chemicals as part of its New Chemicals Review program.

  3. Evaluation of Visualization Using a 50/50 (Contrast Media/Glucose 5% Solution) Technique for Radioembolization as an Alternative to a Standard Sandwich Technique.

    Science.gov (United States)

    Paprottka, Karolin J; Todica, Andrei; Ilhan, Harun; Rübenthaler, Johannes; Schoeppe, Franziska; Michl, Marlies; Heinemann, Volker; Bartenstein, Peter; Reiser, Maximilian F; Paprottka, Philipp M

    2017-11-01

    Radioembolization (RE) with 90 yttrium ( 90 Y) resin microspheres generally employs a sandwich technique with separate sequential administration of contrast medium (CM), followed by vehicle (e.g., glucose 5% [G5] solution), then 90 Y resin microspheres (in G5), then G5, and then CM again to avoid contact of CM and microspheres under fluoroscopic guidance. This study evaluates the visualization quality and safety of a modified sandwich technique with a 50/50-mixture of CM (Imeron 300) and G5 for administration of 90 Y resin microspheres. A retrospective analysis of 81 RE procedures in patients with primary or secondary liver tumors was performed. The quality of angiographic visualization of the hepatic vessels was assessed before the first injection and immediately before the whole dose has been injected. Visualization and flow rate were graded on a 5-point scale: 1 = very good to 5 = not visible/no antegrade flow. Univariate logistic regression models and multiple linear regression models were used to evaluate the prognostic variables associated with visualization and flow scores. Visualization quality was inversely related to flow rate, the lower the flow rate the better the grade of the visualization. Visualization quality was also inversely related to body-mass-index (BMI). Performing RE with the 50/50-CM/G5 mixture resulted in a mean injection time for 1 GBq of 15 min. No clinically significant adverse events, including radiation-induced liver disease were reported. RE with a 50/50-mixture of CM and G5 for administration of 90 Y resin microspheres in a modified sandwich technique is a safe administration alternative and provides good visualization of hepatic vessels, which is inversely dependent on flow rate and BMI. Injection time was reduced compared with our experience with the standard sandwich technique.

  4. Diagnostic accuracy of low and high tube voltage coronary CT angiography using an X-ray tube potential-tailored contrast medium injection protocol.

    Science.gov (United States)

    Albrecht, Moritz H; Nance, John W; Schoepf, U Joseph; Jacobs, Brian E; Bayer, Richard R; Litwin, Sheldon E; Reynolds, Michael A; Otani, Katharina; Mangold, Stefanie; Varga-Szemes, Akos; De Santis, Domenico; Eid, Marwen; Apfaltrer, Georg; Tesche, Christian; Goeller, Markus; Vogl, Thomas J; De Cecco, Carlo N

    2018-05-01

    To compare the diagnostic accuracy between low-kilovolt peak (kVp) (≤ 100) and high-kVp (> 100) third-generation dual-source coronary CT angiography (CCTA) using a kVp-tailored contrast media injection protocol. One hundred twenty patients (mean age = 62.6 years, BMI = 29.0 kg/m 2 ) who underwent catheter angiography and CCTA with automated kVp selection were separated into two cohorts (each n = 60, mean kVp = 84 and 117). Contrast media dose was tailored to the kVp level: 70 = 40 ml, 80 = 50 ml, 90 = 60 ml, 100 = 70 ml, 110 = 80 ml, and 120 = 90 ml. Contrast-to-noise ratio (CNR) was measured. Two observers evaluated image quality and the presence of significant coronary stenosis (> 50% luminal narrowing). Diagnostic accuracy (sensitivity/specificity) with ≤ 100 vs. > 100 kVp CCTA was comparable: per patient = 93.9/92.6% vs. 90.9/92.6%, per vessel = 91.5/97.8% vs. 94.0/96.8%, and per segment = 90.0/96.7% vs. 90.7/95.2% (all P > 0.64). CNR was similar (P > 0.18) in the low-kVp vs. high-kVp group (12.0 vs. 11.1), as ws subjective image quality (P = 0.38). Contrast media requirements were reduced by 38.1% in the low- vs. high-kVp cohort (53.6 vs. 86.6 ml, P tube voltage selection with a tailored contrast media injection protocol allows CCTA to be performed at ≤ 100 kVp with substantial dose reductions and equivalent diagnostic accuracy for coronary stenosis detection compared to acquisitions at > 100 kVp. • Low-kVp coronary CT angiography (CCTA) enables reduced contrast and radiation dose. • Diagnostic accuracy is comparable between ≤ 100 and > 100 kVp CCTA. • Image quality is similar for low- and high-kVp CCTA. • Low-kVp image acquisition is facilitated by automated tube voltage selection. • Tailoring contrast injection protocols to the automatically selected kVp-level is feasible.

  5. Multidetector computed tomography with triple-bolus contrast medium administration protocol for preoperative anatomical and functional assessment of potential living renal donors

    International Nuclear Information System (INIS)

    Knox, Matthew K.; Rivers-Bowerman, Michael D.; Bardgett, Harry P.; Cowan, Nigel C.

    2010-01-01

    To evaluate multidetector computed tomography (MDCT) with a triple-bolus contrast administration protocol for preoperative anatomical and functional assessment of living renal donors. Fifty-five potential living renal donors underwent MDCT of which 27 proceeded to donor nephrectomy. A triple-bolus contrast administration protocol was used for simultaneous acquisition of arterial, nephrographic, and excretory phases. MDCT images were independently reviewed in random order by two radiologists blinded to surgical anatomy findings. Diagnostic accuracy for anatomical variants was quantified by sensitivity and specificity. Differential renal function (DRF) was derived from MDCT for 54 patients and compared with technetium-99 m dimercaptosuccinic acid renography (Tc-99 m DMSA). All triple-bolus MDCT examinations were technically adequate. Accessory renal arteries and veins were identified at surgery in 33% (n = 9/27) and 22% (n = 6/27) of donor kidneys. The mean difference between MDCT-derived DRF and DMSA was 0.8% (95% CI 0.1-1.6) with 95% limits of agreement of -4.6% (95% CI -3.3 to -5.9) to 6.3% (95% CI 5.0-7.6). MDCT delivered a mean (SD, range) radiation dose of 9.5 (3.6, 3.6-17.3) mSv. MDCT with a triple-bolus contrast administration provides accurate anatomical and functional evaluation of living renal donors. (orig.)

  6. Effect of duration of contrast material injection on peak enhancement times and values of the aorta, main portal vein, and liver at dynamic MDCT with the dose of contrast medium tailored to patient weight

    International Nuclear Information System (INIS)

    Erturk, S.M.; Ichikawa, T.; Sou, H.; Tsukamoto, T.; Motosugi, U.; Araki, T.

    2008-01-01

    Aim: To investigate the effects of contrast material injection duration on peak enhancement times and attenuation values of the aorta, main portal vein, and liver at MDCT when the dose of contrast material is adjusted to patient weight. Material and methods: Seventy-five patients were randomly assigned to one of five groups, with durations of injection of 25, 30, 35, 40, or 45 s. All patients were injected with 2 ml/kg iodine (300 mg/ml). Attenuation values and peak enhancement times for the aorta, main portal vein, and liver were determined. The relationship between patient weight and enhancement times and values, the differences regarding peak enhancement times, and the relationship between injection duration and enhancement values were investigated using Pearson correlation, analysis of variance (ANOVA), and Spearman rank correlation, respectively. Results: No significant correlations were seen between patient weight and peak enhancement times or values. Mean peak enhancement times for the aorta, main portal vein, and liver were 9-11 s, 18-22 s, and 30-34 s, respectively (p > 0.05). The correlations between injection duration and peak enhancement values were significant and negative. Conclusions: Regardless of patient weight and injection duration, peak enhancement times of aorta, main portal vein and liver were approximately 10, 20, and 30 s, respectively. The enhancement values tended to be higher for shorter injection durations

  7. Dominance hierarchies, diversity and species richness of vascular plants in an alpine meadow: contrasting short and medium term responses to simulated global change

    Directory of Open Access Journals (Sweden)

    Juha M. Alatalo

    2014-05-01

    Full Text Available We studied the impact of simulated global change on a high alpine meadow plant community. Specifically, we examined whether short-term (5 years responses are good predictors for medium-term (7 years changes in the system by applying a factorial warming and nutrient manipulation to 20 plots in Latnjajaure, subarctic Sweden. Seven years of experimental warming and nutrient enhancement caused dramatic shifts in dominance hierarchies in response to the nutrient and the combined warming and nutrient enhancement treatments. Dominance hierarchies in the meadow moved from a community being dominated by cushion plants, deciduous, and evergreen shrubs to a community being dominated by grasses, sedges, and forbs. Short-term responses were shown to be inconsistent in their ability to predict medium-term responses for most functional groups, however, grasses showed a consistent and very substantial increase in response to nutrient addition over the seven years. The non-linear responses over time point out the importance of longer-term studies with repeated measurements to be able to better predict future changes. Forecasted changes to temperature and nutrient availability have implications for trophic interactions, and may ultimately influence the access to and palatability of the forage for grazers. Depending on what anthropogenic change will be most pronounced in the future (increase in nutrient deposits, warming, or a combination of them both, different shifts in community dominance hierarchies may occur. Generally, this study supports the productivity–diversity relationship found across arctic habitats, with community diversity peaking in mid-productivity systems and degrading as nutrient availability increases further. This is likely due the increasing competition in plant–plant interactions and the shifting dominance structure with grasses taking over the experimental plots, suggesting that global change could have high costs to biodiversity in the

  8. Comparison of the Effect of Dual-Axis Rotational Coronary Angiography Versus Conventional Coronary Angiography on Frequency of Acute Kidney Injury, X-Ray Exposure Time, and Quantity of Contrast Medium Injected.

    Science.gov (United States)

    Di Serafino, Luigi; Turturo, Maurizio; Lanzone, Saverio; Marano, Melissa; Scognamiglio, Gabriella; Trimarco, Bruno; Cirillo, Plinio; Esposito, Giovanni; D'Agostino, Carlo

    2018-02-07

    Dual-axis rotational coronary angiography (DARCA) has already been shown to reduce both the amount of contrast medium and radiation exposure compared with conventional coronary angiography (CCA). However, a clinical benefit of such imaging modality has never been demonstrated. The aim of this study was to evaluate the efficacy of DARCA to prevent acute kidney injury (AKI) compared with CCA. Consecutive patients who underwent coronary angiography were enrolled to DARCA (n = 80) or CCA (n = 80). Patients presenting with ST-segment elevation myocardial infarction or previously underwent coronary artery bypass graft were excluded. The 2 groups were homogeneous in terms of both clinical and procedural characteristics. Total x-ray time and total amount of contrast medium were significantly lower in the DARCA group compared with the CCA group (x-ray time 3.2 minutes [1.8 to 7.0] vs 5.1 minutes [2.6 to 9.9], p = 0.002; contrast medium amount 40 ml [31 to 116] vs 80 ml [50 to 150], p <0.001). AKI more often occurred in the CCA group compared with the DARCA group (16 [20%] vs 4 [5%], p = 0.007). Moreover, in patients presenting with acute coronary syndrome (ACS) or who underwent percutaneous coronary intervention (PCI), AKI more often occurred in the CCA group compared with the DARCA group (ACS patients, 6 [29%] vs 2 [6%], p = 0.04, and PCI patients, 11 [33%] vs 0 [0%], p <0.001). In addition, in patients with high pretest probability of coronary artery disease, AKI more often occurred in the CCA group compared with the DARCA group (11 [55%] vs 2 [6%], p <0.001). In conclusion, DARCA significantly reduces both x-ray exposure and amount of contrast medium usage, thereby reducing the occurrence of AKI compared with CCA. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Randomized trial of one-hour sodium bicarbonate vs standard periprocedural saline hydration in chronic kidney disease patients undergoing cardiovascular contrast procedures.

    Science.gov (United States)

    Kooiman, Judith; de Vries, Jean-Paul P M; Van der Heyden, Jan; Sijpkens, Yvo W J; van Dijkman, Paul R M; Wever, Jan J; van Overhagen, Hans; Vahl, Antonie C; Aarts, Nico; Verberk-Jonkers, Iris J A M; Brulez, Harald F H; Hamming, Jaap F; van der Molen, Aart J; Cannegieter, Suzanne C; Putter, Hein; van den Hout, Wilbert B; Kilicsoy, Inci; Rabelink, Ton J; Huisman, Menno V

    2018-01-01

    Guidelines advise periprocedural saline hydration for prevention of contrast induced-acute kidney injury (CI-AKI). We analysed whether 1-hour sodium bicarbonate hydration administered solely prior to intra-arterial contrast exposure is non-inferior to standard periprocedural saline hydration in chronic kidney disease (CKD) patients undergoing elective cardiovascular diagnostic or interventional contrast procedures. We performed an open-label multicentre non-inferiority trial between 2011-2014. Patients were randomized to 1 hour pre-procedure sodium bicarbonate hydration (250 ml 1.4%, N = 168) or 4-12 hours saline hydration (1000 ml 0.9%, N = 165) prior to and following contrast administration (2000 ml of saline total). Primary outcome was the relative serum creatinine increase (%) 48-96 hours post contrast exposure. Secondary outcomes were: incidence of CI-AKI (serum creatinine increase>25% or >44μmol/L), recovery of renal function, the need for dialysis, and hospital costs within two months follow-up. Mean relative creatinine increase was 3.1% (95%CI 0.9 to 5.2%) in the bicarbonate and 1.1% (95%CI -1.2 to 3.5%) in the saline arm, mean difference 1.9% (95%CI -1.2 to 5.1%, p-non-inferiority sodium bicarbonate and 12 (7.5%) to saline (p = 0.79). Renal function did not fully recover in 40.0% and 44.4% of CI-AKI patients, respectively (p = 0.84). No patient required dialysis. Mean costs for preventive hydration and clinical preparation for the contrast procedure were $1158 for sodium bicarbonate vs. $1561 for saline (p sodium bicarbonate prior to elective cardiovascular diagnostic or therapeutic contrast procedures is non-inferior to standard periprocedural saline hydration in CKD patients with respect to renal safety and results in considerable healthcare savings. Netherlands Trial Register (http://www.trialregister.nl/trialreg/index.asp), Nr NTR2699.

  10. Indirect MR venography: contrast medium protocols, postprocessing and combination in diagnosing pulmonary emboli with MRI; Indirekte MR-Phlebografie: Kontrastmittelprotokolle, Nachverarbeitung und Kombination mit Lungenemboliediagnostik in der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Kluge, A.; Bachmann, G. [Diagnostische Radiologie, Kerckhoff-Klinik, Bad Nauheim (Germany); Rominger, M. [Diagnostische Radiologie, Phillips-Univ. Marburg (Germany); Schoenburg, M. [Herzchirurgie, Kerckhoff-Klinik, Bad Nauheim (Germany)

    2004-07-01

    Purpose: Integration of MR venography in a comprehensive MR imaging protocol in patients with suspected pulmonary embolism (PE) and evaluation of contrast media dosage, timing and postprocessing for diagnostic accuracy. Materials and Methods: Fortyeight consecutive inpatients with suspected PE or deep vein thrombosis were examined by MR venography according to one of the following protocols: protocol I: MR venography only, 0.25 mmol/kg bodyweight (BW) Gadopentate dimeglumine(Gd-DTPA) as single dose, bolus timing; protocol II: MR angiography of pulmonary arteries with a cumulative dosage of 0.25 mmol/kg contrast media, modification of coil setting for MR venography without further contrast media application; protocol III: as protocol II but with 0.125 mmol/kg BW, followed by MR venography. Signal-to-noise ratio, contrast-to-noise ratio, number of definable vascular segments and image quality were evaluated. The results were compared to conventional bilateral venography. Results: All MR venography examinations were of diagnostic quality and the examination time was below 10 min. MR venography could be performed in all 48 patients comparted to 43 of 48 patients for conventional venography. Significantly more superficial and deep veins of the leg could be visualized by MR venography (94% compared to 83% for conventional venography). Sensitivity and specificity were 100% and 92%, respectively. Quality differed significantly between 0.125 mmol/kg (protocol III) and 0.25 mmol/kg Gd-DTPA (protocols I and II) while timing did not influence quality (protocol I vs. II). (orig.) [German] Ziel: Integration der MR-Phlebografie in ein umfassendes Konzept der MRT-Diagnostik bei Verdacht auf Lungenembolie (LE). Untersuchung des Einflusses von Kontrastmittelmenge, -bolusform und Verzoegerungszeit sowie der Nachverarbeitung auf die diagnostische Qualitaet von MR-Phlebografien. Material und Methode: Bei 48 konsekutiven stationaeren Patienten mit Verdacht auf Beinvenenthrombose (TVT

  11. Influence of tri-iodinated water soluble X-ray contrast medium for uro, angio and cholangiography on the plasmic coagulation system

    International Nuclear Information System (INIS)

    Kaps, H.P.

    1982-01-01

    In-vitro coagulation studies comprising overall and individual factor determinations were carried out with the aim of clarifying the nature of unforeseen incidents arising from the use of contrast media in X-ray diagnosis. In all tests a reproducible, dose-dependent, exponential coagulation inhibition was obtained, and resulted in complete inhibition at higher dose levels. This effect occurred by a factor of ten earlier, on average, with iodine ipamide, representative of liver passage bile CM, compared to uro, and angiographic CM diatrozoate and iodine thalamate used for kidney passage. Hepatotrophic CM act initially hypercoagulative at low dises through activation of the thrombin coagulase complex; later inhibition of coagulation sets in through direct fixation on functional proteins and their subsequent denaturation. A discussion is given of the importance of direct physico-chemical toxicity, histamine liberation reactions and cellular reactions, and the controversial role of the complement system is presented. (orig./MG) [de

  12. Preoperative mapping of arterial spinal supply using 3.0-T MR angiography with an intravasal contrast medium and high-spatial-resolution steady-state

    International Nuclear Information System (INIS)

    Mordasini, Pasquale; El-Koussy, Marwan; Schmidli, Jürg; Bonel, Harald Marcel; Ith, Michael; Gralla, Jan; Schroth, Gerhard; Hoppe, Hanno

    2012-01-01

    Introduction: Preoperative mapping of the arterial spinal supply prior to thoracoabdominal aortic aneurysm repair is highly relevant because of high risk for postoperative ischemic spinal cord injuries such as paraparesis or paraplegia. Methods: Twenty-four consecutive patients prior to surgical thoracoabdominal aortic aneurysm repair were investigated. All patients underwent steady-state MR angiography (MRA) of the spinal vasculature with 3-T MRI. The sequence used was a steady-state coronary 3D FLASH with 0.7-mm isotropic voxels. MRA was performed using an intravasal contrast agent. Studies were evaluated by three readers including delineation of arterial spinal supply including both aortic origin and spinal canal entry by three readers. Results: Identification and localization of the Adamkiewicz artery and its spinal canal entry was successful in all patients. Overall depiction of the vascular anatomy was graded as very good in 3 (12.5%), good in 14 (58.4%), sufficient in 5 (20.8%), and poor in 2 (8.3%) patients. Depiction of segmental artery aortic exit level was graded as good in 6 (25.0%), sufficient in 10 (41.7%), poor in 4 (16.7%) and not identifiable in 4 (16.7%) patients. Delineation of segmental artery entry level into the spinal canal was graded as very good in 4 (16.7%), good in 11 (45.8%), sufficient in 6 (25.0%), and poor in 3 (12.5%) patients. Conclusions: The use of 3-T MRA with an intravascular contrast agent and steady-state enables AKA localization including its segmental arteries with regard to the level of aortic origin and spinal canal entry in most patients.

  13. Induction of Upregulation and Downregulation of the T-Cell Activation Marker CD98 in Patients Undergoing Contrast-Enhanced CT with Iodinated Non-Ionic Dimeric Contrast Medium

    Energy Technology Data Exchange (ETDEWEB)

    Bohm, Ingrid; Schild, Hans H. [University of Bonn, Bonn (Germany)

    2009-02-15

    This study was designed to determine prospectively the expression of the multifunctional CD98 protein in peripheral white blood cells in patients receiving iodinated contrast media (CM) for a computed tomography (CT) examination. In 12 adult patients that received non-ionic dimeric CM (iosimenol or iodixanol), the expression of CD98 was analyzed from samples of peripheral white blood cells obtained prior to, one hour, and 24 hours after CM injection by the use of flow cytometry analysis and the use of the direct immunofluorescence technique. Overall, expression of CD98 was significantly downregulated 24 hours after CM injection (51.9%+-10.8% vs. 38.8%+-16.9%; p < 0.04). Patients that received iosimenol exhibited a more pronounced but not significant decrease of CD98 expression both one hour and 24 hours after CM injection. In an analysis of specific patient responses, CD98 downregulation occurred in eight patients. In two patients, CD98 was upregulated, and in the remaining two patients, expression remained unchanged. No patient acquired an adverse CM reaction. This is the first demonstration that CM may be a regulator of CD98 expression. To determine if upregulation is associated with an increased risk for the acquisition of an adverse CM-induced hypersensitivity reaction and if downregulation is associated without a risk for the acquisition of an adverse CM induced hypersensitivity reaction, further studies with a larger population of patients are required

  14. The value of fat saturation sequences and contrast medium administration in MRI of degenerative disease of the posterior/perispinal elements of the lumbosacral spine

    Energy Technology Data Exchange (ETDEWEB)

    D' Aprile, P. [San Paolo Hospital, Department of Neuroradiology, Bari (Italy); U.O. Radiologia, Sezione di Neuroradiologia, Ospedale ' ' S. Paolo' ' , Via Caposcardicchio, Bari (Italy); Tarantino, A. [San Paolo Hospital, Department of Neuroradiology, Bari (Italy); Jinkins, J.R. [State University of New York, Department of Radiology, Downstate Medical Center, Brooklyn, NY (United States); Brindicci, D. [San Paolo Hospital, Department of Radiology, Bari (Italy)

    2007-02-15

    Degenerative-inflammatory lumbar spinal pathology is one of the most common reasons why individuals seek medical care, and low back pain is the main symptom among those most commonly associated with this pathologic condition. Pain is commonly attributed to degenerative disc disease, particularly herniated discs, but many different spinal and perispinal structures may undergo degenerative-inflammatory phenomena and produce pain: discs, bone, facet joints, ligaments and muscles. In particular, in patients with non-radicular low back pain, this syndrome may arise from changes of the posterior elements/perispinal tissues of the lumbar spine (i.e., the ''posterior vertebral compartment''). They include: facet joint pathology (e.g., osteoarthritis, joint effusion, synovitis and synovial cysts), spondylolysis, spinal/perispinal ligamentous degenerative-inflammatory changes and perispinal muscular changes. It is well known that magnetic resonance is the most sensitive imaging method for the evaluation of spinal degenerative pathology, even in the initial stages of the disease. T2-weighted sequences with fat saturation, and when indicated the use of contrast-enhanced T1-weighted images with fat saturation, permit the visualization of degenerative-inflammatory changes of the posterior elements of the lumbar spine that in most cases would have been overlooked with conventional non-fat suppressed imaging. (orig.)

  15. The value of fat saturation sequences and contrast medium administration in MRI of degenerative disease of the posterior/perispinal elements of the lumbosacral spine

    International Nuclear Information System (INIS)

    D'Aprile, P.; Tarantino, A.; Jinkins, J.R.; Brindicci, D.

    2007-01-01

    Degenerative-inflammatory lumbar spinal pathology is one of the most common reasons why individuals seek medical care, and low back pain is the main symptom among those most commonly associated with this pathologic condition. Pain is commonly attributed to degenerative disc disease, particularly herniated discs, but many different spinal and perispinal structures may undergo degenerative-inflammatory phenomena and produce pain: discs, bone, facet joints, ligaments and muscles. In particular, in patients with non-radicular low back pain, this syndrome may arise from changes of the posterior elements/perispinal tissues of the lumbar spine (i.e., the ''posterior vertebral compartment''). They include: facet joint pathology (e.g., osteoarthritis, joint effusion, synovitis and synovial cysts), spondylolysis, spinal/perispinal ligamentous degenerative-inflammatory changes and perispinal muscular changes. It is well known that magnetic resonance is the most sensitive imaging method for the evaluation of spinal degenerative pathology, even in the initial stages of the disease. T2-weighted sequences with fat saturation, and when indicated the use of contrast-enhanced T1-weighted images with fat saturation, permit the visualization of degenerative-inflammatory changes of the posterior elements of the lumbar spine that in most cases would have been overlooked with conventional non-fat suppressed imaging. (orig.)

  16. Automated tube voltage selection for radiation dose and contrast medium reduction at coronary CT angiography using 3{sup rd} generation dual-source CT

    Energy Technology Data Exchange (ETDEWEB)

    Mangold, Stefanie [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Eberhard-Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Wichmann, Julian L. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Schoepf, U.J. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States); Poole, Zachary B.; Varga-Szemes, Akos; De Cecco, Carlo N. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Canstein, Christian [Siemens Medical Solutions, Malvern, PA (United States); Caruso, Damiano [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University of Rome ' ' Sapienza' ' , Department of Radiological Sciences, Oncology and Pathology, Rome (Italy); Bamberg, Fabian; Nikolaou, Konstantin [Eberhard-Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany)

    2016-10-15

    To investigate the relationship between automated tube voltage selection (ATVS) and body mass index (BMI) and its effect on image quality and radiation dose of coronary CT angiography (CCTA). We evaluated 272 patients who underwent CCTA with 3{sup rd} generation dual-source CT (DSCT). Prospectively ECG-triggered spiral acquisition was performed with automated tube current selection and advanced iterative reconstruction. Tube voltages were selected by ATVS (70-120 kV). BMI, effective dose (ED), and vascular attenuation in the coronary arteries were recorded. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Five-point scales were used for subjective image quality analysis. Image quality was rated good to excellent in 98.9 % of examinations without significant differences for proximal and distal attenuation (all p ≥.0516), whereas image noise was rated significantly higher at 70 kV compared to ≥100 kV (all p <.0266). However, no significant differences were observed in SNR or CNR at 70-120 kV (all p ≥.0829). Mean ED at 70-120 kV was 1.5 ± 1.2 mSv, 2.4 ± 1.5 mSv, 3.6 ± 2.7 mSv, 5.9 ± 4.0 mSv, 7.9 ± 4.2 mSv, and 10.7 ± 4.1 mSv, respectively (all p ≤.0414). Correlation analysis showed a moderate association between tube voltage and BMI (r =.639). ATVS allows individual tube voltage adaptation for CCTA performed with 3{sup rd} generation DSCT, resulting in significantly decreased radiation exposure while maintaining image quality. (orig.)

  17. Feasibility of low-dose contrast medium high pitch CT angiography for the combined evaluation of coronary, head and neck arteries.

    Directory of Open Access Journals (Sweden)

    Zhiwei Wang

    Full Text Available PURPOSE: To evaluate the image quality and radiation dose of combined heart, head, and neck CT angiography (CTA using prospectively electrocardiography (ECG-triggered high-pitch spiral scan protocol, compared with single coronary CTA. MATERIALS AND METHODS: 151 consecutive patients were prospectively included and randomly divided into three groups. Group 1 (n = 47 underwent combined heart, neck, and head CTA using prospectively ECG-triggered high-pitch spiral (Flash scan protocol with a single-phase intravenous injection of iodinated contrast and saline flush; Group 2 (n = 51 underwent single coronary CTA with Flash scan protocol; and Group 3 (n = 53 underwent single coronary CTA with prospective sequence scan protocol. All patients were examined on a dual source CT (Definition FLASH. The image quality was determined for each CT study. RESULTS: Patients of scanning protocol Group 1, 2, and 3 showed no significant differences in age, sex, heart rates, and BMI. Evaluation of coronary artery image quality showed comparable results in the three scanning protocol groups on a per patient-based analysis. In group 1, image quality was found to be sufficient to be diagnostic in all arterial segments of carotid arteries. The mean dose-length product (DLP for group 1 was 256.3±24.5 mGy×cm and was significantly higher in comparison with group 2 (93.4±19.9 mGy×cm; p < 0.001. However, there was no significant difference of DLP between group 1 and group 3 (254.1±69.9 mGy×cm. CONCLUSIONS: The combined heart, neck, and head arteries scan using prospectively electrocardiography (ECG-triggered high-pitch spiral scan protocol in 1 single examination resulted in an excellent opacification of the aorta, the carotid arteries, and the coronary arteries and provided a good image quality with low radiation dose.

  18. Dialysis and contrast media

    International Nuclear Information System (INIS)

    Morcos, Sameh K.; Thomsen, Henrik S.; Webb, Judith A.W.

    2002-01-01

    In a previous survey we revealed uncertainty among responders about (a) whether or not to perform hemodialysis in patients with severely reduced renal function who had received contrast medium; and (b) when to perform hemodialysis in patients on regular treatment with hemodialysis or continuous ambulatory dialysis who received contrast medium. Therefore, the Contrast Media Safety Committee of The European Society of Urogenital Radiology decided to review the literature and to issue guidelines. The committee performed a Medline search. Based on this, a report and guidelines were prepared. The report was discussed at the Ninth European Symposium on Urogenital Radiology in Genoa, Italy. Hemodialysis and peritoneal dialysis safely remove both iodinated and gadolinium-based contrast media. The effectiveness of hemodialysis depends on many factors including blood and dialysate flow rate, permeability of dialysis membrane, duration of hemodialysis and molecular size, protein binding, hydrophilicity, and electrical charge of the contrast medium. Generally, several hemodialysis sessions are needed to removal all contrast medium, whereas it takes 3 weeks for continuous ambulatory dialysis to remove the agent completely. There is no need to schedule the dialysis in relation to the injection of iodinated or MR contrast media or the injection of contrast agent in relation to the dialysis program. Hemodialysis does not protect poorly functioning kidneys against contrast-medium-induced nephrotoxicity. Simple guidelines are given. (orig.)

  19. Dialysis and contrast media

    Energy Technology Data Exchange (ETDEWEB)

    Morcos, Sameh K. [Department of Diagnostic Imaging, Northern General Hospital, Sheffield Teaching Hospitals NHS Trust, Sheffield S5 7AU (United Kingdom); Thomsen, Henrik S. [Department of Diagnostic Radiology 54E2, Copenhagen University Hospital at Herlev, Herlev Ringvej 75, 2730 Herlev (Denmark); Webb, Judith A.W. [Department of Diagnostic Imaging, St Bartholomew' s Hospital, London EC1A 7BE (United Kingdom)

    2002-12-01

    In a previous survey we revealed uncertainty among responders about (a) whether or not to perform hemodialysis in patients with severely reduced renal function who had received contrast medium; and (b) when to perform hemodialysis in patients on regular treatment with hemodialysis or continuous ambulatory dialysis who received contrast medium. Therefore, the Contrast Media Safety Committee of The European Society of Urogenital Radiology decided to review the literature and to issue guidelines. The committee performed a Medline search. Based on this, a report and guidelines were prepared. The report was discussed at the Ninth European Symposium on Urogenital Radiology in Genoa, Italy. Hemodialysis and peritoneal dialysis safely remove both iodinated and gadolinium-based contrast media. The effectiveness of hemodialysis depends on many factors including blood and dialysate flow rate, permeability of dialysis membrane, duration of hemodialysis and molecular size, protein binding, hydrophilicity, and electrical charge of the contrast medium. Generally, several hemodialysis sessions are needed to removal all contrast medium, whereas it takes 3 weeks for continuous ambulatory dialysis to remove the agent completely. There is no need to schedule the dialysis in relation to the injection of iodinated or MR contrast media or the injection of contrast agent in relation to the dialysis program. Hemodialysis does not protect poorly functioning kidneys against contrast-medium-induced nephrotoxicity. Simple guidelines are given. (orig.)

  20. A risk score including microdeletions improves relapse prediction for standard and medium risk precursor B-cell acute lymphoblastic leukaemia in children.

    Science.gov (United States)

    Sutton, Rosemary; Venn, Nicola C; Law, Tamara; Boer, Judith M; Trahair, Toby N; Ng, Anthea; Den Boer, Monique L; Dissanayake, Anuruddhika; Giles, Jodie E; Dalzell, Pauline; Mayoh, Chelsea; Barbaric, Draga; Revesz, Tamas; Alvaro, Frank; Pieters, Rob; Haber, Michelle; Norris, Murray D; Schrappe, Martin; Dalla Pozza, Luciano; Marshall, Glenn M

    2018-02-01

    To prevent relapse, high risk paediatric acute lymphoblastic leukaemia (ALL) is treated very intensively. However, most patients who eventually relapse have standard or medium risk ALL with low minimal residual disease (MRD) levels. We analysed recurrent microdeletions and other clinical prognostic factors in a cohort of 475 uniformly treated non-high risk precursor B-cell ALL patients with the aim of better predicting relapse and refining risk stratification. Lower relapse-free survival at 7 years (RFS) was associated with IKZF1 intragenic deletions (P 5 × 10 -5 (P < 0·0001) and High National Cancer Institute (NCI) risk (P < 0·0001). We created a predictive model based on a risk score (RS) for deletions, MRD and NCI risk, extending from an RS of 0 (RS0) for patients with no unfavourable factors to RS2 +  for patients with 2 or 3 high risk factors. RS0, RS1, and RS2 +  groups had RFS of 93%, 78% and 49%, respectively, and overall survival (OS) of 99%, 91% and 71%. The RS provided greater discrimination than MRD-based risk stratification into standard (89% RFS, 96% OS) and medium risk groups (79% RFS, 91% OS). We conclude that this RS may enable better early therapeutic stratification and thus improve cure rates for childhood ALL. © 2017 John Wiley & Sons Ltd.

  1. Sensitivity of Non-Contrast Computed Tomography for Small Renal Calculi with Endoscopy as the Gold Standard.

    Science.gov (United States)

    Bhojani, Naeem; Paonessa, Jessica E; El Tayeb, Marawan M; Williams, James C; Hameed, Tariq A; Lingeman, James E

    2018-04-03

    To compare the sensitivity of non-contrast CT to endoscopy for detection of renal calculi. Imaging modalities for detection of nephrolithiasis have centered on abdominal x-ray (KUB), ultrasound (US), and non-contrast computed tomography (CT). Sensitivities of 58-62% (KUB), 45% (US), and 95-100% (CT) have been previously reported. However, these results have never been correlated with endoscopic findings. Idiopathic calcium oxalate stone formers with symptomatic calculi requiring ureteroscopy (URS) were studied. At the time of surgery, the number and location of all calculi within the kidney were recorded followed by basket retrieval. Each calculus was measured and sent for micro CT and infrared spectrophotometry. All CT scans were reviewed by the same genitourinary radiologist who was blinded to the endoscopic findings. The radiologist reported on the number, location, and size of each calculus. 18 renal units were studied in 11 patients. Average time from CT scan to URS was 28.6 days. The mean number of calculi identified per kidney was 9.2±6.1 for endoscopy and 5.9±4.1 for CT (p<0.004). The mean size of total renal calculi (sum of longest stone diameters) per kidney was 22.4±17.1 mm and 18.2±13.2 mm for endoscopy and CT, respectively (p=0.06). CT scan underreports the number of renal calculi, probably missing some small stones and unable to distinguish those lying in close proximity to one another. However, the total stone burden seen by CT is, on average, accurate when compared to that found on endoscopic examination. Copyright © 2018. Published by Elsevier Inc.

  2. Multiscale based adaptive contrast enhancement

    Science.gov (United States)

    Abir, Muhammad; Islam, Fahima; Wachs, Daniel; Lee, Hyoung

    2013-02-01

    A contrast enhancement algorithm is developed for enhancing the contrast of x-ray images. The algorithm is based on Laplacian pyramid image processing technique. The image is decomposed into three frequency sub-bands- low, medium, and high. Each sub-band contains different frequency information of the image. The detail structure of the image lies on the high frequency sub-band and the overall structure lies on the low frequency sub-band. Apparently it is difficult to extract detail structure from the high frequency sub-bands. Enhancement of the detail structures is necessary in order to find out the calcifications on the mammograms, cracks on any object such as fuel plate, etc. In our proposed method contrast enhancement is achieved from high and medium frequency sub-band images by decomposing the image based on multi-scale Laplacian pyramid and enhancing contrast by suitable image processing. Standard Deviation-based Modified Adaptive contrast enhancement (SDMACE) technique is applied to enhance the low-contrast information on the sub-bands without overshooting noise. An alpha-trimmed mean filter is used in SDMACE for sharpness enhancement. After modifying all sub-band images, the final image is derived from reconstruction of the sub-band images from lower resolution level to upper resolution level including the residual image. To demonstrate the effectiveness of the algorithm an x-ray of a fuel plate and two mammograms are analyzed. Subjective evaluation is performed to evaluate the effectiveness of the algorithm. The proposed algorithm is compared with the well-known contrast limited adaptive histogram equalization (CLAHE) algorithm. Experimental results prove that the proposed algorithm offers improved contrast of the x-ray images.

  3. Intracavitary application of contrast medium in the follow-up of complicated tube-drained pleural empyema: Conventional radiography vs CT; Die intrakavitaere Kontrastmittelgabe bei der Nachsorge des komplizierten langzeitdrainierten Thoraxempyems: Roentgendurchleuchtung im Vergleich zur Computertomographie

    Energy Technology Data Exchange (ETDEWEB)

    Duex, M. [Radiologische Klinik, Abteilung Radiodiagnostik der Ruprecht-Karls-Univ., Heidelberg (Germany); Bischoff, H.; Schmaehl, A.; Tuengerthal, S. [Roentgenabteilung der LVA Baden, Klinik fuer Thoraxerkrankungen, Heidelberg-Rohrbach (Germany)

    1997-07-01

    Purpose: To define the value of conventional radiography compared with CT in the follow-up of complicated, long-term tube drained pleural empyema after intracavitary application of contrast medium. Methods: 28 patients with complicated pleural empyema (stage III) and longterm tube drainage were submitted to fluoroscopy of the pleural cavity and a CT of the thorax after contrast medium had been instilled into the pleural space. Both examinations were judged by the following criteria: Number and morphology of pleural cavities, quality of drainage and accompanying thoracic disease. Results: 49 pleural cavities were diagnosed. Judgement of drainage corresponded in 79% of cases and differed 21% with proof of further not drained cavities only on CT. 4 bronchopleural fistulas were diagnosed by fluoroscopy, of which only 2 were evident on CT. Accompanying thoracic disease was reliably detected by CT only. Conclusions: Diagnosis of bronchopleural fistulas and judgement of the pleural drainage is best possible using fluoroscopy after application of contrast medium into the pleural space. CT is most accurate to detect further cavities that have not been drained, to look for concomitant thoracic disease, and to judge the morphology of the pleural cavity. Conventional radiography of the pleural space is effective and recommended to be used as a first line investigation for the follow-up of stage III empyemas. Patients in poor general condition (fever, elevated blood markers indicating inflammation) should be examined by both fluoroscopy and CT. (orig.) [Deutsch] Ziel: Untersuchung zur radiologischen Nachsorge komplizierter, langzeitdrainierter Thoraxempyeme mit Hilfe der Durchleuchtung gegenueber CT nach intrakavitaerer Kontrastmittelgabe. Methoden: 28 Patienten mit kompliziertem Thoraxempyem (Stadium III) und Langzeitdrainage erhielten nach Instillation von Kontrastmittel in die Pleurahoehle eine Thoraxdurchleuchtung und ein natives Thorax-CT. Beide Untersuchungen wurden nach

  4. Comparative evaluation of modified canal staining and clearing technique, cone-beam computed tomography, peripheral quantitative computed tomography, spiral computed tomography, and plain and contrast medium-enhanced digital radiography in studying root canal morphology.

    Science.gov (United States)

    Neelakantan, Prasanna; Subbarao, Chandana; Subbarao, Chandragiri V

    2010-09-01

    This study investigated the accuracy of cone-beam computed tomography (CBCT), peripheral quantitative computed tomography (pQCT), spiral computed tomography (SCT), plain (plain digi), and contrast medium-enhanced digital radiographs (contrast digi) in studying root canal morphology. The root canal anatomy was analyzed in 95 teeth using CBCT, pQCT, SCT, plain digi, and contrast digi. After flushing out the radiopaque dye, access cavities were sealed, and the teeth were subject to the modified canal staining and clearing technique. The number of root canals (Vertucci classification and Gulabivala's additional classes) was calculated by three calibrated endodontists and two maxillofacial radiologists. Erroneous or unsuccessful identifications of root canals were statistically analyzed by one-way analysis of variance (p = 0.05). The modified canal staining and clearing technique identified an average of 1.8 root canals per mandibular central incisor, 2.3 per maxillary first premolar, 3.9 per maxillary first molar, 3.8 per maxillary and mandibular second molar, and 4.3 per mandibular first molar. CBCT and pQCT were erroneous in 0.29% and 2.05% cases, whereas SCT, contrast digi, and plain digi were unsuccessful in 15.58%, 14.7%, and 23.8%, respectively. There was a significant difference between all the methods (p technique where there was no significant difference (p > 0.05). CBCT and pQCT were as accurate as the modified canal staining and tooth clearing technique in identifying root canal systems. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. Data on consistency among different methods to assess atherosclerotic plaque echogenicity on standard ultrasound and intraplaque neovascularization on contrast-enhanced ultrasound imaging in human carotid artery

    Directory of Open Access Journals (Sweden)

    Mattia Cattaneo

    2016-12-01

    Full Text Available Here we provide the correlation among different carotid ultrasound (US variables to assess echogenicity n standard carotid US and to assess intraplaque neovascularization on contrast enhanced US. We recruited 45 consecutive subjects with an asymptomatic≥50% carotid artery stenosis. Carotid plaque echogenicity at standard US was visually graded according to Gray–Weale classification (GW and measured by the greyscale median (GSM, a semi-automated computerized measurement performed by Adobe Photoshop®. On CEUS imaging IPNV was graded according to the visual appearance of contrast within the plaque according to three different methods: CEUS_A (1=absent; 2=present; CEUS_B a three-point scale (increasing IPNV from 1 to 3; CEUS_C a four-point scale (increasing IPNV from 0 to 3. We have also implemented a new simple quantification method derived from region of interest (ROI signal intensity ratio as assessed by QLAB software. Further information is available in “Contrast-enhanced ultrasound imaging of intraplaque neovascularization and its correlation to plaque echogenicity in human carotid arteries atherosclerosis (M. Cattaneo, D. Staub, A.P. Porretta, J.M. Gallino, P. Santini, C. Limoni et al., 2016 [1].

  6. Computer-based image analysis in radiological diagnostics and image-guided therapy 3D-Reconstruction, contrast medium dynamics, surface analysis, radiation therapy and multi-modal image fusion

    CERN Document Server

    Beier, J

    2001-01-01

    This book deals with substantial subjects of postprocessing and analysis of radiological image data, a particular emphasis was put on pulmonary themes. For a multitude of purposes the developed methods and procedures can directly be transferred to other non-pulmonary applications. The work presented here is structured in 14 chapters, each describing a selected complex of research. The chapter order reflects the sequence of the processing steps starting from artefact reduction, segmentation, visualization, analysis, therapy planning and image fusion up to multimedia archiving. In particular, this includes virtual endoscopy with three different scene viewers (Chap. 6), visualizations of the lung disease bronchiectasis (Chap. 7), surface structure analysis of pulmonary tumors (Chap. 8), quantification of contrast medium dynamics from temporal 2D and 3D image sequences (Chap. 9) as well as multimodality image fusion of arbitrary tomographical data using several visualization techniques (Chap. 12). Thus, the softw...

  7. Suction/Inspiration against resistance or standardized Mueller maneuver : a new breathing technique to improve contrast density within the pulmonary artery: a pilot CT study.

    Science.gov (United States)

    Gutzeit, Andreas; Froehlich, Johannes M; Wälti, Stephan; Roos, Justus E; Meissnitzer, Matthias; Hergan, Klaus; von Weymarn, Constantin; Czell, David; Goyen, Matthias; Reischauer, Carolin

    2015-11-01

    Our aim was to prospectively investigate whether the recently introduced suction/inspiration against resistance breathing method leads to higher computed tomography (CT) contrast density in the pulmonary artery compared to standard breathing. The present study was approved by the Medical Ethics committee and all subjects gave written informed consent. Fifteen patients, each without suspicious lung emboli, were randomly assigned to four different groups with different breathing maneuvers (suction against resistance, Valsalva, inspiration, expiration) during routine CT. Contrast enhancement in the central and peripheral sections of the pulmonary artery were measured and compared with one another. Peripheral enhancement during suction yielded increased mean densities of 138.14 Hounsfield units (HU) (p = 0.001), compared to Valsalva and a mean density of 67.97 HU superior to inspiration (p = 0.075). Finally, suction in comparison to expiration resulted in a mean increase of 30.51 HU (p = 0.42). Central parts of pulmonary arteries presented significantly increased enhancement values (95.74 HU) for suction versus the Valsalva technique (p = 0.020), while all other mean densities were in favour of suction (versus inspiration: p = 0.201; versus expiration: p = 0.790) without reaching significance. Suction/Inspiration against resistance is a promising technique to improve contrast density within pulmonary vessels, especially in the peripheral parts, in comparison to other breathing maneuvers. • Suction/Inspiration against resistance is promising to improve contrast density within the pulmonary artery. • Patients potentially suffering pulmonary embolism are able to follow suction/inspiration against resistance. • Contrast density after suction is superior in comparison to other breathing maneuvers.

  8. Contrast-enhanced computed tomography for the diagnosis of fatty liver: prospective study with same-day biopsy used as the reference standard

    International Nuclear Information System (INIS)

    Kim, Dae Yoon; Park, Seong Ho; Lee, Seung Soo; Kim, Hye Jin; Kim, So Yeon; Kim, Min-Young; Lee, Yedaun; Kim, Tae Kyoung; Khalili, Korosh; Bae, Mi Hyun; Lee, Joo Yeon; Lee, Sung-Gyu; Yu, Eun Sil

    2010-01-01

    Purpose: The study purpose was to prospectively determine the accuracy of contrast-enhanced CT in diagnosing fatty liver using same-day biopsy as the reference standard. One hundred seventy-nine potential living liver donors underwent unenhanced and portal-phase contrast-enhanced hepatic CT and subsequent liver biopsy on the same day. Attenuation difference between the liver and the spleen on unenhanced ( pre L-S) and contrast-enhanced ( post L-S) images and blood-subtracted hepatic attenuation on contrast-enhanced images ( post L-B), calculated by [L - 0.3 x (0.75 x P + 0.25 x A) ]/0.7 where L, P and A represent the attenuation of the liver, main portal vein and abdominal aorta, respectively, were obtained. The accuracy of these indices in diagnosing fatty liver according to various threshold levels, 5%-30% histological steatosis in increments of 5%, was compared using ROC analysis. The area under the ROC curve for pre L-S, post L-S and post L-B was 0.663-0.918, 0.712-0.847 and 0.821-0.923, respectively, depending on the threshold levels of hepatic steatosis. The accuracy of pre L-S and post L-S did not differ (P ≥ 0.054), despite a trend towards a lower accuracy with post L-S. post L-B yielded higher accuracy than pre L-S at threshold levels of 5% and 10% (P ≤ 0.002) and similar accuracy to pre L-S at the other threshold levels (P ≥ 0.144). Portal-phase contrast-enhanced CT has a similar, or even greater, accuracy than unenhanced CT in diagnosing fatty liver. (orig.)

  9. Contrast medium extravasation in intravenous urography

    International Nuclear Information System (INIS)

    Tosch, U.; Becker-Gaab, C.; Hahn, D.

    1984-01-01

    Aetiology and diagnostic procedure of calyceal fornix rupture during intravenous urography are discussed. In the literature the fornix rupture is discribed as a spontaneous event - not so in the four cases presented. In two cases a sudden increase in intrapelvic pressure was due to an ureteric calculus, in the other cases an obstruction of the ureter was secondary to neoplasm. It is recommended to perform a CT as soon as a contrastmedium extravasation in intravenous urography is diagnosed. (orig.) [de

  10. Suction/inspiration against resistance or standardized Mueller maneuver: a new breathing technique to improve contrast density within the pulmonary artery: a pilot CT study

    International Nuclear Information System (INIS)

    Gutzeit, Andreas; Froehlich, Johannes M.; Weymarn, Constantin von; Goyen, Matthias; Waelti, Stephan; Roos, Justus E.; Meissnitzer, Matthias; Hergan, Klaus; Czell, David; Reischauer, Carolin

    2015-01-01

    Our aim was to prospectively investigate whether the recently introduced suction/inspiration against resistance breathing method leads to higher computed tomography (CT) contrast density in the pulmonary artery compared to standard breathing. The present study was approved by the Medical Ethics committee and all subjects gave written informed consent. Fifteen patients, each without suspicious lung emboli, were randomly assigned to four different groups with different breathing maneuvers (suction against resistance, Valsalva, inspiration, expiration) during routine CT. Contrast enhancement in the central and peripheral sections of the pulmonary artery were measured and compared with one another. Peripheral enhancement during suction yielded increased mean densities of 138.14 Hounsfield units (HU) (p = 0.001), compared to Valsalva and a mean density of 67.97 HU superior to inspiration (p = 0.075). Finally, suction in comparison to expiration resulted in a mean increase of 30.51 HU (p = 0.42). Central parts of pulmonary arteries presented significantly increased enhancement values (95.74 HU) for suction versus the Valsalva technique (p = 0.020), while all other mean densities were in favour of suction (versus inspiration: p = 0.201; versus expiration: p = 0.790) without reaching significance. Suction/Inspiration against resistance is a promising technique to improve contrast density within pulmonary vessels, especially in the peripheral parts, in comparison to other breathing maneuvers. (orig.)

  11. Suction/inspiration against resistance or standardized Mueller maneuver: a new breathing technique to improve contrast density within the pulmonary artery: a pilot CT study

    Energy Technology Data Exchange (ETDEWEB)

    Gutzeit, Andreas [Paracelsus Medical University Salzburg, Department of Radiology, Salzburg (Austria); Hirslanden Hospital St. Anna, Institute of Radiology and Nuclear Medicine, Clinical Research Unit, Lucerne (Switzerland); Kantonsspital Winterthur, Department of Radiology, Winterthur (Switzerland); Froehlich, Johannes M.; Weymarn, Constantin von; Goyen, Matthias [Hirslanden Hospital St. Anna, Institute of Radiology and Nuclear Medicine, Clinical Research Unit, Lucerne (Switzerland); Waelti, Stephan [Cantonal Hospital St. Gallen, Department of Radiology and Nuclear Medicine, St. Gallen (Switzerland); Roos, Justus E. [Duke University Medical Center, Department of Radiology, Durham, NC (United States); Meissnitzer, Matthias; Hergan, Klaus [Paracelsus Medical University Salzburg, Department of Radiology, Salzburg (Austria); Czell, David [Cantonal Hospital Winterthur, Department of Neurology, Winterthur (Switzerland); Reischauer, Carolin [Paracelsus Medical University Salzburg, Department of Radiology, Salzburg (Austria); Hirslanden Hospital St. Anna, Institute of Radiology and Nuclear Medicine, Clinical Research Unit, Lucerne (Switzerland)

    2015-11-15

    Our aim was to prospectively investigate whether the recently introduced suction/inspiration against resistance breathing method leads to higher computed tomography (CT) contrast density in the pulmonary artery compared to standard breathing. The present study was approved by the Medical Ethics committee and all subjects gave written informed consent. Fifteen patients, each without suspicious lung emboli, were randomly assigned to four different groups with different breathing maneuvers (suction against resistance, Valsalva, inspiration, expiration) during routine CT. Contrast enhancement in the central and peripheral sections of the pulmonary artery were measured and compared with one another. Peripheral enhancement during suction yielded increased mean densities of 138.14 Hounsfield units (HU) (p = 0.001), compared to Valsalva and a mean density of 67.97 HU superior to inspiration (p = 0.075). Finally, suction in comparison to expiration resulted in a mean increase of 30.51 HU (p = 0.42). Central parts of pulmonary arteries presented significantly increased enhancement values (95.74 HU) for suction versus the Valsalva technique (p = 0.020), while all other mean densities were in favour of suction (versus inspiration: p = 0.201; versus expiration: p = 0.790) without reaching significance. Suction/Inspiration against resistance is a promising technique to improve contrast density within pulmonary vessels, especially in the peripheral parts, in comparison to other breathing maneuvers. (orig.)

  12. MDCT for suspected acute appendicitis in adults: impact of oral and IV contrast media at standard-dose and simulated low-dose techniques.

    Science.gov (United States)

    Keyzer, Caroline; Cullus, Pierre; Tack, Denis; De Maertelaer, Viviane; Bohy, Pascale; Gevenois, Pierre Alain

    2009-11-01

    The objective of this study was to prospectively investigate the influence of oral, IV, and oral and IV contrast media on the information provided by MDCT at standard and simulated low radiation doses in adults suspected of having acute appendicitis. One hundred thirty-one consecutive patients (80 women, 51 men; age range, 18-87 years; mean age, 37 years) suspected of having appendicitis were randomly assigned to either ingest or not ingest iodinated contrast material. Thereafter, all patients underwent IV unenhanced and enhanced abdominopelvic MDCT with a 4 x 2.5 mm collimation at 120 kVp and 100 mAs(eff). Dose reduction corresponding to 30 mAs(eff) was simulated. Two radiologists independently read scans during separate sessions, assessed appendix visualization, and proposed a diagnosis (i.e., appendicitis or an alternative diagnosis). The final diagnosis was based on either surgical findings or clinical follow-up. Data were analyzed by factorial analysis of multiple correspondences followed by an ascending hierarchic classification method. Factorial analysis and ascending hierarchic classification revealed that, in terms of diagnostic correctness, reader influence predominated over the influence of IV and oral contrast media use and radiation dose but that correctness was also influenced by the patient's sex (p = 0.048) and was lower in cases of alternative diseases (p technique.

  13. Effect of reduced x-ray tube voltage, low iodine concentration contrast medium, and sinogram-affirmed iterative reconstruction on image quality and radiation dose at coronary CT angiography: results of the prospective multicenter REALISE trial.

    Science.gov (United States)

    Yin, Wei-Hua; Lu, Bin; Gao, Jian-Bo; Li, Pei-Ling; Sun, Kai; Wu, Zhi-Feng; Yang, Wen-Jie; Zhang, Xiao-Qin; Zheng, Min-Wen; McQuiston, Andrew D; Meinel, Felix G; Schoepf, Uwe Joseph

    2015-01-01

    Both low tube voltage and sinogram-affirmed iterative reconstruction (IR) techniques hold promise to decrease radiation dose at coronary CT angiography (CCTA). The increased iodine contrast at low tube voltage allows for minimizing iodine load. To assess the effect of reduced x-ray tube voltage, low iodine concentration contrast medium and IR on image quality and radiation dose at CCTA. Two hundred thirty-one consecutive patients with suspected coronary artery disease were enrolled in this prospective, multicenter trial and randomized to 1 of 2 dual-source CCTA protocols: 120-kVp with 370 mgI/mL iopromide or iopamidol (n = 116; 44 women; 55.3 ± 9.8 years) or 100 kVp with 270 mgI/mL iodixanol (n = 115; 48 women; 54.2 ± 10.4 years). Reconstruction was performed with filtered back projection and IR. Attenuation, image noise, signal-to-noise ratio, and contrast-to-noise ratio were measured and image quality scored. Size-specific dose estimates and effective doses were calculated. There were no significant differences in mean arterial attenuation (406.6 ± 76.7 vs 409.7 ± 65.2 Hounsfield units; P = .739), image noise (18.7 ± 3.8 vs 17.9 ± 3.4 Hounsfield units; P = .138), signal-to-noise ratio (22.5 ± 5.4 vs 23.7 ± 6.1; P = .126), contrast-to-noise ratio (17.5 ± 5.5 vs 18.3 ± 6.1; P = .286), or image quality scores (4.1 ± 0.9 vs 4.0 ± 0.9; P > .05) between 120-kVp filtered back projection-reconstructed and 100-kVp IR-reconstructed series. Mean iodine dose was 26.5% lower (18.3 ± 0.5 vs 24.9 ± 0.9 g; P x-ray tube voltage and IR allows for decreasing the iodine load and effective radiation dose at CCTA while maintaining image quality. Copyright © 2015 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

  14. Dynamic contrast-enhanced MR imaging in predicting progression of enhancing lesions persisting after standard treatment in glioblastoma patients: a prospective study

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Roh-Eul; Choi, Hye Jeong; You, Sung-Hye; Kang, Koung Mi; Yun, Tae Jin; Kim, Ji-Hoon; Sohn, Chul-Ho [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Choi, Seung Hong [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University, Center for Nanoparticle Research, Institute for Basic Science, and School of Chemical and Biological Engineering, Seoul (Korea, Republic of); Seoul National University, School of Chemical and Biological Engineering, Seoul (Korea, Republic of); Kim, Tae Min [Seoul National University College of Medicine, Department of Internal Medicine, Cancer Research Institute, Seoul (Korea, Republic of); Park, Chul-Kee [Seoul National University College of Medicine, Department of Neurosurgery, Biomedical Research Institute, Seoul (Korea, Republic of); Park, Sung-Hye; Won, Jae-Kyung [Seoul National University College of Medicine, Department of Pathology, Seoul (Korea, Republic of); Kim, Il Han [Seoul National University College of Medicine, Department of Radiation Oncology, Cancer Research Institute, Seoul (Korea, Republic of); Lee, Soon Tae [Seoul National University College of Medicine, Department of Neurology, Seoul (Korea, Republic of)

    2017-08-15

    To prospectively explore the value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in predicting the progression of enhancing lesions persisting after standard treatment in patients with surgically resected glioblastoma (GBM). Forty-seven GBM patients, who underwent near-total tumorectomy followed by concurrent chemoradiation therapy (CCRT) with temozolomide (TMZ) between May 2014 and February 2016, were enrolled. Twenty-four patients were finally analyzed for measurable enhancing lesions persisting after standard treatment. DCE-MRI parameters were calculated at enhancing lesions. Mann-Whitney U tests and multivariable stepwise logistic regression were used to compare parameters between progression (n = 16) and non-progression (n = 8) groups. Mean K{sup trans} and v{sub e} were significantly lower in progression than in non-progression (P = 0.037 and P = 0.037, respectively). The 5th percentile of the cumulative K{sup trans} histogram was also significantly lower in the progression than in non-progression group (P = 0.017). Mean v{sub e} was the only independent predictor of progression (P = 0.007), with a sensitivity of 100%, specificity of 63%, and an overall accuracy of 88% at a cut-off value of 0.873. DCE-MRI may help predict the progression of enhancing lesions persisting after the completion of standard treatment in patients with surgically resected GBM, with mean v{sub e} serving as an independent predictor of progression. (orig.)

  15. Dynamic contrast-enhanced MR imaging in predicting progression of enhancing lesions persisting after standard treatment in glioblastoma patients: a prospective study

    International Nuclear Information System (INIS)

    Yoo, Roh-Eul; Choi, Hye Jeong; You, Sung-Hye; Kang, Koung Mi; Yun, Tae Jin; Kim, Ji-Hoon; Sohn, Chul-Ho; Choi, Seung Hong; Kim, Tae Min; Park, Chul-Kee; Park, Sung-Hye; Won, Jae-Kyung; Kim, Il Han; Lee, Soon Tae

    2017-01-01

    To prospectively explore the value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in predicting the progression of enhancing lesions persisting after standard treatment in patients with surgically resected glioblastoma (GBM). Forty-seven GBM patients, who underwent near-total tumorectomy followed by concurrent chemoradiation therapy (CCRT) with temozolomide (TMZ) between May 2014 and February 2016, were enrolled. Twenty-four patients were finally analyzed for measurable enhancing lesions persisting after standard treatment. DCE-MRI parameters were calculated at enhancing lesions. Mann-Whitney U tests and multivariable stepwise logistic regression were used to compare parameters between progression (n = 16) and non-progression (n = 8) groups. Mean K trans and v e were significantly lower in progression than in non-progression (P = 0.037 and P = 0.037, respectively). The 5th percentile of the cumulative K trans histogram was also significantly lower in the progression than in non-progression group (P = 0.017). Mean v e was the only independent predictor of progression (P = 0.007), with a sensitivity of 100%, specificity of 63%, and an overall accuracy of 88% at a cut-off value of 0.873. DCE-MRI may help predict the progression of enhancing lesions persisting after the completion of standard treatment in patients with surgically resected GBM, with mean v e serving as an independent predictor of progression. (orig.)

  16. Contrast-enhanced digital mammography

    Energy Technology Data Exchange (ETDEWEB)

    Dromain, Clarisse [Department of Radiology, Institut Gustave-Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France)], E-mail: dromain@igr.fr; Balleyguier, Corinne; Adler, Ghazal [Department of Radiology, Institut Gustave-Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France); Garbay, Jean Remi [Department of Surgery, Institut Gustave-Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France); Delaloge, Suzette [Department of Medicine, Institut Gustave-Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France)

    2009-01-15

    CEDM is a recent development of digital mammography using the intra-venous injection of an iodinated contrast agent in conjunction with a mammography examination. Two techniques have been developed to perform CEDM examinations: the temporal subtraction technique with acquisition of high-energy images before and after contrast medium injection and the dual energy technique with acquisition of a pair of low and high-energy images only after contrast medium injection. The temporal subtraction technique offered the possibility to analyze the kinetic curve of enhancement of breast lesions, similarly to breast MRI. The dual energy technique do not provide information about the kinetic of tumor enhancement but allows the acquisition of multiples views of the same breast or bilateral examination and is less sensitive to patient motion than temporal CEDM. Initial clinical experience has shown the ability of CEDM to map the distribution of neovasculature induced by cancer using mammography. Moreover, previous studies have shown a superiority of MX + CEDM, either for the assessment of the probability of malignancy than for BIRADS assessment comparing to MX alone. The potential clinical applications are the clarification of mammographically equivocal lesions, the detection of occult lesions on standard mammography, particularly in dense breast, the determination of the extent of disease, the assessment of recurrent disease and the monitoring of the response to chemotherapy. CEDM should result in a simple way to enhance the detection and the characterization of breast lesions.

  17. Value of 100 kVp scan with sinogram-affirmed iterative reconstruction algorithm on a single-source CT system during whole-body CT for radiation and contrast medium dose reduction: an intra-individual feasibility study.

    Science.gov (United States)

    Nagayama, Y; Nakaura, T; Oda, S; Tsuji, A; Urata, J; Furusawa, M; Tanoue, S; Utsunomiya, D; Yamashita, Y

    2018-02-01

    To perform an intra-individual investigation of the usefulness of a contrast medium (CM) and radiation dose-reduction protocol using single-source computed tomography (CT) combined with 100 kVp and sinogram-affirmed iterative reconstruction (SAFIRE) for whole-body CT (WBCT; chest-abdomen-pelvis CT) in oncology patients. Forty-three oncology patients who had undergone WBCT under both 120 and 100 kVp protocols at different time points (mean interscan intervals: 98 days) were included retrospectively. The CM doses for the 120 and 100 kVp protocols were 600 and 480 mg iodine/kg, respectively; 120 kVp images were reconstructed with filtered back-projection (FBP), whereas 100 kVp images were reconstructed with FBP (100 kVp-F) and the SAFIRE (100 kVp-S). The size-specific dose estimate (SSDE), iodine load and image quality of each protocol were compared. The SSDE and iodine load of 100 kVp protocol were 34% and 21%, respectively, lower than of 120 kVp protocol (SSDE: 10.6±1.1 versus 16.1±1.8 mGy; iodine load: 24.8±4versus 31.5±5.5 g iodine, pquality. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  18. Prospective evaluation of reduced dose computed tomography for the detection of low-contrast liver lesions. Direct comparison with concurrent standard dose imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pooler, B.D.; Lubner, Meghan G.; Kim, David H.; Chen, Oliver T. [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States); Li, Ke; Chen, Guang-Hong [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States); University of Wisconsin School of Medicine and Public Health, Department of Medical Physics, Madison, WI (United States); Pickhardt, Perry J. [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States); University of Wisconsin School of Medicine and Public Health, E3/311 Clinical Science Center, Department of Radiology, Madison, WI (United States)

    2017-05-15

    To prospectively compare the diagnostic performance of reduced-dose (RD) contrast-enhanced CT (CECT) with standard-dose (SD) CECT for detection of low-contrast liver lesions. Seventy adults with non-liver primary malignancies underwent abdominal SD-CECT immediately followed by RD-CECT, aggressively targeted at 60-70 % dose reduction. SD series were reconstructed using FBP. RD series were reconstructed with FBP, ASIR, and MBIR (Veo). Three readers - blinded to clinical history and comparison studies - reviewed all series, identifying liver lesions ≥4 mm. Non-blinded review by two experienced abdominal radiologists - assessing SD against available clinical and radiologic information - established the reference standard. RD-CECT mean effective dose was 2.01 ± 1.36 mSv (median, 1.71), a 64.1 ± 8.8 % reduction. Pooled per-patient performance data were (sensitivity/specificity/PPV/NPV/accuracy) 0.91/0.78/0.60/0.96/0.81 for SD-FBP compared with RD-FBP 0.79/0.75/0.54/0.91/0.76; RD-ASIR 0.84/0.75/0.56/0.93/0.78; and RD-MBIR 0.84/0.68/0.49/0.92/0.72. ROC AUC values were 0.896/0.834/0.858/0.854 for SD-FBP/RD-FBP/RD-ASIR/RD-MBIR, respectively. RD-FBP (P = 0.002) and RD-MBIR (P = 0.032) AUCs were significantly lower than those of SD-FBP; RD-ASIR was not (P = 0.052). Reader confidence was lower for all RD series (P < 0.001) compared with SD-FBP, especially when calling patients entirely negative. Aggressive CT dose reduction resulted in inferior diagnostic performance and reader confidence for detection of low-contrast liver lesions compared to SD. Relative to RD-ASIR, RD-FBP showed decreased sensitivity and RD-MBIR showed decreased specificity. (orig.)

  19. A survey of contrast media used in coronary angiograph

    International Nuclear Information System (INIS)

    Weikl, A.; Hubmann, M.

    1982-01-01

    In recent years, various contrast media have been developed for use in coronary angiography. These contrast media may be divided into ionic contrast media of high osmolality, those of low osmolality, and nonionic contrast materials. We conducted our own clinical studies with 40 patients. In random succession a standard contrast medium (ionic, of high osmolality) and a new-generation contrast medium (either nonionic or ionic with low osmolality) were injected into the right and left coronary arteries. After each injection we measured the systolic and diastolic blood pressure using a liquid-filled coronary catheter. In addition, the change in the length of the cardiac cycle was registered in terms of the R-R interval (in ms) and at the same time, leads I, II, and III of the ECG were recorded. We studied the influence of the various contrast media on the activity of ATPase in in vitro experiments, using Lasser and Lang's. When ionic contrast media of low osmolality and nonionic contrast media were utilized the heart rate showed no change. Disturbances of rhythm such as ventricular tachycardia or fibrillation were not observed. All of the contrast media used produced the same ECG changes. These changes can be ascribed to the inhibition of ATPase. The arterial blood pressure was lowered significantly only by ionic contrast media of high osmolality only. (orig.)

  20. A randomized controlled trial comparing hydration therapy to additional hemodialysis or N-acetylcysteine for the prevention of contrast medium-induced nephropathy: the Dialysis-versus-Diuresis (DVD) Trial.

    Science.gov (United States)

    Reinecke, H; Fobker, M; Wellmann, J; Becke, B; Fleiter, J; Heitmeyer, C; Breithardt, G; Hense, H-W; Schaefer, R M

    2007-03-01

    Contrast medium-induced nephropathy (CIN) is a serious complication with increasing frequency and an unfavorable prognosis. Previous analyses of surrogate parameters have suggested beneficial effects of hemodialysis that are assessed in this randomized clinical trial. We performed a prospective single-center trial in 424 consecutive patients with serum creatinine concentrations between 1.3- 3.5 mg/dl who underwent elective coronary angiography. Patients were randomized to one of three treatment strategies with all patients receiving pre- and postprocedural hydration: One group received no additional therapy, patients in the second group were hemodialyzed once, and the third group received oral N-acetylcysteine. The frequency of CIN (defined as an increase in serum creatinine>or=0.5 mg/dl) from 48 to 72 h after catheterization was 6.1% in the hydration-only group, 15.9% with hemodialysis treatment, and 5.3% in the N-ACC group (intention-to-treat analysis; P=0.008). There were no differences between the treatment groups with regard to increased (>or=0.5 mg/dl) serum creatinine concentrations after 30-60 days (4.8%, 5.1%, and 3.1%, respectively; P=0.700). Analyses of long-term follow-up (range 63 to 1316 days) by Cox regressions models of the study groups found quite similar survival rates (P=0.500). In contrast to other (retrospective) studies, long-term survival of patients with vs those without CIN within 72 h was not different, but patients who still had elevated creatinine concentrations at 30-60 days suffered from a markedly higher 2-year mortality (46% vs 17%, P=0.002). In conclusion, hemodialysis in addition to hydration therapy for the prevention of CIN provided no evidence for any outcome benefit but evidence for probable harm. Increased creatinine concentrations at 30-60 days, but not within 72 h, were associated with markedly reduced long-term survival.

  1. Short-Term High-Dose Vitamin E to Prevent Contrast Medium-Induced Acute Kidney Injury in Patients With Chronic Kidney Disease Undergoing Elective Coronary Angiography: A Randomized Placebo-Controlled Trial.

    Science.gov (United States)

    Rezaei, Yousef; Khademvatani, Kamal; Rahimi, Behzad; Khoshfetrat, Mehran; Arjmand, Nasim; Seyyed-Mohammadzad, Mir-Hossein

    2016-03-15

    Contrast medium-induced acute kidney injury (CIAKI) is a leading cause of acquired renal impairment. The effects of antioxidants have been conflicting regarding the prevention of CIAKI. We performed a study of vitamin E use to decrease CIAKI in patients undergoing elective coronary angiography. In a placebo-controlled randomized trial at 2 centers in Iran, 300 patients with chronic kidney disease-defined as estimated glomerular filtration rate vitamin E 12 hours before plus 400 mg vitamin E 2 hours before coronary angiography or to receive placebo. The primary end point was the development of CIAKI, defined as an increase ≥0.5 mg/dL or ≥25% in serum creatinine that peaked within 72 hours. Based on an intention-to-treat analysis, CIAKI developed in 10 (6.7%) and 21 (14.1%) patients in the vitamin E and placebo groups, respectively (P=0.037). Change in white blood cell count from baseline to peak value was greater in the vitamin E group compared with the placebo group (-500 [-1500 to 200] versus 100 [-900 to 600]×10(3)/mL, P=0.001). In multivariate analysis, vitamin E (odds ratio 0.408, 95% CI 0.170-0.982, P=0.045) and baseline Mehran score (odds ratio 1.257, 95% CI 1.007-1.569; P=0.043) predicted CIAKI. Prophylactic short-term high-dose vitamin E combined with 0.9% saline infusion is superior to placebo for prevention of CIAKI in patients undergoing elective coronary angiography. URL: https://www.clinicaltrials.gov/. Unique identifier: NCT02070679. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  2. Aspiration of Barium Contrast

    OpenAIRE

    Fuentes Santos, Cristina; Steen, Bárbara

    2014-01-01

    The aspiration of barium contrast is a rare complication that may occur during studies of the digestive tract. Barium is an inert material that can cause anywhere from an asymptomatic mechanical obstruction to serious symptoms of respiratory distress that can result in patient death. We present the case of a 79-year-old male patient in whom we observed the presence of contrast medium residue in the lung parenchyma as an incidental finding during hospitalization. When the patient’s medical fil...

  3. Cryo-scanning electron microscopy (Cryo-SEM) of semen frozen in medium-straws from good and sub-standard freezer AI-boars.

    Science.gov (United States)

    Hernández, Marta; Ekwall, Hans; Roca, Jordi; Vazquez, Juan Maria; Martinez, Emilio; Rodríguez-Martínez, Heriberto

    2007-02-01

    A major limiting factor for commercial cryopreservation of boar semen for artificial insemination (AI) is the large individual variation to cooling, where the degree of cell dehydration during ice (re)shaping seems to play a major role. This study investigated, in the frozen state, the degree of dehydration and ice crystal distribution in boar semen doses whose spermatozoa displayed different viability after thawing. Cross-sectioned medium-straws (0.5 mL, n=10) from a total of 10 stud boars classified as "good"(n=5) or sub-standard (e.g., "bad" freezers, n=5) by conventional analyses (computer assisted motility and sperm viability) were examined by Cryo-scanning electron microscopy (Cryo-SEM) to determine whether differences between groups could be already distinguishable prior to thawing. The degree of hydration was monitored in relation to the areas of ice crystal formed extracellularly (lakes), the areas of frozen, concentrated extender (veins) where spermatozoa were located and the degree of compartmentalization (number of lakes) present. Irrespectively of the region studied, the gradient of main dehydration (as lakes) observed along the cross-section area of the straws was very irregular. Most spermatozoa were enclosed in the freezing extender matrix and no obvious signs of external membrane damage were observed. None of the Cryo-SEM variables significantly correlated with post-thaw sperm parameters (p>0.05). However, we identified significant differences (p<0.0001) among boars for all ultrastructure variables studied, including the size of the veins, where differences in solute concentration is expected. We concluded that despite the large variability in ice crystal formation during the conventional freezing process among boars, this is unrelated to inter-boar post-thaw sperm differences.

  4. Micropropagation of dahlia in static liquid medium using slow-release tools of medium ingredients

    NARCIS (Netherlands)

    Klerk, de G.J.M.; Brugge, ter J.

    2011-01-01

    Growth of dahlia shoots in vitro was ca. 4 times faster in liquid medium than on solidified medium. In liquid standard medium (3% sucrose, macroelements according to Driver–Kuniyuki Walnut medium, microelements according to Murashige–Skoog medium, 0.44 µM benzylaminopurine), the major medium

  5. Prognosis prediction of non-enhancing T2 high signal intensity lesions in glioblastoma patients after standard treatment: application of dynamic contrast-enhanced MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Rihyeon; Yun, Tae Jin; Kim, Ji-Hoon; Sohn, Chul-Ho [Seoul National University Hospital, Department of Radiology, 101 Daehak-ro, Jongno-gu, Seoul (Korea, Republic of); Choi, Seung Hong [Seoul National University Hospital, Department of Radiology, 101 Daehak-ro, Jongno-gu, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, 103 Daehak-ro, Jongno-gu, Seoul (Korea, Republic of); Seoul National University, Center for Nanoparticle Research, Institute for Basic Science (IBS), Daehak-dong, Gwanak-gu, Seoul (Korea, Republic of); Seoul National University, School of Chemical and Biological Engineering, Daehak-dong, Gwanak-gu, Seoul (Korea, Republic of); Lee, Soon-Tae [Seoul National University Hospital, Department of Neurology, Seoul (Korea, Republic of); Park, Chul-Kee [Seoul National University Hospital, Department of Neurosurgery, Seoul (Korea, Republic of); Kim, Tae Min [Seoul National University Hospital, Department of Internal Medicine, Seoul (Korea, Republic of); Park, Sun-Won [Seoul National University College of Medicine, Department of Radiology, SMG-SNU Boramae Medical Center, Seoul (Korea, Republic of); Park, Sung-Hye [Seoul National University Hospital, Department of Pathology, Seoul (Korea, Republic of); Kim, Il Han [Seoul National University Hospital, Department of Radiation Oncology, Seoul (Korea, Republic of)

    2017-03-15

    To identify candidate imaging biomarkers for early disease progression in glioblastoma multiforme (GBM) patients by analysis of dynamic contrast-enhanced (DCE) MR parameters of non-enhancing T2 high signal intensity (SI) lesions. Forty-nine GBM patients who had undergone preoperative DCE MR imaging and received standard treatment were retrospectively included. According to the Response Assessment in Neuro-Oncology criteria, patients were classified into progression (n = 21) or non-progression (n = 28) groups. We analysed the pharmacokinetic parameters of Ktrans, Ve and Vp within non-enhancing T2 high SI lesions of each tumour. The best percentiles of each parameter from cumulative histograms were identified by the area under the receiver operating characteristic curve (AUC) and were compared using multivariate stepwise logistic regression. For the differentiation of early disease progression, the highest AUC values were found in the 99th percentile of Ktrans (AUC 0.954), the 97th percentile of Ve (AUC 0.815) and the 94th percentile of Vp (AUC 0.786) (all p < 0.05). The 99th percentile of Ktrans was the only significant independent variable from the multivariate stepwise logistic regression (p = 0.002). We found that the Ktrans of non-enhancing T2 high SI lesions in GBM patients holds potential as a candidate prognostic marker in future prospective studies. (orig.)

  6. Spiegel. Medium. Kunst

    DEFF Research Database (Denmark)

    Kacunko, Slavko

    and cultural perspective. From 1800 on, the great incentive was to push forward the material-physical and optical-mechanical and especially the media ‘exploitation’ of the mirror. The significance of the mirror as a central meta-medium of the visual emerged in a particularly striking way in the late 1830s....... That ricochets through media theory, theories of art and culture and through cultural historiography. A repository is one thing, a transmitter another: the distinction will act crucially on the quest for appropriate perspectives and classifications of what in terms of disciplines would rather appear...... or as synaesthesia gone mute. It stands in contrast with the mirror, which assumes the status of a medium facility or meta-medium of visual transference, encountering its only medial and operative limitation within the analogue or digital repository media. The present proposal for an artistic and cultural history...

  7. Contrast Materials

    Science.gov (United States)

    ... a red blood cell— and have a high degree of "echogenicity", or ability to reflect ultrasound waves. ... and radiologist to understand the potential risks and benefits of the contrast-enhanced scan. For MR imaging, ...

  8. Aspiration of Barium Contrast

    Directory of Open Access Journals (Sweden)

    Cristina Fuentes Santos

    2014-01-01

    Full Text Available The aspiration of barium contrast is a rare complication that may occur during studies of the digestive tract. Barium is an inert material that can cause anywhere from an asymptomatic mechanical obstruction to serious symptoms of respiratory distress that can result in patient death. We present the case of a 79-year-old male patient in whom we observed the presence of contrast medium residue in the lung parenchyma as an incidental finding during hospitalization. When the patient’s medical file was reviewed, images were found of a barium swallow study that the patient had undergone months earlier, and we were able to observe the exact moment of the aspiration of the contrast material. The patient had been asymptomatic since the test.

  9. Comparison of neutral and positive enteral contrast media for MDCT enteroclysis

    International Nuclear Information System (INIS)

    Aiyappan, Senthil Kumar; Kalra, Naveen; Sandhu, Manavjit Singh; Kochhar, Rakesh; Wig, Jai Dev; Khandelwal, Niranjan

    2012-01-01

    Objective: To compare neutral and positive enteral contrast media for MDCT enteroclysis (MDCTE) in various small bowel diseases. Materials and methods: 40 patients with suspicion of small bowel diseases were divided randomly into two equal groups. In one group, water was used as neutral enteral contrast and in other group, 2% water soluble iodinated contrast was used as positive enteral contrast. All MDCTE were done on a 16-slice multidetector row CT unit. The findings of MDCTE were compared with the standards of reference. Results: There were 12 cases of abdominal tuberculosis (30%), 5 cases of bowel masses (12%), 4 cases of Crohn's disease (10%), 3 cases of small bowel adhesions (7%), 2 cases of midgut volvulus (5%), 2 cases of segmental enteritis (5%) and 12 of all cases (30%) were normal. There was no statistically significant difference between neutral and positive enteral contrast with regards to bowel distention, contrast reflux and evaluation of duodenum. Abnormal bowel wall enhancement was appreciated only with use of neutral enteral contrast (n = 12). Evaluation of ileocaecal junction was possible in all 20 patients (100%) with positive enteral contrast but in only 17 patients (85%) with neutral enteral contrast. Overall sensitivity and specificity of MDCTE with use of neutral contrast medium (100 and 88% respectively) was greater for evaluation of small bowel diseases, when compared to MDCTE using positive enteral contrast medium (92.8 and 83.3% respectively). Conclusions: Water is a good enteral contrast medium for MDCT enteroclysis examination and allows better evaluation of abnormal bowel wall enhancement. Ileocaecal junction evaluation is better with positive enteral contrast medium.

  10. Problems and Opportunities of an International Financial Reporting Standard for Small and Medium-sized Entities. The EAA FRSC's Comment on the IASB's Discussion Paper

    DEFF Research Database (Denmark)

    Thinggaard, Frank; Evans, Lisa; Gebhardt, Günther

    2005-01-01

    and questions arising from this. This paper briefly introduces the background to the publication of the Discussion Paper. This is followed by a review of prior litterature on SME financial reporting implications, prepared by the European Accountin Association's Financial Reporting Standards Committee...

  11. Shift from National Reporting to Reporting in Accordance with International Financial Reporting Standard for Small and Medium-sized Entities and Its Effect on Financial Management – the Case of the Czech Republic

    OpenAIRE

    Struhařová, Kateřina

    2010-01-01

    The aim of this paper is to evaluate the effect of the shift from Financial Reporting under the Czech legislature (CZ GAAP) to the International Financial Reporting Standard for financial management in Small and Medium-sized Enterprises (IFRS for SMEs). The reasons for the shift and major differences between CZ GAAP and IFRS for SMEs are mentioned, as well as the changes relevant to the shift. Not only changes in accounting departments are defined but also the changes that affect a company as...

  12. Novel Modeling of Task vs. Rest Brain State Predictability Using a Dynamic Time Warping Spectrum: Comparisons and Contrasts with Other Standard Measures of Brain Dynamics.

    Science.gov (United States)

    Dinov, Martin; Lorenz, Romy; Scott, Gregory; Sharp, David J; Fagerholm, Erik D; Leech, Robert

    2016-01-01

    Dynamic time warping, or DTW, is a powerful and domain-general sequence alignment method for computing a similarity measure. Such dynamic programming-based techniques like DTW are now the backbone and driver of most bioinformatics methods and discoveries. In neuroscience it has had far less use, though this has begun to change. We wanted to explore new ways of applying DTW, not simply as a measure with which to cluster or compare similarity between features but in a conceptually different way. We have used DTW to provide a more interpretable spectral description of the data, compared to standard approaches such as the Fourier and related transforms. The DTW approach and standard discrete Fourier transform (DFT) are assessed against benchmark measures of neural dynamics. These include EEG microstates, EEG avalanches, and the sum squared error (SSE) from a multilayer perceptron (MLP) prediction of the EEG time series, and simultaneously acquired FMRI BOLD signal. We explored the relationships between these variables of interest in an EEG-FMRI dataset acquired during a standard cognitive task, which allowed us to explore how DTW differentially performs in different task settings. We found that despite strong correlations between DTW and DFT-spectra, DTW was a better predictor for almost every measure of brain dynamics. Using these DTW measures, we show that predictability is almost always higher in task than in rest states, which is consistent to other theoretical and empirical findings, providing additional evidence for the utility of the DTW approach.

  13. Novel modeling of task versus rest brain state predictability using a dynamic time warping spectrum: comparisons and contrasts with other standard measures of brain dynamics

    Directory of Open Access Journals (Sweden)

    Martin eDinov

    2016-05-01

    Full Text Available Dynamic time warping, or DTW, is a powerful and domain-general sequence alignment method for computing a similarity measure. Such dynamic programming-based techniques like DTW are now the backbone and driver of most bioinformatics methods and discoveries. In neuroscience it has had far less use, though this has begun to change. We wanted to explore new ways of applying DTW, not simply as a measure with which to cluster or compare similarity between features but in a conceptually different way. We have used DTW to provide a more interpretable spectral description of the data, compared to standard approaches such as the Fourier and related transforms. The DTW approach and standard discrete Fourier transform (DFT are assessed against benchmark measures of neural dynamics. These include EEG microstates, EEG avalanches and the sum squared error (SSE from a multilayer perceptron (MLP prediction of the EEG timeseries, and simultaneously acquired FMRI BOLD signal. We explored the relationships between these variables of interest in an EEG-FMRI dataset acquired during a standard cognitive task, which allowed us to explore how DTW differentially performs in different task settings. We found that despite strong correlations between DTW and DFT-spectra, DTW was a better predictor for almost every measure of brain dynamics. Using these DTW measures, we show that predictability is almost always higher in task than in rest states, which is consistent to other theoretical and empirical findings, providing additional evidence for the utility of the DTW approach.

  14. Quantification of pulmonary regurgitation in patients with repaired Tetralogy of Fallot by 2D phase-contrast MRI: Differences between the standard method of velocity averaging and a pixel-wise analysis.

    Science.gov (United States)

    Sotelo, Julio; Bächler, Pablo; Urbina, Jesús; Crelier, Gerard; Toro, Lida; Ferreiro, Myriam; Valverde, Israel; Andia, Marcelo; Tejos, Cristian; Irarrazaval, Pablo; Uribe, Sergio

    2017-01-01

    To compare the values of pulmonary regurgitation in patients with repaired Tetralogy of Fallot quantified from two-dimensional phase-contrast data, by using a new pixel-wise analysis and the standard velocity-averaging method. Quantitative in silico and in vivo analysis. Hospital Sótero del Río. The magnetic resonance images were acquired using a Philips Achieva 1.5T scanner. Twenty-five patients with repaired Tetralogy of Fallot who underwent cardiovascular magnetic resonance imaging requested by their referring physicians were included in this study. Using a computational fluid dynamics simulation, we validated our pixel-wise method, quantifying the error of our method in comparison with the standard method. The patients underwent a standard two-dimensional phase-contrast magnetic resonance imaging acquisition for quantifying pulmonary artery flow. Pulmonary regurgitation fraction was estimated by using our pixel-wise and the standard method. The two-dimensional flow profiles were inspected looking for simultaneous antegrade and retrograde flows in the same cardiac phase. Statistical analysis was performed with t-test for related samples, Bland-Altman plots, and Pearson correlation coefficient. Estimation of pulmonary regurgitation fraction using the pixel-wise analysis revealed higher values compared with the standard method (39 ± 16% vs. 30 ± 22%, p-value <0.01). Eight patients (32%) had a difference of more than 10% between methods. Analysis of two-dimensional flow profiles in these patients revealed simultaneous antegrade and retrograde flows through the pulmonary artery during systole-early diastole. Quantification of pulmonary regurgitation fraction in patients with repaired Tetralogy of Fallot through a pixel-wise analysis yields higher values of pulmonary regurgitation compared with the standard velocity-averaging method.

  15. Quantification of pulmonary regurgitation in patients with repaired Tetralogy of Fallot by 2D phase-contrast MRI: Differences between the standard method of velocity averaging and a pixel-wise analysis

    Directory of Open Access Journals (Sweden)

    Julio Sotelo

    2017-09-01

    Full Text Available Objectives To compare the values of pulmonary regurgitation in patients with repaired Tetralogy of Fallot quantified from two-dimensional phase-contrast data, by using a new pixel-wise analysis and the standard velocity-averaging method. Design Quantitative in silico and in vivo analysis. Setting Hospital Sótero del Río. The magnetic resonance images were acquired using a Philips Achieva 1.5T scanner. Participants Twenty-five patients with repaired Tetralogy of Fallot who underwent cardiovascular magnetic resonance imaging requested by their referring physicians were included in this study. Main outcome measures Using a computational fluid dynamics simulation, we validated our pixel-wise method, quantifying the error of our method in comparison with the standard method. The patients underwent a standard two-dimensional phase-contrast magnetic resonance imaging acquisition for quantifying pulmonary artery flow. Pulmonary regurgitation fraction was estimated by using our pixel-wise and the standard method. The two-dimensional flow profiles were inspected looking for simultaneous antegrade and retrograde flows in the same cardiac phase. Statistical analysis was performed with t-test for related samples, Bland–Altman plots, and Pearson correlation coefficient. Results Estimation of pulmonary regurgitation fraction using the pixel-wise analysis revealed higher values compared with the standard method (39 ± 16% vs. 30 ± 22%, p-value <0.01. Eight patients (32% had a difference of more than 10% between methods. Analysis of two-dimensional flow profiles in these patients revealed simultaneous antegrade and retrograde flows through the pulmonary artery during systole–early diastole. Conclusion Quantification of pulmonary regurgitation fraction in patients with repaired Tetralogy of Fallot through a pixel-wise analysis yields higher values of pulmonary regurgitation compared with the standard velocity-averaging method.

  16. Randomized Trials Comparing Inactivated Vaccine after Medium- or High-titer Measles Vaccine with Standard Titer Measles Vaccine after Inactivated Vaccine

    DEFF Research Database (Denmark)

    Aaby, Peter; Ravn, Henrik; Benn, Christine S.

    2016-01-01

    Background: Observational studies have suggested that girls have higher mortality if their most recent immunization is an inactivated vaccine rather than a live vaccine. We therefore reanalyzed 5 randomized trials of early measles vaccine (MV) in which it was possible to compare an inactivated......) compared with a standard titer MV (after inactivated vaccine). Girls had a MRR of 1.89 (1.27-2.80), whereas there was no effect for boys, the sex-differential effect being significant (P = 0.02). Excluding measles cases did not alter these conclusions, the MRR after inactivated vaccines (after MTMV or HTMV......) being 1.40 (1.06-1.86) higher overall and 1.92 (1.29-2.86) for girls. Control for variations in national immunization schedules for other vaccines did not modify these results. Conclusions: After 9 months of age, all children had been immunized against measles, and mortality in girls was higher when...

  17. Radiation exposure in the follow-up of patients with urolithiasis comparing digital tomosynthesis, non-contrast CT, standard KUB, and IVU.

    Science.gov (United States)

    Astroza, Gaston M; Neisius, Andreas; Wang, Agnes J; Nguyen, Giao; Toncheva, Greta; Wang, Chu; Januzis, Natalie; Lowry, Carolyn; Ferrandino, Michael N; Neville, Amy N; Yoshizumi, Terry T; Preminger, Glenn M; Lipkin, Michael E

    2013-10-01

    To compare the effective doses (EDs) associated with imaging modalities for follow-up of patients with urolithiasis, including stone protocol non-contrast computed tomography (NCCT), kidney, ureter, and bladder radiograph (KUB), intravenous urogram (IVU), and digital tomosynthesis (DT). A validated Monte-Carlo simulation-based software PCXMC 2.0 (STUK) designed for estimation of patient dose from medical X-ray exposures was used to determine the ED for KUB, IVU (KUB scout plus three tomographic images), and DT (two scouts and one tomographic sweep). Simulations were performed using a two-dimensional stationary field onto the corresponding body area of the built-in digital phantom, with actual kVp, mAs, and geometrical parameters of the protocols. The ED for NCCT was determined using an anthropomorphic male phantom that was placed prone on a 64-slice GE Healthcare volume computed tomography (VCT) scanner. High-sensitivity metal oxide semiconductor field effect transistors dosimeters were placed at 20 organ locations and used to measure organ radiation doses. The ED for a stone protocol NCCT was 3.04±0.34 mSv. The ED for a KUB was 0.63 and 1.1 mSv for the additional tomographic film. The total ED for IVU was 3.93 mSv. The ED for DT performed with two scouts and one sweep (14.2°) was 0.83 mSv. Among the different imaging modalities for follow-up of patients with urolithiasis, DT was associated with the least radiation exposure (0.83 mSv). This ED corresponds to a fifth of NCCT or IVU studies. Further studies are needed to demonstrate the sensitivity and specificity of DT for the follow-up of nephrolithiasis patients.

  18. Integrated Fluorine-18 Fluorodeoxyglucose (18F-FDG) PET/CT Compared to Standard Contrast-Enhanced CT for Characterization and Staging of Pulmonary Tumors Eligible for Surgical Resection

    Energy Technology Data Exchange (ETDEWEB)

    Quaia, E.; Tona, G.; Gelain, F.; Lubin, E.; Pizzolato, R.; Boscolo, E.; Bussoli, L. (Dept. of Radiology, Cattinara Hospital, Univ. of Trieste, Trieste (Italy))

    2008-11-15

    Background: Accurate staging is necessary to determine the appropriate therapy in patients with lung cancer. Few studies have compared integrated fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) and contrast-enhanced CT in the characterization and staging of pulmonary tumors considered eligible for surgical resection. Purpose: To compare 18F-FDG PET/CT with standard contrast-enhanced CT for the diagnosis and staging of lung neoplasms eligible for surgical resection. Material and Methods: Seventy-six consecutive patients (56 male, 20 female; mean age+-SD, 63.4+-20 years) with 84 pulmonary tumors suspected for malignancy and considered eligible for surgical resection were prospectively enrolled. Seventy-three malignant (65 non-small-cell lung carcinomas, one small-cell lung cancer, two carcinoids, and five metastases) and 11 benign lung tumors (three hamartomas, two sarcoidosis, one amyloidosis, one Wegener granulomatosis, one tuberculosis, and three areas of scarring) were finally diagnosed by histology. Tumor staging was based on the revised American Joint Committee on Cancer. Results: In lesion characterization, the sensitivity and specificity of 18F-FDG PET/CT versus contrast-enhanced CT were 90% vs. 83% and 18% vs. 63% (P<0.05, McNemar test), respectively. In nodal staging, the sensitivity and specificity of 18F-FDG PET/CT versus contrast-enhanced CT were 78% vs. 46% and 80% vs. 93% (P<0.05), respectively. Conclusion: In patients with lung neoplasms considered eligible for surgical resection, 18F-FDG PET/CT versus contrast-enhanced CT revealed higher sensitivity in nodal staging, but lower specificity both in lesion characterization and nodal staging.

  19. Shift from National Reporting to Reporting in Accordance with International Financial Reporting Standard for Small and Medium-sized Entities and Its Effect on Financial Management – the Case of the Czech Republic

    Directory of Open Access Journals (Sweden)

    Struhařová Kateřina

    2010-12-01

    Full Text Available The aim of this paper is to evaluate the effect of the shift from Financial Reporting under the Czech legislature (CZ GAAP to the International Financial Reporting Standard for financial management in Small and Medium-sized Enterprises (IFRS for SMEs. The reasons for the shift and major differences between CZ GAAP and IFRS for SMEs are mentioned, as well as the changes relevant to the shift. Not only changes in accounting departments are defined but also the changes that affect a company as a whole. Furthermore, information from Financial Reporting used in Financial Management is described. Also, the effect of the changes in Financial Reporting on this information and related modifications affecting Financial Management are evaluated.

  20. Contrast media on abdominal computed tomography

    International Nuclear Information System (INIS)

    Skalpe, I.O.; Oestensen, H.M.

    1984-01-01

    Abdominal computed tomography was performed in 55 patients before and after intravenous injection of 60 ml of a non-ionic (iohexol) or an ionic (metrizoate) contrast medium. The adverse effects were recorded and a series of measurements of attenuation values before and after the contrast medium injection was performed in the aorta and in hepatic and renal parenchyma. Only minor adverse effects were seen with both contrast media, but iohexol was clearly better tolerated than metrizoate. No difference in the enhancement properties was found between the two contrast media. (orig.)

  1. Study and determination of the national dosimetric standards in terms of air kerma for X-rays radiation fields of low and medium-energies; Etude et realisation des references dosimetriques nationales en termes de kerma dans l'air pour les faisceaux de rayons X de basses et moyennes energies

    Energy Technology Data Exchange (ETDEWEB)

    Ksouri, W

    2008-12-15

    Progress in radiation protection and radiotherapy, and the increased needs in terms of accuracy lead national metrology institutes to improve the standard. For ionizing radiation, the standard is defined by an absolute instrument used for air kerma rate measurement. The aim of the thesis is to establish standards, in terms of air kerma for X-rays beams of low and medium-energies. This work enables to complement the standard beam range of the Laboratoire National Henri Becquerel (LNHB). Two free-air chambers have been developed, WK06 for medium-energy and WK07 for low-energy. The air-kerma rate is corrected by several correction factors. Some are determined experimentally; and the others by using Monte Carlo simulations. The uncertainty budget of the air-kerma rate at one standard deviation has been established. These dosimetric standards were compared with those of counterparts' laboratories and are consistent in terms of degree of equivalence. (author)

  2. Modified MacConkey medium which allows simple and reliable identification of Providencia stuartii.

    Science.gov (United States)

    Thaller, M C; Berlutti, F; Pantanella, F; Pompei, R; Satta, G

    1992-08-01

    This work describes a modified MacConkey medium (MCP medium) enabling the simple identification of Providencia stuartii, an emerging nosocomial pathogen. A total of 813 strains, belonging to the families Enterobacteriaceae and Pseudomonadaceae, were tested on MCP medium; all P. stuartii strains were phosphatase positive, as were 97.5% of Morganella morganii strains, in contrast with all other tested organisms. A simple discriminating test, such as the ornithine or citrate test, allowed identification of strains of these species. We have also compared the reliabilities of P. stuartii identification by commercial kits (API 20E system) by using a standard MacConkey or MCP medium. Sixteen and three-tenths percent of P. stuartii strains were misidentified by using the former procedure, while with the latter all strains were correctly identified. Finally, the MCP medium was used over a 6-month period in our routine clinical laboratory. Of a total of 1,278 seeded urine samples from elderly patients, we isolated 103 P. stuartii strains which were all correctly identified by coupling MCP medium and the API 20E system. Seventeen and one-half percent of these strains were misidentified when the API 20E system was used in combination with standard MacConkey medium.

  3. Polychromatic diffraction contrast tomography

    International Nuclear Information System (INIS)

    King, A.; Reischig, P.; Adrien, J.; Peetermans, S.; Ludwig, W.

    2014-01-01

    This tutorial review introduces the use of polychromatic radiation for 3D grain mapping using X-ray diffraction contrast tomography. The objective is to produce a 3D map of the grain shapes and orientations within a bulk, millimeter-sized polycrystalline sample. The use of polychromatic radiation enables the standard synchrotron X-ray technique to be applied in a wider range of contexts: 1) Using laboratory X-ray sources allows a much wider application of the diffraction contrast tomography technique. 2) Neutron sources allow large samples, or samples containing high Z elements to be studied. 3) Applied to synchrotron sources, smaller samples may be treated, or faster measurements may be possible. Challenges and particularities in the data acquisition and processing, and the limitations of the different variants, are discussed. - Highlights: • We present a tutorial review of polychromatic diffraction contrast tomography techniques. • The use of polychromatic radiation allows the standard synchrotron DCT technique to be extended to a range of other sources. • The characteristics and limitations of all variants of the techniques are derived, discussed and compared. • Examples using laboratory X-ray and cold neutron radiation are presented. • Suggestions for the future development of these techniques are presented

  4. Changes in plasmahistamine concentration and in blood electrolyte levels affter venous application of non-ionic contrast media

    International Nuclear Information System (INIS)

    Jansen, O.; Weiss, H.D.; Stolle, H.; Schallock, J.

    1990-01-01

    Considering that the different physicochemical properties of the non-ionic contrast media can lead to different conditions concerning histamine release and blood electrolyte levels, the authors made a comparative analysis of the contrast media, and with a placebo, under standardized conditions of application. The monomeric, non-ionic contrast media were found to induce no changes in the release of histamine. Changes in electrolyte levels were all in all discrete after application of the monomeric, non-ionic contrast medium and the dimeric, non-ionic Iotrolan. In-vivo measurements showed a slight Ca ++ -depressing effect of the contrast media, which was strongest with Iohexol. The dimeric Iotrolan had the least hemodilutive effect but the same Ca ++ -depression as the monomeric contrast media. The Ca ++ -depressing effect of the non-ionic contrast media is for one part due to the hemodilution, but it may also be caused in addition by a direct effect on cell membranes. (orig./MG) [de

  5. Contrast-induced nephropathy

    Energy Technology Data Exchange (ETDEWEB)

    Persson, P.B. [Inst. of Physiology, Humboldt Univ., Medizinische Fakultaet (Charite), Berlin (Germany)

    2005-11-15

    How contrast medium-induced nephropathy (CIN) comes about is not fully understood, although CIN constitutes a leading cause of renal failure. Here, a short review of clinical trials and a more thorough outline of mechanisms thought to cause CIN are outlined. Osmolality is only one of several physicochemical properties of contrast media (CM). Iso-osmolar CM are dimers, not monomers. Thus, they have physicochemical features different from other CM, e. g., in terms of viscosity (which is over fivefold greater than plasma viscosity). This may be of considerable pathophysiologic and clinical importance. There are studies providing evidence for a greater perturbation in renal functions by iso-osmolar CM in comparison to nonionic low-osmolar CM. Conversely, some previous clinical trials indicate an advantage of the iso-osmolar CM. This review highlights altered rheological properties, perturbation of renal hemodynamics, regional hypoxia, auto- and paracrine factors (adenosine, endothelin, reactive oxygen species) and direct cytotoxic effects, which are all thought to participate in causing CIN. It is concluded that the use of CM in general, and high viscous iso-osmolar CM in particular, can be deleterious to the kidney due to augmented resistance in the renal tubules. (orig.)

  6. Chemically defined medium and Caenorhabditis elegans

    Science.gov (United States)

    Szewczyk, Nathaniel J.; Kozak, Elena; Conley, Catharine A.

    2003-01-01

    BACKGROUND: C. elegans has been established as a powerful genetic system. Use of a chemically defined medium (C. elegans Maintenance Medium (CeMM)) now allows standardization and systematic manipulation of the nutrients that animals receive. Liquid cultivation allows automated culturing and experimentation and should be of use in large-scale growth and screening of animals. RESULTS: We find that CeMM is versatile and culturing is simple. CeMM can be used in a solid or liquid state, it can be stored unused for at least a year, unattended actively growing cultures may be maintained longer than with standard techniques, and standard C. elegans protocols work well with animals grown in defined medium. We also find that there are caveats to using defined medium. Animals in defined medium grow more slowly than on standard medium, appear to display adaptation to the defined medium, and display altered growth rates as they change the composition of the defined medium. CONCLUSIONS: As was suggested with the introduction of C. elegans as a potential genetic system, use of defined medium with C. elegans should prove a powerful tool.

  7. Homogenization of High-Contrast Brinkman Flows

    KAUST Repository

    Brown, Donald L.

    2015-04-16

    Modeling porous flow in complex media is a challenging problem. Not only is the problem inherently multiscale but, due to high contrast in permeability values, flow velocities may differ greatly throughout the medium. To avoid complicated interface conditions, the Brinkman model is often used for such flows [O. Iliev, R. Lazarov, and J. Willems, Multiscale Model. Simul., 9 (2011), pp. 1350--1372]. Instead of permeability variations and contrast being contained in the geometric media structure, this information is contained in a highly varying and high-contrast coefficient. In this work, we present two main contributions. First, we develop a novel homogenization procedure for the high-contrast Brinkman equations by constructing correctors and carefully estimating the residuals. Understanding the relationship between scales and contrast values is critical to obtaining useful estimates. Therefore, standard convergence-based homogenization techniques [G. A. Chechkin, A. L. Piatniski, and A. S. Shamev, Homogenization: Methods and Applications, Transl. Math. Monogr. 234, American Mathematical Society, Providence, RI, 2007, G. Allaire, SIAM J. Math. Anal., 23 (1992), pp. 1482--1518], although a powerful tool, are not applicable here. Our second point is that the Brinkman equations, in certain scaling regimes, are invariant under homogenization. Unlike in the case of Stokes-to-Darcy homogenization [D. Brown, P. Popov, and Y. Efendiev, GEM Int. J. Geomath., 2 (2011), pp. 281--305, E. Marusic-Paloka and A. Mikelic, Boll. Un. Mat. Ital. A (7), 10 (1996), pp. 661--671], the results presented here under certain velocity regimes yield a Brinkman-to-Brinkman upscaling that allows using a single software platform to compute on both microscales and macroscales. In this paper, we discuss the homogenized Brinkman equations. We derive auxiliary cell problems to build correctors and calculate effective coefficients for certain velocity regimes. Due to the boundary effects, we construct

  8. Diagnostic accuracy of a standardized scheme for identification of Streptococcus uberis in quarter milk samples: A comparison between conventional bacteriological examination, modified Rambach agar medium culturing, and 16S rRNA gene sequencing.

    Science.gov (United States)

    Wald, Regina; Baumgartner, Martina; Urbantke, Verena; Stessl, Beatrix; Wittek, Thomas

    2017-02-01

    Bacteriological examination of milk samples is a prerequisite for pathogen-specific therapy and aids in limiting antimicrobial resistance. The aims of this study were to establish a standardized scheme for reliable Streptococcus uberis identification in routine diagnosis and to evaluate the accuracy of conventional tests and growing patterns of Strep. uberis on a selective medium (modified Rambach agar medium, MRAM) using 16S rRNA gene sequencing analysis as a reference method. We obtained isolates of presumptive Strep. uberis (n = 336) from quarter milk samples of dairy cows with intramammary infections and classified the isolates into 2 clusters using biochemical characterization. In cluster 1 (n = 280), cocci grew as non-hemolytic colonies, hydrolyzing esculin, carrying no Lancefield antigen (A/B/C/D/G) or Christie Atkins Munch-Petersen factor, and their growth was inhibited on an Enterococcus agar. Production of β-d-galactosidase on MRAM was shown by 257 of the cluster 1 isolates (91.79%), and 16S rRNA gene sequencing verified 271 (96.79%) of the isolates to be Strep. uberis. In 264 isolates (94.29%), MRAM agreed with the sequencing results. In cluster 2 (n = 56), isolates showed different characteristics: 37 (66.07%) were β-d-galactosidase-positive, and based on 16S sequencing results, 36 (64.29%) were identified correctly as Strep. uberis using biochemical methods. Identification success in this group differed significantly between routine diagnosis and MRAM application: MRAM agreed with sequencing results in 47 isolates (83.93%). To identify Strep. uberis and differentiate it from other lactic acid bacteria in routine diagnosis, we suggest using catalase reaction, hemolysis, esculin hydrolysis, and growth on enterococci agar. Isolates that show a typical biochemical profile can be identified satisfactorily with these tests. For Strep. uberis isolates with divergent patterns, application of MRAM as a follow-up test increased the diagnostic accuracy to 94

  9. 7 CFR 51.2751 - U.S. Medium Virginia.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false U.S. Medium Virginia. 51.2751 Section 51.2751... STANDARDS) United States Standards for Shelled Virginia Type Peanuts Grades § 51.2751 U.S. Medium Virginia. “U.S. Medium Virginia” consists of shelled Virginia type peanut kernels of similar varietal...

  10. Development of contrast media

    International Nuclear Information System (INIS)

    Krause, W.

    1993-01-01

    Description of all contrast media (ionic and nonionic monomers, ionic and nonionic dimers) was presented. Chemotoxicity, osmolality and viscosity of some contrast agents were analyzed. The main adverse reactions to ionic and nonionic contrast media were described

  11. Hypersensitivity to contrast media and dyes.

    Science.gov (United States)

    Brockow, Knut; Sánchez-Borges, Mario

    2014-08-01

    This article updates current knowledge on hypersensitivity reactions to diagnostic contrast media and dyes. After application of a single iodinated radiocontrast medium (RCM), gadolinium-based contrast medium, fluorescein, or a blue dye, a hypersensitivity reaction is not a common finding; however, because of the high and still increasing frequency of those procedures, patients who have experienced severe reactions are nevertheless frequently encountered in allergy departments. Evidence on allergologic testing and management is best for iodinated RCM, limited for blue dyes, and insufficient for fluorescein. Skin tests can be helpful in the diagnosis of patients with hypersensitivity reactions to these compounds. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Radiographic contrast media

    International Nuclear Information System (INIS)

    Golman, K.; Holtz, E.; Almen, T.

    1987-01-01

    Contrast media are used in diagnostic radiology to enhance the X-ray attenuation between a body structure of interest and the surrounding tissue. A detail becomes perceptible on a roentgenogram only when its contrast exceeds a minimum value in relation to the background. Small areas of interest must have higher contrast than the background. The contrast effect depends on concentration of the contrast media with the body. A high contrast media concentration difference thus gives rise to more morphological details in the radiographs. Contrast media can be divided into negative contrast media such as air and gas which attenuate X-rays less than the body tissues, and positive contrast materials which attenuate X-rays more than the body tissues. The positive contrast media all contain either iodine (atomic number 53) or barium (atomic number 56) and can be divided into water-insoluble and water-soluble contrast media

  13. Addition of lacal anesthetics to contrast media. Pt. 2

    International Nuclear Information System (INIS)

    Nilsson, P.; Almen, T.; Golman, K.; Jonsson, K.; Nyman, U.; Malmoe Allmaenna Sjukhus

    1988-01-01

    The acute intravenous toxicity (i.v. LD 50 ) of solutions of the ratio 1.5 contrast media metrizoate or diatrizoate and the ratio 3.0 contrast medium metrizamide was determined in mice with and without the addition of local anesthetics to the solutions. The two local anesthetics mepivacaine or lidocaine were added to final concentrations up to 2.0 mg/ml of the contrast medium solutions. This corresponds to clinically used concentrations. All additions of local anesthetics to the solutions increased the mortalities caused by the contrast medium solutions. Addition of local anesthetics to a final concentration of 2 mg/ml approximately doubled the acute intravenous toxicity of the contrast media. The ratio 3 contrast media produce less hypertonic solutions than the ratio 1.5 contrast media and should be preferred for angiography because they cause less pain and do not require the addition of local anesthetics which increase the acute toxicity of the solutions. (orig.)

  14. Hadrons in medium

    Indian Academy of Sciences (India)

    medium properties of hadrons. I discuss the relevant symmetries of QCD and how they might affect the observed hadron properties. I then discuss at length the observable consequences of in-medium changes of hadronic properties in reactions with ...

  15. Medium is the message

    NARCIS (Netherlands)

    Kuipers, G.; Ritzer, G.

    2012-01-01

    "The medium is the message" is a phrase coined by Canadian media theorist Marshall McLuhan (1911-1980), in his book Understanding Media: The Extensions of Man (1964). In this book, McLuhan examines the impact of media on societies and human relations, arguing for the primacy of the medium -

  16. [Effects of sludge compost used as lawn medium on lawn growth and soil and water environment].

    Science.gov (United States)

    Jin, Shu-Quan; Zhou, Jin-Bo; Chen, Ruo-Xia; Lin, Bin; Wang, De-Yao

    2013-10-01

    To address effect of the sludge compost-containing medium on the growth of Manila lawn and environment quality, a pot experiment was conducted using six treatments based on contrasting sludge compost addition volume ratios in the soil system (i. e., 0% , 10% , 25% , 50% , 75% and 100%). The results indicated that the growth potential of Manila lawn was increased with increasing sludge compost addition volume ratio. The content of Hg in Manila plant was significantly positively correlated with that in the lawn medium. Although the contents of Cr, Cd and Hg in the lawn medium were synchronously increased with increasing sludge compost addition volume ratio in the soil system, their contents were all lower than the critical levels of third-class standard in the National Soil Environmental Quality Standard. The heavy metal and nitrate concentrations detected in percolating water were significantly positively correlated with those in the lawn medium, respectively. When the sludge compost addition volume ratio was more than 50% in this study, both heavy metal and nitrate concentrations in percolating water would exceed the maximum allowable levels of the National Groundwater Environment Quality Standard.

  17. 21 CFR 133.103 - Asiago medium cheese.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Asiago medium cheese. 133.103 Section 133.103 Food... HUMAN CONSUMPTION CHEESES AND RELATED CHEESE PRODUCTS Requirements for Specific Standardized Cheese and Related Products § 133.103 Asiago medium cheese. Asiago medium cheese conforms to the definition and...

  18. 30 CFR 75.703-2 - Approved grounding mediums.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Approved grounding mediums. 75.703-2 Section 75... AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Grounding § 75.703-2 Approved grounding mediums. For purposes of grounding offtrack direct-current machines, the following grounding mediums are...

  19. A technique for determining the deuterium/hydrogen contrast map in neutron macromolecular crystallography.

    Science.gov (United States)

    Chatake, Toshiyuki; Fujiwara, Satoru

    2016-01-01

    A difference in the neutron scattering length between hydrogen and deuterium leads to a high density contrast in neutron Fourier maps. In this study, a technique for determining the deuterium/hydrogen (D/H) contrast map in neutron macromolecular crystallography is developed and evaluated using ribonuclease A. The contrast map between the D2O-solvent and H2O-solvent crystals is calculated in real space, rather than in reciprocal space as performed in previous neutron D/H contrast crystallography. The present technique can thus utilize all of the amplitudes of the neutron structure factors for both D2O-solvent and H2O-solvent crystals. The neutron D/H contrast maps clearly demonstrate the powerful detectability of H/D exchange in proteins. In fact, alternative protonation states and alternative conformations of hydroxyl groups are observed at medium resolution (1.8 Å). Moreover, water molecules can be categorized into three types according to their tendency towards rotational disorder. These results directly indicate improvement in the neutron crystal structure analysis. This technique is suitable for incorporation into the standard structure-determination process used in neutron protein crystallography; consequently, more precise and efficient determination of the D-atom positions is possible using a combination of this D/H contrast technique and standard neutron structure-determination protocols.

  20. Local interstellar medium

    International Nuclear Information System (INIS)

    Crutcher, R.M.; and Radio Astronomy Laboratory, University of California, Berkeley)

    1982-01-01

    Analysis of the velocities of optical interstellar lines shows that the Sun is immersed in a coherently moving local interstellar medium whose velocity vector agrees with that of the interstellar wind observed through backscatter of solar H Lyα and He lambda584 photons. The local interstellar medium consists of both cool clouds and warm intercloud medium gas, has a mass of perhaps approx.30 M/sub sun/, does not have severe depletion of trace elements from the gas phase, and appears to be material which has been shocked and accelerated by stellar winds and supernovae associated with the Sco-Oph OB association

  1. Variable effects of radiological contrast media on thrombus growth in a rabbit jugular vein thrombosis model

    NARCIS (Netherlands)

    Levi, M. [=Marcel M.; Biemond, B. J.; Sturk, A.; Hoek, J.; ten Cate, J. W.

    1991-01-01

    We studied the effect of an ionic high osmolar contrast medium (Ioxitalamate), an ionic low osmolar contrast medium (Ioxaglate) and various nonionic low osmolar contrast media (Iopamidol, Iopromide and Iohexol) on thrombus growth in a rabbit jugular vein thrombosis model. Thrombus growth was

  2. HIRENASD medium unstructured

    Data.gov (United States)

    National Aeronautics and Space Administration — Unstructured HIRENASD mesh: - medium size (16 million nodes, 39 million elements) - for node centered solvers - 31.05.2011 - caution: dimensions in mm

  3. Concept medium programme

    DEFF Research Database (Denmark)

    Bjerrum, Peter

    2005-01-01

    The present essay is an attempt to determine the architectural project of the 21st century in relation to a modern conception of space as the medium of architecture, and of sociality as its program...

  4. Late adverse reactions to intravascular iodinated contrast media

    International Nuclear Information System (INIS)

    Webb, Judith A.W.; Stacul, Fulvio; Thomsen, Henrik S.; Morcos, Sameh K.

    2003-01-01

    Late adverse reactions to intravascular iodinated contrast media are defined as reactions occurring 1 h to 1 week after contrast medium injection. They have received increasing interest over the past decade, but their prevalence remains uncertain and their pathophysiology is not fully understood. The Contrast Media Safety Committee of the European Society of Urogenital Radiology decided to review the literature and to issue guidelines. An extensive literature search was carried out and summarized in a report. Based on the available information, simple guidelines have been drawn up. The report and guidelines were discussed at the 8th European Symposium on Urogenital Radiology in Genoa. Late adverse reactions after intravascular iodinated contrast medium include symptoms such as nausea, vomiting, headache, itching, skin rash, musculoskeletal pain, and fever. A significant proportion of these reactions is unrelated to the contrast medium; however, allergy-like skin reactions are well-documented side effects of contrast media with an incidence of approximately 2%. Late reactions appear to be commoner after non-ionic dimers. The majority of late skin reactions after contrast medium exposure are probably T-cell-mediated allergic reactions. Patients at increased risk of late skin reactions are those with a history of previous contrast medium reaction and those on interleukin-2 treatment. Most skin reactions are self-limiting and resolve within a week. Management is symptomatic and similar to the management of other drug-induced skin reactions. (orig.)

  5. Concept medium programme

    DEFF Research Database (Denmark)

    Bjerrum, Peter

    2005-01-01

    The present essay is an attempt to determine the architectural project of the 21st century in relation to a modern conception of space as the medium of architecture, and of sociality as its program......The present essay is an attempt to determine the architectural project of the 21st century in relation to a modern conception of space as the medium of architecture, and of sociality as its program...

  6. Contrastes de Forma: Contrastes de ilusiones (I)

    OpenAIRE

    Salvador González, José María

    1986-01-01

    Primera parte del análisis crítico de los principales movimientos artísticos representados en la Exposición Contrastes de Forma, organizada por varios museos de Nueva York en el Museo de Arte Contemporáneo de Caracas.

  7. Towards Dynamic Contrast Specific Ultrasound Tomography

    NARCIS (Netherlands)

    Demi, Libertario; van Sloun, Ruud J. G.; Wijkstra, Hessel; Mischi, Massimo

    2016-01-01

    We report on the first study demonstrating the ability of a recently-developed, contrast-enhanced, ultrasound imaging method, referred to as cumulative phase delay imaging (CPDI), to image and quantify ultrasound contrast agent (UCA) kinetics. Unlike standard ultrasound tomography, which exploits

  8. Defined medium for Moraxella bovis.

    OpenAIRE

    Juni, E; Heym, G A

    1986-01-01

    A defined medium (medium MB) for Moraxella bovis was formulated. Nineteen strains grew well on medium MB. One strain was auxotrophic for asparagine, and another was auxotrophic for methionine. Strains of M. equi and M. lacunata also grew on medium MB. All strains had an absolute requirement for thiamine and were stimulated by or actually required the other growth factors in the medium.

  9. Interstellar depletions and the filling factor of the hot interstellar medium

    International Nuclear Information System (INIS)

    Dwek, E.; Scalo, J.M.

    1979-01-01

    We have examined theoretically the evolution of refractory interstellar grain abundances and corresponding metal deplections in the solar neighborhood. The calculations include a self-consistent treatment of red-giant winds, planetary nebulae, protostellar nebulae, and suprnovae as sources of grains and star formation, and of encounters with supernova blast waves as sinks. We find that in the standard two-phase model for the interstellar medium (ISM), grain destruction is very efficient, and the abundance of refractory grains should be negligible, contrary to observations. In a cloudy three-phase ISM most grains reside in the warm and cold phases of the medium. Supernova blast waves expand predominantly in the hot and tenuous phase of the medium and are showed down as they propagate through a cloud. In order to obtain significant (approx.3) depletions of metals presubably locked up in refractory grain cores, the destruction of grains that reside in the clouds must be minimal. This requires that (a) the density contrast between the cloud and intercloud medium be sufficiently high, and (b) the filling factor of the hot and tenuous gas of the interstellar medium, which presumably gives rise to the O VI absorption and soft X-ray emission, be nearly unity. Much larger depletions (> or approx. =10) must reflect accretion of mantles within interstellar clouds

  10. General perceptual contrast metric

    Science.gov (United States)

    Liberg, Anna; Hasler, David

    2003-06-01

    A combined achromatic and chromatic contrast metric for digital images and video is presented in this paper. Our work is aimed at tuning any parametric rendering algorithm in an automated way by computing how much details an observer perceives in a rendered scene. The contrast metric is based on contrast analysis in spatial domain of image sub-bands constructed by pyramidal decomposition of the image. The proposed contrast metric is the sum of the perceptual contrast of every pixel in the image at different detail levels corresponding to different viewing distances. The novel metric shows high correlation with subjective experiments. Important applications involve optimal parameter set of any image rendering and contrast enhancement technique or auto exposure of an image capturing device.

  11. Standardized CT examination of the multitraumatized patient

    Energy Technology Data Exchange (ETDEWEB)

    Leidner, B. [Department of Diagnostic Radiology, Oskarshamn Hospital (Sweden)]|[Department of Diagnostic Radiology, Huddinge University Hospital (Sweden); Adiels, M. [Department of Diagnostic Radiology, Oskarshamn Hospital (Sweden); Aspelin, P. [Department of Diagnostic Radiology, Huddinge University Hospital (Sweden); Gullstrand, P.; Wallen, S. [Department of Surgery, Oskarshamn Hospital (Sweden)

    1998-12-01

    The aim of this study was to develop a standardized non-helical-CT protocol including head, body and proximal extremities in order to achieve a good time efficiency and diagnostic accuracy in the initial radiological evaluation of the multitraumatized patient. A total of 111 circulatory stable blunt trauma patients, brought in to a trauma level II-III hospital, were examined according to a standardized CT protocol. After examining the head with contiguous 10-mm slices without IV contrast medium injection, the trunk was examined with 10-mm slices every 30 mm through thorax-abdomen-pelvis with IV contrast medium enhancement (occasionally modified). All data in the medical reports were collected and used as ``end-point``, and the outcome of the CT examination was compared with this final diagnosis. Mean examination time was 20 min (range 12-32 min). In total, 55 head injuries, 89 thoracic injuries, 27 abdominal/pelvic injuries and 62 fractures were found. Computed tomography correctly identified the injuries, except one brain stem injury, one contusion/rupture of the heart, one hepatic injury, two intestinal injuries, eight vertebral injuries and one joint dislocation. A standardized non-helical-CT examination of the head and body may be achieved in 20 min. Its diagnostic accuracy was high, except for vertebral column injuries, which is why we recommend it as the method of choice for initial radiological examination of multitraumatized patients. When available, helical scanning would improve both examination speed and accuracy. (orig.) With 6 figs., 40 refs.

  12. Phase contrast image synthesis

    DEFF Research Database (Denmark)

    Glückstad, J.

    1996-01-01

    A new method is presented for synthesizing arbitrary intensity patterns based on phase contrast imaging. The concept is grounded on an extension of the Zernike phase contrast method into the domain of full range [0; 2 pi] phase modulation. By controlling the average value of the input phase funct...... function and by choosing appropriate phase retardation at the phase contrast filter, a pure phase to intensity imaging is accomplished. The method presented is also directly applicable in dark field image synthesis....

  13. Phase Contrast Imaging

    International Nuclear Information System (INIS)

    Menk, Ralf Hendrik

    2008-01-01

    All standard (medical) x-ray imaging technologies, rely primarily on the amplitude properties of the incident radiation, and do not depend on its phase. This is unchanged since the discovery by Roentgen that the intensity of an x-ray beam, as measured by the exposure on a film, was related to the relative transmission properties of an object. However, recently various imaging techniques have emerged which depend on the phase of the x-rays as well as the amplitude. Phase becomes important when the beam is coherent and the imaging system is sensitive to interference phenomena. Significant new advances have been made in coherent optic theory and techniques, which now promise phase information in medical imaging. The development of perfect crystal optics and the increasing availability of synchrotron radiation facilities have contributed to a significant increase in the application of phase based imaging in materials and life sciences. Unique source characteristics such as high intensity, monochromaticity, coherence and high collimating provide an ideal source for advanced imaging. Phase contrast imaging has been applied in both projection and computed tomography modes, and recent applications have been made in the field of medical imaging. Due to the underlying principle of X-ray detection conventional image receptors register only intensities of wave fields and not their phases. During the last decade basically five different methods were developed that translate the phase information into intensity variations. These methods are based on measuring the phase shift φ directly (using interference phenomena), the gradient ∇ φ , or the Laplacian ∇ 2 φ. All three methods can be applied to polychromatic X-ray sources keeping in mind that the native source is synchrotron radiation, featuring monochromatic and reasonable coherent X-ray beams. Due to the vast difference in the coefficients that are driven absorption and phase effects (factor 1,000-10,000 in the energy

  14. Comparison of two fat-suppressed magnetic resonance imaging pulse sequences to standard t2-weighted images for brain parenchymal contrast and lesion detection in dogs with inflammatory intracranial disease.

    Science.gov (United States)

    Young, Benjamin D; Mankin, Joseph M; Griffin, John F; Fosgate, Geoffrey T; Fowler, Jennifer L; Levine, Jonathan M

    2015-01-01

    T2-weighted (T2w) sequences are commonly relied upon in magnetic resonance imaging protocols for the detection of brain lesions in dogs. Previously, the effect of fluid suppression via fluid-attenuated inversion recovery (FLAIR) has been compared to T2-weighting with mixed results. Short tau inversion recovery (STIR) has been reported to increase the detection of some CNS lesions in people. The purpose of the current study was to evaluate the effect of fat suppression on brain parenchymal contrast resolution and lesion detection in dogs. We compared three sequences: T2w images, STIR, and T2w FLAIR with chemical fat suppression (T2-FLAIR-FS) in dogs with meningoencephalitis. Dogs with meningoencephalitis and dogs with idiopathic epilepsy were retrospectively identified and anonymized. Evaluators recorded the presence or absence of lesions within 12 predetermined brain regions on randomized sequences, viewing and scoring each sequence individually. Additionally, signal-to-noise ratios, contrast-to-noise ratios, and relative contrast (RC) were measured in a reference population. Short tau inversion recovery sequences had the highest RC between gray and white matter. While descriptively more lesions were identified by evaluators on T2-FLAIR-FS images, there was no statistical difference in the relative sensitivity of lesion detection between the sequences. Nor was there a statistical difference in false lesion detection within our reference population. Short tau inversion recovery may be favored for enhanced anatomic contrast depiction in brain imaging. No benefit of the inclusion of a fat-suppressed T2-FLAIR sequence was found. © 2014 American College of Veterinary Radiology.

  15. Neutron phase contrast imaging beamline at CIRUS, reactor, India.

    Science.gov (United States)

    Kashyap, Yogesh S; Agrawal, Ashish; Sarkar, P S; Shukla, Mayank; Roy, T; Sinha, Amar

    2012-04-01

    This paper presents the development of neutron phase contrast imaging facility at medium flux research reactor, CIRUS, India. The approach adopted for this study is innovative in the sense that both conventional and phase contrast imaging can be performed within same experiment hutch without any major modification in the experimental hutch or collimator. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Late adverse reactions to intravascular iodine based contrast media

    DEFF Research Database (Denmark)

    Bellin, Marie-France; Stacul, Fulvio; Webb, Judith A W

    2011-01-01

    DEFINITION: Late adverse reactions (LAR) to contrast media (CM) are defined as reactions occurring 1 h to 1 week after exposure. NEED FOR REVIEW: In view of more prospective studies of LAR and new data about their pathophysiology, the Contrast Medium Safety Committee (CMSC) of the European Societ...

  17. Concept medium program

    DEFF Research Database (Denmark)

    Bjerrum, Peter

    2003-01-01

    The present essays is an attempt to dertermine the architecural project of the 21st century in realation to a modern conception of space as the medium of architecture, and of society as its program. This attempt adopts the internal point of view of an architect in describing a modern architectura...

  18. Radon in geological medium

    International Nuclear Information System (INIS)

    Hricko, J.

    1995-01-01

    The paper presented deals with behavior of the radon in geological medium and with some results of the radon survey in Bratislava and Kosice regions. 1) The a v has been detected in the holes 0.80 m deep. The density of observations - 3 reference areas (one represents 20 stations) per 1 km 2 . The radon risk maps in 1:25000 and 1:50000 scales have been compiled. The 56.8% of the project area lies in low radon risk, 37.6% in medium radon risk and 5.6% in high radon risk. Follow-up monitoring of the equivalent volume radon activity (EVRA) at the flats, located in the areas with high radon risk of the surface layer, has showed values several times higher than Slovak limits (Marianka, Raca, Vajnory). The evidence that neotectonic is excellent medium for rising up emanation to the subsurface layer, is shown on the map. The tectonic zone of Liscie udolie in Bratislava-Karlova Ves area has been clearly detected by profile radon survey (a v > 50 kBq/m 3 ). 2) At present, northern half of the area of Kosice in question was covered by radon survey. The low and medium radon risks have been observed here, while localities with high radon risk are small in extent. The part of radon risk and soil permeability map from northern Kosice area is shown. (J.K.) 3 figs., 2 refs

  19. Evaluation of a low-dose CT protocol with oral contrast for assessment of acute appendicitis

    Energy Technology Data Exchange (ETDEWEB)

    Platon, Alexandra; Jlassi, Helmi; Becker, Christoph D.; Poletti, Pierre-Alexandre [University Hospital of Geneva, Department of Radiology, Geneva 14 (Switzerland); Rutschmann, Olivier T. [University Hospital of Geneva, Emergency Center, Geneva (Switzerland); Verdun, Francis R. [University Institute for Radiation Physics, Lausanne (Switzerland); Gervaz, Pascal [University Hospital of Geneva, Clinic of Digestive Surgery, Geneva (Switzerland)

    2009-02-15

    The aim of this study was to evaluate a low-dose CT with oral contrast medium (LDCT) for the diagnosis of acute appendicitis and compare its performance with standard-dose i.v. contrast-enhanced CT (standard CT) according to patients' BMIs. Eighty-six consecutive patients admitted with suspicion of acute appendicitis underwent LDCT (30 mAs), followed by standard CT (180 mAs). Both examinations were reviewed by two experienced radiologists for direct and indirect signs of appendicitis. Clinical and surgical follow-up was considered as the reference standard. Appendicitis was confirmed by surgery in 37 (43%) of the 86 patients. Twenty-nine (34%) patients eventually had an alternative discharge diagnosis to explain their abdominal pain. Clinical and biological follow-up was uneventful in 20 (23%) patients. LDCT and standard CT had the same sensitivity (100%, 33/33) and specificity (98%, 45/46) to diagnose appendicitis in patients with a body mass index (BMI) {>=} 18.5. In slim patients (BMI < 18.5), sensitivity to diagnose appendicitis was 50% (2/4) for LDCT and 100% (4/4) for standard CT, while specificity was identical for both techniques (67%, 2/3). LDCT may play a role in the diagnostic workup of patients with a BMI {>=} 18.5. (orig.)

  20. Compressive Phase Contrast Tomography

    International Nuclear Information System (INIS)

    Maia, Filipe; MacDowell, Alastair; Marchesini, Stefano; Padmore, Howard A.; Parkinson, Dula Y.; Pien, Jack; Schirotzek, Andre; Yang, Chao

    2010-01-01

    When x-rays penetrate soft matter, their phase changes more rapidly than their amplitude. Interference effects visible with high brightness sources creates higher contrast, edge enhanced images. When the object is piecewise smooth (made of big blocks of a few components), such higher contrast datasets have a sparse solution. We apply basis pursuit solvers to improve SNR, remove ring artifacts, reduce the number of views and radiation dose from phase contrast datasets collected at the Hard X-Ray Micro Tomography Beamline at the Advanced Light Source. We report a GPU code for the most computationally intensive task, the gridding and inverse gridding algorithm (non uniform sampled Fourier transform).

  1. Describing contrast across scales

    Science.gov (United States)

    Syed, Sohaib Ali; Iqbal, Muhammad Zafar; Riaz, Muhammad Mohsin

    2017-06-01

    Due to its sensitive nature against illumination and noise distributions, contrast is not widely used for image description. On the contrary, the human perception of contrast along different spatial frequency bandwidths provides a powerful discriminator function that can be modeled in a robust manner against local illumination. Based upon this observation, a dense local contrast descriptor is proposed and its potential in different applications of computer vision is discussed. Extensive experiments reveal that this simple yet effective description performs well in comparison with state of the art image descriptors. We also show the importance of this description in multiresolution pansharpening framework.

  2. Late adverse reactions to intravascular iodine based contrast media

    DEFF Research Database (Denmark)

    Bellin, Marie-France; Stacul, Fulvio; Webb, Judith A W

    2011-01-01

    DEFINITION: Late adverse reactions (LAR) to contrast media (CM) are defined as reactions occurring 1 h to 1 week after exposure. NEED FOR REVIEW: In view of more prospective studies of LAR and new data about their pathophysiology, the Contrast Medium Safety Committee (CMSC) of the European Society...... or delayed reading intradermal). The main risk factors for LAR are a previous reaction to contrast medium, a history of allergy, and interleukin-2 treatment. Most skin reactions are mild or moderate and self-limiting. MANAGEMENT: Management is symptomatic and similar to the management of other drug...

  3. Chemically Defined Medium and Caenorhabditis elegans: A Powerful Approach

    Science.gov (United States)

    Szewczyk, N. J.; Kozak, E.; Conley, C. A.

    2003-01-01

    C. elegans has been established as a powerful genetic system. Growth in a chemically defined medium (C. elegans Maintenance Medium (CeMM)) now allows standardization and systematic manipulation of the nutrients that animals receive. Liquid cultivation allows automated culturing and experimentation and should be of me in large-scale growth and screening of animals. Here we present our initial results from developing culture systems with CeMM. We find that CeMM is versatile and culturing is simple. CeMM can be used in a solid or liquid state, it can be stored unused for at least a year, unattended actively growing cultures may be maintained longer than with standard techniques, and standard C. elegans protocols work well with animals grown in defined medium. We also find that there are caveats of using defined medium. Animals in defined medium grow more slowly than on standard medium, appear to display adaptation to the defined medium, and display altered growth rates as they change defined medium composition. As was suggested with the introduction of C. elegans as a potential genetic system, use of defined medium with C. elegans should prove a powerful tool.

  4. Prolonged retainment of contrast media in renal tumours by oily X-ray contrast media

    International Nuclear Information System (INIS)

    Ryzkov, V.K.; Anisimov, V.N.

    1990-01-01

    In 194 patients with renal tumours an angiographic investigation with the oily X-ray contrast medium Iodolipol was carried out. A selective tropism of oily X-ray contrast media was found in the malignant zones only. The application of the preparation caused no complications. The oily X-ray contrast medium persisted in the tumours over several weeks or months. After embolization of the renal arteria a moderate size reduction of malign tumours in the first 10-14 d was seen. The ability of Iodolipol for a lasting retainment in malign tumour tissue allows a follow-up of the involution of the pathologic focus after arterial embolization of the tumour vessels. (author)

  5. Contrast media in urography, angiography and computerized tomography

    International Nuclear Information System (INIS)

    Taenzer, V.; Zeitler, E.

    1983-01-01

    The fact that new contrast media have been introduced in Germany or are currently undergoing clinical trials prompted the authors to assemble available experiences in a special edition of ''Roentgen-Fortschritte''. Particular prominence is given in the publication to preclinical and clinical experiences with another new non-ionic contrast medium, Iopromide. Experimental and clinical studies both indicate changes in certain clinically pertinent properties of the new contrast media. (orig./MG) [de

  6. Contrast enhancement of the gyri in herpes simplex encephalitis

    International Nuclear Information System (INIS)

    Schumacher, K.A.; Langer, M.; Langer, R.

    1982-01-01

    A case of herpes simplex encephalitis was examined by computer tomography. Both cerebral hemispheres showed contrast enhancement of the gyri. The cause of this is considered. The increased contrast medium accumulation in the affected areas is probably due to the marked vascular proliferation which can be demonstrated anatomically, and to the rapid escape of contrast from the capillaries into the interstitial spaces. The findings of other authors, which differ somewhat, are discussed. (orig.) [de

  7. Second harmonic inversion for ultrasound contrast harmonic imaging

    Science.gov (United States)

    Pasovic, Mirza; Danilouchkine, Mike; Faez, Telli; van Neer, Paul L. M. J.; Cachard, Christian; van der Steen, Antonius F. W.; Basset, Olivier; de Jong, Nico

    2011-06-01

    Ultrasound contrast agents (UCAs) are small micro-bubbles that behave nonlinearly when exposed to an ultrasound wave. This nonlinear behavior can be observed through the generated higher harmonics in a back-scattered echo. In past years several techniques have been proposed to detect or image harmonics produced by UCAs. In these proposed works, the harmonics generated in the medium during the propagation of the ultrasound wave played an important role, since these harmonics compete with the harmonics generated by the micro-bubbles. We present a method for the reduction of the second harmonic generated during nonlinear-propagation-dubbed second harmonic inversion (SHI). A general expression for the suppression signals is also derived. The SHI technique uses two pulses, p' and p'', of the same frequency f0 and the same amplitude P0 to cancel out the second harmonic generated by nonlinearities of the medium. Simulations show that the second harmonic is reduced by 40 dB on a large axial range. Experimental SHI B-mode images, from a tissue-mimicking phantom and UCAs, show an improvement in the agent-to-tissue ratio (ATR) of 20 dB compared to standard second harmonic imaging and 13 dB of improvement in harmonic power Doppler.

  8. Second harmonic inversion for ultrasound contrast harmonic imaging

    International Nuclear Information System (INIS)

    Pasovic, Mirza; Danilouchkine, Mike; Faez, Telli; Van Neer, Paul L M J; Van der Steen, Antonius F W; De Jong, Nico; Cachard, Christian; Basset, Olivier

    2011-01-01

    Ultrasound contrast agents (UCAs) are small micro-bubbles that behave nonlinearly when exposed to an ultrasound wave. This nonlinear behavior can be observed through the generated higher harmonics in a back-scattered echo. In past years several techniques have been proposed to detect or image harmonics produced by UCAs. In these proposed works, the harmonics generated in the medium during the propagation of the ultrasound wave played an important role, since these harmonics compete with the harmonics generated by the micro-bubbles. We present a method for the reduction of the second harmonic generated during nonlinear-propagation-dubbed second harmonic inversion (SHI). A general expression for the suppression signals is also derived. The SHI technique uses two pulses, p' and p'', of the same frequency f 0 and the same amplitude P 0 to cancel out the second harmonic generated by nonlinearities of the medium. Simulations show that the second harmonic is reduced by 40 dB on a large axial range. Experimental SHI B-mode images, from a tissue-mimicking phantom and UCAs, show an improvement in the agent-to-tissue ratio (ATR) of 20 dB compared to standard second harmonic imaging and 13 dB of improvement in harmonic power Doppler.

  9. MR mammography: influence of menstrual cycle on the dynamic contrast enhancement of fibrocystic disease

    International Nuclear Information System (INIS)

    Rieber, A.; Nuessle, K.; Merkle, E.; Tomczak, R.; Brambs, H.J.; Kreienberg, R.

    1999-01-01

    Magnetic resonance mammography (MRM) provides data regarding the nature of tumours based on contrast medium dynamics; fibrocystic changes in the breast, however, may lead to false-positive results. This study investigated whether the contrast medium dynamics of fibrocystic changes are dependent on the menstrual cycle. Twenty-four patients with palpable lumps but normal mammographies and ultrasound studies were examined. The MRM technique was performed during the first and second part of the menstrual cycle using a FLASH 3D sequence, both native and at 1, 2, 3 and 8 min after intravenous application of 0.15 mmol/kg body weight of gadodiamide. The calculated time-intensity curves were evaluated based on the following criteria: early percentage of contrast medium uptake in relation to the native value; formation of a plateau phenomenon after the second minute; the point of maximal contrast medium uptake; and calculation of the contrast enhancing index. During the second half of the menstrual cycle, a generally greater contrast medium uptake was observed. Nevertheless, when further diagnostic criteria, such as continuous contrast medium increase as a function of time, were considered, there was no increased rate of false-positive findings. The phase of the menstrual cycle may affect the specificity of the examination, if only the quantitative contrast medium uptake and the percentage of contrast medium uptake in the first 2 min are considered. A control MRM during the other half of the cycle may then be indicated and additional diagnostic criteria may improve specificity. (orig.)

  10. Generalized Phase Contrast

    CERN Document Server

    Glückstad, Jesper

    2009-01-01

    Generalized Phase Contrast elevates the phase contrast technique not only to improve phase imaging but also to cross over and interface with diverse and seemingly disparate fields of contemporary optics and photonics. This book presents a comprehensive introduction to the Generalized Phase Contrast (GPC) method including an overview of the range of current and potential applications of GPC in wavefront sensing and phase imaging, structured laser illumination and image projection, optical trapping and manipulation, and optical encryption and decryption. The GPC method goes further than the restrictive assumptions of conventional Zernike phase contrast analysis and achieves an expanded range of validity beyond weak phase perturbations. The generalized analysis yields design criteria for tuning experimental parameters to achieve optimal performance in terms of accuracy, fidelity and light efficiency. Optimization can address practical issues, such as finding an optimal spatial filter for the chosen application, ...

  11. Mamografia Espectral de Contraste

    OpenAIRE

    Martins, Inês Santiago; Pereira, Inês; Pacheco, Hugo Pisco; Moutinho, Leonor

    2014-01-01

    A mamografia de contraste é uma aplicação recente possível com a mamografia digital directa, que utiliza contraste iodado endovenoso tendo como princípio a neovascularização induzida no cancro da mama, permitindo obter informação morfológica e funcional. Na mamografia espectral de contraste realiza-se uma aquisição simultânea com alta e baixa energia para cada incidência após administração de contraste iodado endovenoso. É depois feita uma imagem recombinada em que são realçadas as áreas que ...

  12. Generalized phase contrast:

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Palima, Darwin

    (GPC) method including an overview of the range of current and potential applications of GPC in wavefront sensing and phase imaging, structured laser illumination and image projection, optical trapping and manipulation, and optical encryption and decryption. The GPC method goes further than......Generalized Phase Contrast elevates the phase contrast technique not only to improve phase imaging but also to cross over and interface with diverse and seemingly disparate fields of contemporary optics and photonics. This book presents a comprehensive introduction to the Generalized Phase Contrast...... efficiency. Optimization can address practical issues, such as finding an optimal spatial filter for the chosen application, and can even enable a Reverse Phase Contrast mode where intensity patterns are converted into a phase modulation....

  13. Medium-energy physics

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    One of the basic challenges of medium-energy physics is the development of a clear picure of the manner in which pions propagate in nuclear matter. Since the pion is a basic quantum of the nuclear force, understanding its propagation in nuclei contributes to our understanding of the basic nature of nuclear forces. Key to such understanding is a comprehensive and precise experimental description of pion interactions both with complex nuclei and few nucleon systems. This is a major objective of the ANL effort in medium-energy physics. Experiments are carried out as a part of a comprehensive nuclear program, and, because of this perspective, the pion studies are expected to give new insights into the nature of nuclear forces. At the present time, almost all experimental activity is concentrated on measurements using various pion beams of the Los Alamos Meson Physics Facility

  14. Liquid chromatographic extraction medium

    Science.gov (United States)

    Horwitz, E. Philip; Dietz, Mark L.

    1994-01-01

    A method and apparatus for extracting strontium and technetium values from biological, industrial and environmental sample solutions using a chromatographic column is described. An extractant medium for the column is prepared by generating a solution of a diluent containing a Crown ether and dispersing the solution on a resin substrate material. The sample solution is highly acidic and is introduced directed to the chromatographic column and strontium or technetium is eluted using deionized water.

  15. Hadrons in the medium

    International Nuclear Information System (INIS)

    Leupold, Stefan

    2005-01-01

    QCD, the theory of the strong interaction, has a non-trivial vacuum structure. One way to characterize this structure is by means of non-vanishing matrix elements of quark or gluon operators, the condensates. In hot and/or dense enough strongly interacting media, QCD is subject to phase transitions or rapid crossovers. Consequently, the condensates typically change with density and temperature. An exciting aspect of hadron physics is the question how these changes affect the properties of hadrons which are put in a strongly interacting environment. Here vector mesons deserve special attention as they couple directly to (virtual) photons. The latter can decay into dileptons which leave the strongly interacting system untouched. Via that process information about possible in-medium modifications of the vector mesons can be carried to the detectors. With the ω-meson as an example I will review our current understanding of the connections between in-medium changes of condensates and the in-medium changes of the properties of hadrons. (author)

  16. Computed tomography after the intra-arterial and intravenous administration of contrast media

    International Nuclear Information System (INIS)

    Young, S.W.

    1981-01-01

    In computed tomography (CT) body scanning, the amount of contrast medium which has accumulated in a tissue is related to the delivery of the contrast agent to the tissue and the contrast medium extraction ratio of the tissue. The two main tissue characteristics responsible for differential contrast medium accumulation are capillary leak and differences in the size of the interstitial space. Given two tissues which leak contrast medium the best CT scanning methodology consists of delivering a rapid bolus of as high a concentration of contrast medium as can be biologically safely delivered. In order to assess the rapid pharmacokinetics, dynamic CT scanning throughout the passage of the bolus is the best technique to employ. Given two tissues, one of which leaks contrast medium and one which does not, optimal technique would utilize a sustained drip infusion, subsequently stopping the infusion, and after the blood pool has declined, obtaining CT scans through the area of interest. The accumulated tissue levels are directly related to the administered concentration, and on this basis, intra-arterial administration is superior to intravenous administration in producing contrast enhancement. The routine intra-arterial administration of contrast medium, although superior, has little practical application in the clinical setting. The contrast enhancement of blood vessels, however, is probably best produced by a sustained bolus infusion, preferably delivered into the vascular structure to be evaluated (i.e., the left foot if the left external iliac vein is to be evaluated). (Auth.)

  17. Evaluation of a low-dose CT protocol with oral contrast for assessment of acute appendicitis.

    Science.gov (United States)

    Platon, Alexandra; Jlassi, Helmi; Rutschmann, Olivier T; Becker, Christoph D; Verdun, Francis R; Gervaz, Pascal; Poletti, Pierre-Alexandre

    2009-02-01

    The aim of this study was to evaluate a low-dose CT with oral contrast medium (LDCT) for the diagnosis of acute appendicitis and compare its performance with standard-dose i.v. contrast-enhanced CT (standard CT) according to patients' BMIs. Eighty-six consecutive patients admitted with suspicion of acute appendicitis underwent LDCT (30 mAs), followed by standard CT (180 mAs). Both examinations were reviewed by two experienced radiologists for direct and indirect signs of appendicitis. Clinical and surgical follow-up was considered as the reference standard. Appendicitis was confirmed by surgery in 37 (43%) of the 86 patients. Twenty-nine (34%) patients eventually had an alternative discharge diagnosis to explain their abdominal pain. Clinical and biological follow-up was uneventful in 20 (23%) patients. LDCT and standard CT had the same sensitivity (100%, 33/33) and specificity (98%, 45/46) to diagnose appendicitis in patients with a body mass index (BMI) >or= 18.5. In slim patients (BMIor= 18.5.

  18. Ex Vivo Perfusion-Simulation Measurements of Microbubbles as a Scattering Contrast Agent for Grating-Based X-Ray Dark-Field Imaging.

    Directory of Open Access Journals (Sweden)

    Astrid Velroyen

    Full Text Available The investigation of dedicated contrast agents for x-ray dark-field imaging, which exploits small-angle scattering at microstructures for contrast generation, is of strong interest in analogy to the common clinical use of high-atomic number contrast media in conventional attenuation-based imaging, since dark-field imaging has proven to provide complementary information. Therefore, agents consisting of gas bubbles, as used in ultrasound imaging for example, are of particular interest. In this work, we investigate an experimental contrast agent based on microbubbles consisting of a polyvinyl-alcohol shell with an iron oxide coating, which was originally developed for multimodal imaging and drug delivery. Its performance as a possible contrast medium for small-animal angiography was examined using a mouse carcass to realistically consider attenuating and scattering background signal. Subtraction images of dark field, phase contrast and attenuation were acquired for a concentration series of 100%, 10% and 1.3% to mimic different stages of dilution in the contrast agent in the blood vessel system. The images were compared to the gold-standard iodine-based contrast agent Solutrast, showing a good contrast improvement by microbubbles in dark-field imaging. This study proves the feasibility of microbubble-based dark-field contrast-enhancement in presence of scattering and attenuating mouse body structures like bone and fur. Therefore, it suggests a strong potential of the use of polymer-based microbubbles for small-animal dark-field angiography.

  19. Small-bowel MRI in children and young adults with Crohn disease: retrospective head-to-head comparison of contrast-enhanced and diffusion-weighted MRI

    International Nuclear Information System (INIS)

    Neubauer, Henning; Evangelista, Laura; Wirth, Clemens; Beer, Meinrad; Pabst, Thomas; Machann, Wolfram; Koestler, Herbert; Hahn, Dietbert; Dick, Anke

    2013-01-01

    Small-bowel MRI based on contrast-enhanced T1-weighted sequences has been challenged by diffusion-weighted imaging (DWI) for detection of inflammatory bowel lesions and complications in patients with Crohn disease. To evaluate free-breathing DWI, as compared to contrast-enhanced MRI, in children, adolescents and young adults with Crohn disease. This retrospective study included 33 children and young adults with Crohn disease ages 17 ± 3 years (mean ± standard deviation) and 27 matched controls who underwent small-bowel MRI with contrast-enhanced T1-weighted sequences and DWI at 1.5 T. The detectability of Crohn manifestations was determined. Concurrent colonoscopy as reference was available in two-thirds of the children with Crohn disease. DWI and contrast-enhanced MRI correctly identified 32 and 31 patients, respectively. All 22 small-bowel lesions and all Crohn complications were detected. False-positive findings (two on DWI, one on contrast-enhanced MRI), compared to colonoscopy, were a result of large-bowel lumen collapse. Inflammatory wall thickening was comparable on DWI and contrast-enhanced MRI. DWI was superior to contrast-enhanced MRI for detection of lesions in 27% of the assessed bowel segments and equal to contrast-enhanced MRI in 71% of segments. DWI facilitates fast, accurate and comprehensive workup in Crohn disease without the need for intravenous administration of contrast medium. Contrast-enhanced MRI is superior in terms of spatial resolution and multiplanar acquisition. (orig.)

  20. Consideration of Adverse Reaction to MDCT Contrast Media

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Won Seok; Shin, Seong Gyu [Dept. of Radiology, Dong A University Medical Center, Busan (Korea, Republic of)

    2012-03-15

    In this experiment, we investigated 82 patients who suffered adverse reactions due to contrast medium. We selected the subjects out of 21,178 people who had an intravenous injection of contrast medium to undergo MDCT examination at one university hospital in Busan in 2007. As a result, the largest groups of the patients were as follows. 52.4% of the patients were male when classify by gender; 28.0% of the patients were 50's by age; 45% of the patients got when it was spring(April and March); 75.6% of the patients had a side effects when the speed of injection is 2.5 mL/sec; 58.5% of the patients were suffered when the volume of injected contrast medium is over 130 mL. Urticaria was the main symptom of side effect as 26.8%. And the main treatment for the effect was alleviating the symptoms before making patients to return home. Thus, practical preventive measures are needed as follows: use the OCS system to observe warning signs at risky patients, secure warming spaces for patients to cope with season changing, prepare enough emergency kits for the patients in danger, and establish CPR call systems, explain the risk of contrast medium and get agree about using contrast medium.

  1. Phase Contrast Imaging

    DEFF Research Database (Denmark)

    1996-01-01

    The invention relates to a method and a system for synthesizing a prescribed intensity pattern based on phase contrast imaging that is not based on the assumption of prior art methods that the pahase shift phi is less than 1 radian. An improved method based on a simple imaging operation with a si......The invention relates to a method and a system for synthesizing a prescribed intensity pattern based on phase contrast imaging that is not based on the assumption of prior art methods that the pahase shift phi is less than 1 radian. An improved method based on a simple imaging operation...

  2. Spiegel. Medium. Kunst

    DEFF Research Database (Denmark)

    Kacunko, Slavko

    to human talent, came the millennia of untiring labours and the play of art and science and thought. The human love-affair with reflection (to cite Mark Pendergast’s subtitle - Mirror/Mirror: A History of the Human Love Affair with Reflection [New York 2003]) has always been a platonic one and I hold...... and cultural perspective. From 1800 on, the great incentive was to push forward the material-physical and optical-mechanical and especially the media ‘exploitation’ of the mirror. The significance of the mirror as a central meta-medium of the visual emerged in a particularly striking way in the late 1830s...

  3. Contrast-enhanced magnetic resonance angiography

    International Nuclear Information System (INIS)

    Vogl, T.J.; Hoffmann, Y.; Muehler, A.; Felix, R.

    1994-01-01

    Magnetic resonance angiography (MRA) protocols are based on standard sequence protocols like time of flight MRA, which evaluates inflowing spins. This technique is limited by a variety of artifacts like the saturation artifact via turbulent blood flow. Contrast media diminish these artifacts like extracellular agents and blood-pool contrast media. The clinical value of the contrast-enhanced MRA for cerebral pathologies is based on the use of the paramagnetic contrast agent Gd-DTPA. For extracerebral diseases this technique is restricted because of the simultaneous visualization of both arterial and venous vascular territorities. Occult venous sinus thrombosis or AV malformations are clinical essential indications for the use of C-MRA. Experimental data prove the excellent contrast abilities of blood-pool agents like Gd-DTPA-polylysin or Gd-DTPA-albumin, which demonstrate long intravascular persistence and retarded excretion. (orig.) [de

  4. Coherent neutrino interactions in a dense medium

    International Nuclear Information System (INIS)

    Kiers, K.; Weiss, N.

    1997-01-01

    Motivated by the effect of matter on neutrino oscillations (the MSW effect) we study in more detail the propagation of neutrinos in a dense medium. The dispersion relation for massive neutrinos in a medium is known to have a minimum at nonzero momentum p∼G F ρ/√(2). We study in detail the origin and consequences of this dispersion relation for both Dirac and Majorana neutrinos both in a toy model with only neutral currents and a single neutrino flavor and in a realistic open-quotes standard modelclose quotes with two neutrino flavors. We find that for a range of neutrino momenta near the minimum of the dispersion relation, Dirac neutrinos are trapped by their coherent interactions with the medium. This effect does not lead to the trapping of Majorana neutrinos. copyright 1997 The American Physical Society

  5. Tensile properties of a bone cement containing non-ionic contrast media.

    Science.gov (United States)

    Kjellson, F; Wang, J S; Almén, T; Mattsson, A; Klaveness, J; Tanner, K E; Lidgren, L

    2001-01-01

    The addition of contrast media such as BaSO4 or ZrO2 to bone cement has adverse effects in joint replacements, including third body wear and particle-induced bone resorption. Ground PMMA containing particles of the non-ionic water-soluble iodine-based X-ray contrast media, iohexol (IHX) and iodixanol (IDX), has, in bone tissue culture, shown less bone resorption than commercial cements. These water-soluble non-ceramic contrast media may change the mechanical properties of acrylic bone cement. The static mechanical properties of bone cement containing either IHX or IDX have been investigated. There was no significant difference in ultimate stress between Palacos R (with 15.0 wt % of ZrO2) and plain cement with 8.0 wt % of IHX or IDX with mass median diameter (MMD) of 15.0 or 16.0 microm, while strain to failure was higher for the latter (p polymer beads, which may prevent areas of the acrylate bead surface from participating in the polymerization. In conclusion, the mechanical properties of bone cement were influenced by the size and amount of contrast medium particles. By choosing the appropriate amount and size of particles of water-soluble non-ionic contrast media the mechanical properties of the new radio-opaque bone cement can be optimized, thus reaching and surpassing given regulatory standards. Copyright 2001 Kluwer Academic Publishers

  6. DENSE MEDIUM CYCLONE OPTIMIZATON

    Energy Technology Data Exchange (ETDEWEB)

    Gerald H. Luttrell; Chris J. Barbee; Peter J. Bethell; Chris J. Wood

    2005-06-30

    Dense medium cyclones (DMCs) are known to be efficient, high-tonnage devices suitable for upgrading particles in the 50 to 0.5 mm size range. This versatile separator, which uses centrifugal forces to enhance the separation of fine particles that cannot be upgraded in static dense medium separators, can be found in most modern coal plants and in a variety of mineral plants treating iron ore, dolomite, diamonds, potash and lead-zinc ores. Due to the high tonnage, a small increase in DMC efficiency can have a large impact on plant profitability. Unfortunately, the knowledge base required to properly design and operate DMCs has been seriously eroded during the past several decades. In an attempt to correct this problem, a set of engineering tools have been developed to allow producers to improve the efficiency of their DMC circuits. These tools include (1) low-cost density tracers that can be used by plant operators to rapidly assess DMC performance, (2) mathematical process models that can be used to predict the influence of changes in operating and design variables on DMC performance, and (3) an expert advisor system that provides plant operators with a user-friendly interface for evaluating, optimizing and trouble-shooting DMC circuits. The field data required to develop these tools was collected by conducting detailed sampling and evaluation programs at several industrial plant sites. These data were used to demonstrate the technical, economic and environmental benefits that can be realized through the application of these engineering tools.

  7. PET/CT with intravenous contrast can be used for PET attenuation correction in cancer patients

    International Nuclear Information System (INIS)

    Berthelsen, A.K.; Holm, S.; Loft, A.; Klausen, T.L.; Andersen, F.; Hoejgaard, L.

    2005-01-01

    If the CT scan of a combined PET/CT study is performed as a full diagnostic quality CT scan including intravenous (IV) contrast agent, the quality of the joint PET/CT procedure is improved and a separate diagnostic CT scan can be avoided. CT with IV contrast can be used for PET attenuation correction, but this may result in a bias in the attenuation factors. The clinical significance of this bias has not been established. Our aim was to perform a prospective clinical study where each patient had CT performed with and without IV contrast agent to establish whether PET/CT with IV contrast can be used for PET attenuation without reducing the clinical value of the PET scan. A uniform phantom study was used to document that the PET acquisition itself is not significantly influenced by the presence of IV contrast medium. Then, 19 patients referred to PET/CT with IV contrast underwent CT scans without, and then with contrast agent, followed by an 18 F-fluorodeoxyglucose whole-body PET scan. The CT examinations were performed with identical parameters on a GE Discovery LS scanner. The PET data were reconstructed with attenuation correction based on the two CT data sets. A global comparison of standard uptake value (SUV) was performed, and SUVs in tumour, in non-tumour tissue and in the subclavian vein were calculated. Clinical evaluation of the number and location of lesions on all PET/CT scans was performed twice, blinded and in a different random order, by two independent nuclear medicine specialists. In all patients, the measured global SUV of PET images based on CT with IV contrast agent was higher than the global activity using non-contrast correction. The overall increase in the mean SUV (for two different conversion tables tested) was 4.5±2.3% and 1.6±0.5%, respectively. In 11/19 patients, focal uptake was identified corresponding to malignant tumours. Eight out of 11 tumours showed an increased SUV max (2.9±3.1%) on the PET images reconstructed using IV contrast

  8. Iodinated contrast media nephrotoxicity

    International Nuclear Information System (INIS)

    Meyrier, A.

    1994-01-01

    In the late seventies, iodinated contrast agents (ICA) were considered to be a major cause of acute iatrogenic renal failure. Over the last decade new contrast agents have been synthesized, nonionic and less hyperosmolar. The incidence of acute renal failure due to ICAs, varies from 3.7 to 70% of cases according to the series, with an average figure of 10.2%. The pathophysiology of ICA nephrotoxicity was mainly studied in laboratory animal models. Three main factors are involved in an inducing ICA-mediated decrease in glomerular filtration rate: reduction of the renal plasma flow, a direct cytotoxic effect on renal tubular cells and erythrocyte alteration leading to intra-renal sludge. Excluding dysglobulinemias with urinary excretion of immunoglobulin light chains, which represent a special case of maximum nephrotoxicity, 4 main risk factors of renal toxicity have been identified in nondiabetic subjects: previous renal failure with serum creatinine levels greater than 140 μmol per liter, extracellular dehydration, age over 60 and use of high doses of ICA and/or repeated ICA injections before serum creatinine levels return to baseline. Preventive measures for avoiding ICA nephrotoxicity are threefold: maintain or restore adequate hydration with saline infusion, stop NSAID treatment several days before ICA administration, and allow a 5 day interval before repeating contrast media injections. New, nonionic and moderately hyperosmolar contrast agents appear to be much less nephrotoxic than conventional ICAs in laboratory animals and in high-risk patients. It is advisable to select such contrast media for investigating high-risk patients. This approach was recently substantiated in well designed, randomized clinical studies which included more than 2 000 patients. (author)

  9. Motion contrast using optical coherence tomography

    Science.gov (United States)

    Fingler, Jeffrey Paul

    Diagnosis of ophthalmic diseases like age-related macular degeneration is very important for treatment of the disease as well as the development of future treatments. Optical coherence tomography (OCT) is an optical interference technique which can measure the three-dimensional structural information of the reflecting layers within a sample. In retinal imaging, OCT is used as the primary diagnostic tool for structural abnormalities such as retinal holes and detachments. The contrast within the images of this technique is based upon reflectivity changes from different regions of the retina. This thesis demonstrates the developments of methods used to produce additional contrast to the structural OCT images based on the tiny fluctuations of motion experienced by the mobile scatterers within a sample. Motion contrast was observed for motions smaller than 50 nm in images of a variety of samples. Initial contrast method demonstrations used Brownian motion differences to separate regions of a mobile Intralipid solution from a static agarose gel, chosen in concentration to minimize reflectivity contrast. Zebrafish embryos in the range of 3-4 days post fertilization were imaged using several motion contrast methods to determine the capabilities of identifying regions of vascular flow. Vasculature identification was demonstrated in zebrafish for blood vessels of all orientations as small as 10 microns in diameter. Mouse retinal imaging utilized the same motion contrast methods to determine the contrast capabilities for motions associated with vasculature within the retina. Improved contrast imaging techniques demonstrated comparable images to fluorescein angiography, the gold standard of retinal vascular imaging. Future studies can improve the demonstrated contrast analysis techniques and apply them towards human retinal motion contrast imaging for ophthalmic diagnostic purposes.

  10. Mamografia com contraste

    OpenAIRE

    Baptista, Rita; Silva, Carina; Reis, Cláudia

    2016-01-01

    O estudo pretendeu apresentar as indicações clínicas, vantagens e princípios da mamografia com contraste, identificar as evoluyções tecnológicas para a mamografia com contraste e caracterizar as práticas e os desafios dos técnicos de radiologia do Hospital de Santarém (único no país a utilizar esta técnica). O cancro da mama é uma das principais causas de morte nas mulheres, em todo o mundo, mas principalmente nos Estados Unidos da América, Canadá, Europa Ocidental e Austrália. Em Portugal, e...

  11. Current iodinated contrast media

    International Nuclear Information System (INIS)

    Stacul, F.

    2001-01-01

    The number of scientific papers on iodinated contrast media is declining. Indeed, comparative trials between high-osmolality and low-osmolality agents largely showed the higher safety and tolerability of the latter, and this is no longer a matter of discussion. Only financial constraints could prevent a total conversion to low-osmolality agents. Research comparing low-osmolality (nonionic monomers, ionic dimer) and iso-osmolality contrast media (nonionic dimers) are still ongoing. Both classes of nonionic compounds proved safer than the ionic dimer. The relative merits of nonionic monomers and nonionic dimers are a matter for debate, and criteria for a selective use of different agents for different procedures could be discussed. (orig.)

  12. Transport phenomena in sharply contrasting media with a diffusion barrier

    International Nuclear Information System (INIS)

    Dvoretskaya, O A; Kondratenko, P S

    2011-01-01

    Using the advection–diffusion equation, we analytically study contaminant transport in a sharply contrasting medium with a diffusion barrier due to localization of a contaminant source in a low-permeability medium. Anomalous diffusion behavior and a crossover between different transport regimes are observed. The diffusion barrier results in exponential attenuation of the source power, retardation of the contaminant plume growth and modification of the concentration distribution at large distances. (paper)

  13. Anisotropic contrast optical microscope.

    Science.gov (United States)

    Peev, D; Hofmann, T; Kananizadeh, N; Beeram, S; Rodriguez, E; Wimer, S; Rodenhausen, K B; Herzinger, C M; Kasputis, T; Pfaunmiller, E; Nguyen, A; Korlacki, R; Pannier, A; Li, Y; Schubert, E; Hage, D; Schubert, M

    2016-11-01

    An optical microscope is described that reveals contrast in the Mueller matrix images of a thin, transparent, or semi-transparent specimen located within an anisotropic object plane (anisotropic filter). The specimen changes the anisotropy of the filter and thereby produces contrast within the Mueller matrix images. Here we use an anisotropic filter composed of a semi-transparent, nanostructured thin film with sub-wavelength thickness placed within the object plane. The sample is illuminated as in common optical microscopy but the light is modulated in its polarization using combinations of linear polarizers and phase plate (compensator) to control and analyze the state of polarization. Direct generalized ellipsometry data analysis approaches permit extraction of fundamental Mueller matrix object plane images dispensing with the need of Fourier expansion methods. Generalized ellipsometry model approaches are used for quantitative image analyses. These images are obtained from sets of multiple images obtained under various polarizer, analyzer, and compensator settings. Up to 16 independent Mueller matrix images can be obtained, while our current setup is limited to 11 images normalized by the unpolarized intensity. We demonstrate the anisotropic contrast optical microscope by measuring lithographically defined micro-patterned anisotropic filters, and we quantify the adsorption of an organic self-assembled monolayer film onto the anisotropic filter. Comparison with an isotropic glass slide demonstrates the image enhancement obtained by our method over microscopy without the use of an anisotropic filter. In our current instrument, we estimate the limit of detection for organic volumetric mass within the object plane of ≈49 fg within ≈7 × 7 μm 2 object surface area. Compared to a quartz crystal microbalance with dissipation instrumentation, where contemporary limits require a total load of ≈500 pg for detection, the instrumentation demonstrated here improves

  14. Determination of contrast media administration to achieve a targeted contrast enhancement in CT

    Science.gov (United States)

    Sahbaee, Pooyan; Li, Yuan; Segars, Paul; Marin, Daniele; Nelson, Rendon; Samei, Ehsan

    2015-03-01

    Contrast enhancement is a key component of CT imaging and offer opportunities for optimization. The design and optimization of new techniques however requires orchestration with the scan parameters and further a methodology to relate contrast enhancement and injection function. In this study, we used such a methodology to develop a method, analytical inverse method, to predict the required injection function to achieve a desired contrast enhancement in a given organ by incorporation of a physiologically based compartmental model. The method was evaluated across 32 different target contrast enhancement functions for aorta, kidney, stomach, small intestine, and liver. The results exhibited that the analytical inverse method offers accurate performance with error in the range of 10% deviation between the predicted and desired organ enhancement curves. However, this method is incapable of predicting the injection function based on the liver enhancement. The findings of this study can be useful in optimizing contrast medium injection function as well as the scan timing to provide more consistency in the way that the contrast enhanced CT examinations are performed. To our knowledge, this work is one of the first attempts to predict the contrast material injection function for a desired organ enhancement curve.

  15. Iodine-based contrast media, multiple myeloma and monoclonal gammopathies: literature review and ESUR Contrast Media Safety Committee guidelines.

    Science.gov (United States)

    Stacul, Fulvio; Bertolotto, Michele; Thomsen, Henrik S; Pozzato, Gabriele; Ugolini, Donatella; Bellin, Marie-France; Bongartz, Georg; Clement, Olivier; Heinz-Peer, Gertraud; van der Molen, Aart; Reimer, Peter; Webb, Judith A W

    2018-02-01

    Many radiologists and clinicians still consider multiple myeloma (MM) and monoclonal gammopathies (MG) a contraindication for using iodine-based contrast media. The ESUR Contrast Media Safety Committee performed a systematic review of the incidence of post-contrast acute kidney injury (PC-AKI) in these patients. A systematic search in Medline and Scopus databases was performed for renal function deterioration studies in patients with MM or MG following administration of iodine-based contrast media. Data collection and analysis were performed according to the PRISMA statement 2009. Eligibility criteria and methods of analysis were specified in advance. Cohort and case-control studies reporting changes in renal function were included. Thirteen studies were selected that reported 824 iodine-based contrast medium administrations in 642 patients with MM or MG, in which 12 unconfounded cases of PC-AKI were found (1.6 %). The majority of patients had intravenous urography with high osmolality ionic contrast media after preparatory dehydration and purgation. MM and MG alone are not risk factors for PC-AKI. However, the risk of PC-AKI may become significant in dehydrated patients with impaired renal function. Hypercalcaemia may increase the risk of kidney damage, and should be corrected before contrast medium administration. Assessment for Bence-Jones proteinuria is not necessary. • Monoclonal gammopathies including multiple myeloma are a large spectrum of disorders. • In monoclonal gammopathy with normal renal function, PC-AKI risk is not increased. • Renal function is often reduced in myeloma, increasing the risk of PC-AKI. • Correction of hypercalcaemia is necessary in myeloma before iodine-based contrast medium administration. • Bence-Jones proteinuria assessment in myeloma is unnecessary before iodine-based contrast medium administration.

  16. Systems and methods for separating particles utilizing engineered acoustic contrast capture particles

    Energy Technology Data Exchange (ETDEWEB)

    Kaduchak, Gregory; Ward, Michael D.

    2018-03-06

    An apparatus for separating particles from a medium includes a capillary defining a flow path therein that is in fluid communication with a medium source. The medium source includes engineered acoustic contrast capture particle having a predetermined acoustic contrast. The apparatus includes a vibration generator that is operable to produce at least one acoustic field within the flow path. The acoustic field produces a force potential minima for positive acoustic contrast particles and a force potential minima for negative acoustic contrast particles in the flow path and drives the engineered acoustic contrast capture particles to either the force potential minima for positive acoustic contrast particles or the force potential minima for negative acoustic contrast particles.

  17. Contrast Agent in Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Vu-Quang, Hieu

    2015-01-01

    cancer cells for cancer diagnosis in MRI. F127-Folate coated SPION were stable in various types of suspension medium for over six months. They could specifically target folate receptor of cancer cells in vitro and in vivo thus enhancing the contrast in MRI T2/T2* weighted images. These are preliminary...... for chemotherapy. The nanoparticles were 150 nm in size with spherical shape, which contained PFOB in the inner core and Dox and ICG in the polymeric shell. More importantly, they could target folate receptor expressing cancer cells, which provide positive in vitro and in vivo NIR and 19F MRI results. In project...

  18. Improvements in gastric diagnosis by using high density contrast media with low viscosity

    International Nuclear Information System (INIS)

    Toischer, H.P.

    1983-01-01

    In a retrospective clinical study, 150 unselected double contrast examinations of the stomach using conventional contrast media (100 g/100 ml barium sulphate) were compared with a similar number of examinations using a high density contrast medium of flow viscosity (250 g/100 ml barium sulphate). The high density contrast medium was distinctly better for demonstrating detail of the gastric mucosa. The uneveness of coating and instability of the older high density contrast media was observed in 15.5% of cases and, in no instance, did this make it impossible to reach a diagnosis. (orig.) [de

  19. Alterations of serum potassium, serum magnesium and adenosine diphosphate due to various contrast media containing iodine

    International Nuclear Information System (INIS)

    Lehrberger, G.

    1979-01-01

    As an introduction of the chemical structure of contrast media is explained. Then follows a survey about the complication rates in examinations with intravascularly applicable iodine-containing contrast media. In the next part clinical symptoms and signs of general and localized contrast media incompatibility reactions, the contrast medium protein reaction and the relationship between allergic reaction and contrast medium are explained. It was tried to attribute the large amount of side-effects to one primary reaction. In this connection the three above-mentioned components were investigated. (orig./MG) [de

  20. Contrast Invariant SNR

    DEFF Research Database (Denmark)

    Weiss, Pierre; Escande, Paul; Dong, Yiqiu

    We design an image quality measure independent of local contrast changes, which constitute simple models of illumination changes. Given two images, the algorithm provides the image closest to the first one with the component tree of the second. This problem can be cast as a specific convex progra...... algorithms based on interior point methods. The algorithm has potential applications in change detection, color image processing or image fusion. A Matlab implementation is available at http://www.math.univ-toulouse.fr/_weiss/PageCodes.html.......We design an image quality measure independent of local contrast changes, which constitute simple models of illumination changes. Given two images, the algorithm provides the image closest to the first one with the component tree of the second. This problem can be cast as a specific convex program...... called isotonic regression. We provide a few analytic properties of the solutions to this problem. We also design a tailored first order optimization procedure together with a full complexity analysis. The proposed method turns out to be practically more efficient and reliable than the best existing...

  1. Pharmacodynamics and tolerance of X-ray contrast media

    International Nuclear Information System (INIS)

    Schmiedel, E.

    1987-01-01

    The improved tolerance of nonionic contrast media compared with conventional contrast media is mainly due to their lower osmolality and reduced allergoid potential. Tolerance advantages that have been definitely proven are, for example, low-pain contrast medium injection and superior systemic tolerance; side effects of an allergic pattern occur less often. Animals experiments have established that nonionic contrast media exercise a comparatively lower influence on the cardiovascular system. The haemodynamics of pulmonary circulation are less adversely affected on intravenous bolus injection. Reduced potential risk is to be expected especially in cardiac and bronchopulmonary high-risk patients. The reduced nephrotoxicity of nonionic contrast media was definitely established by clinical studies. Further systematic studies will however be required to provide an answer to the question whether this also entails a reduction in the incidence of renal failures induced by contrast media. (orig.) [de

  2. Effects of radiographic contrast media on the serum complement system

    International Nuclear Information System (INIS)

    Tirone, P.; Boldrini, E.

    1983-01-01

    The authors explored the activation of the complement system produced by a nonionic organic iodine compound, namely iopamidol, which is proposed as a contrast medium for radiographic examination by intravenous and intra-arterial injection. The study was conducted in vitro versus established ionic contrasts (diatrizoate, iothalamate, acetrizoate) and a nonionic compound (metrizamide). The adopted experimental model was the immunohemolytic detector system, in which the immune complex consisted of goat erythrocytes sensitized with the corresponding antibody (hemolysin), and complement (C') was supplied by guinea pig serum. All the products caused complement activation. The results show that nonionic contrast media produce less activation of the complement system than the traditional ionic contrast. Thus the use of nonionic contrast for radiological procedures necessitating the introduction of contrast material into the blood compartment would imply a reduced risk of anaphylactoid reactions. (orig.)

  3. A method for the investigation of cholegraphic contrast media

    International Nuclear Information System (INIS)

    Otto, H.

    1982-01-01

    Isolated perfused rat livers were used for investigating possible interactions between two simultaneously injected contrast media, and which technique, using parenteral application of cholegraphic media, is optimal. The results show that excretion of a parenteral contrast medium is reduced by giving an oral contrast medium at the same time. Simultaneous administration of two different contrast media therefore does not result in improved diagnostic information. The effect depends on the dose, and a sufficiently long interval should be observed between giving an oral and a parenteral contrast medium. A comparison of excretion values following injection of a bolus and prolonged infusion shows higher biliary contrast concentration and increased excretion after a single injection. Comparing only the period after the infusion, no difference was found between these two methods of administration. The single injection offers pharmacokinetic advantages, but an infusion is better tolerated and has fewer side effects. A rapid infusion of 10 to 15 minutes is therefore recommended as the optimal means of administration. (orig.) [de

  4. Contrast-enhanced MR imaging monitoring of acute tumor response to chemotherapy

    International Nuclear Information System (INIS)

    Ranney, D.F.; Cohen, J.M.; Antich, P.P.; Endman, W.A.; Kulkarni, P.; Weinreb, J.C.; Giovanella, B.

    1987-01-01

    Treatment responses of human malignant melanomas were monitored at millimeter resolution in athymic mice by injecting a new polymeric contrast agent, Gd-DTPA-dextran (0.1 mmol Gd/kg, intravenously). Proton MR imaging (0.35 T, spin-echo, repetition time = 0.5 second, echo time = 50 msec) was performed 30 hours after administering diphtheria toxin. Pre-contrast medium images revealed only homogeneous intermediate-intensity tumor masses. Post-contrast medium images of untreated (viable) tumors demonstrated 32% enhancement throughout the entire mass. Post-contrast medium images of toxin-treated tumors revealed marked enhancement (65%) of the histologically viable outer rims, lesser enhancement (38%) of heavily damaged subregions, and no enhancement of dead tumor. These acute, contrast medium-enhanced MR images accurately identified tumor subregions that survived for longer than one week

  5. New MR contrast agent

    International Nuclear Information System (INIS)

    Grossman, C.D.; Subramanian, G.; Schneider, R.; Szeverenyi, N.E.; Rosenbaum, A.M.; Gagne, G.; Tillapaugh-Fay, G.; Berlin, R.; Ritter-Hrncirik, C.; Yu, S.

    1990-01-01

    This paper evaluates an MR contrast agent-meglumine tris-(2,6-dicarboxypyridine) gadolinium (III) or gadolinium dipicolinate (Gd-DPC)-produced in-house. Rats were anesthetized with pentobarbital. For renal imaging, bowel motion artifact was minimized with glucagon (0.014 mg/kg, intravenous (IV)). Enhanced images were generated on a 2-T chemical shift imaging system with a 31-cm horizontal bore magnet after IV injection of Gd-DPC (100 μM/kg). Coronal sections of the kidneys and sagittal sections of the brain, 2 mm thick, were made. Six to eight excitations and 128 or 356 phase-encoding steps were used for each image. Control animals were injected with equivalent doses of gadopentetate dimeglumine

  6. Contrast enhancement of mail piece images

    Science.gov (United States)

    Shin, Yong-Chul; Sridhar, Ramalingam; Demjanenko, Victor; Palumbo, Paul W.; Hull, Jonathan J.

    1992-08-01

    A New approach to contrast enhancement of mail piece images is presented. The contrast enhancement is used as a preprocessing step in the real-time address block location (RT-ABL) system. The RT-ABL system processes a stream of mail piece images and locates destination address blocks. Most of the mail pieces (classified into letters) show high contrast between background and foreground. As an extreme case, however, the seasonal greeting cards usually use colored envelopes which results in reduced contrast osured by an error rate by using a linear distributed associative memory (DAM). The DAM is trained to recognize the spectra of three classes of images: with high, medium, and low OCR error rates. The DAM is not forced to make a classification every time. It is allowed to reject as unknown a spectrum presented that does not closely resemble any that has been stored in the DAM. The DAM was fairly accurate with noisy images but conservative (i.e., rejected several text images as unknowns) when there was little ground and foreground degradations without affecting the nondegraded images. This approach provides local enhancement which adapts to local features. In order to simplify the computation of A and (sigma) , dynamic programming technique is used. Implementation details, performance, and the results on test images are presented in this paper.

  7. Oral contrast agents in abdominal MR imaging

    International Nuclear Information System (INIS)

    Heuck, A.F.; Schhidbauer, E.; Allgayer, B.

    1991-01-01

    This paper compares Gd-DTPA, FE 2+ SO 4 , and Fe 2 Cl 3 -EDTA solutions as oral contrast agents in abdominal/pelvic MR imaging. MR imaging was performed at 1.5 T in 62 patients with tumors or inflammatory disorders of the abdomen and pelvis and in 28 normal volunteers. After precontrast imaging, an oral contrast medium was administered. Thirty subjects received 700-1,200 mL of a Gd-DTPA solution (1.0 mM; 15 g of mannitol per liter), 30 ingested the same amount of 5.0 mM Fe 2+ SO 4 , and 30 received Fe 2 Cl 3 -EDTA solution. The postcontrast study included T1- and T2-weighted spin-echo sequences and T1- and T2*-weighted gradient-echo sequences. Bowel peristalsis was reduced with intravenous application of Buscopan. Gd-DTPA, Fe 2+ SO 4 solution, and Fe 2 Cl 3 -EDTA solution provided homogeneous hyperintense signal intensity and high contrast of stomach and duodenum in all sequences, with significantly improved delineation of pathologic structures and abdominal organs in 78% of cases. Best contrast was achieved in T1-weighted sequences

  8. Contrast media for radiological examination in gastrointestinal tract leakage

    NARCIS (Netherlands)

    A.Z. Ginai (Abida)

    1987-01-01

    textabstractThe aim of this investigation has been to find a safe and suitable contrast medium for radiological evaluation of the gastrointestinal tract in cases where leakage outside the GIT can be suspected. Leakage outside the gastro-intestinal tract lumen can occur in many ways eg.,

  9. Ameliorative effect of green tea against contrast-induced renal tubular cell injury.

    Science.gov (United States)

    Nasri, Hamid; Hajian, Shabnam; Ahmadi, Ali; Baradaran, Azar; Kohi, Golnoosh; Nasri, Parto; Rafieian-Kopaei, Mahmoud

    2015-11-01

    Reactive oxygen species are a mediator of kidney damage by contrast media, and green tea is a potent-free radical scavenger. This study was designed to examine whether green tea could protect against the nephrotoxicity induced by contrast media. Forty rats were randomly divided into 4 groups. Group 1 was control; group 2 received contrast medium (intravenous iodixanol, 10 mL/kg, as a single dose); group 3 received contrast medium and then green tea extract for 3 days (10 mg/kg/d, intraperitoneal); and group 4 first received green tea and then contrast medium. Histological changes (degeneration, vacuolization of tubular renal cells, dilatation of tubular lumen, and presence of debris in the lumens) were assessed and recorded as scores from zero to 4. The sum of scores were used as the overal renal injury level. Groups 3 and 4 with green tea treatment had significantly higher overall scores than the control group, but significantly lower scores than group 2 with contrast medium only. A similar trend was seen for dilatation and degeneration levels. Vacuolization level was not significantly lower in the green tea groups as compared to the contrast medium group. Debris level was not significantly lower in group 3 than group 2. The differences were not significant between groups 3 and 4.   Conclusions. We observed beneficial effect of green tea against nephrotoxicity of contrast media. Green tea extract may offer an inexpensive and nontoxic intervention strategy in patients with a risk for nephrotoxicity with contrast media.

  10. Contrast media induced acute renal failure in diabetics

    International Nuclear Information System (INIS)

    Rambausek, M.

    1985-01-01

    Dehydration, preexisting renal insufficiency, multiple myeloma and insulin-dependent diabetes mellitus are known risk factors for a radiocontrast medium induced acute renal failure. In 90% of patients with insulin-dependent diabetes mellitus, renal insufficiency and proteinuria, a further detoriation of renal function can be expected after i.v. administration of radiocontrast medium. Recent concepts on the genesis of acute renal failure after radiocontrast medium in multiple myeloma emphasize the role of tubular blocade (tubular precipitation of myeloma protein with contrast medium). In insulin-dependent diabetic patients we found altered carbohydrate composition of urinary Tamm Horsfall Protein (THP), with increased glucose and diminished N-acetyl-neuraminicacid content. This was paralleled by a difference in an in-vitro system of coprecipitation where THP of diabetes triggered more pronounced calcium dependent coprecipitation of contrast medium and albumin. These in-vitro findings might be important for the explanation of the genesis of radiocontrast medium-induced acute renal failure in insulin-dependent diabetes mellitus. (orig.) [de

  11. The interaction of radiographic contrast media with immune globulins

    International Nuclear Information System (INIS)

    Bauer, K.

    1983-01-01

    As a special form of contrast medium incidents, various reaction modes between iodinated contrast media and immunoglobulins are described. Theoretical explanations and typical examples are given for each of the four different possible action mechanisms. Diagnostic precautions are proposed in order to avoid unfavourable reactions especially with paraproteins. Special attention is drawn to the antigen-antibody like reaction between iodinated contrast media and IgM paraproteins. Some immunological criteria are recalled to attention, this type of reaction has to meet stringently. Only by this, misinterpretations of inevident conclusions from analogy can be prevented in future similar cases. (orig.) [de

  12. Medium energy heavy ion operations at RHIC

    International Nuclear Information System (INIS)

    Drees, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blackler, I.M.C.; Blaskiewicz, M.; Brown, K.A.; Brennan, M.; Bruno, D.; Butler, J.; Carlson, C.; Connolly, R.; D'Ottavio, T.; Fischer, W.; Fu, W.; Gassner, D.; Harvey, M.; Hayes, T.; Huang, H.; Hulsart, R.; Ingrassia, P.; Kling, N.; Lafky, M.; Laster, J.; Lee, R.C.; Litvinenko, V.; Luo, Y.; MacKay, W.W.; Marr, G.; Mapes, M.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Naylor, C.; Nemesure, S.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Sampson, P.; Satogata, T.; Schoefer, V.; Schultheiss, C.; Severino, F.; Shrey, T.; Smith, K.S.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; van Kuik, B.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

    2011-01-01

    As part of the search for a phase transition or critical point on the QCD phase diagram, an energy scan including 5 different energy settings was performed during the 2010 RHIC heavy ion run. While the top beam energy for heavy ions is at 100 GeV/n and the lowest achieved energy setpoint was significantly below RHICs injection energy of approximately 10 GeV/n, we also provided beams for data taking in a medium energy range above injection energy and below top beam energy. This paper reviews RHIC experience and challenges for RHIC medium energy operations that produced full experimental data sets at beam energies of 31.2 GeV/n and 19.5 GeV/n. The medium energy AuAu run covered two beam energies, both above the RHIC injection energy of 9.8 GeV but well below the standard store energy of 100 GeV (see table 1). The low energy and full energy runs with heavy ions in FY10 are summarized in (1) and (2). Stochastic Cooling ((3)) was only used for 100 GeV beams and not used in the medium energy run. The efficiency of the transition from 100 GeV operation to 31.2 GeV and then to 19.5 GeV was remarkable. Setup took 32 h and 19 h respectively for the two energy settings. The time in store, defined to be the percentage of time RHIC provides beams in physics conditions versus calendar time, was approximately 52% for the entire FY10 heavy ion run. In both medium energy runs it was well above this average, 68% for 31.5 GeV and 82% for 19.5 GeV. For both energies RHIC was filled with 111 bunches with 1.2 10 9 and 1.3 10 9 ions per bunch respectively.

  13. Medium energy heavy ion operations at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Drees, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blackler, I.M.C.; Blaskiewicz, M.; Brown, K.A.; Brennan, M.; Bruno, D.; Butler, J.; Carlson, C.; Connolly, R.; D' Ottavio, T.; Fischer, W.; Fu, W.; Gassner, D.; Harvey, M.; Hayes, T.; Huang, H.; Hulsart, R.; Ingrassia, P.; Kling, N.; Lafky, M.; Laster, J.; Lee, R.C.; Litvinenko, V.; Luo, Y.; MacKay, W.W.; Marr, G.; Mapes. M.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Naylor, C.; Nemesure, S.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Sampson, P.; Satogata, T.; Schoefer, V.; Schultheiss, C.; Severino, F.; Shrey, T.; Smith, K.S.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; van Kuik, B.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

    2011-03-28

    As part of the search for a phase transition or critical point on the QCD phase diagram, an energy scan including 5 different energy settings was performed during the 2010 RHIC heavy ion run. While the top beam energy for heavy ions is at 100 GeV/n and the lowest achieved energy setpoint was significantly below RHICs injection energy of approximately 10 GeV/n, we also provided beams for data taking in a medium energy range above injection energy and below top beam energy. This paper reviews RHIC experience and challenges for RHIC medium energy operations that produced full experimental data sets at beam energies of 31.2 GeV/n and 19.5 GeV/n. The medium energy AuAu run covered two beam energies, both above the RHIC injection energy of 9.8 GeV but well below the standard store energy of 100 GeV (see table 1). The low energy and full energy runs with heavy ions in FY10 are summarized in [1] and [2]. Stochastic Cooling ([3]) was only used for 100 GeV beams and not used in the medium energy run. The efficiency of the transition from 100 GeV operation to 31.2 GeV and then to 19.5 GeV was remarkable. Setup took 32 h and 19 h respectively for the two energy settings. The time in store, defined to be the percentage of time RHIC provides beams in physics conditions versus calendar time, was approximately 52% for the entire FY10 heavy ion run. In both medium energy runs it was well above this average, 68% for 31.5 GeV and 82% for 19.5 GeV. For both energies RHIC was filled with 111 bunches with 1.2 10{sup 9} and 1.3 10{sup 9} ions per bunch respectively.

  14. Comparative study of pneumocystography, positive contrast cystography and double contrast cystography in dogs

    International Nuclear Information System (INIS)

    Thibaut, J.; Parada, E.; Vargas, L.; Deppe, R.; Born, R.

    1997-01-01

    In order to compare three radiographic techniques: pneumocystography, positive contrast cystography and double contrast cystography, three series of 24 radiographs each in lateral and ventrodorsal projections were made. Six healthy adult male dogs with weight ranging between 7 and 16 kg were used. Food was withheld for 24 hours and two enemas were made before the series of radiographs were taken. Dogs were anaesthetized with sodium thiopental (20 mg/kg i.v.). The contrast medium was introduced through a urethral catheter. Pneumocystography was performed in the first series introducing air (10 ml/kg) in the bladder. Positive contrast cystography was performed in the second series introducing Hypaque M-60% diluted, contributing 100 mg of iodine per ml (10 ml/kg). In the double contrast cystography Hypaque M-60% diluted (10 ml) was introduced, in concentration of 150 mg of iodine per ml. Then air was introduced (10 ml/kg) through a catheter. Plates were taken in both projections at 1 and 10 minutes for each technique. The radiographic plates of each series were analized comparing the characteristics of radiographic density, outline and size. In neumocystography, positive contrast and double contrast cystography, the radiographic density was predominantly low, high and intermediate, respectively. The radiographic outline was mainly regular for the three techniques. With respect to bladder size, there was a decrease of height and an increase of length and width at 10 minutes. Comparing these three radiographic techniques, it can be concluded that the one that best outlines the bladder mucosa is double contrast. Pneumocystography provides the best image for opaque structures and cystography best shows the position of the urinary bladder [es

  15. Financial reporting by small and medium enterprises in Thailand

    OpenAIRE

    Ploybut, Sutthirat

    2012-01-01

    The increasing complexity of financial reporting requirements, especially accounting standards, leads many countries to consider moving to simpler reporting requirements for small and medium enterprises (SMEs) in order to reduce reporting burdens. In response to such concern, the International Accounting Standards Board (IASB) also released the IFRS for SMEs, an international accounting standard intended for SMEs worldwide. In Thailand, SMEs are required by law to prepare and publish general ...

  16. MR mammography: influence of menstrual cycle on the dynamic contrast enhancement of fibrocystic disease

    Energy Technology Data Exchange (ETDEWEB)

    Rieber, A.; Nuessle, K.; Merkle, E.; Tomczak, R.; Brambs, H.J. [Ulm Univ. (Germany). Abt. Radiologie 1 (Roentgendiagnostik); Kreienberg, R. [Ulm Univ. (Germany). Dept. of Gynecology

    1999-08-01

    Magnetic resonance mammography (MRM) provides data regarding the nature of tumours based on contrast medium dynamics; fibrocystic changes in the breast, however, may lead to false-positive results. This study investigated whether the contrast medium dynamics of fibrocystic changes are dependent on the menstrual cycle. Twenty-four patients with palpable lumps but normal mammographies and ultrasound studies were examined. The MRM technique was performed during the first and second part of the menstrual cycle using a FLASH 3D sequence, both native and at 1, 2, 3 and 8 min after intravenous application of 0.15 mmol/kg body weight of gadodiamide. The calculated time-intensity curves were evaluated based on the following criteria: early percentage of contrast medium uptake in relation to the native value; formation of a plateau phenomenon after the second minute; the point of maximal contrast medium uptake; and calculation of the contrast enhancing index. During the second half of the menstrual cycle, a generally greater contrast medium uptake was observed. Nevertheless, when further diagnostic criteria, such as continuous contrast medium increase as a function of time, were considered, there was no increased rate of false-positive findings. The phase of the menstrual cycle may affect the specificity of the examination, if only the quantitative contrast medium uptake and the percentage of contrast medium uptake in the first 2 min are considered. A control MRM during the other half of the cycle may then be indicated and additional diagnostic criteria may improve specificity. (orig.) With 2 figs., 2 tabs., 24 refs.

  17. X-ray phase-contrast imaging

    Science.gov (United States)

    Endrizzi, Marco

    2018-01-01

    X-ray imaging is a standard tool for the non-destructive inspection of the internal structure of samples. It finds application in a vast diversity of fields: medicine, biology, many engineering disciplines, palaeontology and earth sciences are just few examples. The fundamental principle underpinning the image formation have remained the same for over a century: the X-rays traversing the sample are subjected to different amount of absorption in different parts of the sample. By means of phase-sensitive techniques it is possible to generate contrast also in relation to the phase shifts imparted by the sample and to extend the capabilities of X-ray imaging to those details that lack enough absorption contrast to be visualised in conventional radiography. A general overview of X-ray phase contrast imaging techniques is presented in this review, along with more recent advances in this fast evolving field and some examples of applications.

  18. Double contrast gastrography in dogs.

    Science.gov (United States)

    Kumar, R; Peshin, P K; Nigam, J M

    1981-09-01

    For experimental evaluation of double contrast gastrography in 9 dogs, sodium iothalamate and air were used for positive and negative contrast, respectively, to delineate the gastric mucosa. The technic was simple and reasonably safe. Results were satisfactory when the stomach was empty, and appropriate volumes of contrast materials were evenly distributed.

  19. Pions in the nuclear medium

    International Nuclear Information System (INIS)

    Chanfray, G.

    1996-07-01

    We discuss various aspects of pion physics in the nuclear medium. We first study s-wave pion-nucleus interaction in connection with chiral symmetry restoration and quark condensate in the nuclear medium. We then address the question of p-wave pion-nucleus interaction and collective pionic modes in nuclei and draw the consequences for in medium ππ correlations especially in the scalar-isoscalar channel. We finally discuss the modification of the rho meson mass spectrum at finite density and/or temperature in connection with relativistic heavy ion collisions

  20. Serum-free human MSC medium supports consistency in human but not in equine adipose-derived multipotent mesenchymal stromal cell culture.

    Science.gov (United States)

    Schubert, Susanna; Brehm, Walter; Hillmann, Aline; Burk, Janina

    2018-01-01

    For clinical applications of multipotent mesenchymal stromal cells (MSCs), serum-free culture is preferable to standardize cell products and prevent contamination with pathogens. In contrast to human MSCs, knowledge on serum-free culture of large animal MSCs is limited, despite its relevance for preclinical studies and development of veterinary cellular therapeutics. This study aimed to evaluate the suitability of a commercially available serum-free human MSC medium for culturing equine adipose-derived MSCs in comparison with human adipose MSCs. Enzyme-free isolation by explant technique and expansion of equine and human cells in the serum-free medium were feasible. However, serum-free culture altered the morphology and complicated handling of equine MSCs, with cell aggregation and spontaneous detachment of multilayers, compared to culture in standard medium supplemented with fetal bovine serum. Furthermore, proliferation and the surface immunophenotype of equine cells were more variable compared to the controls and appeared to depend on the lot of the serum-free medium. Particularly the expression of CD90 was different between experimental groups (P cultured in serum-free medium (5.21-83.40%) compared to standard medium (86.20-99.50%). Additionally, small subpopulations expressing MSC exclusion markers such as CD14 (0.28-11.60%), CD34 (0.00-9.87%), CD45 (0.35-10.50%), or MHCII (0.00-3.67%) were found in equine samples after serum-free culture. In contrast, human samples displayed a more consistent morphology and a consistent CD29 + (98.60-99.90%), CD73 + (94.60-98.40%), CD90 + (99.60-99.90%), and CD105 + (97.40-99.80%) immunophenotype after culture in serum-free medium. The obtained data demonstrate that the serum-free medium was suitable for human MSC culture but did not lead to entirely satisfactory results in equine MSCs. This underlines that requirements regarding serum-free culture conditions are species-specific, indicating a need for serum-free media to

  1. Distributed medium access control in wireless networks

    CERN Document Server

    Wang, Ping

    2013-01-01

    This brief investigates distributed medium access control (MAC) with QoS provisioning for both single- and multi-hop wireless networks including wireless local area networks (WLANs), wireless ad hoc networks, and wireless mesh networks. For WLANs, an efficient MAC scheme and a call admission control algorithm are presented to provide guaranteed QoS for voice traffic and, at the same time, increase the voice capacity significantly compared with the current WLAN standard. In addition, a novel token-based scheduling scheme is proposed to provide great flexibility and facility to the network servi

  2. Physical experiments on the utility of non-iodine-containing contrast media

    International Nuclear Information System (INIS)

    Kirschner, H.; Burmester, U.; Stringaris, K.; Jentsch, F.

    1979-01-01

    Because of the excellent ability of the CT scanner in analyzing absorption, the use of non-iodine-containing contrast media will be discussed. Experimental studies of the chemical elements with the atomic number Z = 1-83 with a scan tension of 120 kV were made to determine how many atoms of a given element are necessary to replace one iodine atom in an iodine-containing contrast medium, whereby the same contrast enhancement in the scan picture as with the iodine-containing contrast medium is produced. (orig.) 891 ORU/orig. 892 MB [de

  3. Organizational liability for adverse reactions to the contrast media

    International Nuclear Information System (INIS)

    Lim, Chang Seon

    2007-01-01

    Contrast medium is a very useful tool for X-ray examinations. But contrast medium has some unavoidable adverse reactions. For those patients who have never received contrast medium before, it is impossible to predict whether they will suffer from certain kinds of adverse reactions. Thus, radiologists should use strategies to minimize adverse events and be prepared to promptly recognize and manage any reactions to the contrast media. If a radiologist commits medical malpractice, he will face civil responsibility. Medical malpractice means a tort or breach of contrast that occurs in a medical setting. Medical malpractices happen, despite the efforts of hospital staff. Many courts have applied the traditional doctrine of respondeat superior in actions against organizations for injuries caused by their employees. It is a legal doctrine, which states that an employer is responsible for employee actions performed within the course of the employment. A hospital is an organization for health purposes. An organization may be convicted of an offense committed by an employee of the organization acting in its behalf and within the scope of this office or employment. Organizational liability involves a wide variety of legal issues, including tort liability, wrongful employment practices, personal injury, breach of fiduciary duty, and so on. Many executive directors of organizations are aware of their personal and organizational risks of exposure to legal liabilities. The employer must have the right to control the physical conduct of the employee and must consent to receive the employee's services, while expecting some benefits from the services offered. Therefore, legal liability can be imposed for improper selection, assignment, training, and supervision of employees. In conclusion, the hospital itself has organizational liability for adverse reactions to the contrast medium

  4. Organizational liability for adverse reactions to the contrast media

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Chang Seon [Konyang University, Daejeon (Korea, Republic of)

    2007-06-15

    Contrast medium is a very useful tool for X-ray examinations. But contrast medium has some unavoidable adverse reactions. For those patients who have never received contrast medium before, it is impossible to predict whether they will suffer from certain kinds of adverse reactions. Thus, radiologists should use strategies to minimize adverse events and be prepared to promptly recognize and manage any reactions to the contrast media. If a radiologist commits medical malpractice, he will face civil responsibility. Medical malpractice means a tort or breach of contrast that occurs in a medical setting. Medical malpractices happen, despite the efforts of hospital staff. Many courts have applied the traditional doctrine of respondeat superior in actions against organizations for injuries caused by their employees. It is a legal doctrine, which states that an employer is responsible for employee actions performed within the course of the employment. A hospital is an organization for health purposes. An organization may be convicted of an offense committed by an employee of the organization acting in its behalf and within the scope of this office or employment. Organizational liability involves a wide variety of legal issues, including tort liability, wrongful employment practices, personal injury, breach of fiduciary duty, and so on. Many executive directors of organizations are aware of their personal and organizational risks of exposure to legal liabilities. The employer must have the right to control the physical conduct of the employee and must consent to receive the employee's services, while expecting some benefits from the services offered. Therefore, legal liability can be imposed for improper selection, assignment, training, and supervision of employees. In conclusion, the hospital itself has organizational liability for adverse reactions to the contrast medium.

  5. Phase contrast STEM for thin samples: Integrated differential phase contrast

    Energy Technology Data Exchange (ETDEWEB)

    Lazić, Ivan, E-mail: ivan.lazic@fei.com; Bosch, Eric G.T.; Lazar, Sorin

    2016-01-15

    It has been known since the 1970s that the movement of the center of mass (COM) of a convergent beam electron diffraction (CBED) pattern is linearly related to the (projected) electrical field in the sample. We re-derive a contrast transfer function (CTF) for a scanning transmission electron microscopy (STEM) imaging technique based on this movement from the point of view of image formation and continue by performing a two-dimensional integration on the two images based on the two components of the COM movement. The resulting integrated COM (iCOM) STEM technique yields a scalar image that is linear in the phase shift caused by the sample and therefore also in the local (projected) electrostatic potential field of a thin sample. We confirm that the differential phase contrast (DPC) STEM technique using a segmented detector with 4 quadrants (4Q) yields a good approximation for the COM movement. Performing a two-dimensional integration, just as for the COM, we obtain an integrated DPC (iDPC) image which is approximately linear in the phase of the sample. Beside deriving the CTFs of iCOM and iDPC, we clearly point out the objects of the two corresponding imaging techniques, and highlight the differences to objects corresponding to COM-, DPC-, and (HA) ADF-STEM. The theory is validated with simulations and we present first experimental results of the iDPC-STEM technique showing its capability for imaging both light and heavy elements with atomic resolution and a good signal to noise ratio (SNR). - Highlights: • First DPC-based atomic resolution images of potential and charge density are obtained. • This is enabled by integration and differentiation of 2D DPC signals, respectively. • Integrated DPC (iDPC) based on 4 quadrant imaging is compared to iCOM imaging. • Noise analysis and comparison with standard STEM imaging modes is provided. • iDPC allows direct imaging of light (C, N, O …) and heavy (Ga, Au …) atoms together.

  6. Post double-contrast sigmoid flush: An adjuvant technique in imaging diverticular disease

    International Nuclear Information System (INIS)

    Lappas, J.C.; Maglinte, D.D.T.; Kopecky, K.K.; Cockerill, E.M.; Lehman, G.A.

    1987-01-01

    In a prospective study, the effect of a low-density contrast medium infusion was evaluated as an adjunct to high-density double-contrast medium sigmoid imaging. Following a double-contrast medium barium enema (DCBE), 52 consecutive patients with sigmoid diverticulosis received an additional 500-700-mL enema with either water or a 1.5%CT barium suspension. Rectosigmoid films were evaluated for luminal distention, visualization of the interhaustral space, definition of diverticula, and interpretation of polypoid defects. While double-contrast medium views were excellent in 21%, improvement in multiple factors by water or 1.5% barium flush resulted in improved sigmoid images in 65% and 73% of patients, respectively. Polyps may be confirmed and artifactual defects confidently excluded. Sigmoid flush, particularly with low-density barium, is a simple adjunct to DCBE that improves visualization of the diverticular sigmoid

  7. Contrast bolus technique with rapid CT scanning

    International Nuclear Information System (INIS)

    Arnold, H.; Kuehne, D.; Rohr, W.; Heller, M.

    1981-01-01

    Twenty-three patients complying with the clinical criteria for brain death were studied by contrast-enhanced CT. In all but one, the great intracranial vessels escaped visualization; accordingly, angiography demonstrated cerebral circulatory arrest. In the remaining case, faint enhancement of the circle of Willis corresponded to angiographic demonstration of the proximal segments of cerebral arteris. Neither in normal brain nor in dead brain did slow CT scanning disclose any postcontrast increase in parenchymal attenuation. An improved technique is proposed to demonstrate the transit of the contrast bolus by rapid CT with image splitting. If cerebral blood flow is preserved, the grey and white matter will enhance significantly following administration of contrast medium. Vice versa, the absence of enhancement confirms brain death, even in instances in which the great cerebral vessels are obscured by hemorrhage or other extensive lesions. Two additional cases of brain death were evaluated by rapid CT scanning. As to brain death, the technique obviates the need for angiography or radionuclide angiography, usually applied in prospective organ donors, because its informative content is superior to that of either method. The CT technique described affords a reliable and safe diagnosis of brain death, and can be interpreted easily. (orig.)

  8. Differential Medium for Vibrio cholerae

    Science.gov (United States)

    Schrank, Gordon D.; Stager, Charles E.; Verwey, W. F.

    1973-01-01

    A differential medium designed for rapid presumptive identification of Vibrio cholerae was described and shown to be useful for enumeration of viable cholera vibrios in the presence of other intestinal bacteria. Images PMID:4764406

  9. The Value of Contrast Echocardiography

    Directory of Open Access Journals (Sweden)

    Shannon C. Treiber

    2016-01-01

    Full Text Available Purpose: There is much evidence-based research proving the effectiveness of contrast echocardiography, but there are still questions and concerns about its specific uses. This study tested the effectiveness of contrast echocardiography in defining the left ventricular endocardial border. Methods: From 30 patients, a total of 60 echocardiograms –– 30 with and 30 without use of contrast –– were retrospectively reviewed by four blinded cardiologists with advanced training in echocardiography. No single cardiologist reviewed contrast and noncontrast images of the same patient. Each set of 30 echocardiograms was then studied for wall-motion scoring. Visualization of left ventricular wall segments and a global visualization confidence level of interpretation were recorded. Results: Of all wall segments (N = 510, 91% were visualized in echocardiograms with use of contrast, whereas 75% of the walls were visualized in echocardiograms without contrast (P < 0.001. Of 30 examinations, 17 contrast echocardiograms were read with high confidence compared to 6 without contrast use (P = 0.004. The number of walls visualized with contrast was increased in 18 patients (60%, whereas noncontrast echocardiograms yielded more visualized walls in 6 patients (20%, P = 0.002. Conclusions: This study demonstrates that contrast is valuable to echocardiographic imaging. Its use should be supported throughout echocardiography clinics and encouraged in certain patients for whom resting and stress echocardiography results without contrast often prove uninterpretable.

  10. Medium effects in direct reactions

    International Nuclear Information System (INIS)

    Karakoc, M; Bertulani, C

    2013-01-01

    We discuss medium corrections of the nucleon-nucleon (NN) cross sections and their influence on direct reactions at intermediate energies ≳50 MeV/nucleon. The results obtained with free NN cross sections are compared with those obtained with a geometrical treatment of Pauli-blocking and Dirac-Bruecker methods. We show that medium corrections may lead to sizable modifications for collisions at intermediate energies and that they are more pronounced in reactions involving weakly bound nuclei.

  11. The optimal use of contrast agents at high field MRI

    International Nuclear Information System (INIS)

    Trattnig, Siegfried; Pinker, Kathia; Ba-Ssalamah, Ahmed; Noebauer-Huhmann, Iris-Melanie

    2006-01-01

    The intravenous administration of a standard dose of conventional gadolinium-based contrast agents produces higher contrast between the tumor and normal brain at 3.0 Tesla (T) than at 1.5 T, which allows reducing the dose to half of the standard one to produce similar contrast at 3.0 T compared to 1.5 T. The assessment of cumulative triple-dose 3.0 T images obtained the best results in the detection of brain metastases compared to other sequences. The contrast agent dose for dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging at 3.0 T can be reduced to 0.1 mmol compared to 0.2 mmol at 1.5 T due to the increased susceptibility effects at higher magnetic field strengths. Contrast agent application makes susceptibility-weighted imaging (SWI) at 3.0 T clinically attractive, with an increase in spatial resolution within the same scan time. Whereas a double dose of conventional gadolinium-based contrast agents was optimal in SWI with respect to sensitivity and image quality, a standard dose of gadobenate dimeglumine, which has a two-fold higher T1-relaxivity in blood, produced the same effect. For MR-arthrography, optimized concentrations of gadolinium-based contrast agents are similar at 3.0 and 1.5 T. In summary, high field MRI requires the optimization of the contrast agent dose in different clinical applications. (orig.)

  12. The illusory nature of standards

    DEFF Research Database (Denmark)

    Linneberg, Mai Skjøtt

    2011-01-01

    Purpose – The purpose of this paper is to investigate the implications of the paradoxical situation in which standard setters are placed when standardising human practice. Contrary to standards, human practices are ambiguous, heterogeneous, and highly context dependent; in contrast, standards...

  13. Can contrast-enhanced ultrasonography improve Zone III REBOA placement for prehospital care?

    Science.gov (United States)

    Chaudery, Muzzafer; Clark, James; Morrison, Jonathan J; Wilson, Mark H; Bew, Duncan; Darzi, Ara

    2016-01-01

    Torso hemorrhage is the primary cause of potentially preventable mortality in trauma. Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been advocated as an adjunct to bridge patients to definitive hemorrhage control. The primary aim of this study was to assess whether contrast-enhanced ultrasonography can improve the accuracy of REBOA placement in the infrarenal aorta (Zone III). A fluoroscopy-free "enhanced" Zone III REBOA technique was developed using a porcine cadaver model. A "standard" over-the-wire Seldinger technique was used, which was enhanced with the addition of a microbubble contrast medium to inflate the balloon, observed with ultrasonography. Following this, attending- and resident-level physicians were randomized into two groups. They were taught either the enhanced with ultrasonography guidance (Group A) or the standard measuring length of catheter insertion (Group B) technique as part of a human cadaver trauma skills course. Outcomes assessed included time (seconds) from insertion to inflation, accuracy, and missed targets. All results were benchmarked against three endovascular experts. There were 20 participants who performed REBOA with Group A (51 [31]) being significantly faster than Group B (90 [63]) (p = 0.003) and more accurate (p = 0.023) with no missed targets. Group B had five missed targets, the most common error being inflation within Zone II. For Zone III REBOA, contrast-enhanced ultrasonography technique is faster and more accurate than the standard technique. This may have value in time-critical and austere environments. Clinical studies are now required to evaluate this approach further.

  14. Quality of roentgenological visualization and tolerance of various intravenous cholegraphic contrast media

    International Nuclear Information System (INIS)

    Tischendorf, P.

    1980-01-01

    The recently introduced intravenous cholegraphic contrast media produce a greater diagnostic yield in radiological routine thanks to improved roentgenological contrasting. Whereas the percentage share of roentgenologically clearly assessable cases is about 75% when using Biligrafin, this percentage is much higher with the more recent contrast media, especially Biliscopin, namely, up to 88%. These new contrast media are also superior in respect of tolerance, since they produce fewer side effects. While side effects must be expected in about 28% of the cases when injecting Biligrafin, the side effect quota is about 10% only with Biliscopin or Endomirabil. If the contrast medium is infused instead of injected, the quota of side effect drops to 2.3% with Biliscopin or 3.9% with Endomirabil. Slight and medium side effects have definitely decreased with the more recent contrast media. The slower and more continually the contrast medium is administered, the fewer are the side effects observed; this becomes particularly noticeable in the case of long-term infusions. However, the likelihood of severe incidents caused by the contrast medium remains unchanged at about 1% of the examined patients, even with the more recently introduced contrast media. (orig.) [de

  15. Properties of conventional contrast media

    International Nuclear Information System (INIS)

    Muetzel, W.

    1981-01-01

    A comprehensive overview is given of the properties of contrast media currently used in computed tomography (CT). The chemical structure of the compounds and the physicochemical properties derived therefrom are described. Emphasis is placed on the importance of the physicochemical properties of contrast media for tolerance and the pharmacokinetic behavior of compounds in the body. An outline is given of the basic ideas governing rational use of contrast media in CT, which result from complex, time-dependent distribution of contrast media in different tissue spaces. (Auth.)

  16. Nuclear magnetic resonance contrast agents

    Science.gov (United States)

    Smith, P.H.; Brainard, J.R.; Jarvinen, G.D.; Ryan, R.R.

    1997-12-30

    A family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC{sub 16}H{sub 14}N{sub 6}. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques. 10 figs.

  17. Defining Small and Medium Enterprises: a critical review

    Directory of Open Access Journals (Sweden)

    Gentrit Berisha

    2015-03-01

    Full Text Available The OECD estimates that small and medium enterprises account for 90% of firms and employ 63% of the workforce in the world (Munro: 2013. Small and medium enterprises account for that amount of businesses thatit is senseless the arbitrariness with which they are defined. Language mainly used for definition is numbers, but it is difficult to find two institutions, statistical agencies or countries who speak the same language in terms of small and medium enterprises. Academics, authors, policy makers apply SMEdefinitions in terms of dichotomy between universality and standardization of a unique definition and relativity and sectored specialization. Although qualitative criteria-characteristics of SMEs easily distinguish them from large businesses, quantitative criteria are mainlyused for their dimensional classification. This paper deals with a critical approachto the definition of small and medium enterprises, inconsistencies in criteria and various proposed approaches to the definition towards universal acceptance.

  18. Chemistry of the interstellar medium

    International Nuclear Information System (INIS)

    Umanskij, S.Ya.

    1979-01-01

    Some aspects of chemistry of interstellar gas-dust clouds are considered. The specific attention is paid to the molecule formation in the interstellar medium. Discussed are the process of hydrogen atom recombination on interstellar specks of dust as well as the formation of double-atom molecules. An ion-molecular mechanism plays the main role in the origination of multiatom molecules. It is noted, that the real progress in chemistry of the interstellar medium will be determined by the development of laboratory investigations at ultralow temperatures and study of the processes proceeding on solid surfaces

  19. Contrast-enhanced peripheral MRA

    DEFF Research Database (Denmark)

    Nielsen, Yousef W; Thomsen, Henrik S

    2012-01-01

    -state MRA. Gadolinium(Gd)-based contrast agents are used for CE-MRA of the peripheral arteries. Extracellular Gd agents have a pharmacokinetic profile similar to iodinated contrast media. Accordingly, these agents are employed for first-pass MRA. Blood-pool Gd-based agents are characterized by prolonged......In the last decade contrast-enhanced magnetic resonance angiography (CE-MRA) has gained wide acceptance as a valuable tool in the diagnostic work-up of patients with peripheral arterial disease. This review presents current concepts in peripheral CE-MRA with emphasis on MRI technique and contrast...... MRI contrast agent is injected intravenously and T1-weighted images are acquired in the subsequent arterial first-pass phase. In order to achieve high quality MR angiograms without interfering venous contamination or artifacts, a number of factors need to be taken into account. This includes magnetic...

  20. Borel sum rules for octet baryons in nuclear medium

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, Y.; Morimatsu, O.

    1992-06-01

    Borel sum rules are examined for octet baryons in the nuclear medium. First, it is noticed that in the medium the dispersion relation is realized for the retarded correlation [Pi][sup R]([omega], q[sup 2]) in the energy [omega]. Then, [Pi][sup R]([omega], q[sup 2]) is split into even and odd parts of [omega] in order to apply the Borel transformation. The obtained Borel sum rules differ from those of previous works. The mass shifts of octet baryons are calculated in the leading order of the operator product expansion with linear density approximation for the condensates. It is found that both scalar and vector condensates of the quark field, and , induce attraction to the octet baryons in the medium in contrast to the results of previous works. It is also found that [delta]M[sub N] > [delta]M[sub [Lambda

  1. Demonstration of flash K-edge angiography utilizing gadolinium-based contrast medium

    Science.gov (United States)

    Sato, Eiichi; Sagae, Michiaki; Obara, Haruo; Germer, Rudolf; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Ichimaru, Toshio; Sato, Shigehiro; Ojima, Hidenori; Takayama, Kazuhiro; Ido, Hideaki

    2005-03-01

    The high-voltage condensers in a polarity-inversion two-stage Marx surge generator are charged from -50 to -70 kV by a power supply, and the electric charges in the condensers are discharged to an x-ray tube after closing gap switches in the surge generator with a trigger device. The x-ray tube is a demountable diode, and the turbomolecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Tungsten characteristic x rays can be produced, since the tube utilizes a disk cathode and a rod target, and bremsstrahlung rays are not emitted in the opposite direction to that of electron acceleration. At a charging voltage of -70 kV, the instantaneous tube voltage and current were 140 kV and 1.0 kA, respectively. The x-ray pulse widths were approximately 90 ns, and the estimated number of K photons was approximately 5×108 photons/cm2 per pulse at 0.5 m from the source of 3.0 mm in diameter.

  2. Activation of platelets by low-osmolar contrast media: differential effects of ionic and nonionic agents

    NARCIS (Netherlands)

    Hardeman, M. R.; Konijnenberg, A.; Sturk, A.; Reekers, J. A.

    1994-01-01

    To determine the effects of an ionic low-osmolar contrast medium (ioxaglate) and two nonionic low-osmolar contrast media (iohexol and iopamidol) on human platelet activation in vitro. Flow cytometry analysis subsequent to reaction with fluorescence-labeled monoclonal antibodies was used to detect

  3. The use of iodinated and gadolinium contrast media during pregnancy and lactation

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Judith A.W. [St. Bartholomew' s Hospital, Department of Diagnostic Imaging, London (United Kingdom); Thomsen, Henrik S. [Copenhagen University Hospital at Herlev, Department of Diagnostic Radiology 54E2, Herlev (Denmark); Morcos, Sameh K. [Northern General Hospital, Department of Diagnostic Imaging, Sheffield (United Kingdom)

    2005-06-01

    The use of iodinated or gadolinium-based contrast media in pregnant or lactating women often causes concerns in the radiology department because of the principle of not exposing a fetus or neonate to any drugs. Because of the uncertainty about the use of contrast media during pregnancy and lactation, the Contrast Media Safety Committee of the European Society of Urogenital Radiology decided to review the literature and draw up guidelines. An extensive literature search was carried out and summarized in a report. Based on the limited information available, simple guidelines have been drawn up. The report and guidelines were discussed at the 11th European Symposium on Urogenital Radiology in Santiago de Compostela, Spain. Mutagenic and teratogenic effects have not been described after administration of gadolinium or iodinated contrast media. Free iodide in radiographic contrast medium given to the mother has the potential to depress fetal/neonatal thyroid function. Neonatal thyroid function should be checked during the 1st week if iodinated contrast media have been given during pregnancy. No effect on the fetus has been seen after gadolinium contrast media. Only tiny amounts of iodinated or gadolinium-based contrast medium given to a lactating mother reach the milk, and only a minute proportion entering the baby's gut is absorbed. The very small potential risk associated with absorption of contrast medium may be considered insufficient to warrant stopping breast-feeding for 24 h following either iodinated or gadolinium contrast agents. (orig.)

  4. The use of iodinated and gadolinium contrast media during pregnancy and lactation

    International Nuclear Information System (INIS)

    Webb, Judith A.W.; Thomsen, Henrik S.; Morcos, Sameh K.

    2005-01-01

    The use of iodinated or gadolinium-based contrast media in pregnant or lactating women often causes concerns in the radiology department because of the principle of not exposing a fetus or neonate to any drugs. Because of the uncertainty about the use of contrast media during pregnancy and lactation, the Contrast Media Safety Committee of the European Society of Urogenital Radiology decided to review the literature and draw up guidelines. An extensive literature search was carried out and summarized in a report. Based on the limited information available, simple guidelines have been drawn up. The report and guidelines were discussed at the 11th European Symposium on Urogenital Radiology in Santiago de Compostela, Spain. Mutagenic and teratogenic effects have not been described after administration of gadolinium or iodinated contrast media. Free iodide in radiographic contrast medium given to the mother has the potential to depress fetal/neonatal thyroid function. Neonatal thyroid function should be checked during the 1st week if iodinated contrast media have been given during pregnancy. No effect on the fetus has been seen after gadolinium contrast media. Only tiny amounts of iodinated or gadolinium-based contrast medium given to a lactating mother reach the milk, and only a minute proportion entering the baby's gut is absorbed. The very small potential risk associated with absorption of contrast medium may be considered insufficient to warrant stopping breast-feeding for 24 h following either iodinated or gadolinium contrast agents. (orig.)

  5. Use of cystatin C and serum creatinine for the diagnosis of contrast-induced nephropathy in patients undergoing contrast-enhanced computed tomography at an oncology centre.

    Science.gov (United States)

    Fortalesa Melo, Joao Italo; Chojniak, Rubens; Costa Silva, Debora Helena; Oliveira Junior, Jose Carlos; Vieira Bitencourt, Almir Galvão; Holanda Silva, Diego; Guimarães, Marcos Duarte; Silva, Hernandes Cerqueira Souza; Dias, Denis Guilherme Teixeira; Rodrigues, Winglison Carli; Brancucci, Ellen Luzia; Cruz, Barbara Martins Soares; Schiavon, Beatriz Nunes; Argenton, Juliana Luz Passos; Camporini, Margareth Arrivabene; Zocchio, Adriana

    2015-01-01

    Our aim was to assess renal function using as laboratory measurements serum creatinine and cystatin C concentrations before and after administration of low-osmolarity (nonionic) iodinated contrast medium in patients with cancer undergoing computed tomography (CT). This prospective study included 400 oncologic outpatients. Serum creatinine and cystatin C concentrations were measured before and 72 h after contrast administration. Glomerular filtration rates (GFRs) were estimated using serum creatinine-based [Modification of Diet in Renal Disease (MDRD) and Cockroft-Gault and cystatin C based (Larsson) equations. Exploratory data analysis was performed. The nonparametric Wilcoxon test was used to compare pre and post contrast of test results and estimated clearance. The confidence interval used in the analysis was 95%. Compared with the pre-contrast values, the mean serum creatinine concentration was significantly higher and average GFRs estimated using MDRD and Cockcroft-Gault equations were significantly lower after the administration of contrast (p serum creatinine and cystatin C concentrations showed changes in renal function among patients with cancer undergoing contrast-enhanced CT examination in this study. No significant renal damage related to the use of low-osmolarity iodinated contrast medium of the type and dosage employed in this study was observed. This contrast medium is thus safe for use in patients with cancer.

  6. Development of a new medium containing date syrup for production ...

    African Journals Online (AJOL)

    USER

    2010-08-16

    Aug 16, 2010 ... statistical approach enabled rapid identification and integration of key medium parameters for optimizing secondary metabolite .... quadratic and interaction effects by standardized Pareto chart (a special type of bar chart ..... represented the production of BLM (mg dl-1) as a function of substrate type or ...

  7. Medium-term changes in Drosophila subobscura chromosomal ...

    Indian Academy of Sciences (India)

    2015-06-02

    Jun 2, 2015 ... Third instar larvae from the F1 were dissected and polytene chromo- somes were stained and squashed in aceto–orcein solution. For each cross, at least eight larvae were analysed. All crosses were carried out in individual vials with 25 mL standard corn-meal-sugar-agar-yeast medium maintained at. 18◦C ...

  8. Animal Locomotion in Different Mediums

    Indian Academy of Sciences (India)

    Wetlands are repositories of unique biodiversity. Wetlandorganisms are well adapted to their habitat, lying at theinterface of aquatic and terrestrial environments. In order tounderstand their adaptations in a better way, it is essential tograsp the basic properties of the medium in which variousorganisms live. This is attempted ...

  9. Animal Locomotion in Different Mediums

    Indian Academy of Sciences (India)

    IAS Admin

    Fishes, moving in water encounter drag forces, which can be of considerable magnitude. If sudden movement is required to catch prey or escape predators in a viscous medium, it is only possible by the contraction of fast, white muscle fibres, which rely on anaerobic glycolysis pathways. Therefore, it is not surprising that.

  10. Molecular spectroscopy of interstellar medium

    International Nuclear Information System (INIS)

    Varshalovich, D.A.; Khersonskij, V.K.

    1980-01-01

    Experimental data obtained in the investigation into molecules of interstellar medium by molecular-spectroscopic methods are discussed generally. Ion-molecule reactions play a significant part in the formation of multiatom molecules in the interstellar medium as well as reactions proceeding on the surface of interstellar dust. More than 50 types of molecules have been detected in the interstellar medium at present. In a wide range of wave lengths over 500 spectral lines belonging to various molecules and molecular fragments have been recorded. Interstellar molecules permit to investigate interstellar gas from all the sides. They are a suitable indicator of the isotope composition of interstellar gas. Radio observations of interstellar molecules make it possible to effectively investigate kinematics and space structure both separate gas-dust complexes and total gas distribution in Galaxy. It is noted that achievements of molecular spectroscopy of the interstellar medium radically change representations of the chemical composition of interstellar gas, of isotope abundance and organic substance in the Universe

  11. Hadron photoproduction at medium energy

    International Nuclear Information System (INIS)

    Dainton, J.B.

    1985-04-01

    Results from measurements of multibody photoproduction at medium incident photon energy (2.8 to 4.8 GeV) are presented and discussed. Particular emphasis is placed on topics which are not well understood and which therefore motivate experiments with the upgraded electron accelerator and storage ring ELSA at the University of Bonn, FR Germany. (author)

  12. Medium term ecohydrological response of peatland bryophytes to canopy disturbance

    Science.gov (United States)

    Leonard, Rhoswen; Kettridge, Nick; Krause, Stefan; Devito, Kevin; Granath, Gustaf; Petrone, Richard; Mandoza, Carl; Waddington, James Micheal

    2016-04-01

    Canopy disturbance in northern forested peatlands is widespread. Canopy changes impact the ecohydrological function of moss and peat, which provide the principal carbon store within these carbon rich ecosystems. Different mosses have contrasting contributions to carbon and water fluxes (e.g. Sphagnum fuscum and Pleurozium schreberi) and are strongly influenced by canopy cover. As a result, changes in canopy cover lead to long-term shifts in species composition and associated ecohydrological function. Despite this, the medium-term response to such disturbance, the associated lag in this transition to a new ecohydrological and biogeochemical regime, is not understood. Here we investigate this medium term ecohydrological response to canopy removal using a randomised plot design within a north Albertan peatland. We show no significant ecohydrological change in treatment plots four years after canopy removal. Notably, Pleurozium schreberi and Sphagnum fuscum remained within respective plots post treatment and there was no significant difference in plot resistance to evapotranspiration or carbon exchange. Our results show that canopy removal alone has little impact on bryophyte ecohydrology in the short/medium term. This resistance to disturbance contrasts strongly with dramatic short-term changes observed within mineral soils suggesting that concurrent shifts in the large scale hydrology induced within such disturbances are necessary to cause rapid ecohydrological transitions. Understanding this lagged response is critical to determine the decadal response of carbon and water fluxes in response to disturbance and the rate at which important medium term ecohydrological feedbacks are invoked.

  13. The new numbers contrast sensitivity chart for contrast sensitivity measurement

    Directory of Open Access Journals (Sweden)

    Bharkbhum Khambhiphant

    2011-10-01

    Conclusions: These charts show reasonable agreement and can be used interchangeably with the MARS. It is helpful for Thai people who can only read numbers in doing the test. We can use them in routinely contrast sensitivity measurement.

  14. A finite-difference contrast source inversion method

    International Nuclear Information System (INIS)

    Abubakar, A; Hu, W; Habashy, T M; Van den Berg, P M

    2008-01-01

    We present a contrast source inversion (CSI) algorithm using a finite-difference (FD) approach as its backbone for reconstructing the unknown material properties of inhomogeneous objects embedded in a known inhomogeneous background medium. Unlike the CSI method using the integral equation (IE) approach, the FD-CSI method can readily employ an arbitrary inhomogeneous medium as its background. The ability to use an inhomogeneous background medium has made this algorithm very suitable to be used in through-wall imaging and time-lapse inversion applications. Similar to the IE-CSI algorithm the unknown contrast sources and contrast function are updated alternately to reconstruct the unknown objects without requiring the solution of the full forward problem at each iteration step in the optimization process. The FD solver is formulated in the frequency domain and it is equipped with a perfectly matched layer (PML) absorbing boundary condition. The FD operator used in the FD-CSI method is only dependent on the background medium and the frequency of operation, thus it does not change throughout the inversion process. Therefore, at least for the two-dimensional (2D) configurations, where the size of the stiffness matrix is manageable, the FD stiffness matrix can be inverted using a non-iterative inversion matrix approach such as a Gauss elimination method for the sparse matrix. In this case, an LU decomposition needs to be done only once and can then be reused for multiple source positions and in successive iterations of the inversion. Numerical experiments show that this FD-CSI algorithm has an excellent performance for inverting inhomogeneous objects embedded in an inhomogeneous background medium

  15. Use of Iodine-based contrast media in digital full-field mammography - initial experience

    International Nuclear Information System (INIS)

    Diekmann, F.; Diekmann, S.; Taupitz, M.; Bick, U.; Winzer, K.-J.; Huettner, C.; Muller, S.; Jeunehomme, F.; Hamm, B.

    2003-01-01

    Aim: To investigate the use of iodine-based contrast media in digital full-field mammography. Methods: After performing initial phantom studies, seven patients underwent digital mammography (Senographe 2000D, GE Medical Systems, Milwaukee, USA) using a specially filtered beam before as well as 60, 120, and 180 seconds after injection of 80 ml of iodine contrast medium (Ultravist 370, Schering AG, Germany). The precontrast mammograms were then subtracted from the postcontrast mammograms and the resulting images compared with a contrast-enhanced dynamic MRI study, performed on all women. Results: Contrast medium accumulation within the tumors was visualized with a good quality in all cases. The conditions under which successful contrast-enhanced digital mammography can be performed were determined in phantom studies. Conclusions: Contrast-enhanced digital mammography has a potential for improving the visualization of breast tumors in mammography using special beam filtering, adjusted X-ray parameters, proper timing, and suitable subtraction software. (orig.) [de

  16. Evaluation of contrast media for bronchography

    International Nuclear Information System (INIS)

    Thompson, I.M.; Whittlesey, G.C.; Slovis, T.L.; Chang, C.H.; Cullen, M.L.; Philippart, A.I.; Stockmann, P.S.; Adkins, E.S.; Klein, M.D.

    1997-01-01

    Background. Bronchography is occasionally needed for the evaluation and management of some congenital pulmonary anomalies as well as some acquired diseases, usually of the tracheo- bronchial tree. There is currently no effective, approved contrast agent for this imaging tech- nique. Objective. We evaluated five agents (barium sulfate, iohexol, propyliodone oily, propyliodone aqueous, and perflubron) in terms of image quality, histologic changes, and effects on hemodynamics, blood gases, and standard laboratory tests in New Zealand White rabbits. Materials and methods. Animals were anesthetized and intubated. Each contrast agent (0.25 ml/kg) was administered intratracheally. Three animals in each group had intravenous lines placed for blood sampling and blood pressure monitoring and were sacrificed at 1 h. An additional three animals for each agent were sacrificed at 24 h and 1 week after imaging. Blood samples were taken immediately before contrast instillation and at 1 h postbronchography. Fluoroscopic images were recorded on standard VHS video tape and evaluated in blind fashion. Segments of lung tissue and bronchi were obtained for histologic examination. Results. Necrosis and/or inflammatory infiltrates were noted in 78 % of the bronchograms performed with propyliodone aqueous, 67 % with propyliodone oily, 55 % with perflubron, and 33 % with iohexol 120, 240 and 350. No histologic damage was observed with barium. The propyliodones gave the best-quality imaging results and the most histologic changes. Iohexol, in any concentration, gave the least acceptable images and a moderate number of histologic changes. Barium sulfate demonstrated acceptable images with virtually no histologic changes. Conclusion. From the histologic and imaging results, barium is the best available contrast material for bronchography. (orig.). With 6 figs., 4 tabs

  17. The Generalised Phase Contrast Method

    DEFF Research Database (Denmark)

    Glückstad, Jesper

    An analytic framework and a complete description for the design and optimisation of on-axis centred spatially filtering common path systems are presented. The Generalised Phase Contrast method is derived and introduced as the common denominator for these systems basically extending Zernike......’s original phase contrast scheme into a much wider range of operation and application. It is demonstrated that the Generalised Phase Contrast method can be successfully applied to the interpretation and subsequent optimisation of a number of different, commonly applied spatially filtering architectures...... designs and parameter settings. Finally, a number of original applications facilitated by the parallel light-beam encoding of the Generalised Phase Contrast method are briefly outlined. These include among others, wavefront sensing and generation, advanced usercontrolled optical micro...

  18. Voluntary attention enhances contrast appearance.

    Science.gov (United States)

    Liu, Taosheng; Abrams, Jared; Carrasco, Marisa

    2009-03-01

    Voluntary (endogenous, sustained) covert spatial attention selects relevant sensory information for prioritized processing. The behavioral and neural consequences of such selection have been extensively documented, but its phenomenology has received little empirical investigation. We asked whether voluntary attention affects the subjective appearance of contrast--a fundamental dimension of visual perception. We used a demanding rapid serial visual presentation (RSVP) task to direct endogenous attention to a given location and measured perceived contrast at the attended and unattended locations. Attention increased perceived contrast of suprathreshold stimuli and also improved performance on a concurrent orientation discrimination task at the cued location. We ruled out response bias as an alternative account of the pattern of results. Thus, this study establishes that voluntary attention enhances perceived contrast. This phenomenological consequence links behavioral and neurophysiological studies on the effects of attention.

  19. Contrast-enhanced endoscopic ultrasonography

    DEFF Research Database (Denmark)

    Reddy, Nischita K; Ioncică, Ana Maria; Săftoiu, Adrian

    2011-01-01

    Contrast agents are increasingly being used to characterize the vasculature in an organ of interest, to better delineate benign from malignant pathology and to aid in staging and directing therapeutic procedures. We review the mechanisms of action of first, second and third generation contrast...... agents and their use in various endoscopic procedures in the gastrointestinal tract. Various applications of contrast-enhanced endoscopic ultrasonography include differentiating benign from malignant mediastinal lymphadenopathy, assessment of depth of invasion of esophageal, gastric and gall bladder...... cancers and visualization of the portal venous system and esophageal varices. In addition, contrast agents can be used to differentiate pancreatic lesions. The use of color Doppler further increases the ability to diagnose and differentiate various pancreatic malignancies. The sensitivity of power Doppler...

  20. 75 FR 67059 - Public Hearings for Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium...

    Science.gov (United States)

    2010-11-01

    ... hearing. ADDRESSES: The November 15 hearing will be held at the Millennium Knickerbocker Hotel Chicago... speakers not use technological aids (e.g., audio-visuals, computer slideshows). However, if you plan to do...

  1. Sugarcane Bagasse: A Potential Medium for Fungal Cultures

    Directory of Open Access Journals (Sweden)

    Arushdeep Sidana

    2014-01-01

    Full Text Available Worldwide, sugarcane industries produce tons of sugarcane bagasse as residual/waste material. This residual material is rich in complex lignocellulosic substances and may be used as a low cost carbon and energy source for the growth of fungal species. The present work was aimed at designing a sugarcane waste-based medium as a substitute for expensive commercial media for growing fungal cultures. Eight species of fungi, namely, Aspergillus niger, Candida albicans, Saccharomyces cerevisiae, Fusarium sp., and four unidentified species F1, F2, F3, and F5, were grown on the sugarcane bagasse medium which produced remarkable results and competed with standard media like potato dextrose agar, Sabouraud dextrose agar, and cornmeal agar. The designed medium was able to provide nourishment to the fungi as well as prevent the growth of any bacterial or fungal contaminant. The production of spores was more in the sugarcane medium as compared with standard media. Hence, this study led to the discovery of a new and efficient medium for fungal cultures as well as decrease in the waste disposal expenses and efforts.

  2. A theory of behavioral contrast.

    Science.gov (United States)

    Killeen, Peter R

    2014-11-01

    The reinforcers that maintain target instrumental responses also reinforce other responses that compete with them for expression. This competition, and its imbalance at points of transition between different schedules of reinforcement, causes behavioral contrast. The imbalance is caused by differences in the rates at which different responses come under the control of component stimuli. A model for this theory of behavioral contrast is constructed by expanding the coupling coefficient of MPR (Killeen, 1994). The coupling coefficient gives the degree of association of a reinforcer with the target response (as opposed to other competing responses). Competing responses, often identified as interim or adjunctive or superstitious behavior, are intrinsic to reinforcement schedules, especially interval schedules. In addition to that base-rate of competition, additional competing responses may spill over from the prior component, causing initial contrast; and they may be modulated by conditioned reinforcement or punishment from stimuli associated with subsequent component change, causing terminal contrast. A formalization of these hypotheses employed (a) a hysteresis model of off-target responses giving rise to initial contrast, and (b) a competing traces model of the suppression or enhancement of ongoing competitive responses by signals of following-schedule transition. The theory was applied to transient contrast, the following schedule effect, and the component duration effect. © Society for the Experimental Analysis of Behavior.

  3. Light Vector Mesons in the Nuclear Medium

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Michael; Nasseripour, Rakhsha; Weygand, Dennis; Djalali, Chaden; Tur, Clarisse; Mosel, Ulrich; Muehlich, Pascal; Adams, Gary; Amaryan, Moscov; Amaryan, Moskov; Ambrozewicz, Pawel; Anghinolfi, Marco; Asryan, Gegham; Avagyan, Harutyun; Baghdasaryan, Hovhannes; Baillie, Nathan; Ball, James; Baltzell, Nathan; Barrow, Steve; Battaglieri, Marco; Bedlinskiy, Ivan; Bektasoglu, Mehmet; Bellis, Matthew; Benmouna, Nawal; Berman, Barry; Biselli, Angela; Blaszczyk, Lukasz; Bouchigny, Sylvain; Boyarinov, Sergey; Bradford, Robert; Branford, Derek; Briscoe, William; Brooks, William; Burkert, Volker; Butuceanu, Cornel; Calarco, John; Careccia, Sharon; Carman, Daniel; Carnahan, Bryan; Casey, Liam; Chen, Shifeng; Cheng, Lu; Cole, Philip; Collins, Patrick; Coltharp, Philip; Crabb, Donald; Crannell, Hall; Crede, Volker; Cummings, John; Dashyan, Natalya; De Vita, Raffaella; De Sanctis, Enzo; Degtiarenko, Pavel; Denizli, Haluk; Dennis, Lawrence; Deur, Alexandre; Dharmawardane, Kahanawita; Dickson, Richard; Dodge, Gail; Doughty, David; Dugger, Michael; Dytman, Steven; Dzyubak, Oleksandr; Egiyan, Hovanes; Egiyan, Kim; Elfassi, Lamiaa; Elouadrhiri, Latifa; Eugenio, Paul; Fedotov, Gleb; Feldman, Gerald; Feuerbach, Robert; Fradi, Ahmed; Funsten, Herbert; Garcon, Michel; Gavalian, Gagik; Gilfoyle, Gerard; Giovanetti, Kevin; Girod, Francois-Xavier; Goetz, John; Gordon, Christopher; Gothe, Ralf; Griffioen, Keith; Guidal, Michel; Guler, Nevzat; Guo, Lei; Gyurjyan, Vardan; Hadjidakis, Cynthia; Hafidi, Kawtar; Hakobyan, Hayk; Hakobyan, Rafael; Hanretty, Charles; Hardie, John; Hassall, Neil; Hersman, F.; Hicks, Kenneth; Hleiqawi, Ishaq; Holtrop, Maurik; Hyde, Charles; Ilieva, Yordanka; Ireland, David; Ishkhanov, Boris; Isupov, Evgeny; Ito, Mark; Jenkins, David; Jo, Hyon-Suk; Johnstone, John; Joo, Kyungseon; Juengst, Henry; Kalantarians, Narbe; Kellie, James; Khandaker, Mahbubul; Khetarpal, Puneet; Kim, Wooyoung; Klein, Andreas; Klein, Franz; Klimenko, Alexei; Kossov, Mikhail; Krahn, Zebulun; Kramer, Laird; Kubarovsky, Valery; Kuhn, Joachim; Kuhn, Sebastian; Kuleshov, Sergey; Lachniet, Jeff; Laget, Jean; Langheinrich, Jorn; Lawrence, David; Li, Ji; Livingston, Kenneth; Lu, Haiyun; MacCormick, Marion; Markov, Nikolai; Mattione, Paul; McAleer, Simeon; McKinnon, Bryan; McNabb, John; Mecking, Bernhard; Mehrabyan, Surik; Melone, Joseph; Mestayer, Mac; Meyer, Curtis; Mibe, Tsutomu; Mikhaylov, Konstantin; Minehart, Ralph; Mirazita, Marco; Miskimen, Rory; Mokeev, Viktor; Moriya, Kei; Morrow, Steven; Moteabbed, Maryam; Mueller, James; Munevar Espitia, Edwin; Mutchler, Gordon; Nadel-Turonski, Pawel; Niccolai, Silvia; Niculescu, Gabriel; Niculescu, Maria-Ioana; Niczyporuk, Bogdan; Niroula, Megh; Niyazov, Rustam; Nozar, Mina; Osipenko, Mikhail; Ostrovidov, Alexander; Park, Kijun; Pasyuk, Evgueni; Paterson, Craig; Pereira, Sergio; Pierce, Joshua; Pivnyuk, Nikolay; Pocanic, Dinko; Pogorelko, Oleg; Pozdnyakov, Sergey; Preedom, Barry; Price, John; Prok, Yelena; Protopopescu, Dan; Raue, Brian; Riccardi, Gregory; Ricco, Giovanni; Ripani, Marco; Ritchie, Barry; Ronchetti, Federico; Rosner, Guenther; Rossi, Patrizia; Sabatie, Franck; Salamanca, Julian; Salgado, Carlos; Santoro, Joseph; Sapunenko, Vladimir; Schumacher, Reinhard; Serov, Vladimir; Sharabian, Youri; Sharov, Dmitri; Shvedunov, Nikolay; Smith, Elton; Smith, Lee; Sober, Daniel; Sokhan, Daria; Stavinsky, Aleksey; Stepanyan, Stepan; Stepanyan, Samuel; Stokes, Burnham; Stoler, Paul; Strakovski, Igor; Strauch, Steffen; Taiuti, Mauro; Tedeschi, David; Tkabladze, Avtandil; Tkachenko, Svyatoslav; Todor, Luminita; Ungaro, Maurizio; Vineyard, Michael; Vlassov, Alexander; Watts, Daniel; Weinstein, Lawrence; Williams, Michael; Wolin, Elliott; Yegneswaran, Amrit; Zana, Lorenzo; Zhang, Bin; Zhang, Jixie; Zhao, Bo; Zhao, Zhiwen

    2008-07-01

    The light vector mesons ($\\rho$, $\\omega$, and $\\phi$) were produced in deuterium, carbon, titanium, and iron targets in a search for possible in-medium modifications to the properties of the $\\rho$ meson at normal nuclear densities and zero temperature. The vector mesons were detected with the CEBAF Large Acceptance Spectrometer (CLAS) via their decays to $e^{+}e^{-}$. The rare leptonic decay was chosen to reduce final-state interactions. A combinatorial background was subtracted from the invariant mass spectra using a well-established event-mixing technique. The $\\rho$ meson mass spectrum was extracted after the $\\omega$ and $\\phi$ signals were removed in a nearly model-independent way. Comparisons were made between the $\\rho$ mass spectra from the heavy targets ($A > 2$) with the mass spectrum extracted from the deuterium target. With respect to the $\\rho$-meson mass, we obtain a small shift compatible with zero. Also, we measure widths consistent with standard nuclear many-body eff

  4. Managing Safety in Small and Medium Enterprises

    DEFF Research Database (Denmark)

    Stephen, legg; Olsen, Kirsten Bendix; Ian S., laird

    2015-01-01

    This paper presents a conceptual model for increasing acceptable working environments for SMEs. It also acts as an editorial for the special issue of Safety Science on ‘Managing safety in small and medium enterprises (SMEs)’. It describes how seven of the ten papers in the special issue originate...... on safety in SMEs, showing how most current policy and legislation on occupational health and safety (OSH) and the work environment is based on large enterprises and that there is a relative paucity of research on OSH in SMEs. In a summary of current knowledge, it is argued that modern OHS legislation...... and interventions to help improve Work environments need to increasingly take account of the specific characteristics of SMEs. The conceptual model for increasing acceptable working environments for SMEs takes its onset in a legislative standard that is built into intervention programmes and includes three...

  5. A medium resolution fingerprint matching system

    Directory of Open Access Journals (Sweden)

    Ayman Mohammad Bahaa-Eldin

    2013-09-01

    Full Text Available In this paper, a novel minutiae based fingerprint matching system is proposed. The system is suitable for medium resolution fingerprint images obtained by low cost commercial sensors. The paper presents a new thinning algorithm, a new features extraction and representation, and a novel feature distance matching algorithm. The proposed system is rotation and translation invariant and is suitable for complete or partial fingerprint matching. The proposed algorithms are optimized to be executed on low resource environments both in CPU power and memory space. The system was evaluated using a standard fingerprint dataset and good performance and accuracy were achieved under certain image quality requirements. In addition, the proposed system was compared favorably to that of the state of the art systems.

  6. In Vivo Differentiation of Complementary Contrast Media at Dual-Energy CT

    Science.gov (United States)

    Mongan, John; Rathnayake, Samira; Fu, Yanjun; Wang, Runtang; Jones, Ella F.; Gao, Dong-Wei

    2012-01-01

    Purpose: To evaluate the feasibility of using a commercially available clinical dual-energy computed tomographic (CT) scanner to differentiate the in vivo enhancement due to two simultaneously administered contrast media with complementary x-ray attenuation ratios. Materials and Methods: Approval from the institutional animal care and use committee was obtained, and National Institutes of Health guidelines for the care and use of laboratory animals were observed. Dual-energy CT was performed in a set of iodine and tungsten solution phantoms and in a rabbit in which iodinated intravenous and bismuth subsalicylate oral contrast media were administered. In addition, a second rabbit was studied after intravenous administration of iodinated and tungsten cluster contrast media. Images were processed to produce virtual monochromatic images that simulated the appearance of conventional single-energy scans, as well as material decomposition images that separate the attenuation due to each contrast medium. Results: Clear separation of each of the contrast media pairs was seen in the phantom and in both in vivo animal models. Separation of bowel lumen from vascular contrast medium allowed visualization of bowel wall enhancement that was obscured by intraluminal bowel contrast medium on conventional CT scans. Separation of two vascular contrast media in different vascular phases enabled acquisition of a perfectly coregistered CT angiogram and venous phase–enhanced CT scan simultaneously in a single examination. Conclusion: Commercially available clinical dual-energy CT scanners can help differentiate the enhancement of selected pairs of complementary contrast media in vivo. © RSNA, 2012 PMID:22778447

  7. Medium modifications with recoil polarization

    Energy Technology Data Exchange (ETDEWEB)

    Brand, J.F.J. van den [Nationaal Instituut voor Kernfysica en Hoge Energiefysica, Amsterdam (Netherlands); Ent, R. [CEBAF, Newport News, VA (United States)

    1994-04-01

    The authors show that the virtual Compton scattering process allows for a precise study of the off-shell electron-nucleon vertex. In a separable model, they show the sensitivity to new unconstrained structure functions of the nucleon, beyond the usual Dirac and Pauli form factors. In addition, they show the sensitivity to bound nucleon form factors using the reaction 4He({rvec e},e{prime},{rvec p}){sup 3}H. A nucleon embedded in a nucleus represents a complex system. Firstly, the bound nucleon is necessarily off-shell and in principle a complete understanding of the dynamical structure of the nucleon is required in order to calculate its off-shell electromagnetic interaction. Secondly, one faces the possibility of genuine medium effects, such as for example quark-exchange contributions. Furthermore, the electromagnetic coupling to the bound nucleon is dependent on the nuclear dynamics through the self-energy of the nucleon in the nuclear medium.

  8. Medium modifications with recoil polarization

    International Nuclear Information System (INIS)

    Brand, J.F.J. van den; Ent, R.

    1994-01-01

    The authors show that the virtual Compton scattering process allows for a precise study of the off-shell electron-nucleon vertex. In a separable model, they show the sensitivity to new unconstrained structure functions of the nucleon, beyond the usual Dirac and Pauli form factors. In addition, they show the sensitivity to bound nucleon form factors using the reaction 4He(rvec e,e',rvec p) 3 H. A nucleon embedded in a nucleus represents a complex system. Firstly, the bound nucleon is necessarily off-shell and in principle a complete understanding of the dynamical structure of the nucleon is required in order to calculate its off-shell electromagnetic interaction. Secondly, one faces the possibility of genuine medium effects, such as for example quark-exchange contributions. Furthermore, the electromagnetic coupling to the bound nucleon is dependent on the nuclear dynamics through the self-energy of the nucleon in the nuclear medium

  9. Medium-dependent control of the bacterial growth rate.

    Science.gov (United States)

    Ehrenberg, Måns; Bremer, Hans; Dennis, Patrick P

    2013-04-01

    By combining results from previous studies of nutritional up-shifts we here re-investigate how bacteria adapt to different nutritional environments by adjusting their macromolecular composition for optimal growth. We demonstrate that, in contrast to a commonly held view the macromolecular composition of bacteria does not depend on the growth rate as an independent variable, but on three factors: (i) the genetic background (i.e. the strain used), (ii) the physiological history of the bacteria used for inoculation of a given growth medium, and (iii) the kind of nutrients in the growth medium. These factors determine the ribosome concentration and the average rate of protein synthesis per ribosome, and thus the growth rate. Immediately after a nutritional up-shift, the average number of ribosomes in the bacterial population increases exponentially with time at a rate which eventually is attained as the final post-shift growth rate of all cell components. After a nutritional up-shift from one minimal medium to another minimal medium of higher nutritional quality, ribosome and RNA polymerase syntheses are co-regulated and immediately increase by the same factor equal to the increase in the final growth rate. However, after an up-shift from a minimal medium to a medium containing all 20 amino acids, RNA polymerase and ribosome syntheses are no longer coregulated; a smaller rate of synthesis of RNA polymerase is compensated by a gradual increase in the fraction of free RNA polymerase, possibly due to a gradual saturation of mRNA promoters. We have also analyzed data from a recent publication, in which it was concluded that the macromolecular composition in terms of RNA/protein and RNA/DNA ratios is solely determined by the effector molecule ppGpp. Our analysis indicates that this is true only in special cases and that, in general, medium adaptation also depends on factors other than ppGpp. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  10. Probing the local interstellar medium

    International Nuclear Information System (INIS)

    Suess, S.T.; Dessler, A.J.

    1985-01-01

    The paper concerns the location of the heliospheric shock, in view of the discrepancy between the theoretical and experimental values. To determine whether the discrepancy may be attributed to parameters used to describe the local interstellar medium [LISM], the authors applied a sophisticated model of solar-wind expansion to deduce a range of parameters for the LISM. Both the interstellar magnetic field and the pressure due to galactic cosmic rays are considered. (U.K.)

  11. ['Gold standard', not 'golden standard'

    NARCIS (Netherlands)

    Claassen, J.A.H.R.

    2005-01-01

    In medical literature, both 'gold standard' and 'golden standard' are employed to describe a reference test used for comparison with a novel method. The term 'gold standard' in its current sense in medical research was coined by Rudd in 1979, in reference to the monetary gold standard. In the same

  12. Effect of ionic and non-ionic contrast media on whole blood viscosity, plasma viscosity and hematocrit in vitro

    International Nuclear Information System (INIS)

    Aspelin, P.

    1978-01-01

    The effect of the ionic contrast media diatrizoate, iocarmate and metrizoate and the non-ionic metrizamide on whole blood viscosity, plasma viscosity and hematocrit was investigated. All the contrast media increased whole blood and plasma viscosity and reduced the hematocrit. The whole blood viscosity increased with increasing osmolality of the contrast medium solutions, whereas the plasma viscosity increased with increasing viscosity of the contrast medium solutions. The higher the osmolality of the contrast media, the lower the hematocrit became. The normal shear-thinning (decreasing viscosity with increasing shear rate) property of blood was reduced when contrast medium was added to the blood. At 50 per cent volume ratio (contrast medium to blood), the ionic contrast media converted the blood into a shear-thickening (increasing viscosity with increasing shear rate) suspension, indicating a marked rigidification of the single red cell, while the non-ionic contrast medium still produced shear-thinning, indicating less rigidification of the red cell (p<0.01). (Auth.)

  13. Contrast Media: Are There Differences in Nephrotoxicity among Contrast Media?

    Science.gov (United States)

    2014-01-01

    Iodinated contrast agents are usually classified based upon their osmolality—high, low, and isosmolar. Iodinated contrast agents are also nephrotoxic in some but not all patients resulting in loss of glomerular filtration rate. Over the past 30 years, nephrotoxicity has been linked to osmolality although the precise mechanism underlying such a link has been elusive. Improvements in our understanding of the pathogenesis of nephrotoxicity and prospective randomized clinical trials have attempted to further explore the relationship between osmolality and nephrotoxicity. In this review, the basis for our current understanding that there are little if any differences in nephrotoxic potential between low and isosmolar contrast media will be detailed using data from clinical studies. PMID:24587997

  14. Detection of neck recurrence in patients with differentiated thyroid cancer: comparison of ultrasound, contrast-enhanced CT and {sup 18}F-FDG PET/CT using surgical pathology as a reference standard: (ultrasound vs. CT vs. {sup 18}F-FDG PET/CT in recurrent thyroid cancer)

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Young Lan; Yoon, Dae Young; Ku, You Jin [Hallym University College of Medicine, Department of Radiology, Kangdong Seong-Sim Hospital, Seoul (Korea, Republic of); Baek, Sora [Hallym University College of Medicine, Department of Nuclear Medicine, Kangdong Seong-Sim Hospital, Seoul (Korea, Republic of); Rho, Young-Soo; Chung, Eun-Jae [Hallym University College of Medicine, Department of Otorhinolaryngology, Ilsong Memorial Institute of Head and Neck Cancer, Kangdong Seong-Sim Hospital, Seoul (Korea, Republic of); Koh, Sung Hye [Hallym University Sacred Heart Hospital, Department of Radiology, Hallym University College of Medicine, Anyang, Gyonggi-do (Korea, Republic of)

    2012-10-15

    To compare the diagnostic performance of ultrasound, contrast-enhanced computed tomography (CT) and {sup 18}F-FDG positron emission tomography (PET)/CT for detecting recurrent differentiated thyroid cancer in the neck. Twenty patients who had undergone previous surgery for differentiated thyroid cancer (19 papillary carcinomas; 1 medullary carcinoma) and presented with pathologically proven recurrence in the neck were included. All patients had undergone ultrasound, CT and PET/CT in the 2 months before further surgery. In each patient, ultrasound, CT and PET/CT images were retrospectively reviewed to determine the presence of loco-regional recurrence by level-by-level analysis. Imaging results were correlated with the histological evaluation of the neck dissection as a standard of reference. Recurrences were found at 52 out of 110 cervical nodal levels surgically explored. The sensitivity, specificity and accuracy were 69.2 %, 89.7 % and 80.0 % for ultrasound; 63.5 %, 94.8 % and 80.0 % for CT; and 53.8 %, 79.3 % and 67.3 % for PET/CT, respectively. ROC analysis revealed higher diagnostic performance with ultrasound than with PET/CT for detecting recurrent tumour. Although no significant difference was found among the three techniques, the sensitivity and specificity of ultrasound and CT were higher than those of PET/CT for the evaluation of cervical recurrence in patients with differentiated thyroid cancer. circle Ultrasound, CT and {sup 18} F-FDG PET/CT can all detect recurrent thyroid cancer. circle Ultrasound and CT have higher sensitivity and specificity. (orig.)

  15. Medium Theory and Social Systems

    DEFF Research Database (Denmark)

    Tække, Jesper

    The  paper  first  gives  a  tentative  theoretical  explanation  of  the  concept  of media,  based  on  the  dichotomies  of  actual/potential  (meaning),  form/medium  (appearance),  and  substratum/material  content  (extension  in  time  and  space).  This  theoretical  explanation  presents......  seen as medium  for  formation. Finally  the  paper  takes  the micro  level  perspective  by  applying  the  theory  to  newsgroups,  interpreting  them as self-organizing interactive systems giving a differentiated and diversified scope for social  inclusion.  ......The  paper  first  gives  a  tentative  theoretical  explanation  of  the  concept  of media,  based  on  the  dichotomies  of  actual/potential  (meaning),  form/medium  (appearance),  and  substratum/material  content  (extension  in  time  and  space).  This  theoretical  explanation  presents......  the  possibility  for  observation both of a social micro and a social macro level from a medium perspective. In the next  section  the paper  frames  the macro  level by  a  tentative  synthesis of  the medium  theory  and  the  sociological systems theory briefly describing a socio...

  16. Spillover effects of international standards

    DEFF Research Database (Denmark)

    Trifkovic, Neda

    Most studies focus on trade effects and organizational outcomes of international standards, neglecting the effect of standards on employees. Using a two-year matched firm–employee panel dataset, this paper finds that the application of standards improves work conditions in small and medium...... enterprises in Vietnam. Certified firms pay higher wages on average. They are also more likely to offer formal contracts and to pay social and health insurance to workers. The estimation accounts for endogenous matching of workers with firms and unobserved heterogeneity using an instrumental variable approach....... The study reveals unexpected benefits from certification, calling for higher investment in standards....

  17. Lack of credibility in food markets - driving medium quality food out of the market

    DEFF Research Database (Denmark)

    Christensen, Jan; Graversen, Jesper Tranbjerg

    Some food markets are dominated by high quality and standard quality segments, whereas me-dium quality products are almost absent. A modeling framework with asymmetric information regard-ing true quality of the products and the resulting lack of consumer confidence is presented. Uncer-tainty rega......Some food markets are dominated by high quality and standard quality segments, whereas me-dium quality products are almost absent. A modeling framework with asymmetric information regard-ing true quality of the products and the resulting lack of consumer confidence is presented. Uncer......-tainty regarding the quality of alleged medium quality products provides certain consumer groups to divert consumptions away from medium quality to either standard or high quality products. These countervailing incentives explain the missing medium quality products. Empirical examples are given to motivate...

  18. How to misuse echo contrast

    Directory of Open Access Journals (Sweden)

    Missios Anna

    2009-01-01

    Full Text Available Abstract Background Primary intracardiac tumours are rare, there are however several entities that can mimic tumours. Contrast echocardiography has been suggested to aid the differentiation of various suspected masses. We present a case where transthoracic echocardiography completely misdiagnosed a left atrial mass, partly due to use of echo contrast. Case presentation An 80 year-old woman was referred for transthoracic echocardiography because of one-month duration of worsening of dyspnoea. Transthoracic echocardiography displayed a large echodense mass in the left atrium. Intravenous injection of contrast (SonoVue, Bracco Inc., It indicated contrast-enhancement of the structure, suggesting tumour. Transesophageal echocardiography revealed, however, a completely normal finding in the left atrium. Subsequent gastroscopy examination showed a hiatal hernia. Conclusion It is noteworthy that the transthoracic echocardiographic exam completely misdiagnosed what seemed like a left atrial mass, which in part was an effect of the use of echo contrast. This example highlights that liberal use of transoesophageal echocardiography is often warranted if optimal display of cardiac structures is desired.

  19. Potential Cost Savings of Contrast-Enhanced Digital Mammography.

    Science.gov (United States)

    Patel, Bhavika K; Gray, Richard J; Pockaj, Barbara A

    2017-06-01

    The purpose of this article is to discuss whether the sensitivity and specificity of contrast-enhanced digital mammography (CEDM) render it a viable diagnostic alternative to breast MRI. That CEDM couples low-energy images (comparable to the diagnostic quality of standard mammography) and subtracted contrast-enhanced mammograms make it a cost-effective modality and a realistic substitute for the more costly breast MRI.

  20. Engineering of Nanoscale Contrast Agents for Optical Coherence Tomography

    OpenAIRE

    Gordon, Andrew Y; Jayagopal, Ashwath

    2014-01-01

    Optical coherence tomography has emerged as valuable imaging modalityin ophthalmology and other fields by enabling high-resolution three-dimensional imaging of tissue. In this paper, we review recent progress in the field of contrast-enhanced optical coherence tomography (OCT). We discuss exogenous and endogenous sources of OCT contrast, focusing on their use with standard OCT systems as well as emerging OCT-based imaging modalities. We include advances in the processing of OCT data that gene...

  1. Contrast enhancement CT by iopamidol

    International Nuclear Information System (INIS)

    Mori, Masaki; Makita, Nobue; Yanai, Kyoko

    1984-01-01

    In order to evaluate the contrast enhancement effect and safety of iopamidol (IOP) in CT examination, IOP was compared with angiographin (AG). In the liver and abdominal aorta, peak CT values were obtained earlier and were higher in the group with AG than in the group with IOP. However, CT values in the group with IOP decreased a little more slowly than those in the group with AG. There was no significant difference in the effect on contrast enhancement between the groups. Intravenous injection of IOP caused lower degree of burning sensation than that of AG, and some of the patients with IOP did not feel burning sensation at all. Changes in clinical laboratory values were slight before and after intravenous injection of IOP. These results suggest that IOP is satisfactory in terms of safety and effect on contrast enhancement in CT examination. (Namekawa, K.)

  2. Multiscale image contrast amplification (MUSICA)

    Science.gov (United States)

    Vuylsteke, Pieter; Schoeters, Emile P.

    1994-05-01

    This article presents a novel approach to the problem of detail contrast enhancement, based on multiresolution representation of the original image. The image is decomposed into a weighted sum of smooth, localized, 2D basis functions at multiple scales. Each transform coefficient represents the amount of local detail at some specific scale and at a specific position in the image. Detail contrast is enhanced by non-linear amplification of the transform coefficients. An inverse transform is then applied to the modified coefficients. This yields a uniformly contrast- enhanced image without artefacts. The MUSICA-algorithm is being applied routinely to computed radiography images of chest, skull, spine, shoulder, pelvis, extremities, and abdomen examinations, with excellent acceptance. It is useful for a wide range of applications in the medical, graphical, and industrial area.

  3. Accounting standards

    NARCIS (Netherlands)

    Stellinga, B.; Mügge, D.

    2014-01-01

    The European and global regulation of accounting standards have witnessed remarkable changes over the past twenty years. In the early 1990s, EU accounting practices were fragmented along national lines and US accounting standards were the de facto global standards. Since 2005, all EU listed

  4. [Relevance of contrast ultrasound with microbubbles in vascular medecine].

    Science.gov (United States)

    Erdmann, Andreas; Ney, Barbara; Alatri, Adriano; Calanca, Luca; Mazzolai, Lucia

    2016-12-07

    Application of ultrasound contrast media has become a standard in diagnostic imaging in cardiology and in the characterization of focal lesions in multiple organs, especially of the liver. In the past years there was a growing body of evidence for their usefulness in vascular medicine. The development of contrast media, microbubbles with a stabilizing envelope and filled with gaz, small enough to pass through pulmonary capillaries made real-time imaging of organ perfusion possible. Ultrasound contrast media are rapidly eliminated by exhalation and can safely be administered to patients with renal failure. The objective of this review is to describe the basic principles of ultrasound contrast imaging and to inform about vascular applications of contrast ultrasound.

  5. Development of brachytherapy medium doserate

    International Nuclear Information System (INIS)

    Atang Susila; Ari Satmoko; Ahmad Rifai; Kristiyanti

    2010-01-01

    Brachytherapy has proven to be an effective treatment for different types of cancers and it become a common treatment modality in most radiotherapy clinics. PRPN has had experience in development of Low Dose Rate Brachytherapy for cervix cancer treatment. However the treatment process using LDR device needs 5 hours in time that the patient feel uncomfort. Therefore PRPN develops Medium Dose Rate Brachytherapy with radiation activity not more than 5 Currie. The project is divided into two stages. Purchasing of TPS software and TDS design are held in 2010, and the construction will be in 2011. (author)

  6. A Heterogeneous Medium Analytical Benchmark

    International Nuclear Information System (INIS)

    Ganapol, B.D.

    1999-01-01

    A benchmark, called benchmark BLUE, has been developed for one-group neutral particle (neutron or photon) transport in a one-dimensional sub-critical heterogeneous plane parallel medium with surface illumination. General anisotropic scattering is accommodated through the Green's Function Method (GFM). Numerical Fourier transform inversion is used to generate the required Green's functions which are kernels to coupled integral equations that give the exiting angular fluxes. The interior scalar flux is then obtained through quadrature. A compound iterative procedure for quadrature order and slab surface source convergence provides highly accurate benchmark qualities (4- to 5- places of accuracy) results

  7. Charmed hadrons in nuclear medium

    International Nuclear Information System (INIS)

    Tolos, L.; Gamermann, D.; Molina, R.; Nieves, J.; Oset, E.; Garcia-Recio, C.; Ramos, A.

    2010-01-01

    We study the properties of charmed hadrons in dense matter within a coupled-channel approach which accounts for Pauli blocking effects and meson self-energies in a self-consistent manner. We analyze the behaviour in this dense environment of dynamically-generated baryonic resonances as well as the open-charm meson spectral functions. We discuss the implications of the in-medium properties of open-charm mesons on the D s0 (2317) and the predicted X(3700) scalar resonances. (authors)

  8. Computed tomography angiography: the effect of different chaser flow rates, volumes, and fluids on contrast enhancement.

    Science.gov (United States)

    Behrendt, Florian F; Jost, Gregor; Pietsch, Hubertus; Keil, Sebastian; Mottaghy, Felix M; Günther, Rolf W; Mahnken, Andreas H

    2011-04-01

    The aim of this study was to intraindividually compare the effect of different chaser flow rates, volumes, and fluids on contrast enhancement in multidetector-row computed tomography. Multidetector-row computed tomography scanning of 5 dogs was performed under standardized conditions using an adapted injection protocol to ensure an identical iodine delivery rate of 1.0 gI/s and a total iodine dose of 300 mg/kg body weight (iopromide 300 and 370). The contrast medium application was followed by a 10-mL saline chaser at different injection rates (0, 2.7, 4, 6, and 8 mL/s) or by different saline chaser volumes (0, 5, 10, and 15 mL) at a flow rate of 4 mL/s. Furthermore, different chaser fluids (NaCl, hydroxyethyl starch 10%, and Dextran 1%) with different viscosities (hydroxyethyl starch 10% and dextran 1%: 3.28 and 5.98 mPa · s at 37°C) were tested (volume: 10 mL; flow rate: 6 mL/s). Each dog was examined with each protocol. The interval between each computed tomography scan session which included 2 measurements was at least 3 days. Dynamic computed tomography scans were acquired at the level of the cephalic vein, cranial vena cava, pulmonary artery, and ascending and descending aorta. Time-enhancement curves were computed, and pulmonary and aortic peak enhancements as well as time-to-peak were analyzed. Increased saline chaser flow rates or increased saline chaser volumes resulted in increased pulmonary and aortic peak contrast enhancement. Peak enhancement was highest and significantly greater compared with no saline chaser for a flow rate of 8 mL/s (pulmonary artery: 816.8 vs. 471.5 HU, P = 0.0079; ascending aorta: 578.7 vs. 384.1 HU, P = 0.0079; descending aorta: 581.4 HU vs. 390.6 HU, P = 0.0159) and a saline volume of 15 mL (pulmonary artery: 670.2 vs. 453.5 HU, P = 0.0079; ascending aorta: 512.1 vs. 370.6 HU, P = 0.0317; descending aorta: 504.0 HU vs. 394.4 HU, P = 0.0159). No significant differences between the peak times for different saline chasers were

  9. The effect of iodine uptake on radiation dose absorbed by patient tissues in contrast enhanced CT imaging. Implications for CT dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Perisinakis, Kostas; Damilakis, John [University of Crete, Department of Medical Physics, Medical School, Heraklion, Crete (Greece); University Hospital of Heraklion, Department of Medical Physics, Heraklion, Crete (Greece); Tzedakis, Antonis; Papadakis, Antonios E. [University Hospital of Heraklion, Department of Medical Physics, Heraklion, Crete (Greece); Spanakis, Kostas [University Hospital of Heraklion, Department of Radiology, Heraklion, Crete (Greece); Hatzidakis, Adam [University Hospital of Heraklion, Department of Radiology, Heraklion, Crete (Greece); University of Crete, Department of Radiology, Medical School, Heraklion, Crete (Greece)

    2018-01-15

    To investigate the effect of iodine uptake on tissue/organ absorbed doses from CT exposure and its implications in CT dosimetry. The contrast-induced CT number increase of several radiosensitive tissues was retrospectively determined in 120 CT examinations involving both non-enhanced and contrast-enhanced CT imaging. CT images of a phantom containing aqueous solutions of varying iodine concentration were obtained. Plots of the CT number increase against iodine concentration were produced. The clinically occurring iodine tissue uptake was quantified by attributing recorded CT number increase to a certain concentration of aqueous iodine solution. Clinically occurring iodine uptake was represented in mathematical anthropomorphic phantoms. Standard 120 kV CT exposures were simulated using Monte Carlo methods and resulting organ doses were derived for non-enhanced and iodine contrast-enhanced CT imaging. The mean iodine uptake range during contrast-enhanced CT imaging was found to be 0.02-0.46% w/w for the investigated tissues, while the maximum value recorded was 0.82% w/w. For the same CT exposure, iodinated tissues were found to receive higher radiation dose than non-iodinated tissues, with dose increase exceeding 100% for tissues with high iodine uptake. Administration of iodinated contrast medium considerably increases radiation dose to tissues from CT exposure. (orig.)

  10. Light propagation in a turbid medium with insonified microbubbles

    Science.gov (United States)

    Leung, Terence S.; Honeysett, Jack E.; Stride, Eleanor; Deng, Jing

    2013-01-01

    Surfactant stabilized microbubbles are widely used clinical contrast agents for ultrasound imaging. In this work, the light propagation through a turbid medium in the presence of microbubbles has been investigated. Through a series of experiments, it has been found that the optical attenuation is increased when the microbubbles in a turbid medium are insonified by ultrasound. Such microbubble enhanced optical attenuation is a function of both applied ultrasound pressure and microbubble concentration. To understand the mechanisms involved, a Monte Carlo (MC) model has been developed. Under ultrasound exposure, the sizes of microbubbles vary in space and time, and their dynamics are modeled by the Rayleigh-Plesset equation. By using Mie theory, the spatially and temporally varying optical scattering and scattering efficiency of microbubbles are determined based on the bubble sizes and internal refractive indices. The MC model is shown to effectively describe a medium with rapidly changing optical scattering, and the results are validated against both computational results using an N-layered diffusion equation model and experimental results using a clinical microbubble contrast agent (SonoVue).

  11. Optimization of image quality in pulmonary CT angiography with low dose of contrast material

    Science.gov (United States)

    Assi, Abed Al Nasser; Abu Arra, Ali

    2017-06-01

    Aim: The aim of this study was to compare objective image quality data for patient pulmonary embolism between a conventional pulmonary CTA protocol with respect to a novel acquisition protocol performed with optimize radiation dose and less amount of iodinated contrast medium injected to the patients during PE scanning. Materials and Methods: Sixty- four patients with Pulmonary Embolism (PE) possibility, were examined using angio-CT protocol. Patients were randomly assigned to two groups: A (16 women and 16 men, with age ranging from 19-89 years) mean age, 62 years with standard deviation 16; range, 19-89 years) - injected contrast agent: 35-40 ml. B (16 women and 16 men, with age ranging from 28-86 years) - injected contrast agent: 70-80 ml. Other scanning parameters were kept constant. Pulmonary vessel enhancement and image noise were quantified; signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Subjective vessel contrast was assessed by two radiologists in consensus. Result: A total of 14 cases of PE (22 %) were found in the evaluated of subjects (nine in group A, and five in group B). All PE cases were detected by the two readers. There was no significant difference in the size or location of the PEs between the two groups, the average image noise was 14 HU for group A and 19 HU for group B. The difference was not statistically significant (p = 0.09). Overall, the SNR and CNR were slightly higher on group B (24.4 and 22.5 respectively) compared with group A (19.4 and 16.4 respectively), but those differences were not statistically significant (p = 0.71 and p = 0.35, respectively). Conclusion and Discussion: Both groups that had been evaluated by pulmonary CTA protocol allow similar image quality to be achieved as compared with each other's, with optimize care dose for both protocol and contrast volume were reduced by 50 % in new protocol comparing to the conventional protocol.

  12. Contrast-enhanced endoscopic ultrasonography

    DEFF Research Database (Denmark)

    Reddy, Nischita K; Ioncica, Ana Maria; Saftoiu, Adrian

    2011-01-01

    cancers and visualization of the portal venous system and esophageal varices. In addition, contrast agents can be used to differentiate pancreatic lesions. The use of color Doppler further increases the ability to diagnose and differentiate various pancreatic malignancies. The sensitivity of power Doppler...

  13. Color contrasting in radioscopy systems

    International Nuclear Information System (INIS)

    Lopaev, V.P.; Pavlov, S.V.; Nazarenko, V.G.

    1979-01-01

    Transformation principles for achromatic radioscopy control systems to color ones have been considered. Described is the developed ''Gamma 1'' roentgen-TV facility with color contrasting, which is based on the principle of analog conversion of brightness signal to a hue. By means of color channels amplifiers realized are the special amplitude characteristics, permitting in comparison with the common method of analogous transformation to obtain the greater number of hues within the identical range of brightnesses of image under investigation due to introducing purple colors. The investigation of amplitude resolution capability of color contrasting device has shown, that in the case of color contrasting of image the amplitude resolution is 1.7-1.8 time higher than in the case of achromatic one. Defectoscopic sensitivity during the testing of 5-20 mm thick steel products in the process of experimental-production tests turned out to be 1.1-1.3 time higher when using color contrasting of radioscopic image. Realization simplicity, high resolution, noise stability and wide functional possibilities of the facility show the prospects for its using during the quality control of welded joints in products of power engineering

  14. Endovascular revascularization of TASC C and D femoropopliteal occlusive disease using carbon dioxide as contrast

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, Cynthia de Almeida; Teivelis, Marcelo Passos; Kuzniec, Sergio; Fukuda, Juliana Maria; Wolosker, Nelson [Hospital Israelita Albert Einstein, São Paulo, SP (Brazil)

    2016-07-01

    To analyze the results of ten angioplasties of TASC C and D femoropopliteal lesions using CO{sub 2} as primary contrast in patients with no formal contraindication to iodine, aiming to decrease allergic reactions and potential nephrotoxicity in high-risk patients. We describe the results of ten angioplasties of TASC C and D femoropopliteal lesions using CO{sub 2} as primary contrast in patients with high risk for open revascularization and no formal contraindication to iodine. We analyzed feasibility of the procedures, complications, quality of the angiographic images, clinical and surgical outcomes, and costs of C and D lesions treated using CO{sub 2} as contrast medium. The use of CO{sub 2} in C and D lesions needed iodine complementation in most of the cases (nine cases) but decreased the potential nephrotoxicity of iodine contrast medium by the reduction of its volume in this group of high-risk patients. The extension of the arterial lesions was the factor that most contributed to the need for iodine supplementation due to the difficulty to visualize the refill after a long arterial occlusion. The use of CO{sub 2} as contrast in patients with C and D lesions with no restriction for iodine contrast medium was an alternative that did not dismiss the need of iodine supplementation in most of the cases, but could decrease the potential nephrotoxicity of iodine constrast medium.

  15. Saliva as a diagnostic medium.

    Science.gov (United States)

    Pink, Richard; Simek, Jiri; Vondrakova, Jana; Faber, Edgar; Michl, Petr; Pazdera, Jindrich; Indrak, Karel

    2009-06-01

    This is a review of current knowledge on the use of saliva, gingival cervical fluid and mucosal transudate in the detection of some oral and systemic diseases as well as drugs. Oral fluid is a diagnostic medium that can be easily collected and with minimal invasion but it has been neglected in the past. Today, saliva is being used more often to diagnose: HIV virus, oro-facial and systemic tumors, cardiovascular disease and in detecting addictive substances. Neutropil levels in saliva may also indicate successful bone marrow transplant. Oral fluid is now systematically being researched and oral fluid analysis is being compared with the analysis of other diagnostic media such as blood and urine. A number of recent studies have focused on oncogenic marker detection and its monitoring in saliva. The latest clinical and laboratory findings on diagnostic markers of oropharyngeal carcinoma in oral fluid could be the beginning of their wider use as a diagnostic medium. Oral fluid can also be also used to diagnose other malignancies such as breast cancer which was one of the first malignant tumors to be detected using genetic protein biomarkers. Raised levels of CA15-3 and the epidermal growth factor (EGF) receptor have been found in patients with breast cancer and elevated levels of CA 125 and the glycoprotein complex in the saliva of ovarian cancer patients. Doubtless, the diagnostic value of saliva, aided by current technological development will increase rapidly in the near future.

  16. Unsaturated medium hydrocarbons pollution evaluation

    International Nuclear Information System (INIS)

    Di Luise, G.

    1991-01-01

    When the so called porous unsaturated medium, that's the vertical subsoil section between both the ground and water-table level, is interested by a hydrocarbons spill, the problem to evaluate the pollution becomes difficult: considering, essentially, the natural coexistence in it of two fluids, air and water, and the interactions between them. This paper reports that the problems tend to increase when a third fluid, the pollutant, immiscible with water, is introduced into the medium: a three-phases flow, which presents several analogies with the flow conditions present in an oil-reservoir, will be established. In such a situation, it would be very useful to handle the matter by the commonly used parameters in the oil reservoirs studies such as: residual saturation, relative permeability, phases mobility, to derive a first semiquantitative estimation of the pollution. The subsoil pollution form hydrocarbons agents is one of the worldwide more diffused causes of contamination: such events are generally referable to two main effects: accidental (oil pipeline breakdowns, e.g.), and continuous (underground tanks breaks, industrial plants leakages, e.g.)

  17. NEW RSW & Wall Medium Fully Tetrahedral Grid

    Data.gov (United States)

    National Aeronautics and Space Administration — New Medium Fully Tetrahedral RSW Grid with viscous wind tunnel wall at the root. This grid is for a node-based unstructured solver. Medium Tet: Quad Surface Faces= 0...

  18. Technical Support Document: 50% Energy Savings Design Technology Packages for Medium Office Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, Brian A.; Wang, Weimin; Lane, Michael D.; Rosenberg, Michael I.; Liu, Bing

    2009-09-01

    This Technical Support Document (TSD) describes the process and methodology for development of the Advanced Energy Design Guide for Medium Offices (AEDG-MO or the Guide), a design guidance document which intends to provide recommendations for achieving 50% energy savings in medium office buildings that just meet the requirements of ANSI/ASHRAE/IESNA Standard 90.1-2004, Energy Standard for Buildings Except Low-Rise Residential Buildings.

  19. Paediatric cardiac catheterization. Controlled, randomized study of two iodinated contrast media: iopromide 300 and ioxaglate 320 mgI/ml

    International Nuclear Information System (INIS)

    Amiel, M.; Revel, D.

    1989-01-01

    Thirty-one children were included in a prospective randomized trial comparing a new non-ionic contrast medium, iopromide 300 and the ionic low osmolar contrast medium, ioxaglate 320 mgI/ml in pediatric cardiac catheterization. There were fewer adverse effects with iopromide but no statistically significant difference was demonstrated in this small population, with a very low incidence of allergoid reactions; this tendency was confirmed by meta-analysis of the multicentre study [fr

  20. The forgotten organ: Contrast enhanced sonography of the spleen

    Energy Technology Data Exchange (ETDEWEB)

    Goerg, Christian [Medizinische Universitaetsklinik, Baldingerstrasse, 35043 Marburg/Lahn (Germany)], E-mail: goergc@med.uni-marburg.de

    2007-11-15

    Objective: Ultrasound contrast agents in conjunction with contrast specific imaging techniques, are increasingly accepted in clinical use for diagnostic imaging in several organs. Contrast enhanced sonography (CES) of second-generation contrast media have shown a spleen-specific uptake of the microbubble contrast agent. The aim of this review is to illustrate indications for the use of CES in patients with suspected (peri-)splenic pathology. Methods: This review based on the experience of transcutaneous CES in 200 patients with (peri-)splenic pathology diagnosed by B-mode sonography at an internal medicine center. CES studies were performed with a contrast-devoted unit (Acuson, Sequoia, Siemens medical solution) that had contrast-specific, continuous-mode software. A low mechanical index was used. A sulfur hexafluoride-based microbubble contrast medium (Sonovue, Bracco SpA, Milan, Italy) was injected. Results: On our experience, there are several clinical conditions which may show an diagnostic advantage of CES in comparison to B-mode US. CES should be performed to investigate: (1) the perisplenic tumor to diagnose or exclude accessory spleen, (2) the small-sized spleen to diagnose functional asplenia/hyposplenia, (3) the inhomogenous spleen of unknown cause to diagnose focal lesions within the spleen, (4) the incidentally found hypoechoic splenic tumor to diagnose high vascular splenic hemangioma, (5) focal lesions suspect for splenic abscess, hematoma, infarction to confirme diagnosis, and (6) patients with abdominal trauma to diagnose or exclude splenic injuriy. Conclusion: CES is of diagnostic value in several clinical circumstances to diagnose accessory spleen, functional asplenia, small-sized splenic involvement, high vascular splenic hemangioma, and vascular splenic pathology like splenic infarction, splenic abscess, and splenic laceration.

  1. Mapping of moveout in a TTI medium

    KAUST Repository

    Stovas, A.

    2012-01-01

    To compute moveout in a transversely isotropic medium with tilted symmetry axis is a very complicated problem. We propose to split this problem into two parts. First, to compute the moveout in a corresponding VTI medium. Second, to map the computed moveout to a TTI medium.

  2. 27 CFR 19.914 - Medium plants.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Medium plants. 19.914... OF THE TREASURY LIQUORS DISTILLED SPIRITS PLANTS Distilled Spirits For Fuel Use Permits § 19.914 Medium plants. Any person wishing to establish a medium plant shall make application for and obtain in...

  3. Optimization of medium composition for apple rootstocks

    African Journals Online (AJOL)

    User

    2011-05-02

    May 2, 2011 ... work of MS medium was also empirical and was deve- loped to optimise the mineral composition of the medium for growth of tobacco callus. A subsequent development such as Woody Plant Medium (WPM) (Lloyd and. McCown, 1981) was based on this previous process. 6-Benzylaminopurine (BA) and ...

  4. Small intestinal emptying time in normal Beagle dogs: a contrast radiographic study

    International Nuclear Information System (INIS)

    Miyabayashi, T.; Morgan, J.P.; Atilola, M.A.O.; Muhumuza, L.

    1986-01-01

    Gastric emptying time and small intestinal transit time in dogs are frequently discussed. However, it is often of interest to the radiologist to know what normal small intestinal emptying times should be. A total of 15 upper gastrointestinal studies was performed on five internal parasite-free, normal, standard Beagle dogs with three studies on each dog, 6 days apart. The ages and weights of the dogs ranged from 2–8 years and from 12.4–13.7 kg, respectively. Following 24-hour fasting, a dose of 10 ml/kg bw of 60% wt/vol barium sulfate suspension was administered through a stomach tube. Then, sequential radiographs were made at 30-minute intervals until the entire contrast medium column was in the colon and cecum. The mean, standard deviation, and range of gastric emptying time, small intestinal transit time, and small intestinal emptying time were 76 ± 16.7 (30–120), 73 ± 16.4 (30–120), and 214 ± 25.1 (180–300) minutes, respectively. This study offers the possibility that small intestinal emptying time may be used to further evaluate patients with suspected small intestinal partial obstruction, pseudo-obstruction, ischemia, or lymphangiectasia

  5. Communications standards

    CERN Document Server

    Stokes, A V

    1986-01-01

    Communications Standards deals with the standardization of computer communication networks. This book examines the types of local area networks (LANs) that have been developed and looks at some of the relevant protocols in more detail. The work of Project 802 is briefly discussed, along with a protocol which has developed from one of the LAN standards and is now a de facto standard in one particular area, namely the Manufacturing Automation Protocol (MAP). Factors that affect the usage of networks, such as network management and security, are also considered. This book is divided into three se

  6. Shoulder arthrography: comparison of morbidity after use of various contrast media

    Energy Technology Data Exchange (ETDEWEB)

    Hall, F.M.; Goldberg, R.P.; Wyshak, G.; Kilcoyne, R.F.

    1985-02-01

    This prospective study compares immediate and delayed patient discomfort in 177 patients following shoulder arthrography using intraarticular combinations of metrizamide, meglumine/sodium diatrizoate, meglumine diatrizoate, lidocaine, epinephrine, and air. Patients receiving conventional ionic monomeric positive contrast media had a 60% (90/150) incidence of moderate or severe delayed exacerbation of their baseline symptoms; only 14% (3/21) of patients receiving metrizamide, a nonionic contrast medium had similar levels of postprocedural discomfort. Morbidity was somewhat diminished with the use of double-contrast (45%, 34/75) rather than single-contrast (75%, 56/75) examinations, and with avoidance of sodium-containing contrast agents or epinephrine. Nonionic or monovalent polymeric contrast media, despite their present high cost, may be the agents of choice if single-contrast arthrography is performed in joints associated with a high incidence of postprocedural pain.

  7. Shoulder arthrography: comparison of morbidity after use of various contrast media

    International Nuclear Information System (INIS)

    Hall, F.M.; Goldberg, R.P.; Wyshak, G.; Kilcoyne, R.F.

    1985-01-01

    This prospective study compares immediate and delayed patient discomfort in 177 patients following shoulder arthrography using intraarticular combinations of metrizamide, meglumine/sodium diatrizoate, meglumine diatrizoate, lidocaine, epinephrine, and air. Patients receiving conventional ionic monomeric positive contrast media had a 60% (90/150) incidence of moderate or severe delayed exacerbation of their baseline symptoms; only 14% (3/21) of patients receiving metrizamide, a nonionic contrast medium had similar levels of postprocedural discomfort. Morbidity was somewhat diminished with the use of double-contrast (45%, 34/75) rather than single-contrast (75%, 56/75) examinations, and with avoidance of sodium-containing contrast agents or epinephrine. Nonionic or monovalent polymeric contrast media, despite their present high cost, may be the agents of choice if single-contrast arthrography is performed in joints associated with a high incidence of postprocedural pain

  8. Minimum resolvable power contrast model

    Science.gov (United States)

    Qian, Shuai; Wang, Xia; Zhou, Jingjing

    2018-01-01

    Signal-to-noise ratio and MTF are important indexs to evaluate the performance of optical systems. However,whether they are used alone or joint assessment cannot intuitively describe the overall performance of the system. Therefore, an index is proposed to reflect the comprehensive system performance-Minimum Resolvable Radiation Performance Contrast (MRP) model. MRP is an evaluation model without human eyes. It starts from the radiance of the target and the background, transforms the target and background into the equivalent strips,and considers attenuation of the atmosphere, the optical imaging system, and the detector. Combining with the signal-to-noise ratio and the MTF, the Minimum Resolvable Radiation Performance Contrast is obtained. Finally the detection probability model of MRP is given.

  9. Osmolality of nonionic contrast media.

    Science.gov (United States)

    Miklautz, H; Fichte, K; Wegscheider, K

    1989-01-01

    Solutions of different low osmolar contrast media (CM) obviously show clinically relevant differences in the osmolality despite equal iodine concentrations and similar molecular structure. To obtain precise and comparable data, the osmolality of five batches (usually) each of contrast media, iopamidol, iohexol, iopromide, and ioxaglate-all preparations commercially available-were measured by means of the vapor pressure method. The osmolality of the solutions of sodium meglumine ioxaglate with the same iodine concentration is lower than that of the nonionic CM examined. Iopromide showed the lowest osmolality and iohexol the highest value of the nonionic preparations. The differences are statistically significant as a rule. They are attributed to a varying association and hydration of the CM molecules in the solution.

  10. Use of cystatin C and serum creatinine for the diagnosis of contrast-induced nephropathy in patients undergoing contrast-enhanced computed tomography at an oncology centre.

    Directory of Open Access Journals (Sweden)

    Joao Italo Fortalesa Melo

    Full Text Available Our aim was to assess renal function using as laboratory measurements serum creatinine and cystatin C concentrations before and after administration of low-osmolarity (nonionic iodinated contrast medium in patients with cancer undergoing computed tomography (CT.This prospective study included 400 oncologic outpatients. Serum creatinine and cystatin C concentrations were measured before and 72 h after contrast administration. Glomerular filtration rates (GFRs were estimated using serum creatinine-based [Modification of Diet in Renal Disease (MDRD and Cockroft-Gault and cystatin C based (Larsson equations. Exploratory data analysis was performed. The nonparametric Wilcoxon test was used to compare pre and post contrast of test results and estimated clearance. The confidence interval used in the analysis was 95%.Compared with the pre-contrast values, the mean serum creatinine concentration was significantly higher and average GFRs estimated using MDRD and Cockcroft-Gault equations were significantly lower after the administration of contrast (p <0.001. It was also observed a significant increase after contrast in the concentration of Cystatin C (p = 0.015. In addition, a decrease in GFR estimated using the average Larsson (p = 0.021 was observed between time points. However, none of the patients presented clinically significant nephropathy.Assessment using serum creatinine and cystatin C concentrations showed changes in renal function among patients with cancer undergoing contrast-enhanced CT examination in this study. No significant renal damage related to the use of low-osmolarity iodinated contrast medium of the type and dosage employed in this study was observed. This contrast medium is thus safe for use in patients with cancer.

  11. Effects of theophyline on contrast

    OpenAIRE

    A.R. Fatahiyan; B. Baqerii; A. Mohseni; A. Makhlouq

    2006-01-01

    Background and purpose: Contrast-induced nephropathy (CN) is one of the most common causes of iatrogenic acute renal failure. In fact CN is the third leading cause of new ARF in hospitalized patients. Radiocontrast-associated ARF is a significant problem in patients with cardiovascular disease. The risk factors for cardiovascular disease also predispose these patients to an increased risk of renal failure. Various strategies have been suggested for preventing CN. Since adenosine may play a ro...

  12. Medium-size nuclear plants

    International Nuclear Information System (INIS)

    Vogelweith, L.; Lavergne, J.C.; Martinot, G.; Weiss, A.

    1977-01-01

    CEA (TECHNICATOME) has developed a range of pressurized water reactors of the type ''CAS compact'' which are adapted to civil ship propulsion, or to electric power production, combined possibly with heat production, up to outputs equivalent to 125 MWe. Nuclear plants equipped with these reactors are suitable to medium-size electric networks. Among the possible realizations, two types of plants are mentioned as examples: 1) Floating electron-nuclear plants; and 2) Combined electric power and desalting plants. The report describes the design characteristics of the different parts of a 125 MWe unit floating electro-nuclear plant: nuclear steam system CAS 3 G, power generating plant, floating platform for the whole plant. The report gives attention to the different possibilities according to site conditions (the plant can be kept floating, in a natural or artificial basin, it can be put aground, ...) and to safety and environment factors. Such unit can be used in places where there is a growing demand in electric power and fresh water. The report describes how the reactor, the power generating plant and multiflash distillation units of an electric power-desalting plant can be combined: choice of the ratio water output/electric power output, thermal cycle combination, choice of the gain ratio, according to economic considerations, and to desired goal of water output. The report analyses also some technical options, such as: choice of the extraction point of steam used as heat supply of the desalting station (bleeding a condensation turbine, or recovering steam at the exhaust of a backpressure turbine), design making the system safe. Lastly, economic considerations are dealt with: combining the production of fresh water and electric power provides usually a much better energy balance and a lower cost for both products. Examples are given of some types of installations which combine medium-size reactors with fresh water stations yielding from 10000 to 120000 m 3 per day

  13. Maxwell-Garnett effective medium theory: Quantum nonlocal effects

    Energy Technology Data Exchange (ETDEWEB)

    Moradi, Afshin, E-mail: a.moradi@kut.ac.ir [Department of Engineering Physics, Kermanshah University of Technology, Kermanshah (Iran, Islamic Republic of)

    2015-04-15

    We develop the Maxwell-Garnett theory for the effective medium approximation of composite materials with metallic nanoparticles by taking into account the quantum spatial dispersion effects in dielectric response of nanoparticles. We derive a quantum nonlocal generalization of the standard Maxwell-Garnett formula, by means the linearized quantum hydrodynamic theory in conjunction with the Poisson equation as well as the appropriate additional quantum boundary conditions.

  14. Cosmological Halos: A Search for the Ionized Intergalactic Medium

    OpenAIRE

    Geller, Robert M.; Sault, Robert J.; Antonucci, Robert; Killeen, Neil E. B.; Ekers, Ron; Desai, Ketan

    1998-01-01

    Standard big bang nucleosynthesis predicts the average baryon density of the Universe to be a few percent of the critical density. Only about one tenth of the predicted baryons have been seen. A plausible respository for the missing baryons is in a diffuse ionized intergalactic medium (IGM). In an attempt to measure the IGM we searched for Thomson-scattered halos around strong high redshift radio sources. Observations of the radio source 1935-692 were made with the Australia Telescope Compact...

  15. Prevention of contrast media nephrotoxicity--the story so far

    Energy Technology Data Exchange (ETDEWEB)

    Morcos, S.K. E-mail: sameh.morcos@sth.nhs.uk

    2004-05-01

    Contrast media nephrotoxicity (CMN) in patients with pre-existing renal impairment remains a clinically significant problem. The first step to reduce the chance of CMN is to identify patients at risk through the use of screening questionnaires and renal function measurement. Patients at risk requiring injection of contrast medium (CM) because of important clinical indications should receive a small dose of either non-ionic iso-osmolar dimeric or non-ionic low osmolar monomeric CM and hydration. Intravenous infusion (1 ml/kg body weight/h) of 0.9% saline starting 4 h before CM injection and continuing for at least 12 h afterwards is effective in reducing the incidence of CMN. Prophylactic haemodialysis does not lower the risk of this complication. The value of pharmacological manipulation with renal vasodilators (calcium channel blockers, dopamine, atrial natriuretic peptide, fenoldopam (selective dopamine-1 receptor agonist), prostaglandin E{sub 1}, non-selective adenosine receptors antagonist (theophylline), non-selective endothelin receptor antagonist or the antioxidant acetylcysteine has not been fully proven. However, haemofiltration for several hours before and after contrast medium injection offers good protection against CMN in patients with advanced renal disease.

  16. Contrast variation in SANS and its application to soft matter

    International Nuclear Information System (INIS)

    Aswal, V.K.

    2010-01-01

    Small-angle neutron scattering (SANS), small-angle X-ray scattering and light scattering (LS) are widely used low Q techniques for the characterization of materials at mesoscopic length scale. Due to differences in the interaction of different radiations with matter, these techniques provide complementary information on the system. The fact that the scattering length is negative (=-0.3742 x 10 -12 cm) for hydrogen and positive (-0.6674 x 10 -12 cm) for deuterium, SANS is an ideal technique for studying the structural aspects of many hydrogenous soft matter systems such as polymers, micellar solutions and biological systems. The contrast between the particle and the medium can be easily enhanced deuterating either or the medium. The multi-components systems are simplified to study them by selectively contrast matching the components with the partial deuteration of the components. In addition, the magnetic interaction of neutron with the matter can be utilized to study the magnetic soft matter system such as ferrofluids to characterize structure along with the nuclear structure. These unique properties of SANS have been extensively used in multidisciplinary research of soft matter involving physics, chemistry, biology and material science. This lecture will provide the usefulness of contrast variation in SANS for studying soft matter with some of our results on micelles, protein solutions and nanoparticles. (author)

  17. Development of contrast-enhanced rodent imaging using functional CT

    Science.gov (United States)

    Liang, Yun; Stantz, Keith M.; Krishnamurthi, Ganapathy; Steinmetz, Rosemary; Hutchins, Gary D.

    2003-05-01

    Micro-computed tomography (microCT) is capable of obtaining high-resolution images of skeletal tissues. However its image contrast among soft tissues remains inadequate for tumor detection. High speed functional computed tomography will be needed to image tumors by employing x-ray contrast medium. The functional microCT development will not only facilitate the image contrast enhancement among different tissues but also provide information of tumor physiology. To demonstrate the feasibility of functional CT in mouse imaging, sequential computed tomography is performed in mice after contrast material administration using a high-speed clinical CT scanner. Although the resolution of the clinical scanner is not sufficient to dissolve the anatomic details of rodents, bulky physiological parameters in major organs such as liver, kidney, pancreas, and ovaries (testicular) can be examined. For data analysis, a two-compartmental model is employed and implemented to characterize the tissue physiological parameters (regional blood flow, capillary permeability, and relative compartment volumes.) The measured contrast dynamics in kidneys are fitted with the compartmental model to derive the kidney tissue physiology. The study result suggests that it is feasible to extract mouse tissue physiology using functional CT imaging technology.

  18. Asymptotic expansions for high-contrast elliptic equations

    KAUST Repository

    Calo, Victor M.

    2014-03-01

    In this paper, we present a high-order expansion for elliptic equations in high-contrast media. The background conductivity is taken to be one and we assume the medium contains high (or low) conductivity inclusions. We derive an asymptotic expansion with respect to the contrast and provide a procedure to compute the terms in the expansion. The computation of the expansion does not depend on the contrast which is important for simulations. The latter allows avoiding increased mesh resolution around high conductivity features. This work is partly motivated by our earlier work in [Domain decomposition preconditioners for multiscale flows in high-contrast media, Multiscale Model Simul. 8 (2010) 1461-1483] where we design efficient numerical procedures for solving high-contrast problems. These multiscale approaches require local solutions and our proposed high-order expansion can be used to approximate these local solutions inexpensively. In the case of a large-number of inclusions, the proposed analysis can help to design localization techniques for computing the terms in the expansion. In the paper, we present a rigorous analysis of the proposed high-order expansion and estimate the remainder of it. We consider both high-and low-conductivity inclusions. © 2014 World Scientific Publishing Company.

  19. Achieving Standardization

    DEFF Research Database (Denmark)

    Henningsson, Stefan

    2016-01-01

    competitive, national customs and regional economic organizations are seeking to establish a standardized solution for digital reporting of customs data. However, standardization has proven hard to achieve in the socio-technical e-Customs solution. In this chapter, the authors identify and describe what has......International e-Customs is going through a standardization process. Driven by the need to increase control in the trade process to address security challenges stemming from threats of terrorists, diseases, and counterfeit products, and to lower the administrative burdens on traders to stay...... to be harmonized in order for a global company to perceive e-Customs as standardized. In doing so, they contribute an explanation of the challenges associated with using a standardization mechanism for harmonizing socio-technical information systems....

  20. Achieving Standardization

    DEFF Research Database (Denmark)

    Henningsson, Stefan

    2014-01-01

    competitive, national customs and regional economic organizations are seeking to establish a standardized solution for digital reporting of customs data. However, standardization has proven hard to achieve in the socio-technical e-Customs solution. In this chapter, the authors identify and describe what has......International e-Customs is going through a standardization process. Driven by the need to increase control in the trade process to address security challenges stemming from threats of terrorists, diseases, and counterfeit products, and to lower the administrative burdens on traders to stay...... to be harmonized in order for a global company to perceive e-Customs as standardized. In doing so, they contribute an explanation of the challenges associated with using a standardization mechanism for harmonizing socio-technical information systems....

  1. Training Standardization

    International Nuclear Information System (INIS)

    Agnihotri, Newal

    2003-01-01

    The article describes the benefits of and required process and recommendations for implementing the standardization of training in the nuclear power industry in the United States and abroad. Current Information and Communication Technologies (ICT) enable training standardization in the nuclear power industry. The delivery of training through the Internet, Intranet and video over IP will facilitate this standardization and bring multiple benefits to the nuclear power industry worldwide. As the amount of available qualified and experienced professionals decreases because of retirements and fewer nuclear engineering institutions, standardized training will help increase the number of available professionals in the industry. Technology will make it possible to use the experience of retired professionals who may be interested in working part-time from a remote location. Well-planned standardized training will prevent a fragmented approach among utilities, and it will save the industry considerable resources in the long run. It will also ensure cost-effective and safe nuclear power plant operation

  2. Tattoo: a multifaceted medium of communication

    Directory of Open Access Journals (Sweden)

    Christian Wymann

    2010-11-01

    Full Text Available This article suggests the systems theoretical distinction of form/medium as a useful tool for distinguishing social phenomena that might look as if they stem from the same process. This is shown to be the case for the tattoo and tattooing. The tattoo is conceived as a medium of communication through which different forms of communication emerge. Tattooing is one of these forms of communication that shapes the medium in a particular way. The current article sheds a special light on its intricate, communicational constellation, for which the concept of parallax is suggested. Law, medicine and cosmetics as other forms of communication use the medium of tattoo in their own way as well. The form/medium distinction allows us to grasp these different forms of communication, while it shows that they share the tattoo as medium. The article’s ultimate goal is to illustrate that the tattoo figures as a multifaceted medium of communication.

  3. Iodinated contrast media and patients with high-risk kidneys. Aiming at rational prevention

    International Nuclear Information System (INIS)

    Fontaine, B.; Frouge, C.; Gagey, N.

    1994-01-01

    Acute renal failure induced by iodinated contrast media (CM) accounts for about 10% of all hospital cases of renal failure, especially in azotemic patients. The specific anatomy and physiology of the inner medulla renalis render it particularly sensitive to even a moderate reduction in blood supply. Renal function will be estimated by measuring serum creatinine levels, before and within 72 hours after administration of the iodinated contrast medium. Hypovolaemia, diabetes mellitus-induced microangiopathy, nephrotoxic drugs and especially dehydratation may provoke renal accidents. Proper hydration, choosing a low osmolality medium and adequately spacing exposures to CM are elementary measures to be adopted to prevent renal failure. (authors)

  4. Buffering the pH of the culture medium does not extend yeast replicative lifespan.

    Science.gov (United States)

    Wasko, Brian M; Carr, Daniel T; Tung, Herman; Doan, Ha; Schurman, Nathan; Neault, Jillian R; Feng, Joey; Lee, Janet; Zipkin, Ben; Mouser, Jacob; Oudanonh, Edward; Nguyen, Tina; Stetina, Torin; Shemorry, Anna; Lemma, Mekedes; Kaeberlein, Matt

    2013-01-01

    During chronological aging of budding yeast cells, the culture medium can become acidified, and this acidification limits cell survival.  As a consequence, buffering the culture medium to pH 6 significantly extends chronological life span under standard conditions in synthetic medium.  In this study, we assessed whether a similar process occurs during replicative aging of yeast cells.  We find no evidence that buffering the pH of the culture medium to pH levels either higher or lower than the initial pH of the medium is able to significantly extend replicative lifespan.  Thus, we conclude that, unlike chronological life span, replicative life span is not limited by acidification of the culture medium or by changes in the pH of the environment.

  5. Magnetic resonance perfusion imaging without contrast media

    International Nuclear Information System (INIS)

    Martirosian, Petros; Graf, Hansjoerg; Schick, Fritz; Boss, Andreas; Schraml, Christina; Schwenzer, Nina F.; Claussen, Claus D.

    2010-01-01

    Principles of magnetic resonance imaging techniques providing perfusion-related contrast weighting without administration of contrast media are reported and analysed systematically. Especially common approaches to arterial spin labelling (ASL) perfusion imaging allowing quantitative assessment of specific perfusion rates are described in detail. The potential of ASL for perfusion imaging was tested in several types of tissue. After a systematic comparison of technical aspects of continuous and pulsed ASL techniques the standard kinetic model and tissue properties of influence to quantitative measurements of perfusion are reported. For the applications demonstrated in this paper a flow-sensitive alternating inversion recovery (FAIR) ASL perfusion preparation approach followed by true fast imaging with steady precession (true FISP) data recording was developed and implemented on whole-body scanners operating at 0.2, 1.5 and 3 T for quantitative perfusion measurement in various types of tissue. ASL imaging provides a non-invasive tool for assessment of tissue perfusion rates in vivo. Images recorded from kidney, lung, brain, salivary gland and thyroid gland provide a spatial resolution of a few millimetres and sufficient signal to noise ratio in perfusion maps after 2-5 min of examination time. Newly developed ASL techniques provide especially high image quality and quantitative perfusion maps in tissues with relatively high perfusion rates (as also present in many tumours). Averaging of acquisitions and image subtraction procedures are mandatory, leading to the necessity of synchronization of data recording to breathing in abdominal and thoracic organs. (orig.)

  6. High-index-contrast subwavelength grating VCSEL

    Science.gov (United States)

    Gilet, Philippe; Olivier, Nicolas; Grosse, Philippe; Gilbert, Karen; Chelnokov, Alexei; Chung, Il-Sug; Mørk, Jesper

    2010-02-01

    In this article, we report our results on 980nm high-index-contrast subwavelength grating (HCG) VCSELs for optical interconnection applications. In our structure, a thin undoped HCG layer replaces a thick p-type Bragg mirror. The HCG mirror can feasibly achieve polarization-selective reflectivities close to 100%. The investigated structure consists of a HCG mirror with an underneath λ/4-thick oxide gap, four p-type GaAlAs/GaAs pairs for current spreading, three InGaAs/GaAs quantum wells, and an n-type GaAlAs/GaAs Bragg mirror. The HCG structure was defined by e-beam lithography and dry etching. The current oxide aperture and the oxide gap underneath the HCG were simultaneously formed by the selective wet oxidation process. Compared to air-gap high contrast grating mirrors demonstrated elsewhere, our grating mirrors are particular since they are supported by thinner λ/4 aluminium oxide layer, and thus are mechanically robust and thinner than usual designs. Sub-milliamp threshold currents and single-transverse-mode operation was obtained. A hero device exhibited maximum singlemode output power of more than 4 mW at room temperature and 1 mw at 70°C, which are the highest values ever reported from the HCG structures. These results build a bridge between a standard VCSEL and a hybrid laser on silicon, making them of potential use for the realization of silicon photonics.

  7. Medium-Based Design: Extending a Medium to Create an Exploratory Learning Environment

    Science.gov (United States)

    Rick, Jochen; Lamberty, K. K.

    2005-01-01

    This article introduces "medium-based" design -- an approach to creating "exploratory learning environments" using the method of "extending a medium". First, the characteristics of exploratory learning environments and medium-based design are described and grounded in related work. Particular attention is given to "extending a medium" --…

  8. The use of contrast media for quality assurance in treatment planning

    International Nuclear Information System (INIS)

    Schultze, J.; Eilf, K.; Zimmermann, J.; Kimmig, B.

    1995-01-01

    In 1303 simulations between 1.1.1993 and 30.9.1993 105 times intravenous contrast media were applied, supplied by oral or endolymphatic contrast agents. It was studied if the previously intended plan had to be altered due to contrast media application. In 17 out of 105 cases (16.2%) the target volume or the preplanned technique had to be altered after contrast media application. Main reason was the existence of anatomical variations especially in kidney and small bowel detected by use of contrast agents. So standard indications for contrast media applications were defined. (orig.) [de

  9. Polarization-Independent Wideband High-Index-Contrast Grating Mirror

    DEFF Research Database (Denmark)

    Bekele, Dagmawi Alemayehu; Park, Gyeong Cheol; Malureanu, Radu

    2015-01-01

    Island-type two-dimensional high-index-contrast grating mirror based on a standard silicon-on-insulator wafer have been experimentally demonstrated. The measured spectra shows a bandwidth of ∼192 nm with a reflectivity over 99% as well as polarization independence. Numerical simulations show...... that the designed mirror has large tolerance to fabrication errors....

  10. Novel contrast-enhanced ultrasound imaging in prostate cancer

    NARCIS (Netherlands)

    Smeenge, Martijn; Mischi, Massimo; Laguna Pes, M. Pilar; de La Rosette, Jean J. M. C. H.; Wijkstra, Hessel

    2011-01-01

    The purposes of this paper were to present the current status of contrast-enhanced transrectal ultrasound imaging and to discuss the latest achievements and techniques now under preclinical testing. Although grayscale transrectal ultrasound is the standard method for prostate imaging, it lacks

  11. Contrast Optimization by Metaheuristic for Inclusion Detection in Nonlinear Ultrasound Imaging

    Science.gov (United States)

    Girault, Jean-Marc; Ménigot, Sébastien

    In ultrasound imaging, improvements have been made possible by taking into account the harmonic frequencies. However, the transmitted signal often consists of providing empirically pre-set transmit frequencies, even if the medium to be explored should be taken into account during the optimization process. To resolve this waveform optimization, transmission of stochastic sequences were proposed combined with a genetic algorithm. A medium with an inclusion was compared in term of contrast to a reference medium without defect. Two media were distinguished thanks an Euclidean distance. In simulation, the optimal distance could be multiplied by 4 in comparison with an usual excitation.

  12. Telemetry Standards

    Science.gov (United States)

    2017-07-01

    6.5.7.4 .TCPPORTS ppp ,qqq,rrr A .TCPPORTS command with a parameter of three comma-separated integers between 0 and 65535 shall be used to...configure TCP ports used by each of the three services defined for Ethernet RMM devices. • Parameters ppp ,qqq,rrr where ppp is the port to be used for...physical medium IPv4 IPv6, IPSec, Apple Talk, ICMP PPP , IEE 802.2 L2TP, MAC, LLDP Ethernet physical layer, DSL USB, ISDN, DOCSIS Packet Frame Bit

  13. Evaluation of reflection interference contrast microscope images of living cells.

    Science.gov (United States)

    Beck, K; Bereiter-Hahn, J

    1981-03-01

    Reflection contrast microscope methods are generally used for studies of those portions of the cell that are turned towards the glass coverslip, to comprehend the structure of the cytoskeleton and the dynamics of cell movement, as well as formation of cell-glass contacts. In incident illumination only reflected light contributes to picture formation. The intensity of which in the case of observation of unstained cells is small because of small refraction differences. To overcome this problem a reflection contrast system was developed by Leitz according to Ploem [49], in which by using contrast preserving measures the reflection becomes prominent in comparison with the lens reflexes. The emerging pictures are a result of interferences of reflections at glass-cell, cell-culture medium and culture medium-cell interfaces. According to Fresnel's equations the reflected intensity depends on the differences of the particular refractive indices and the thickness of the layers, which determine the phase of interfering beams. In idealized systems of thin films the reflected intensity is a measure for their optical constants. Relative reflection measurements from glass-cell areas is comparison with the known glass-medium reflection, can therefore be revealing as far as refraction index, cell-glass distance or cell thickness are concerned. The estimates by Bereiter-Hahn et al. [15] were made in the assumption of vertical illumination neglecting its actual conical shape: the comparison of two Fresnel functions of cytological relevant measurements show - in accordance with Gingell and Todd [24] - that this is only permitted under certain conditions, depending on the required accuracy of the measurements; an incidence angle of about 30 degrees leads to an error of about 10%, an angle of 50 degrees to more than 50%.

  14. Dreams of a New Medium

    Directory of Open Access Journals (Sweden)

    Aden Evens

    2009-01-01

    Full Text Available Problematic at best, the desire for a transparent interface nevertheless drives much of digital culture and technology. But not the Web; or at least, not Web 1.0. Thoroughly commercialized, comfortably parsed into genres, serving billions of pages of predigested content to passive consumers, the World Wide Web as developed in the '90s unabashedly embraces its role as medium. While so many digital technologies work to hide their mediacy--drawing in the user with a total simulated sensorium, dematerializing the resistances of size and weight, untangling the knots of cables tying user to machine and machine to cubicle, minimizing the interface--Web 1.0 proudly clings to the browser as a glaring reminder of its medial character. While Web 2.0 has not forsaken the browser altogether, it nevertheless seems to offer a different sort of mediation. Arising alongside the atomization of browser functions, the ubiquitization of connectivity, and the coincidence of producer and user, Web 2.0 retains the form of a medium while reaching for the experiential logic of immediacy. This is not the immediacy of the transparent interface; rather, Web 2.0 effects an immediate relationship between the individual and culture. The interface does not disappear, but its mediacy is subsumed under the general form of cultural participation. Focusing on the "version upgrade" from Web 1.0 to 2.0, this essay will explore the implications for mediacy of this transition, noting that the fantasy of immediacy which drives Web 2.0 is layered and complex. The typical account of immediacy proposes to eliminate the interface and so construct a virtual reality (VR. But Web 2.0 mostly sidesteps the virtual, propelled instead by a fantasy of intuition in which the Web already knows what you want because it is you. Crucially, fantasies about the digital are effective: the computer's futurity inhabits our world, finding its expression in politics, advertising, budgeting, strategic planning

  15. Engineering of Nanoscale Contrast Agents for Optical Coherence Tomography.

    Science.gov (United States)

    Gordon, Andrew Y; Jayagopal, Ashwath

    2014-01-30

    Optical coherence tomography has emerged as valuable imaging modalityin ophthalmology and other fields by enabling high-resolution three-dimensional imaging of tissue. In this paper, we review recent progress in the field of contrast-enhanced optical coherence tomography (OCT). We discuss exogenous and endogenous sources of OCT contrast, focusing on their use with standard OCT systems as well as emerging OCT-based imaging modalities. We include advances in the processing of OCT data that generate improved tissue contrast, including spectroscopic OCT (SOCT), as well as work utilizing secondary light sources and/or detection mechanisms to create and detect enhanced contrast, including photothermal OCT (PTOCT) and photoacoustic OCT (PAOCT). Finally, we conclude with a discussion of the translational potential of these developments as well as barriers to their clinical use.

  16. Effects of iodinated contrast media on renal function in patients with multiple myeloma

    International Nuclear Information System (INIS)

    Jacob, H.M.

    1980-01-01

    Case histories of 89 patients with definite myoloma of the years 1959 to 1974 were investigated in a retrospective study. 41 intravenous urographies were carried out in 31 of these patients. There was no correlation between deterioration of the renal function and contrast medium application. Relevant literature on the subject has been compiled. By 1979, 19 case studies and 5 general studies had been published which have been summarized in tables in the present study. Analyses of these case histories have shown that acute renal failure was often due to other causes and not to contrast medium application. If these cases are left out of account 8 cases remain in which lethal renal failure occurred after intravenous urography of myeloma patients. The diiodinated contrast media formerly used was less well tolerated than the present triiodinated contrast media. Further risk factors were dehydratation and/or abdominal compression. Both measures are no longer employed in intravenous urography. (orig./MG) [de

  17. Double blind evaluation of the effects of various contrast media on extremity veins in the dog

    Energy Technology Data Exchange (ETDEWEB)

    Laerum, F.; Dehner, L.P.; Rysavy, J.; Amplatz, K.

    Canine superficial extremity veins were examined grossly and microscopically in a double blind fashion for endothelial damage and phlebitis one hour and four days after the injection of ionic monomeric or dimeric, and non-ionic monomeric, 300 mg I/ml, contrast media. Superficial veins of all four extremities and the tail vein were injected with the same amounts of contrast medium after application of tourniquets for 20 minutes following the injections. Silver staining and prefixation of the veins were done in situ. The specimens were evaluated together with cross-sectioned, hematoxylin-eosin stained biopsies. On the basis of a randomized study of 77 dogs, endothelial damage or thrombosis caused by various contrast media as seen in man was not demonstrated. This may be due to species differences. It is postulated that canine endothelium may have a higher resistance to contrast medium injury than human endothelium.

  18. Double blind evaluation of the effects of various contrast media on extremity veins in the dog

    International Nuclear Information System (INIS)

    Laerum, F.; Dehner, L.P.; Rysavy, J.; Amplatz, K.; Minnesota Univ., Minneapolis

    1987-01-01

    Canine superficial extremity veins were examined grossly and microscopically in a double blind fashion for endothelial damage and phlebitis one hour and four days after the injection of ionic monomeric or dimeric, and non-ionic monomeric, 300 mg I/ml, contrast media. Superficial veins of all four extremities and the tail vein were injected with the same amounts of contrast medium after application of tourniquets for 20 minutes following the injections. Silver staining and prefixation of the veins were done in situ. The specimens were evaluated together with cross-sectioned, hematoxylin-eosin stained biopsies. On the basis of a randomized study of 77 dogs, endothelial damage or thrombosis caused by various contrast media as seen in man was not demonstrated. This may be due to species differences. It is postulated that canine endothelium may have a higher resistance to contrast medium injury than human endothelium. (orig.)

  19. Document delivery services contrasting views

    CERN Document Server

    1999-01-01

    Design and maintain document delivery services that are ideal for academic patrons! In Document Delivery Services: Contrasting Views, you'll visit four university library systems to discover the considerations and challenges each library faced in bringing document delivery to its clientele. This book examines the questions about document delivery that are most pressing in the profession of library science. Despite their own unique experiences, you'll find common practices among all four?including planning, implementation of service, and evaluation of either user satisfaction and/or vendor per

  20. Contrast media for radiological examination in gastrointestinal tract leakage

    International Nuclear Information System (INIS)

    Ginai-Karamat, A.Z.

    1987-01-01

    The aim of this investigation has been to find a safe and suitable contrast medium (CM) for radiological evaluation of the gastrointestinal tract (GIT) in cases where leakage outside the GIT can be suspected. An experimental study was carried out to evaluate the reactions of various available CM in the bronchi and lungs, mediastinum, pleura and peritoneum of rats. The CM evaluated in the experimental study were, pure barium sulphate (without any additives), commercial barium sulphate (Micropaque, with additives), Dionosil, Hytrast, Gastrografin, Amipaque (in pleura Omnipaque) and Hexabrix. (Auth.)

  1. Dust in the interplanetary medium

    Energy Technology Data Exchange (ETDEWEB)

    Mann, Ingrid; Lamy, Herve [Belgian Institute for Space Aeronomy, Brussels (Belgium); Czechowski, Andrzej [Space Research Center, Polish Academy of Sciences, Warsaw (Poland); Meyer-Vernet, Nicole; Zaslavsky, Arnaud, E-mail: ingrid.mann@aeronomie.b [LESIA, Observatoire de Paris, Meudon (France)

    2010-12-15

    The mass density of dust particles that form from asteroids and comets in the interplanetary medium of the solar system is, near 1 AU, comparable to the mass density of the solar wind. It is mainly contained in particles of micrometer size and larger. Dust and larger objects are destroyed by collisions and sublimation and hence feed heavy ions into the solar wind and the solar corona. Small dust particles are present in large number and as a result of their large charge to mass ratio deflected by electromagnetic forces in the solar wind. For nanodust particles of sizes {approx_equal}1-10 nm, recent calculations show trapping near the Sun and outside from about 0.15 AU ejection with velocities close to solar wind velocity. The fluxes of ejected nanodust are detected near 1 AU with the plasma wave instrument onboard the STEREO spacecraft. Although such electric signals have been observed during dust impacts before, the interpretation depends on several different parameters and data analysis is still in progress.

  2. Studies in medium energy physics

    International Nuclear Information System (INIS)

    Green, A.; Hoffmann, G.W.; McDonough, J.; Purcell, M.J.; Ray, R.L.; Read, D.E.; Worn, S.D.

    1991-12-01

    This document constitutes the (1991--1992) technical progress report and continuation proposal for the ongoing medium energy nuclear physics research program supported by the US Department of Energy through special Research Grant DE-FG05-88ER40444. The experiments discussed are conducted at the Los Alamos National Laboratory's (LANL) Clinton P. Anderson Meson Physics Facility (LAMPF) and the Alternating Gradient Synchrotron (AGS) facility of the Brookhaven National Laboratory (BNL). The overall motivation for the work discussed in this document is driven by three main objectives: (1) provide hadron-nucleon and hadron-nucleus scattering data which serve to facilitate the study of effective two-body interactions, test (and possibly determine) nuclear structure, and help study reaction mechanisms and dynamics; (2) provide unique, first-of-a-kind ''exploratory'' hadron-nucleus scattering data in the hope that such data will lead to discovery of new phenomena and new physics; and (3) perform precision tests of fundamental interactions, such as rare decay searches, whose observation would imply fundamental new physics

  3. The interstellar medium in galaxies

    CERN Document Server

    1997-01-01

    It has been more than five decades ago that Henk van de Hulst predicted the observability of the 21-cm line of neutral hydrogen (HI ). Since then use of the 21-cm line has greatly improved our knowledge in many fields and has been used for galactic structure studies, studies of the interstellar medium (ISM) in the Milky Way and other galaxies, studies of the mass distribution of the Milky Way and other galaxies, studies of spiral struc­ ture, studies of high velocity gas in the Milky Way and other galaxies, for measuring distances using the Tully-Fisher relation etc. Regarding studies of the ISM, there have been a number of instrumen­ tal developments over the past decade: large CCD's became available on optical telescopes, radio synthesis offered sensitive imaging capabilities, not only in the classical 21-cm HI line but also in the mm-transitions of CO and other molecules, and X-ray imaging capabilities became available to measure the hot component of the ISM. These developments meant that Milky Way was n...

  4. Phase contrast STEM for thin samples: Integrated differential phase contrast.

    Science.gov (United States)

    Lazić, Ivan; Bosch, Eric G T; Lazar, Sorin

    2016-01-01

    It has been known since the 1970s that the movement of the center of mass (COM) of a convergent beam electron diffraction (CBED) pattern is linearly related to the (projected) electrical field in the sample. We re-derive a contrast transfer function (CTF) for a scanning transmission electron microscopy (STEM) imaging technique based on this movement from the point of view of image formation and continue by performing a two-dimensional integration on the two images based on the two components of the COM movement. The resulting integrated COM (iCOM) STEM technique yields a scalar image that is linear in the phase shift caused by the sample and therefore also in the local (projected) electrostatic potential field of a thin sample. We confirm that the differential phase contrast (DPC) STEM technique using a segmented detector with 4 quadrants (4Q) yields a good approximation for the COM movement. Performing a two-dimensional integration, just as for the COM, we obtain an integrated DPC (iDPC) image which is approximately linear in the phase of the sample. Beside deriving the CTFs of iCOM and iDPC, we clearly point out the objects of the two corresponding imaging techniques, and highlight the differences to objects corresponding to COM-, DPC-, and (HA) ADF-STEM. The theory is validated with simulations and we present first experimental results of the iDPC-STEM technique showing its capability for imaging both light and heavy elements with atomic resolution and a good signal to noise ratio (SNR). Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Les milieux de contraste en radiographie: propriétés, applications, indications et contre-indications, I.

    Science.gov (United States)

    Breton, L

    1986-06-01

    The author describes the contrast media most commonly used in veterinary radiography. Emphasis is given to its physical properties and applications rather than examination techniques. There is also a reminder of the indications and contraindications for each examination using a given contrast medium.

  6. Les milieux de contraste en radiographie: Propriétés, applications, indications et contre-indications, II.

    Science.gov (United States)

    Breton, L

    1986-07-01

    The author describes the contrast media most commonly used in veterinary radiography. Emphasis is given to their physical properties and their applications rather than examination techniques. There is also a reminder of the indications and contra-indications for each examination using a given contrast medium.

  7. Commercialization of vein contrast enhancement

    Science.gov (United States)

    Lovhoiden, Gunnar; Deshmukh, Harshal; Vrancken, Carlos; Zhang, Yong; Zeman, Herbert D.; Weinberg, Devin

    2003-07-01

    An ongoing clinical study of an experimental infrared (IR) device, the Vein Contrast Enhancer (VCE) that visualizes surface veins for medical access, indicates that a commercial device with the performance of the existing VCE would have significant clinical utility for even a very skilled phlebotomist. A proof-of-principle prototype VCE device has now been designed and constructed that captures IR images of surface veins with a commercial CCD camera, transfers the images to a PC for real-time software image processing to enhance the vein contrast, and projects the enhanced images back onto the skin with a modified commercial LCD projector. The camera and projector are mounted on precision slides allowing for precise mechanical alignment of the two optical axes and for measuring the effects of axes misalignment. Precision alignment of the captured and projected images over the entire field-of-view is accomplished electronically by software adjustments of the translation, scaling, and rotation of the enhanced images before they are projected back onto the skin. This proof-of-principle prototype will be clinically tested and the experience gained will lead to the development of a commercial device, OnTarget!, that is compact, easy to use, and will visualize accessible veins in almost all subjects needing venipuncture.

  8. High index contrast photonics platform

    Science.gov (United States)

    Chu, Sai T.; Little, Brent E.; Hryniewicz, John V.; Johnson, Fred G.; King, Oliver; Gill, Dave; Chen, Wenlu; Chen, Wei

    2005-10-01

    A new low-loss high-index-contrast photonics platform has been developed for integrated optics and microwave photonics. The platform consists of a material system that has an index contrast that is adjustable from 0 to 25% and which is processed using conventional CMOS tools. The platform allows one to four orders of magnitude reduction in the size of optical components compared with conventional planar technologies. As an example, meter long path lengths occupy coils that are millimeters in diameter. Microwave photonic building blocks that are enabled include large bit count programmable delay lines for beam steering and shaping that fit in less than a square centimeter and which have delays controllable from 5 fsec to 10 nsec. Also enabled are arrays of high order tunable filters, a hundred micrometers in size, having linewidths ranging from tens of MHz to tens of GHz. These filters can be tuned over several hundred GHz, and when placed in Vernier architectures can be tuned across the C band (5 THz). An optical chip typically consists of dozens of optical elements. Each element is placed in its own micro-control loop that consists of a thin film heater for thermo-optic control and a thermistor for electronic feedback. The micro-control loops impart intelligence to the optical chip.

  9. Contact double-contrast cholangiography.

    Science.gov (United States)

    Hishida, Y

    1979-05-01

    Recently operative cholangiography has become an essential step in biliary surgery. However, an usual technique in which x-ray film is set beneath the patient has its limitation in visualization of fine changes. The author devised a new technique to resolve this problem. A triangular mammography film designed for good positioning is vaccum-packed, coupled with an intensifying screen of the same size, and then is sterilized in advance. Barium solution mixed with Gascon drop (a defoaming agent) is used as contrast material. The duodenum and head of the pancreas are mobilized. Usual cholangiography is performed at first, introducing angiographic media through a catheter placed into the catheter placed into the common duct via the cystic duct. After this study a triangle film pack is set beneath the second part of the duodenum. Two to three milliliters of barium, 1 to 2 ml of Gascon, and 15 ml of air are pushed in; thus a contact double-contrast cholangiogram is obtained. This technique promises clear demonstration of the distal bile duct without risk, and even fine mucosal plicae may be discernible in the film.

  10. Death associated with bronchography. Question role of heating the contrast agent

    Energy Technology Data Exchange (ETDEWEB)

    McAlister, W.H.

    1989-07-01

    A young woman died following bronchography. The bilateral bronchogram done under general anesthesia without fluoroscopic control was associated with extensive small airway filling or 'alveolarization' of the contrast medium. The oily Dionosil used had been heated in an autoclave. Experiments showed that the viscosity of oily Dionosil decreases with heating. The lowered viscosity could have contributed to the increased 'alveolarization' of the contrast agent and death of the patient. (orig.).

  11. Prevention of contrast-induced nephropathy by use of bicarbonate solution: preliminary results and literature review.

    Science.gov (United States)

    Silva, Ricardo Gonçalves da; Silva, Nelson Gonçalves da; Lucchesi, Fabiano; Burdmann, Emmanuel A

    2010-01-01

    The incidence of contrast-induced nephropathy has increased simultaneously with the increase in contrast medium use in diagnostic and interventional procedures. The incidence of contrast-induced nephropathy in the general population is low, but increases exponentially in patients with risk factors, such as diabetes and chronic kidney disease. Several strategies have been used in order to prevent contrast-induced nephropathy. The most efficient strategies are saline hydration (0.9% or 0.45%), use of low-or iso-osmolality contrast medium, and sodium bicarbonate infusion. The aim of this study was to review the pertinent literature and to assess the efficacy of hydration with 1.3% sodium bicarbonate compared with hydration with 0.9% saline solution in preventing contrast-induced nephropathy in high-risk patients. A systematic search of the literature was conducted in PubMed by using the following keywords: bicarbonate, nephropathy, contrast medium, and acute kidney failure. In addition, 27 patients with diabetes and/or chronic kidney disease, diagnosed with some kind of cancer were randomized for study. None of the patients developed contrast-induced nephropathy characterized as a 0.5 mg/ dL-increase and/or a relative 25%-increase in baseline creatinine. The literature review strongly suggested that sodium bicarbonate is effective in preventing contrast-induced nephropathy. Regarding the randomized study, saline solution and bicarbonate solution had similar efficacy in preventing contrast-induced nephropathy. However, the small number of patients does not allow definite conclusions.

  12. [Evaluation of low contrast resolution in cone beam CT using FPD].

    Science.gov (United States)

    Sakamoto, Kiyoshi; Miura, Koui; Ueda, Ken; Baba, Rika; Kamakura, Toshiko; Sakamoto, Rieko; Okabe, Masakazu; Nakao, Norio

    2006-04-20

    We examined the low contrast resolution of cone beam CT (CBCT) equipped with an indirect-type flat panel detector and compared it with a commercial CT unit (Robusto) . In CBCT, the X-ray tube voltage of 110 kV was used, and in the Robusto, the usual 120 kV was used for examinations. The computed tomography dose index (CTDI) of the two systems was measured, and images scanned at about the same exposure to radiation were compared. The modulation transfer factors of the two systems were measured, and the convolution kernel that was the nearest to the characteristic of CBCT was chosen among kernels of the Robusto. A water phantom with a diameter of 200 mm was scanned, Wiener spectra were calculated, and signal-to-noise ratios were compared. The low contrast resolution phantom was scanned, and detectability and contrast-to-noise ratio (CNR) were measured. In addition, we placed diluted contrast medium into a phantom, scanned the phantom, and measured the detectability and CNR. When the X-ray irradiation condition of CBCT was 75 mAs at 110 kV, the equal dose of radioactivity in the Robusto was 50 mAs at 120 kV. In the low contrast resolution phantom, detectability was 8.7%mm in CBCT, and 9.4%mm in the Robusto. In the low contrast resolution evaluation phantom, CNR was 1.39 in CBCT, and 2.69 in the Robusto. With diluted contrast medium, CNR was 1.28 in CBCT, and 0.60 in the Robusto. CBCT was inferior to the Robusto in a low contrast resolution phantom, but CBCT was superior to the Robusto using diluted contrast medium. We found that CBCT was useful in examinations using contrast media.

  13. Late adverse reactions to intravascular iodine based contrast media

    DEFF Research Database (Denmark)

    Bellin, Marie-France; Stacul, Fulvio; Webb, Judith A W

    2011-01-01

    DEFINITION: Late adverse reactions (LAR) to contrast media (CM) are defined as reactions occurring 1 h to 1 week after exposure. NEED FOR REVIEW: In view of more prospective studies of LAR and new data about their pathophysiology, the Contrast Medium Safety Committee (CMSC) of the European Society...... of Urogenital Radiology (ESUR) reviewed the literature on LAR and updated their guidelines. CLINICAL FEATURES AND PATHOLOGY: LAR after CM include symptoms such as nausea, vomiting, headache, itching, skin rash, musculoskeletal pain, and fever. Skin reactions are well-documented LAR to CM with an incidence...... of approximately 2%-4% after nonionic monomers. LAR are commoner by a factor of three to four after nonionic dimers. The commonest skin reactions are maculopapular rashes, erythema and skin swelling. These reactions are T cell-mediated immune reactions, and the diagnosis may be confirmed using skin tests (patch...

  14. Parametric Mapping of Contrasted Ovarian Transvaginal Sonography

    Science.gov (United States)

    Korhonen, Katrina; Moore, Ryan; Lyshchik, Andrej; Fleischer, Arthur C.

    2014-01-01

    The purpose of this study was to assess the accuracy of parametric analysis of transvaginal contrast-enhanced ultrasound (TV-CEUS) for distinguishing benign versus malignant ovarian masses. A total of 48 ovarian masses (37 benign and 11 borderline/malignant) were examined with TV-CEUS (Definity, Lantheus, North Bilreca, MA; Philips iU22, Bothell, WA). Parametric images were created offline with a quantification software (Bracco Suisse SA, Geneva, Switzerland) with map color scales adjusted such that abnormal hemodynamics were represented by the color red and the presence of any red color could be used to differentiate benign and malignant tumors. Using these map color scales, low values of the perfusion parameter were coded in blue, and intermediate values of the perfusion parameter were coded in yellow. Additionally, for each individual color (red, blue, or yellow), a darker shade of that color indicated a higher intensity value. Our study found that the parametric mapping method was considerably more sensitive than standard ROI analysis for the detection of malignant tumors but was also less specific than standard ROI analysis. Parametric mapping allows for stricter cut-off criteria, as hemodynamics are visualized on a finer scale than ROI analyses, and as such, parametric maps are a useful addition to TV-CEUS analysis by allowing ROIs to be limited to areas of highest malignant potential. PMID:26002525

  15. Medium of Instruction in Thai Science Learning

    Science.gov (United States)

    Chanjavanakul, Natpat

    The goal of this study is to compare classroom discourse in Thai 9th grade science lessons with English or Thai as a medium of instruction. This is a cross-sectional study of video recordings from five lessons in an English-medium instruction class and five lessons in a Thai- medium instruction class from a Thai secondary school. The study involved two teachers and two groups of students. The findings show the use of both English and Thai in English-medium lessons. Students tend to be more responsive to teacher questions in Thai than in English. The findings suggest the use of students' native language during English-medium lessons to help facilitate learning in certain situations. Additionally, the study provides implications for research, practice and policy for using English as a medium of instruction.

  16. Calculating Retinal Contrast from Scene Content: A Program

    Directory of Open Access Journals (Sweden)

    John J. McCann

    2018-01-01

    Full Text Available This paper describes a computer program for calculating the contrast image on the human retina from an array of scene luminances. We used achromatic transparency targets and measured test target's luminances with meters. We used the CIE standard Glare Spread Function (GSF to calculate the array of retinal contrast. This paper describes the CIE standard, the calculation and the analysis techniques comparing the calculated retinal image with observer data. The paper also describes in detail the techniques of accurate measurements of HDR scenes, conversion of measurements to input data arrays, calculation of the retinal image, including open source MATLAB code, pseudocolor visualization of HDR images that exceed the range of standard displays, and comparison of observed sensations with retinal stimuli.

  17. PET/CT with intravenous contrast can be used for PET attenuation correction in cancer patients

    DEFF Research Database (Denmark)

    Berthelsen, A K; Holm, S; Loft, A

    2005-01-01

    PURPOSE: If the CT scan of a combined PET/CT study is performed as a full diagnostic quality CT scan including intravenous (IV) contrast agent, the quality of the joint PET/CT procedure is improved and a separate diagnostic CT scan can be avoided. CT with IV contrast can be used for PET attenuation...... correction, but this may result in a bias in the attenuation factors. The clinical significance of this bias has not been established. Our aim was to perform a prospective clinical study where each patient had CT performed with and without IV contrast agent to establish whether PET/CT with IV contrast can...... be used for PET attenuation without reducing the clinical value of the PET scan. METHODS: A uniform phantom study was used to document that the PET acquisition itself is not significantly influenced by the presence of IV contrast medium. Then, 19 patients referred to PET/CT with IV contrast underwent CT...

  18. A new procedure for imaging liver and spleen with water soluble contrast media in liposomes

    International Nuclear Information System (INIS)

    Zherbin, E.A.; Davidenkova, E.F.; Khanson, K.P.; Gubareva, A.V.; Zhdanova, N.V.; Aliyakparov, M.T.; Loshakova, L.V.; Fomina, Eh.V.; Rozenberg, O.A.

    1983-01-01

    The problems of long-term, reversible, and safe contrast investigation of liver and spleen and reduction of the irritating action of water-soluble contrast media on the wall of blood vessels are unresolved. The production and experimental application of contrast media encapsulated in liposomes are described. It is possible to produce a liposome preparation with 10-20 % Verografin content. After intravenous injection it leads to a quick (after 16-30 min), persisting (10-12 h) and reversible (24-30 h) contrast imaging of liver and spleen in rodents. The contrast medium has no pathological effects on heart, blood and circulatory system and on the morphology of liver, spleen, heart, lungs, kidneys and urinary bladder. The perspectives of clinical application of such contrast media are discussed. (author)

  19. Optical illusions induced by rotating medium

    Science.gov (United States)

    Zang, XiaoFei; Huang, PengCheng; Zhu, YiMing

    2018-03-01

    Different from the traditional single-function electromagnetic wave rotators (rotate the electromagnetic wavefronts), we propose that rotating medium can be extended to optical illusions such as breaking the diffraction limit and overlapping illusion. Furthermore, the homogeneous but anisotropic rotating medium is simplified by homogeneous and isotropic positive-index materials according to the effective medium theory, which is helpful for future device fabrication. Finite element simulations for the two-dimensional case are performed to demonstrate these properties.

  20. Evaluation of the equine digital flexor tendon sheath using diagnostic ultrasound and contrast radiography

    International Nuclear Information System (INIS)

    Redding, W.R.

    1994-01-01

    This study was designed to evaluate the normal anatomy of the digital flexor tendon sheath using contrast radiography and diagnostic ultrasound. Iodinated contrast medium was injected into eight cadaver limbs and the limbs immediately frozen. Lateromedial and dorsopalmar/plantar radiographs were made. These limps were then cut transversely and proximal to distal radiographs of each slab were made. This cross sectional contrast methodology allowed the visualization of the relative size and shape of the superficial and deep digital flexor tendons as well as the potential space taken by effusions of the digital flexor tendon sheath. The second part of the study used twelve live animals with normal digital flexor tendon sheaths. Ultrasonographic measurement of the structures of the digital flexor tendon sheath at each level were compiled. This documented the ability of diagnostic ultrasound to image: 1) the superficial and deep digital flexor tendons, 2) the proximal and distal ring of the manica flexoria, 3) the straight and oblique sesamoidean ligaments, and 4) the mesotendinous attachments to the superficial and deep flexor tendons. Iodinated contrast medium was then injected into the digital flexor tendon sheath and the ultrasonography repeated. These images were compared with those obtained from contrast radiography and prosections of twenty normal limbs. The iodinated contrast medium enhanced sonographic imaging of the structures of the digital tendon sheath, particularly the abaxial borders of the superficial digital flexor tendon branches and the mesotendinous attachments to the superficial and deep digital flexor tendons

  1. Myths and misconceptions concerning contrast media-induced anaphylaxis: a narrative review.

    Science.gov (United States)

    Böhm, Ingrid; Morelli, John; Nairz, Knud; Silva Hasembank Keller, Patricia; Heverhagen, Johannes T

    2017-03-01

    Contrast-enhanced radiological examinations are an increasingly important diagnostic tool in modern medicine. All approved and available contrast media (iodinated and gadolinium-based) are safe compounds that are well-tolerated by most patients. However, a small percentage of patients exhibit contrast medium-induced adverse drug reactions that are dose-dependent and predictable (type A) or an even smaller cohort experience so-called type B (dose-independent, non-predictable). To increase patients' safety, recommendations/guidelines have been put forth in the literature and advice passed down informally by radiologists in practice to ensure contrast media safety. Through these, both reasonable suggestions as well as misinterpretations and myths (such as the misleading terms "allergy-like" reactions, and "iodine-allergy", the wrong assumption that the initial contact to a contrast medium could not induce an allergy, the estimation that an anti-allergy premedication could suppress all possible adverse reactions, and interleukin-2 as a risk/trigger for contrast medium adverse events) have arisen. Since the latter are not only unhelpful but also potentially reduce patients' safety, such myths and misconceptions are the focus of this review.

  2. Peripheral blood eosinophilia associated with gastrointestinal administration of iodinated contrast media.

    Science.gov (United States)

    Plavsic, Branko M; Newman, Alan C; Reuther, Warren L; Terry, James A; Drnovsek, Valerie H

    2003-03-01

    This study was designed to assess whether gastrointestinal administration of iodinated contrast media results in peripheral blood eosinophilia. We studied 110 patients in a retrospective review. Diatrizoate meglumine and diatrizoate sodium for abdominal CT were administered to 98 of these patients; 22 of the 98 had also been given the same contrast medium administered by enema. The remaining 12 patients were given diatrizoate sodium for gastrointestinal fluoroscopy. A control group of 65 patients underwent single-contrast barium upper gastrointestinal or enema examinations. WBC and eosinophil counts were determined approximately 24 hr before the examination and every 24 hr thereafter, through the ninth day. Eosinophilia was detected in 17 (15.5%) of 110 patients after gastrointestinal administration of iodinated contrast media. The prevalence of eosinophilia after administration of iodinated contrast media was statistically significantly different compared with that in the control group, in which none of the 65 patients had eosinophilia (p contrast agents and lasted through the sixth day, with a peak on the fifth day. The prevalence of eosinophilia was independent of route of application, dose, or type of iodinated contrast medium. Eosinophilia in all cases was clinically asymptomatic. Eosinophilia that is caused by gastrointestinal administration of iodinated contrast media is a transient, clinically silent phenomenon. It may lead to unnecessary workup for known conditions associated with eosinophilia.

  3. Bioadhesive agents in addition to oral contrast media - evaluation in an animal model

    International Nuclear Information System (INIS)

    Conrad, R.; Schneider, G.; Textor, J.; Schild, H.H.; Fimmers, R.

    1998-01-01

    Purpose: To evaluate the additional effect of bioadhesives in combination with iotrolan and barium as oral contrast media in an animal model. Method: The bioadhesives Noveon, CMC, Tylose and Carbopol 934 were added to iotrolan and barium. The solutions were administered to rabbits by a feeding tube. The animals were investigated by computed tomography (CT) and radiography after 0,5, 4, 12, 24 and in part after 48 hours. Mucosal coating and contrast filling of the bowel were evaluated. Results: Addition of bioadhesives to oral contrast media effected long-term contrast in the small intestine and colon, but no improvement in continuous filling and coating of the gastrointestinal tract was detected. Mucosal coating was seen only in short regions of the caecum and small intestine. In CT the best results for coating were observed with tylose and CMC, in radiography additionally with carbopol and noveon. All contrast medium solutions were well tolerated. Conclusion: The evaluated contrast medium solutions with bioadhesives have shown long-term contrast but no improvement in coating in comparison to conventional oral contrast media. (orig.) [de

  4. Ultrasound contrast agents: An overview

    International Nuclear Information System (INIS)

    Cosgrove, David

    2006-01-01

    With the introduction of microbubble contrast agents, diagnostic ultrasound has entered a new era that allows the dynamic detection of tissue flow of both the macro and microvasculature. Underpinning this development is the fact that gases are compressible, and thus the microbubbles expand and contract in the alternating pressure waves of the ultrasound beam, while tissue is almost incompressible. Special software using multiple pulse sequences separates these signals from those of tissue and displays them as an overlay or on a split screen. This can be done at low acoustic pressures (MI < 0.3) so that the microbubbles are not destroyed and scanning can continue in real time. The clinical roles of contrast enhanced ultrasound scanning are expanding rapidly. They are established in echocardiography to improve endocardial border detection and are being developed for myocardial perfusion. In radiology, the most important application is the liver, especially for focal disease. The approach parallels that of dynamic CT or MRI but ultrasound has the advantages of high spatial and temporal resolution. Thus, small lesions that can be indeterminate on CT can often be studied with ultrasound, and situations where the flow is very rapid (e.g., focal nodular hyperplasia where the first few seconds of arterial perfusion may be critical to making the diagnosis) are readily studied. Microbubbles linger in the extensive sinusoidal space of normal liver for several minutes whereas they wash out rapidly from metastases, which have a low vascular volume and thus appear as filling defects. The method has been shown to be as sensitive as three-phase CT. Microbubbles have clinical uses in many other applications where knowledge of the microcirculation is important (the macrocirculation can usually be assessed adequately using conventional Doppler though there are a few important situations where the signal boost given by microbubbles is useful, e.g., transcranial Doppler for evaluating

  5. Ultrasound contrast agents: an overview.

    Science.gov (United States)

    Cosgrove, David

    2006-12-01

    With the introduction of microbubble contrast agents, diagnostic ultrasound has entered a new era that allows the dynamic detection of tissue flow of both the macro and microvasculature. Underpinning this development is the fact that gases are compressible, and thus the microbubbles expand and contract in the alternating pressure waves of the ultrasound beam, while tissue is almost incompressible. Special software using multiple pulse sequences separates these signals from those of tissue and displays them as an overlay or on a split screen. This can be done at low acoustic pressures (MI<0.3) so that the microbubbles are not destroyed and scanning can continue in real time. The clinical roles of contrast enhanced ultrasound scanning are expanding rapidly. They are established in echocardiography to improve endocardial border detection and are being developed for myocardial perfusion. In radiology, the most important application is the liver, especially for focal disease. The approach parallels that of dynamic CT or MRI but ultrasound has the advantages of high spatial and temporal resolution. Thus, small lesions that can be indeterminate on CT can often be studied with ultrasound, and situations where the flow is very rapid (e.g., focal nodular hyperplasia where the first few seconds of arterial perfusion may be critical to making the diagnosis) are readily studied. Microbubbles linger in the extensive sinusoidal space of normal liver for several minutes whereas they wash out rapidly from metastases, which have a low vascular volume and thus appear as filling defects. The method has been shown to be as sensitive as three-phase CT. Microbubbles have clinical uses in many other applications where knowledge of the microcirculation is important (the macrocirculation can usually be assessed adequately using conventional Doppler though there are a few important situations where the signal boost given by microbubbles is useful, e.g., transcranial Doppler for evaluating

  6. Malignant Cerebral Edema following CT Myelogram Using Isovue-M 300 Intrathecal Nonionic Water-Soluble Contrast: A Case Report

    International Nuclear Information System (INIS)

    Kelley, B.C.; Arnold, P.M.; Roh, S.; Johnson, Ph.L.

    2011-01-01

    Lumbar myelogram utilizing nonionic contrast is a commonly performed procedure to identify spinal pathology. Complication rates are low. Cerebral edema has been shown to occur following intrathecal injection of ionic contrast; however, no current literature has documented this complication relating to the ubiquitously used nonionic contrast medium. We report a case of a patient who developed malignant cerebral edema following a lumbar myelogram with Isovue-M 300 nonionic water-soluble intrathecal contrast. We believe this is the first reported case of cerebral edema resulting from the use of a nonionic contrast

  7. Contrast-enhanced 3D MR DSA for intracranial vessels

    Energy Technology Data Exchange (ETDEWEB)

    Tominaga, Satoru; Ishikura, Reiichi; Ando, Kumiko; Morikawa, Tsutomu; Nakao, Norio [Hyogo Coll. of Medicine, Nishinomiya (Japan); Ikeda, Jyota

    1999-12-01

    We performed serial scans of ultrafast 3D MR angiography sequence which was improved to shorten acquisition time by means of zero-filling interpolation after injection of the contrast medium and called it contrast-enhanced three-dimensional (3D) magnetic resonance (MR) digital subtraction angiography (DSA). The parameters were 3.8/1.3/35 (TR/TE/flip angle), a slab thickness of 60 mm, a voxel size of 2.3 x 1.2 x 3.7 mm, a scan time of 2.9 s. The measurement was sequentially performed for 10 to 15 times after administration of 0.1 mmol/kg of Gd-DTPA. Total acquisition time was almost 30 to 45 s. All images of each set were subtracted with precontrast images and then the maximum intensity projection (MIP) were performed. In all cases, contrast-enhanced 3D MR DSA could clearly depict sequential change of the cranial vessels from the arterial phase to the venous phase. The view from different angle on any phase could be obtained and stereoscopic view was possible. The time intensity curve was obtained from signal intensity measured on the source images. The combination of conventional 3D TOF MRA with contrast-enhanced 3D MR DSA was the useful study which could replace cerebral angiography. (author)

  8. SU-E-T-56: Brain Metastasis Treatment Plans for Contrast-Enhanced Synchrotron Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Obeid, L; Adam, J [Grenoble Institut des Neurosciences, La Tronche, Rhone-Alpes (France); Tessier, A [Centre Hospitalier Universitaire, La Tronche, Rhone-Alpes (France); Vautrin, M; Benkebil, M [DOSIsoft, Cachan, Ile de France (France); Sihanath, R [Centre Hospitalier Universitaire, La Tronche, Rhone- Alpes (France)

    2014-06-01

    Purpose: Iodine-enhanced radiotherapy is an innovative treatment combining the selective accumulation of an iodinated contrast agent in brain tumors with irradiations using monochromatic medium energy x-rays. The aim of this study is to compare dynamic stereotactic arc-therapy and iodineenhanced SSRT. Methods: Five patients bearing brain metastasis received a standard helical 3D-scan without iodine. A second scan was acquired 13 min after an 80 g iodine infusion. Two SSRT treatment plans (with/without iodine) were performed for each patient using a dedicated Monte Carlo (MC) treatment planning system (TPS) based on the ISOgray TPS. Ten coplanar beams (6×6 cm2, shaped with collimator) were simulated. MC statistical error objective was less than 5% in the 50% isodose. The dynamic arc-therapy plan was achieved on the Iplan Brainlab TPS. The treatment plan validation criteria were fixed such that 100% of the prescribed dose is delivered at the beam isocentre and the 70% isodose contains the whole target volume. The comparison elements were the 70% isodose volume, the average and maximum doses delivered to organs at risk (OAR): brainstem, optical nerves, chiasma, eyes, skull bone and healthy brain parenchyma. Results: The stereotactic dynamic arc-therapy remains the best technique in terms of dose conformation. Iodine-enhanced SSRT presents similar performances to dynamic arc-therapy with increased brainstem and brain parenchyma sparing. One disadvantage of SSRT is the high dose to the skull bone. Iodine accumulation in metastasis may increase the dose by 20–30%, allowing a normal tissue sparing effect at constant prescribed dose. Treatment without any iodine enhancement (medium-energy stereotactic radiotherapy) is not relevant with degraded HDVs (brain, parenchyma and skull bone) comparing to stereotactic dynamic arc-therapy. Conclusion: Iodine-enhanced SSRT exhibits a good potential for brain metastasis treatment regarding the dose distribution and OAR criteria.

  9. Visible Contrast Energy Metrics for Detection and Discrimination

    Science.gov (United States)

    Ahumada, Albert; Watson, Andrew

    2013-01-01

    Contrast energy was proposed by Watson, Robson, & Barlow as a useful metric for representing luminance contrast target stimuli because it represents the detectability of the stimulus in photon noise for an ideal observer. Like the eye, the ear is a complex transducer system, but relatively simple sound level meters are used to characterize sounds. These meters provide a range of frequency sensitivity functions and integration times depending on the intended use. We propose here the use of a range of contrast energy measures with different spatial frequency contrast sensitivity weightings, eccentricity sensitivity weightings, and temporal integration times. When detection threshold are plotting using such measures, the results show what the eye sees best when these variables are taken into account in a standard way. The suggested weighting functions revise the Standard Spatial Observer for luminance contrast detection and extend it into the near periphery. Under the assumption that the detection is limited only by internal noise, discrimination performance can be predicted by metrics based on the visible energy of the difference images

  10. Cumulative phase delay imaging for contrast-enhanced ultrasound tomography

    International Nuclear Information System (INIS)

    Demi, Libertario; Van Sloun, Ruud J G; Wijkstra, Hessel; Mischi, Massimo

    2015-01-01

    Standard dynamic-contrast enhanced ultrasound (DCE-US) imaging detects and estimates ultrasound-contrast-agent (UCA) concentration based on the amplitude of the nonlinear (harmonic) components generated during ultrasound (US) propagation through UCAs. However, harmonic components generation is not specific to UCAs, as it also occurs for US propagating through tissue. Moreover, nonlinear artifacts affect standard DCE-US imaging, causing contrast to tissue ratio reduction, and resulting in possible misclassification of tissue and misinterpretation of UCA concentration. Furthermore, no contrast-specific modality exists for DCE-US tomography; in particular speed-of-sound changes due to UCAs are well within those caused by different tissue types. Recently, a new marker for UCAs has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental component is in fact observable for US propagating through UCAs, and is absent in tissue. In this paper, tomographic US images based on CPD are for the first time presented and compared to speed-of-sound US tomography. Results show the applicability of this marker for contrast specific US imaging, with cumulative phase delay imaging (CPDI) showing superior capabilities in detecting and localizing UCA, as compared to speed-of-sound US tomography. Cavities (filled with UCA) which were down to 1 mm in diameter were clearly detectable. Moreover, CPDI is free of the above mentioned nonlinear artifacts. These results open important possibilities to DCE-US tomography, with potential applications to breast imaging for cancer localization. (fast track communication)

  11. Computer-aided diagnosis in contrast-enhanced CT colonography: an approach based on contrast

    International Nuclear Information System (INIS)

    Luboldt, Wolfgang; Kroll, Manuela; Vogl, Thomas J.; Mann, Carolin; Vonthein, Reinhard; Stueker, Dietmar; Luz, Oliver; Claussen, Claus D.; Tryon, Cathy L.

    2002-01-01

    Automation in colorectal mass detection is achieved as soon as the voxels representing colorectal masses can be automatically segmented. We tested the Hounsfield (HU) value in intensely contrast enhanced high-resolution CT colonography for automated segmentation of colorectal masses in 18 patients with 35 polyps (28<10 mm, 7 ≥10 mm) and 7 carcinomas. Mean HU values of the colonic wall and masses were determined to deduce a gradient threshold for a segmentation process, which encodes the voxels bordering the colonic lumen with a colour ranging in intensity from 0 to 100% according to the selected gradient threshold range in the volume rendering. The results of the automated segmentation process were superimposed on a virtual double contrast and endoscopic display and validated through correlation with morphology. Mean HU values and their standard deviations for the colonic wall, polyps <10 mm, polyps ≥10 mm and carcinomas were 63±24, 154±38, 116±41 and 108±29 HU, respectively. A gradient threshold ranging from 90 to 160 HU resulted in colour pools in 6 of 7 of polyps ≥10 mm, and 6 of 7 carcinomas that were significant enough to prospectively guide the reader's attention to these masses. Due to the superposition of ''false-positive'' voxels in the projection view, the virtual endoscopic perspective was superior to the virtual double contrast display for controlling the segmentation results. The HU value is promising for automated segmentation of colorectal masses but needs to be combined with morphological parameters to render automated colorectal mass detection more accurate. Further refinements of the method with subsequent analysis of its accuracy, as well as analogue studies with contrast-enhanced MRI, appear warranted. More information at http://www.multiorganscreening.org (orig.)

  12. Frequency standards

    CERN Document Server

    Riehle, Fritz

    2006-01-01

    Of all measurement units, frequency is the one that may be determined with the highest degree of accuracy. It equally allows precise measurements of other physical and technical quantities, whenever they can be measured in terms of frequency.This volume covers the central methods and techniques relevant for frequency standards developed in physics, electronics, quantum electronics, and statistics. After a review of the basic principles, the book looks at the realisation of commonly used components. It then continues with the description and characterisation of important frequency standards

  13. Properties of medium-density fiberboard produced in an oil-heated laboratory press

    Science.gov (United States)

    O. Suchsland; G.E. Woodson

    1976-01-01

    Medium-density fiberboards from pressurized double-disk refined fibers have a close correlation between layer density and layer dynamic modulus of elasticity. Density distribution over the thickness was readily controlled by manipulating platen temperature and applied pressure. Thus, overall modulus of elasticity could be adjusted. In contrast to modulus of elasticity...

  14. Emerging Culture of English-Medium Instruction in Korea: Experiences of Korean and International Students

    Science.gov (United States)

    Kim, Jeongyeon; Tatar, Bradley; Choi, Jinsook

    2014-01-01

    This study aims to contrastively examine Korean and international students' experiences of taking subject courses at a Korean university. Focusing on the viewpoints of the students, rather than central authorities, we attempt to reveal how language use and cultural factors are interpenetrated in the praxis of English-medium instruction (EMI). The…

  15. Borel sum rules for octet baryons in nuclear medium

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, Y.; Morimatsu, O.

    1992-06-01

    Borel sum rules are examined for octet baryons in the nuclear medium. First, it is noticed that in the medium the dispersion relation is realized for the retarded correlation {Pi}{sup R}({omega}, q{sup 2}) in the energy {omega}. Then, {Pi}{sup R}({omega}, q{sup 2}) is split into even and odd parts of {omega} in order to apply the Borel transformation. The obtained Borel sum rules differ from those of previous works. The mass shifts of octet baryons are calculated in the leading order of the operator product expansion with linear density approximation for the condensates. It is found that both scalar and vector condensates of the quark field, and , induce attraction to the octet baryons in the medium in contrast to the results of previous works. It is also found that |{delta}M{sub N}| > |{delta}M{sub {Lambda}}| > |{delta}M{sub {Sigma}}| {approx} |{delta}M{sub {Xi}}|. The absolute values, however, turn out to be one order of magnitude larger than those empirically known if a Borel mass of around 1 GeV is used in the present approximation. (author).

  16. K- nuclear potentials from in-medium chirally motivated models

    International Nuclear Information System (INIS)

    Cieply, A.; Gazda, D.; Mares, J.; Friedman, E.; Gal, A.

    2011-01-01

    A self-consistent scheme for constructing K - nuclear optical potentials from subthreshold in-medium KN s-wave scattering amplitudes is presented and applied to analysis of kaonic atoms data and to calculations of K - quasibound nuclear states. The amplitudes are taken from a chirally motivated meson-baryon coupled-channel model, both at the Tomozawa-Weinberg leading order and at the next to leading order. Typical kaonic atoms potentials are characterized by a real part -Re V K - chiral =85±5 MeV at nuclear matter density, in contrast to half this depth obtained in some derivations based on in-medium KN threshold amplitudes. The moderate agreement with data is much improved by adding complex ρ- and ρ 2 -dependent phenomenological terms, found to be dominated by ρ 2 contributions that could represent KNN→YN absorption and dispersion, outside the scope of meson-baryon chiral models. Depths of the real potentials are then near 180 MeV. The effects of p-wave interactions are studied and found secondary to those of the dominant s-wave contributions. The in-medium dynamics of the coupled-channel model is discussed and systematic studies of K - quasibound nuclear states are presented.

  17. Relevant Standards

    Indian Academy of Sciences (India)

    .86: Ethernet over LAPS. Standard in China and India. G.7041: Generic Framing Procedure (GFP). Supports Ethernet as well as other data formats (e.g., Fibre Channel); Protocol of ... IEEE 802.3x for flow control of incoming Ethernet data ...

  18. Advanced method of double contrast examination of the stomach

    International Nuclear Information System (INIS)

    Vlasov, P.V.; Yakimenko, V.F.

    1981-01-01

    An advanced method of double contrast examination of the stomach with the use of high concentrated barium suspension is described. It is shown that concentration of barium suspension must be not less than 200 mass/volume per cent to obtain the sharp image of the mucosal microrelief 6 standard position are recommended for the double contrast examination of all stomach walls. 200 patients with different digestive system diseases are examined with the help of developed methods. The sharp image of the mucosal microrelief is obtained in 70% cases [ru

  19. A Novel Approach for Controlling the Band Formation in Medium Mn Steels

    Science.gov (United States)

    Farahani, H.; Xu, W.; van der Zwaag, S.

    2018-03-01

    Formation of the microstructural ferrite/pearlite bands in medium Mn steels is an undesirable phenomenon commonly addressed through fast cooling treatments. In this study, a novel approach using the cyclic partial phase transformation concept is applied successfully to prevent microstructural band formation in a micro-chemically banded Fe-C-Mn-Si steel. The effectiveness of the new approach is assessed using the ASTM E1268-01 standard. The cyclic intercritical treatments lead to formation of isotropic microstructures even for cooling rates far below the critical one determined in conventional continuous cooling. In contrast, isothermal intercritical experiments have no effect on the critical cooling rate to suppress microstructural band formation. The origin of the suppression of band formation either by means of fast cooling or a cyclic partial phase transformation is investigated in detail. Theoretical modeling and microstructural observations confirm that band formation is suppressed only if the intercritical annealing treatment leads to partial reversion of the austenite-ferrite interfaces. The resulting interfacial Mn enrichment is responsible for suppression of the band formation upon final cooling at low cooling rates.

  20. 49 CFR 236.811 - Speed, medium.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Speed, medium. 236.811 Section 236.811 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, medium. A speed not exceeding 40 miles per hour. ...