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Yang L, Bettmann MA. Identification of the portal vein: wedge hepatic venography with CO2 or iodinated contrast medium. Acad Radiol 1999; 6:89-93. [PMID: 12680430 DOI: 10.1016/s1076-6332(99)80487-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
RATIONALE AND OBJECTIVES The purpose of this study was to evaluate the utility of CO2 versus iodinated contrast medium for wedge hepatic venography in identifying portal vein anatomy during transjugular intrahepatic portosystemic shunt (TIPS) procedures. MATERIALS AND METHODS Wedge hepatic venograms obtained with CO2 or iodinated contrast medium and direct portograms of 43 patients undergoing TIPS procedures were analyzed retrospectively. Wedge venography was performed in 23 patients with CO2 and in 21 with iodinated contrast medium; direct portography was subsequently performed in 42 of 44 patients with iodinated contrast medium and in one with CO2. All cases were reviewed systematically to compare portal vein anatomy and completeness of anatomic identification between direct portography and wedge venography, and the results with CO2 were compared to those with iodinated contrast material. RESULTS On the basis of opacification of the main portal trunk, branches, or both, the portal vein appearance (definition of the portal bifurcation) was good to excellent in 21 of 23 patients imaged with CO2 but in only two of 20 patients imaged with iodinated contrast medium. Wedge venograms agreed with direct portograms in 91% (21 of 23) of the CO2 cases and in 10% (two of 20) of the iodinated contrast medium cases. The two patients with poor opacification using CO2 had poor delineation of the main portal trunk, branches, and varices. TIPS could not be created in three patients, In two, abnormal morphology was identified at CO2 venography; in the third, wedge venography was not performed. CONCLUSION Wedge hepatic venography with CO2 compared with iodinated contrast medium has a substantially higher likelihood of correctly and completely identifying the location and anatomy of the portal vein.
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Weg N, Scheer MR, Gabor MP. Liver lesions: improved detection with dual-detector-array CT and routine 2.5-mm thin collimation. Radiology 1998; 209:417-26. [PMID: 9807568 DOI: 10.1148/radiology.209.2.9807568] [Citation(s) in RCA: 120] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To determine the feasibility and clinical benefit of routine performance of helical computed tomography (CT) with 2.5-mm collimation for the detection of liver lesions. MATERIALS AND METHODS Twenty patients with small (< or = 10-mm-diameter) liver lesions (total number of lesions, 167) were evaluated with a dual-detector-array CT scanner during the portal venous phase of contrast material enhancement. The acquisition was performed with 2.5-mm collimation during a single breath hold. The identical data set was used to perform reconstructions with 2.5-mm, 5.0-mm, 7.5-mm, and 10.0-mm section thicknesses with 50% section overlap. Each set of images was evaluated by three radiologists to determine lesion detection rates and conspicuity. RESULTS Use of 2.5-mm-thick sections resulted in a 46% increase in detection rate versus use of 10.0-mm-thick sections (167 lesions vs 90 lesions), a 33% increase versus use of 7.5-mm-thick sections (167 vs 112), and an 18% increase versus use of 5-mm-thick sections (167 vs 137). Lesion conspicuity and radiologist confidence in lesion detection and characterization of lesion margins increased as section thickness decreased. CONCLUSION CT of the liver can be performed routinely with 2.5-mm collimation with a dual-detector CT system, yielding greater conspicuity of small lesions and improved lesion detection.
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Claassens OE, Menkveld R, Harrison KL. Evaluation of three substitutes for Percoll in sperm isolation by density gradient centrifugation. Hum Reprod 1998; 13:3139-43. [PMID: 9853871 DOI: 10.1093/humrep/13.11.3139] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Silane-coated silica particle solutions (ISolate(TM) and PureSperm)TM)) and iodixanol (OptiPrep(TM)) were compared to polyvinylpyrrolidone (PVP)-coated silica particles (Percoll(TM)) in their efficacy to recover spermatozoa by gradient centrifugation for use in assisted reproductive procedures. Efficacy was assessed in terms of percentages of sperm recovery, sperm vitality and motility, normal sperm morphology and normal sperm chromatin condensation. No significant difference was found in the recovery of spermatozoa for men with both normal sperm counts and oligozoospermia, between PVP-coated and silane-coated particle solutions. Iodixanol had significantly lower sperm recovery compared to the other products. Sperm vitality, progressive motility, normal morphology and normal chromatin condensation did not differ significantly between any of the sperm isolation products.
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Stacul F, Cova M, Assante M, Hougens Grynne B, Haider T. Comparison between the efficacy of dimeric and monomeric non-ionic contrast media (iodixanol vs iopromide) in urography in patients with mild to moderate renal insufficiency. Br J Radiol 1998; 71:918-22. [PMID: 10195004 DOI: 10.1259/bjr.71.849.10195004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Non-ionic dimers induce less diuresis than non-ionic monomers, resulting in increased opacification of the urinary tract in intravenous (i.v.) urography. This double blind, comparative, randomized, parallel trial compared the efficacy of iodixanol (non-ionic dimer) and iopromide (non-ionic monomer) in 100 patients with mild to moderate renal insufficiency (serum creatinine of 135 to 265 mumol l-1) who underwent i.v. urography. A total dose of 600 mgI kg-1 bw of iodixanol (320 mgI ml-1) or iopromide (300 mgI ml-1) was injected. Radiographs were blindly evaluated by three radiologists who analysed different parameters (renal border visualization, nephrogram density, calyceal filling and density, papillary blush detection, delineation of collecting ducts, renal pelvis opacification, visualization of ureters, bladder density, bladder distention). Densitometric evaluation on the renal pelvis and bladder was also performed. Iodixanol showed better filling and density of the calyces (p = 0.004), more frequent detection of papillary blush (p = 0.003) and better opacification of the renal pelvis (p = 0.006). No significant differences between the two contrast media were found in regard to other parameters. In conclusion, the results confirmed theoretical expectations. The non-ionic dimer iodixanol is to be preferred to a non-ionic monomer such as iopromide in i.v. urography on patients with impaired renal function.
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Møller-Larsen A, Christensen T. Isolation of a retrovirus from multiple sclerosis patients in self-generated Iodixanol gradients. J Virol Methods 1998; 73:151-61. [PMID: 9766886 DOI: 10.1016/s0166-0934(98)00052-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The use of Iodixanol, a relatively new iodinated gradient medium, is described for isolation of a retrovirus, which was harvested from the supernatant of lymphoid cell lines originating from patients with multiple sclerosis (MS). The virus is produced in low amounts and has been shown to be fragile, as manifested in a loss of surface glycoproteins when purified in other gradient media. The gradient fractions were analysed after centrifugation in Iodixanol by incorporation of 3H-UTP, reverse transcriptase (RT) assays and electron microscopy (EM) and it was found that Iodixanol does not cause the degree of damage to the particles observed previously. These more favourable conditions are probably due to low viscosity and almost iso-osmotic conditions even in high concentrations. Furthermore, these advantages go together with higher reproducibility in self-forming gradients, easier handling and shorter centrifugation time. Iodixanol can also be used for preparation of HTLV-1.
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Abstract
PURPOSE To determine the value of parenchymal findings at contrast material-enhanced spiral computed tomography (CT) in patients suspected to have pulmonary embolism (PE). MATERIALS AND METHODS Eighty-eight patients suspected to have PE underwent contrast-enhanced spiral CT and ventilation-perfusion scintigraphy. Concordance between CT and scintigraphic results was used to diagnose or exclude PE. Pulmonary angiography was attempted in all patients with discordant CT and scintigraphic results or indeterminate scans. Parenchymal CT scans were assessed by two radiologists who were not aware of the diagnosis and who had access only to lung window images. RESULTS Twenty-six patients had PE; 62 did not. Wedge-shaped pleural-based consolidation was seen in 16 patients with PE (62%) and 17 patients without PE (27%) (P < .05) (sensitivity, 62%; specificity, 73%). Linear bands were seen in 12 patients with PE (46%) and 13 patients without PE (21%) (P < .05) (sensitivity, 46%; specificity, 79%). There was no statistically significant difference in the frequency of non-wedge-shaped consolidation, areas of decreased attenuation, or atelectasis. Central and lower-lobe segmental pulmonary arteries that contained emboli were enlarged (P < .05). CONCLUSION Parenchymal findings may suggest further investigations when results of spiral CT are inconclusive in diagnosis of PE.
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Zhang J, Kang DE, Xia W, Okochi M, Mori H, Selkoe DJ, Koo EH. Subcellular distribution and turnover of presenilins in transfected cells. J Biol Chem 1998; 273:12436-42. [PMID: 9575200 DOI: 10.1074/jbc.273.20.12436] [Citation(s) in RCA: 123] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The mechanisms by which mutations in presenilin-1 (PS1) and presenilin-2 (PS2) result in the Alzheimer's disease phenotype are unclear. Full-length PS1 and PS2 are each processed into stable proteolytic fragments after their biosynthesis in transfected cells. PS1 and PS2 have been localized by immunocytochemistry to the endoplasmic reticulum (ER) and Golgi compartments, but previous studies could not differentiate between the full-length presenilin proteins and their fragments. We carried out subcellular fractionation of cells stably transfected with PS1 or PS2 to determine the localization of full-length presenilins and their fragments. Full-length PS1 and PS2 were principally distributed in ER fractions, whereas the N- and C-terminal fragments were localized predominantly to the Golgi fractions. In cells expressing the PS1 mutant lacking exon 9 (DeltaE9), we observed only full-length molecules that were present in the ER and Golgi fractions. The turnover rate was considerably slower for the DeltaE9 holoprotein, apparently due to decreased degradation within the ER. Our results suggest that that full-length presenilin proteins are primarily ER resident molecules and undergo endoproteolysis within the ER. The fragments are subsequently transported to the Golgi compartment, where their turnover rate is much slower than that of the full-length presenilin in the ER.
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Oliva V, Common A, Bettmann MA. Prospective randomized crossover pilot study of the safety and efficacy of carbon dioxide versus iodinated contrast for peripheral angiography. Acad Radiol 1998; 5 Suppl 1:S58-9; discussion S60-2. [PMID: 9561045 DOI: 10.1016/s1076-6332(98)80060-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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van der Burg MP, Basir I, Bouwman E. No porcine islet loss during density gradient purification in a novel iodixanol in University of Wisconsin solution. Transplant Proc 1998; 30:362-3. [PMID: 9532080 DOI: 10.1016/s0041-1345(97)01308-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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235
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Watanabe N, Oriuchi N, Higuchi T, Yukihiro M, Fukushima Y, Tomiyoshi K, Hirano T, Inoue T, Endo K. In vitro effect of contrast agents during immunoradiometric assay for tumour-associated antigens. Nucl Med Commun 1998; 19:63-70. [PMID: 9515548 DOI: 10.1097/00006231-199801000-00009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The aim of this study was to investigate if contrast agents interfere with the performance of an immunoradiometric assay (IRMA) in vitro for serum tumour-associated antigen. Each of five carcinoembryonic antigen (CEA)-positive sera, CA-130-positive sera and tissue polypeptide antigen (TPA)-positive sera was mixed with six contrast agents: Ioversol 350, Iopamidol 370, Iomeprol 300, Iomeprol 400, Iohexol 300 and Gadopenteic acid in 50:50, 50:20, 50:5.0, 50:1.0, 50:0.5 and 50:0.1 microl proportions. Following IRMA, the interference of binding rates in each mixture was calculated, and the serum concentrations of CEA, CA-130 and TPA were estimated and compared with the originals. All contrast agents used were able to inhibit the binding rate with IRMA and the inhibition rates were in proportion to the amount of contrast agent. The detection of serum concentrations of CEA, CA-130 and TPA was significantly inhibited in the mixtures with more than 5.0 microl of contrast agent in all cases. Apart from Iomeprol 400, there was no significant inhibition of detection at the lowest concentrations of contrast agents. Iomeprol 400 was the strongest inhibitor and Gadopenteic acid the weakest inhibitor for each IRMA of the contrast agents employed. In conclusion, our results demonstrate that contrast agents may reduce the immunoreaction of antibody and antigen and lead to in vitro inhibition during immunoassays. It would be unwise to perform any plasma/serum immunoassay on a sample collected within 24 h of the administration of contrast agent considering the pharmacokinetics.
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Sinitsyn VE. [Clinical use of non-ionic dimers]. VESTNIK RENTGENOLOGII I RADIOLOGII 1997:41-2. [PMID: 9504000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Breen DJ, Janzen DL, Zwirewich CV, Nagy AG. Blunt bowel and mesenteric injury: diagnostic performance of CT signs. J Comput Assist Tomogr 1997; 21:706-12. [PMID: 9294556 DOI: 10.1097/00004728-199709000-00005] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE Our goal was to determine the sensitivity and specificity of various CT signs of blunt bowel and mesenteric injury. METHOD The CT findings of 31 patients with blunt abdominal trauma were retrospectively assessed by three observers in consensus. All patients had laparotomy within 24 h of CT. The study group consisted of 19 patients with surgically proven bowel and/or mesenteric injury. The control group consisted of 12 traumatized patients who had no bowel or mesenteric injury. The CT signs assessed were presence, location, and extent of intraperitoneal fluid, extraluminal air, bowel wall thickening, bowel wall discontinuity, mesenteric streaking, and mesenteric hematoma. RESULTS In the 12 cases of bowel injury (9 transmural injury, 3 partial thickness injury), the CT sign of bowel wall thickening had sensitivity of 50% and specificity of 84% and the CT sign of bowel wall discontinuity had sensitivity of 58% and specificity of 95%. Extraluminal air was a specific but relatively insensitive sign of transmural bowel injury (sensitivity 44%, specificity 100%). In the 13 patients with mesenteric injuries, the CT sign of mesenteric hematoma had sensitivity of 54% and specificity of 94%. Isolated mesenteric streaking was a less specific sign of mesenteric injury (sensitivity 77%, specificity 44%). The finding of peritoneal fluid with no visible solid organ injury was a useful sign of bowel or mesenteric injury, occurring in 11 of 19 (58%) study patients and none of the controls (p < 0.001). CONCLUSION Bowel wall thickening, bowel wall discontinuity, extraluminal air, and mesenteric hematoma are reasonably specific CT signs of bowel and mesenteric injury following blunt abdominal trauma. The presence of a moderate to large volume of intraperitoneal fluid without visible solid organ injury is an important sign of bowel or mesenteric injury.
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Smith TT, Byers M, Kaftani D, Whitford W. The use of iodixanol as a density gradient material for separating human sperm from semen. ARCHIVES OF ANDROLOGY 1997; 38:223-30. [PMID: 9140619 DOI: 10.3109/01485019708994881] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Iodixanol, a new nonionic density gradient material with relatively low osmolality and high density, was evaluated to determine its suitability for the separation of human sperm from semen for their subsequent therapeutic use. Using a three-layer iodixanol gradient (approximately 1.17/1.15/1.05 g/mL), sperm were centrifuged at 1000g for 30 min and collected from the 1.05/1.15 interface. Using this method, a mean of 78% of the motile and 99% of the morphologically normal sperm originally present in the semen were recovered at the interface. There was no significant increase in the percentage of motile or morphologically normal sperm in the final preparation compared to the original semen. Sperm survived iodixanol density gradient centrifugation well, showing only modest declines in motility (18%) and velocity (35%) during a subsequent 24-h incubation period. When iodixanol was compared to Percoll density gradient centrifugation with semen from the same ejaculate, there was no significant difference between methods with regard to sperm yield, enrichment of motile or morphologically normal sperm in the preparation or sperm survival following separation. Iodixanol provides a suitable, nontoxic alternative to Percoll for the preparation of human sperm for therapeutic use.
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Eckstein F, Adam C, Sittek H, Becker C, Milz S, Schulte E, Reiser M, Putz R. Non-invasive determination of cartilage thickness throughout joint surfaces using magnetic resonance imaging. J Biomech 1997; 30:285-9. [PMID: 9119830 DOI: 10.1016/s0021-9290(97)81146-3] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Data on articular cartilage thickness in the living are important for the design for computer models, aimed at preoperatively assessing the effect of surgical procedures on joint contact and load transmission, and for the calculation of cartilage material properties from its deformational behavior as determined during arthroscopy. A non-invasive method for measuring cartilage thickness in living subjects is, however, not available. A technique based on magnetic resonance imaging has therefore been tested for assessing articular cartilage thickness throughout joint surfaces. The accuracy is determined by comparing cartilage thickness maps obtained from three patellar specimens with a fat-suppressed three-dimensional gradient-echo sequence (resolution 2 x 0.31 x 0.31 mm) to those obtained with CT arthrography, A-mode ultrasound and anatomical sections. The distribution patterns are quantitatively compared using image analysis. The highest agreement was obtained for MRI and the sections (50% identical pixels), but all techniques yielded very similar results. On average, MR slightly underestimated the cartilage thickness compared with CT and the sections, and overestimated it compared with ultrasound. No evidence of differences in the degree of similarity could be detected in areas of thin and thick cartilage. We conclude that, if the resolution and accuracy of the method presented are considered acceptable, MRI is available for repeatable determination of topographical maps of articular cartilage thickness in living subjects. These data can be used to determine joint contact and stress in computer models and to calculate cartilage material properties in vivo.
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Cartwright IJ, Higgins JA, Wilkinson J, Bellavia S, Kendrick JS, Graham JM. Investigation of the role of lipids in the assembly of very low density lipoproteins in rabbit hepatocytes. J Lipid Res 1997; 38:531-45. [PMID: 9101434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Our aims were i) to determine which lipids colocalize with newly synthesized apolipoprotein (apo) B in the lumen of the rough endoplasmic reticulum (RER), and thus may play a role in the stabilization and/or translocation of this protein; and ii) to determine the intracellular sites of assembly of lipids into very low density lipoprotein (VLDL). In order to do this, we have developed a new method for the separation of ER-derived microsomes on self-generated gradients of iodixanol. Rabbit liver microsomes were resolved into two broad peaks, the lighter peak contained smooth vesicles and the heavier peak contained rough vesicles. Each peak was collected in a number of subfractions. A single gradient thus separates the initial events in the secretion process (RER fractions), from later events (smooth endoplasmic reticulum (SER) fractions). The microsomal fractions were separated into membranes and lumenal contents, and the mass of apoB and VLDL lipids determined by ELISA or high performance thin-layer chromatography, respectively. The biosynthetic relationships of apoB and lipids were investigated, in timed or chase experiments, by incubation of isolated rabbit hepatocytes with radiolabeled precursors of apoB or lipids, followed by isolation and analysis of the microsomal fractions. The results indicate that very small amounts of triacylglycerol, cholesterol, and cholesteryl ester co-localize with apoB into the lumen of the RER. The bulk of the VLDL lipids were in the lumen of the SER. However, some newly synthesized triacyl-glycerol, phospholipid, cholesterol, and cholesteryl ester were also transferred to the lumen of the RER and were chased into the SER lumen. Double-labeling experiments showed that cholesteryl ester produced from newly synthesized cholesterol (labeled with [3H]mevalonate and [14C]oleate) was almost exclusively present in the RER, while cholesteryl ester in the SER was labeled only with [14C]oleate. Thus, distinct intracellular lipid-pools may be involved at different stages in the assembly of VLDL.
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Groell R, Schaffler GJ, Rienmueller R, Kern R. Vascular air embolism: location, frequency, and cause on electron-beam CT studies of the chest. Radiology 1997; 202:459-62. [PMID: 9015074 DOI: 10.1148/radiology.202.2.9015074] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE To determine the frequency and location of venous air emboli that occur with the use of electron-beam computed tomographic (CT) studies of the chest. MATERIALS AND METHODS Findings from 677 patients who underwent chest electron-beam CT with intravenous administration of contrast material were reviewed. Unenhanced CT studies were performed in 127 (18.8%) of these patients while the intravenous cannula was in place but before injection of contrast material. RESULTS Air emboli were observed on CT studies in 79 (11.7%) of 677 patients. Emboli were small (up to three air bubbles less than 1 cm in diameter) in 70 (10.3%) patients and were moderate (more than three air bubbles or bubbles 1-2 cm in diameter) in nine (1.3%) patients. Air emboli were located in the main pulmonary artery (n = 54 [8.0%]), superior vena cava (n = 12 [1.8%]), right ventricle (n = 10 [1.5%]), subclavian or brachiocephalic vein (n = 6 [0.9%]), and right atrium (n = 5 [0.7%]). Seven patients (1.0%) had emboli in more than one location. Air emboli were depicted on unenhanced CT scans of seven (5.5%) of 127 patients. No association was found between the frequency of air embolism and injection flow, injection site, or amount or type of contrast agent. CONCLUSION Intravenous administration of contrast material may cause small to moderate-sized air emboli. Knowledge of the common locations of emboli can help radiologists distinguish them from image artifacts or paravasal air collections.
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Taupitz M, Wagner S, Schuhmann-Giampieri G, Baumann S, Wolf KJ, Finke I, Hamm B. [Electron-beam tomographic imaging of the coronary arteries: an experimental comparison between monomeric and dimeric x-ray contrast media]. ROFO-FORTSCHR RONTG 1997; 166:3-7. [PMID: 9072100 DOI: 10.1055/s-2007-1015368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PURPOSE Comparison of a monomeric and a dimeric radiographic contrast medium in the visualisation of the coronary arteries via electron beam tomography (EBT). MATERIAL AND METHODS In a total of 6 Göttingen minipigs the heart was examined by EBT (40 sections, ECG-triggering, 1.5 mm section thickness, 100 ms acquisition time) after injection of both iopamidol (monomer, 370 mg l/ml) and iotrolan (dimer, 320 mg l/ml) at a dose of 740 mg l/kg. Injection rate and scan delay were adjusted to heart rate and circulation time. RESULTS The intravascular increase in density after intravenous injection of iotrolan was significantly higher and longer than after injection of iopamidol (> 300 HE: 28 +/- 4 versus 17 +/- 5 cardiac cycles; p < 0.05). Iotrolan attained a higher score in the visualisation of the coronary arteries in three-dimensional surface reconstructions (p < 0.05). CONCLUSION The dimeric contrast medium iotrolan proved superior to the monomeric agent iopamidol for visualisation of the coronary arteries via EBT.
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Graf O, Gazelle GS, Kreuzer S, Halpern EF, Boehm P, Lechner G, Mueller PR. Enhancement of hepatic parenchyma, aorta, and portal vein in helical CT: comparison of iodixanol and iopromide. AJR Am J Roentgenol 1997; 168:213-7. [PMID: 8976948 DOI: 10.2214/ajr.168.1.8976948] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The purpose of this study was to determine hepatic, aortic, and portal vein enhancement with a new dimeric, nonionic, isotonic contrast medium (iodixanol) in a routinely performed helical CT protocol and compare enhancement characteristics with those of a monomeric, nonionic, low-osmolality contrast medium (iopromide). SUBJECTS AND METHODS In 81 patients, we injected 150 ml of iodixanol (320 mg I/ml), iodixanol (300 mg I/ml), or iopromide (300 mg I/ml). Injection rate was 5 ml/sec. A dual-phase helical CT scan was obtained (first helical scan began at 30 sec. second helical scan began at 70 sec), and enhancement characteristics were assessed. Results were analyzed taking into account various intrinsic parameters of patients. RESULTS During the second imaging phase, iodixanol at 320 mg I/ml and iodixanol at 300 mg I/ml provided significantly higher enhancement of the liver (75 H, 69 H, 62 H), aorta (144 H, 140 H, 122 H), and portal vein (147 H, 147 H, 118 H) than did iopromide at 300 mg I/ml. No significant differences were observed during the first imaging phase. CONCLUSION The combination of higher vascular and parenchymal enhancement levels after injection of the isotonic agent may represent a different quality of tissue enhancement. Such an enhancement would be characterized more by a higher contribution of the blood pool compartment to absolute enhancement levels than by a contribution of the interstitial compartment. Further studies are needed to determine whether the use of isotonic agents effects lesion conspicuity.
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Ando H, Kaneko K, Ito F, Seo T, Watanabe Y, Ito T. Anatomy and etiology of extrahepatic portal vein obstruction in children leading to bleeding esophageal varices. J Am Coll Surg 1996; 183:543-7. [PMID: 8957454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND The cause of extrahepatic portal vein obstruction in childhood is unknown. We investigated the anatomical features of extra hepatic portal vein obstruction to clarify its cause. STUDY DESIGN We studied portal venous anatomy in 10 patients with extrahepatic portal vein obstruction without hepatic disturbances ranging in age from 1 to 7 years (mean age, 4.2 years) using ultrasonography, portal venography, cholangio-computed tomography, and magnetic resonance imaging. RESULTS The extrahepatic portal vein was not obliterated, but it crossed over the common bile duct from the left to the right side at the cranial level of the pancreas and ran in a cranial direction along the right side of the common bile duct or coiled itself around the bile duct. Thus, the extrahepatic portal vein formed a tortuous eta-shape. CONCLUSIONS The portal vein was not obstructed in patients with extrahepatic portal vein obstruction but formed a characteristic eta-shape by coiling itself around the common bile duct, suggesting that extrahepatic portal vein obstruction has an embryological cause.
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Peck D, Lum PA. Castleman disease in the porta hepatis: biphasic helical computed tomography. Can Assoc Radiol J 1996; 47:410-2. [PMID: 8943910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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Kjaersgaard P, Jakobsen JA, Nossen JO, Berg KJ. Determination of glomerular filtration rate with Visipaque in patients with severely reduced renal function. Eur Radiol 1996; 6:865-71. [PMID: 8972324 DOI: 10.1007/bf00240692] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Iodixanol (Visipaque, Nycomed Imaging AS, Oslo, Norway), and isotonic, dimeric and non-ionic contrast medium (CM), and iohexol (Omnipaque, Nycomed Imaging AS, Oslo, Norway), a low-osmolar, monomeric and non-ionic contrast medium, were used as glomerular filtration rate (GFR) markers in patients with severely impaired renal function. Different methods for determining GFR were compared. A total of 16 patients with s-creatinine > 400 mumol/l were enrolled in the study; 8 in each CM group. Serum-iodine was measured, and plasma CM clearance was determined using the Bröchner-Mortensen method, the single-sample method and conventional method. The ratios between the results obtained from the conventional method and each of the two other methods were calculated. These data were plotted against the mean of the pairs compared, and the upper and lower limits of agreement were calculated as the mean ratio +/- 2SD. The comparison showed a high degree of agreement between methods, and the two simpler methods seem to be good alternatives to the conventional method, which gave good estimates of GFR (vs that determined by means of renal 125I-iothalamate clearance) when 24-h blood samples were included. However, slight overestimations of GFR, due to extrarenal excretion of the CM, were observed. In summary, serum clearance of iodixanol, as determined by the Bröchner-Mortensen method or single-sample method seems to be a simple and accurate marker for GFR in patients with severely reduced renal function. The findings obtained with iodixanol were similar to those obtained with iohexol.
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Yoshizako T, Sugimura K, Kawamitsu H, Yoshikawa K. Two-dimensional time-of-flight MR venography: assessment with detection of chronic deep venous thrombosis in combination with magnetization transfer contrast. J Comput Assist Tomogr 1996; 20:957-64. [PMID: 8933799 DOI: 10.1097/00004728-199611000-00017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE The purpose of this study was to determine the optimum imaging parameters for 2D-TOF MR venography (MRV) of the pelvis and suprapopliteal deep venous system in combination with off-resonance magnetization transfer constant (MTC) and to evaluate the use of MRV in patients suspected of having chronic deep venous thrombosis (DVT) by comparing its accuracy with that of conventional venography (CV). METHOD MRV was performed in 10 normal subjects to determine the optimum imaging parameters. Systematically varied scan parameters included flip angles ranging from 30 to 120 degrees by 10 degrees increments. Best TR was calculated by using the theoretical relation between the optimal TR and flow velocity. We then evaluated the use of MRV in 26 patients (total 52 deep venous systems) suspected of having chronic DVT by comparing its accuracy in evaluating the intrapelvic and suprapopliteal deep venous system with that of CV. RESULTS The optimal imaging parameters for intrapelvic and suprapopliteal venous system MRV were found to be a flip angle of 60 degrees and a pulse sequence of 35/6.9 (TR ms/TE ms) combined with an off-resonance MTC technique. All the main veins of the intrapelvic and suprapopliteal venous systems were clearly demonstrated in each subject. The sensitivity of MRV was 100% and its specificity was 100% for diagnosis of pelvic venous stenosis. The collateral vessels were demonstrated with MRV in all patients. CONCLUSION 2D-TOF off-resonance MTC MRV of the pelvis and the suprapopliteal lower extremities is suitable for evaluation of intrapelvic branches and suprapopliteal deep venous system and chronic DVT.
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Hasuo K, Mizushima A, Mihara F, Hashiguchi N, Murayama S, Uchino A, Matsumoto S, Gibo M, Torii Y, Komori K, Masuda K. Intra-arterial digital subtraction angiography with extra-large fields using a computed radiography system in evaluating peripheral vascular disease. RADIATION MEDICINE 1996; 14:229-33. [PMID: 8988500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The authors evaluated the usefulness of intra-arterial digital subtraction angiography (DSA) with extra-large field sizes using a computed radiography (CR) system in evaluating peripheral vascular disease (PVD). Intra-arterial DSA using CR was performed in 55 patients with suspected PVD. A 4 F catheter was advanced into the abdominal aorta via the transbrachial approach and 90 ml of contrast medium was injected during six exposures using a long leg changer mounting a total of 18 imaging plates on six surfaces. Visualization of the superficial femoral and popliteal arteries was judged as diagnostic in all cases. The abdominal aorta, iliac arteries, and subtrifurcation were also visualized in most cases, but visualization was suboptimal in some cases. As a complication, median nerve palsy occurred in one case. This technique is thought to be a useful method for evaluating PVD because of the advantages of a large field of view and wide exposure latitude, in spite of its relatively long processing time.
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Helmberger H, Baum U, Dittler HJ, Sendler A, Schulte B, Herter B, Fink U, Gerhardt P. Adenocarcinoma of the gastro-esophageal junction: CT for monitoring during neoadjuvant chemotherapy. Eur J Radiol 1996; 23:107-10. [PMID: 8886719 DOI: 10.1016/0720-048x(96)01028-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE A clinical study was performed to assess the diagnostic value of spiral CT for evaluation of response during neoadjuvant chemotherapy (CTx) in patients with adenocarcinoma of the gastro-esophageal-junction (GEJ). Results were compared to those of endoscopy. METHODS AND MATERIAL Twenty-five patients with histologically proven adenocarcinoma of the GEJ scheduled to undergo neoadjuvant CTx were studied. Before CT examination, 1200 ml of a vanilla flavoured paraffin emulsion were applied orally to the fasting patients and 40 mg BuscopanR or 2 mg glucagon were injected i.v. for hypotonia. Iodine (100 ml) was injected automatically (3 ml/s) and the CT scan was started 10 s after complete administration of CM. For response evaluation to CTx, four standardized parameters were measured by two experienced, blinded radiologists. The results were categorized according to the WHO classification of 1981 and compared to those of endoscopy. RESULTS In 24 of 25 patients endoscopic and computed tomographic response evaluation showed a close correlation (r = 0.96). CONCLUSION Spiral CT with negative oral contrast agent is a suitable technique for monitoring of GEJ masses. In combination with standardized metric parameters it offers a quantitative response evaluation in patients with GEJ masses during neoadjuvant CTx.
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