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Sample records for blood pool contrast

  1. Magnetic resonance angiography with blood-pool contrast agents: future applications

    International Nuclear Information System (INIS)

    Fink, C.; Goyen, M.; Lotz, J.

    2007-01-01

    Blood pool agents remain in the intravascular space for a longer time period. Therefore the optimal imaging window for vascular structures is widened to about 30 minutes. Gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany) is the first blood-pool contrast agent approved in Europe for contrast-enhanced magnetic resonance angiography (MRA) of vessels in the abdomen, pelvis and lower extremity in adults. Other possible applications of blood-pool agents are now being considered, such as assessment of venous thromboembolism, coronary artery disease or sinus venous thrombosis. Perfusion MR imaging holds promise for detecting lung perfusion defects with higher spatial resolution and reduced scan time compared with radionuclide scintigraphy. In coronary artery disease, blood-pool agents enable a substantial increase in the quality of coronary artery imaging. Quantitative myocardial perfusion and myocardial viability seem to be possible, although modifications in protocols and sequence design are necessary for optimal results. Other novel applications of blood-pool agents include monitoring of inflammatory changes in systemic lupus erythematosus and evaluation of tumour invasion into lymph nodes and more reliable assessment of cerebral venous and sinus thrombosis. (orig.)

  2. Combined blood pool and extracellular contrast agents for pediatric and young adult cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Joyce T. [Ann and Robert Lurie Children' s Hospital of Chicago, Division of Pediatric Cardiology, 225 E. Chicago Ave., Box 21, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Robinson, Joshua D. [Ann and Robert Lurie Children' s Hospital of Chicago, Division of Pediatric Cardiology, 225 E. Chicago Ave., Box 21, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Deng, Jie [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States); Rigsby, Cynthia K. [Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States)

    2016-12-15

    A comprehensive cardiac magnetic resonance (cardiac MR) study including both late gadolinium enhancement (LGE) and MR angiography may be indicated for patients with a history of acquired or congenital heart disease. To study the novel use of an extracellular agent for assessment of LGE combined with a blood pool contrast agent for detailed MR angiography evaluation to yield a comprehensive cardiac MR study in these patients. We reviewed clinical cardiac MR studies utilizing extracellular and blood pool contrast agents and noted demographics, clinical data and adverse events. We rated LGE image quality and MR angiography image quality for each vascular segment and calculated inter-rater variability. We also quantified contrast-to-noise ratio (CNR). Thirty-three patients (mean age 13.9 ± 3 years) received an extracellular contrast agent (10 gadobenate dimeglumine, 23 gadopentetate dimeglumine) and blood pool contrast agent (33 gadofosveset trisodium). No adverse events were reported. MRI indications included Kawasaki disease (8), cardiomyopathy and coronary anatomy (15), repaired congenital heart disease (8), and other (2). Mean LGE quality was 2.6 ± 0.6 with 97% diagnostic imaging. LGE quality did not vary by type of contrast agent given (P = 0.07). Mean MR angiography quality score was 4.7 ± 0.6, with high inter-rater agreement (k = 0.6-0.8, P < 0.002). MR angiography quality did not vary by type of contrast agent used (P = 0.6). Cardiac MR studies utilizing both extracellular and blood pool contrast agents are feasible and safe and provide excellent-quality LGE and MR angiography images. The use of two contrast agents allows for a comprehensive assessment of both myocardial viability and vascular anatomy during the same exam. (orig.)

  3. Relaxivity of blood pool contrast agent depends on the host tissue as suggested by semianalytical simulations

    DEFF Research Database (Denmark)

    Jensen, Birgitte Fuglsang; Østergaard, Leif; Kiselev, Valerij G

    Concentration of MRI contrast agents (CA) is commonly determined indirectly using their relaxation effect. In quantitative perfusion studies, the change in the relaxation following a bolus passage is converted into concentrations assuming identical relaxivities for tissue and blood. Simulations...... presented in this study demonstrate that the relaxivity of blood pool CA depends significantly on both the host tissue and the pulse sequence, in agreement with previous experiments. In particular, the relaxation effect of Gd-based CA in brain tissues is several-fold larger than in bulk blood. The results...

  4. Combined respiratory and cardiac triggering improves blood pool contrast-enhanced pediatric cardiovascular MRI

    International Nuclear Information System (INIS)

    Vasanawala, Shreyas S.; Newman, Beverley; Chan, Frandics P.; Alley, Marcus T.

    2011-01-01

    Contrast-enhanced cardiac MRA suffers from cardiac motion artifacts and often requires a breath-hold. This work develops and evaluates a blood pool contrast-enhanced combined respiratory- and ECG-triggered MRA method. An SPGR sequence was modified to enable combined cardiac and respiratory triggering on a 1.5-T scanner. Twenty-three consecutive children referred for pediatric heart disease receiving gadofosveset were recruited in HIPAA-compliant fashion with IRB approval and informed consent. Children underwent standard non-triggered contrast-enhanced MRA with or without suspended respiration. Additionally, a free-breathing-triggered MRA was acquired. Triggered and non-triggered studies were presented in blinded random order independently to two radiologists twice. Anatomical structure delineation was graded for each triggered and non-triggered acquisition and the visual quality on triggered MRA was compared directly to that on non-triggered MRA. Triggered images received higher scores from each radiologist for all anatomical structures on each of the two reading sessions (Wilcoxon rank sum test, P < 0.05). In direct comparison, triggered images were preferred over non-triggered images for delineating cardiac structures, with most comparisons reaching statistical significance (binomial test, P < 0.05). Combined cardiac and respiratory triggering, enabled by a blood pool contrast agent, improves delineation of most anatomical structures in pediatric cardiovascular MRA. (orig.)

  5. MRT of experimental liver abscesses - comparison of a new blood pool contrast agent with gadolinium-DTPA

    International Nuclear Information System (INIS)

    Dick, A.; Adam, G.; Spuentrup, E.; Prescher, A.; Muehler, A.; Guenther, R.W.

    1996-01-01

    Purpose: In an experimental pyogenic liver abscess model, the signal intensities were compared intraindividually and interindividually after the application of a new blood pool contrast agent, 24-gadolinium-DTPA (diethylenetriamine-pentaacetic acid) cascade polymer, and after the application of gadopentetate dimeglumine. Methods: In 20 rabbits with experimentally induced liver abscesses, the relative signal intensities of the liver, abscess centre, abscess wall and portal vein were assessed before and between 30 seconds and 60 minutes after injection of a 25 μmol/kg dose of gadolinium polymer and of 100 μmol/kg of gadolinium-DTPA, respectively. Measurements were performed at 1.5 Tesla, using a head coil and a Flash-2-D sequence. Results: The interindividual comparison (unpaired T-test, p [de

  6. Validation of Perfusion Quantification with 3D Gradient Echo Dynamic Contrast-Enhanced Magnetic Resonance Imaging Using a Blood Pool Contrast Agent in Skeletal Swine Muscle.

    Directory of Open Access Journals (Sweden)

    Stefan Hindel

    Full Text Available The purpose of our study was to validate perfusion quantification in a low-perfused tissue by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI with shared k-space sampling using a blood pool contrast agent. Perfusion measurements were performed in a total of seven female pigs. An ultrasonic Doppler probe was attached to the right femoral artery to determine total flow in the hind leg musculature. The femoral artery was catheterized for continuous local administration of adenosine to increase blood flow up to four times the baseline level. Three different stable perfusion levels were induced. The MR protocol included a 3D gradient-echo sequence with a temporal resolution of approximately 1.5 seconds. Before each dynamic sequence, static MR images were acquired with flip angles of 5°, 10°, 20°, and 30°. Both static and dynamic images were used to generate relaxation rate and baseline magnetization maps with a flip angle method. 0.1 mL/kg body weight of blood pool contrast medium was injected via a central venous catheter at a flow rate of 5 mL/s. The right hind leg was segmented in 3D into medial, cranial, lateral, and pelvic thigh muscles, lower leg, bones, skin, and fat. The arterial input function (AIF was measured in the aorta. Perfusion of the different anatomic regions was calculated using a one- and a two-compartment model with delay- and dispersion-corrected AIFs. The F-test for model comparison was used to decide whether to use the results of the one- or two-compartment model fit. Total flow was calculated by integrating volume-weighted perfusion values over the whole measured region. The resulting values of delay, dispersion, blood volume, mean transit time, and flow were all in physiologically and physically reasonable ranges. In 107 of 160 ROIs, the blood signal was separated, using a two-compartment model, into a capillary and an arteriolar signal contribution, decided by the F-test. Overall flow in hind leg muscles

  7. MR angiography of collateral arteries in a hind limb ischemia model: comparison between blood pool agent Gadomer and small contrast agent Gd-DTPA.

    Directory of Open Access Journals (Sweden)

    Karolien Jaspers

    Full Text Available The objective of this study was to compare the blood pool agent Gadomer with a small contrast agent for the visualization of ultra-small, collateral arteries (diameter0.10. Inter-observer variation was 24% and 18% for Gadomer and Gd-DTPA, respectively. In conclusion, blood pool agent Gadomer improved vessel conspicuity compared to Gd-DTPA. Steady-state MRA can be considered as an excellent non-invasive alternative to intra-arterial XRA for the visualization of ultra-small collateral arteries.

  8. Morphology of drying blood pools

    Science.gov (United States)

    Laan, Nick; Smith, Fiona; Nicloux, Celine; Brutin, David; D-Blood project Collaboration

    2016-11-01

    Often blood pools are found on crime scenes providing information concerning the events and sequence of events that took place on the scene. However, there is a lack of knowledge concerning the drying dynamics of blood pools. This study focuses on the drying process of blood pools to determine what relevant information can be obtained for the forensic application. We recorded the drying process of blood pools with a camera and measured the weight. We found that the drying process can be separated into five different: coagulation, gelation, rim desiccation, centre desiccation, and final desiccation. Moreover, we found that the weight of the blood pool diminishes similarly and in a reproducible way for blood pools created in various conditions. In addition, we verify that the size of the blood pools is directly related to its volume and the wettability of the surface. Our study clearly shows that blood pools dry in a reproducible fashion. This preliminary work highlights the difficult task that represents blood pool analysis in forensic investigations, and how internal and external parameters influence its dynamics. We conclude that understanding the drying process dynamics would be advancement in timeline reconstitution of events. ANR funded project: D-Blood Project.

  9. 3D pulmonary perfusion MRI and MR angiography of pulmonary embolism in pigs after a single injection of a blood pool MR contrast agent

    Energy Technology Data Exchange (ETDEWEB)

    Fink, Christian; Ley, Sebastian; Puderbach, Michael; Plathow, Christian; Kauczor, Hans-Ulrich [Department of Radiology, Innovative Cancer Diagnostic and Therapy, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg (Germany); Bock, Michael [Department of Medical Physics in Radiology, Innovative Cancer Diagnostic and Therapy, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg (Germany)

    2004-07-01

    The purpose of this study was to assess the feasibility of contrast-enhanced 3D perfusion MRI and MR angiography (MRA) of pulmonary embolism (PE) in pigs using a single injection of the blood pool contrast Gadomer. PE was induced in five domestic pigs by injection of autologous blood thrombi. Contrast-enhanced first-pass 3D perfusion MRI (TE/TR/FA: 1.0 ms/2.2 ms/40 ; voxel size: 1.3 x 2.5 x 4.0 mm{sup 3}; TA: 1.8 s per data set) and high-resolution 3D MRA (TE/TR/FA: 1.4 ms/3.4 ms/40 ; voxel size: 0.8 x 1.0 x 1.6 mm{sup 3}) was performed during and after a single injection of 0.1 mmol/kg body weight of Gadomer. Image data were compared to pre-embolism Gd-DTPA-enhanced MRI and post-embolism thin-section multislice CT (n=2). SNR measurements were performed in the pulmonary arteries and lung. One animal died after induction of PE. In all other animals, perfusion MRI and MRA could be acquired after a single injection of Gadomer. At perfusion MRI, PE could be detected by typical wedge-shaped perfusion defects. While the visualization of central PE at MRA correlated well with the CT, peripheral PE were only visualized by CT. Gadomer achieved a higher peak SNR of the lungs compared to Gd-DTPA (21{+-}8 vs. 13{+-}3). Contrast-enhanced 3D perfusion MRI and MRA of PE can be combined using a single injection of the blood pool contrast agent Gadomer. (orig.)

  10. High-resolution blood-pool-contrast-enhanced MR angiography in glioblastoma: tumor-associated neovascularization as a biomarker for patient survival. A preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Puig, Josep; Blasco, Gerard; Remollo, Sebastian; Hernandez, David; Pedraza, Salvador [Hospital Universitari Dr Josep Trueta, Research Unit of Diagnostic Imaging Institute (IDI), Department of Radiology [Girona Biomedical Research Institute] IDIBGI, Girona (Spain); Daunis-i-Estadella, Josep; Mateu, Gloria [University of Girona, Department of Computer Science, Applied Mathematics and Statistics, Girona (Spain); Alberich-Bayarri, Angel [La Fe Polytechnics and University Hospital, Biomedical Imaging Research Group (GIBI230), La Fe Health Research Institute, Valencia (Spain); Essig, Marco [University of Manitoba, Department of Radiology, Winnipeg (Canada); Jain, Rajan [NYU School of Medicine, Division of Neuroradiology, Department of Radiology, New York, NY (United States); Puigdemont, Montserrat [Hospital Universitari Dr Josep Trueta, Catalan Institute of Oncology (ICO), Hospital Cancer Registry, Girona (Spain); Sanchez-Gonzalez, Javier [Philips Healthcare Iberica, Madrid (Spain); Wintermark, Max [Stanford University, Department of Radiology, Neuroradiology Division, Palo Alto, CA (United States)

    2016-01-15

    The objective of the study was to determine whether tumor-associated neovascularization on high-resolution gadofosveset-enhanced magnetic resonance angiography (MRA) is a useful biomarker for predicting survival in patients with newly diagnosed glioblastomas. Before treatment, 35 patients (25 men; mean age, 64 ± 14 years) with glioblastoma underwent MRI including first-pass dynamic susceptibility contrast (DSC) perfusion and post-contrast T1WI sequences with gadobutrol (0.1 mmol/kg) and, 48 h later, high-resolution MRA with gadofosveset (0.03 mmol/kg). Volumes of interest for contrast-enhancing lesion (CEL), non-CEL, and contralateral normal-appearing white matter were obtained, and DSC perfusion and DWI parameters were evaluated. Prognostic factors were assessed by Kaplan-Meier survival and Cox proportional hazards model. Eighteen (51.42 %) glioblastomas were hypervascular on high-resolution MRA. Hypervascular glioblastomas were associated with higher CEL volume and lower Karnofsky score. Median survival rates for patients with hypovascular and hypervascular glioblastomas treated with surgery, radiotherapy, and chemotherapy were 15 and 9.75 months, respectively (P < 0.001). Tumor-associated neovascularization was the best predictor of survival at 5.25 months (AUC = 0.794, 81.2 % sensitivity, 77.8 % specificity, 76.5 % positive predictive value, 82.4 % negative predictive value) and yielded the highest hazard ratio (P < 0.001). Tumor-associated neovascularization detected on high-resolution blood-pool-contrast-enhanced MRA of newly diagnosed glioblastoma seems to be a useful biomarker that correlates with worse survival. (orig.)

  11. Cardiac blood pool emission tomography

    International Nuclear Information System (INIS)

    Itti, R.; Philippe, L.; Lorgeron, J.M.; Charbonnier, B.; Raynaud, P.; Brochier, M.

    1983-01-01

    After blood pool labeling using technetium-99m, a series of cardiac pictures is acquired during the rotation of a gamma-camera about the patient. Computer processing leads to reconstruction of various tomographic slices from the original planar projection. Electrocardiographic gating selects the different phases of the cardiac cycle. Individual slices through the left ventricular region are added in order to provide ''thick'' slices on which global and regional parameters of the left ventricular function can be determined. Due to the proportionality existing between count rates and labeled blood volumes, any geometrical model can be avoided. The delineation of regions of interest for count integration is made easier due to the absence of superimposition of structures; no correction for background is necessary. Tomography thus appears to be more consistent and more accurate than the classical methods using planar projections. In addition, right ventricular morphological and kinetic studies can be performed in the same conditions as for the left ventricle [fr

  12. Early modifications of hepatic perfusion measured by functional CT in a rat model of hepatocellular carcinoma using a blood pool contrast agent

    International Nuclear Information System (INIS)

    Fournier, Laure S.; Cuenod, Charles Andre; Bazelaire, Cedric de; Siauve, Nathalie; Frija, Guy; Clement, Olivier; Rosty, Christophe; Tran, Phuong Lan

    2004-01-01

    Macromolecular contrast-enhanced functional CT was performed to characterize early perfusion changes in hepatocellular carcinoma (HCC). Fourteen rats with chemically induced primary liver tumors ranging pathologically from hyperplasia to HCC and 15 control rats were investigated. Two dynamic CT scans using an experimental macromolecular contrast agent were performed on a single slice 11 and 18 weeks after tumor induction followed by pathological examination. A deconvolution mathematical model was applied, yielding the hepatic perfusion index (HPI), mean transit time (MTT), liver distribution volume (LDV) and arterial, portal and total blood flows (FA, FP, FT). Analysis was performed on one slice per rat, containing overall two hyperplasia, six dysplasia and 15 HCC. On the first scans, HCC at an early pathological stage had a low FP (-30%, P=0.002) but a normal arterial-portal balance. On the scan contemporary to pathology, HCC perfusion parameters showed an inversion of the arterial-portal balance (HPI +212%, P<0.0001), with a high FA (+56%, P=0.002) and a low FP (-69%, P<0.0001). Sensitivity and specificity of detection of HCC by perfusion CT were high (87 and 80%) on late scans; but also on the earlier scans (86 and 65%), even though only one (7%) was visible to the eye. Perfusion-CT allowed early detection of HCC. This technique could contribute in the detection and characterization of liver lesions in clinical studies. (orig.)

  13. Combined magnetic resonance imaging of deep venous thrombosis and pulmonary arteries after a single injection of a blood pool contrast agent

    Energy Technology Data Exchange (ETDEWEB)

    Hansch, Andreas; Neumann, Steffi; Baltzer, Pascal; Waginger, Matthias; Kaiser, Werner A.; Mentzel, Hans-Joachim [Friedrich-Schiller-University Jena, Institute of Diagnostic and Interventional Radiology, Jena (Germany); Betge, Stefan; Poehlmann, Gunther [Friedrich-Schiller-University Jena, Department of Internal Medicine I, Jena (Germany); Pfeil, Alexander; Wolf, Gunter [Friedrich-Schiller-University Jena, Department of Internal Medicine III, Jena (Germany); Boettcher, Joachim [SRH Klinikum Gera, Institute of Diagnostic and Interventional Radiology, Gera (Germany)

    2011-02-15

    Agreement rate between magnetic resonance imaging (MRI) and Doppler ultrasound (DUS) for the detection of deep vein thrombosis (DVT) in the lower extremities was attempted by using the intravascular MRI contrast agent gadofosveset trisodium. The potential of this method to detect pulmonary embolism (PE) was also evaluated. Forty-three consecutive inpatients with ultrasound-confirmed DVT but no clinical signs of PE were prospectively enrolled in this feasibility study. MRI was performed after a single injection of gadofosveset trisodium. The pulmonary arteries were imaged using a 3D Fast Low Angle Shot (FLASH) gradient recalled echo sequence. Additionally, pulmonary arteries, abdominal veins, pelvic and leg veins were imaged using a fat-suppressed 3D gradient echo Volume Interpolated Breath-hold Examination (VIBE FS). Gadofosveset trisodium-enhanced MRI detected more thrombi in the pelvic region, upper leg and lower leg than the initial DUS. In addition, PE was detected in 16 of the 43 DVT patients (37%). This study shows the feasibility of a combined protocol for the MRI diagnosis of DVT and PE using gadofosveset trisodium. This procedure is not only more sensitive in detecting DVT compared to standard DUS, but is also able to detect PE in asymptomatic patients. (orig.)

  14. Parametric tomography of the cardiac blood pool

    International Nuclear Information System (INIS)

    Meyer, M.; Schwartz, K.D.

    1990-01-01

    In nuclear cardiology image processing is performed usually in 3 of 4 dimensions. ECG-gated SPECT (GSPECT) would make it possible to obtain all 4 dimensions of space and time during one examination, but its duration as well as radiation dose is limited resulting in a low signal-to-noise ratio. Sensitive feature extractions from the amount of data are necessary, e.g. Fourier filtering or extracting isovolumetric intervals. The relatively large amount of calculations and storage requirements often handicaps tomographic ventriculography because a high number of sections have to be processed and the temporal resolution is limited. A new list-mode oriented tomographic algorithm demands less storage and fewer calculations: The Fourier coefficient extraction and the filtered back projection, both of which are linear operations, could be interchanged in the case of thoracic SPECT. The feature extraction algorithm process internal list-mode heart cycles for discrimination of invalid cycles, for end-diastolic and end-systolic synthesis as well as for Fourier analysis of the first harmonic in 10 ms steps. Reconstruction operations are applied also to modified distribution matrices of Fourier coefficients. By only processing 4 spatial matrix sequences (end-diastolic and end-systolic images, amplitude and phase values) parametric tomography becomes practicable and could be also performed by a minicomputer with 64 KByte memory in addition to the possibilities of the planar left ventricular gated imaging. If there are 3 or more processors available a complete feature extraction on-the-fly will be possible. The numerical algorithms were tested with respect to stable reconstructions by phantoms. First results of a patient examination are used to explore effective display techniques, and preliminary modes are demonstrated. It is the purpose of this study to obtain additional information about the gated planar cardiac blood pool imaging in the field of SPECT. (author)

  15. Equilibrium blood pool scanning in the evaluation of hemophilic arthropathy

    International Nuclear Information System (INIS)

    Spies, S.; Green, D.; Rana, N.A.; Milgram, J.W.; Mintzer, R.

    1978-01-01

    Arthropathy was evaluated in six patients with severe hemophilia (factor VIII<1%) using the technique of blood pool scanning. Employing an in vivo method for erythrocyte labelling with technetium-99m, a dynamic perfusion sequence was obtained using a scintillation camera over the joint(s) to be examined. Subsequently, equilibrium blood pool images of the joints were obtained to determine regional blood volume. In young patients with repeated episodes of acute hemarthrosis, increased vascularity and increased blood pool in the affected joints were demonstrated. In older patients with fixed, contracted joints and degenerative arthropathy, vascularity and regional blood volume were not abnormal. Blood pool scanning is a safe, non-invasive technique that augments the clinical and radiographic examination of the joints. The method is helpful in distinguishing acute joint bleeding from chronic synovitis and arthritis, and may prove useful in selecting patients for synovectomy. (author)

  16. Nanoparticle encapsulation in red blood cells enables blood-pool magnetic particle imaging hours after injection

    International Nuclear Information System (INIS)

    Rahmer, J; Gleich, B; Borgert, J; Antonelli, A; Sfara, C; Magnani, M; Tiemann, B; Weizenecker, J

    2013-01-01

    Magnetic particle imaging (MPI) is a new medical imaging approach that is based on the nonlinear magnetization response of super-paramagnetic iron oxide nanoparticles (SPIOs) injected into the blood stream. To date, real-time MPI of the bolus passage of an approved MRI SPIO contrast agent injected into the tail vein of living mice has been demonstrated. However, nanoparticles are rapidly removed from the blood stream by the mononuclear phagocyte system. Therefore, imaging applications for long-term monitoring require the repeated administration of bolus injections, which complicates quantitative comparisons due to the temporal variations in concentration. Encapsulation of SPIOs into red blood cells (RBCs) has been suggested to increase the blood circulation time of nanoparticles. This work presents first evidence that SPIO-loaded RBCs can be imaged in the blood pool of mice several hours after injection using MPI. This finding is supported by magnetic particle spectroscopy performed to quantify the iron concentration in blood samples extracted from the mice 3 and 24 h after injection of SPIO-loaded RBCs. Based on these results, new MPI applications can be envisioned, such as permanent 3D real-time visualization of the vessel tree during interventional procedures, bleeding monitoring after stroke, or long-term monitoring and treatment control of cardiovascular diseases. (paper)

  17. Evaluation of hepatic hemangioma by Tc-99 m red blood cell hepatic blood pool scan

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Myung Hee [Chonbuk National University Medical School, Chonju (Korea, Republic of)

    2005-02-15

    Hemangioma is the most common benign tumor of the liver, with a prevalence estimated as high as 7%. Tc-99m red blood cell (RBC) hepatic blood pool scan with single photon emission computed tomography (SPECT) imaging is extremely useful for the confirmation or exclusion of hepatic hemangiomas. The classic finding of absent or decreased perfusion and increased blood pooling ('perfusion/blood pool mismatch') is the key diagnostic element in the diagnosis of hemangiomas. The combination of early arterial flow and delayed blood pooling ('perfusion/blood pool match') is shown uncommonly. In giant hemangioma, filling with radioactivity appears first in the periphery, with progressive central fill-in on sequential RBC blood pool scan. However, the reverse filling pattern, which begins first in the center with progressive peripheral filling, is also rarely seen. Studies with false-positive blood pooling have been reported infrequently in nonhemangiomas, including hemangiosarcoma, hepatocellular carcinoma, hepatic adenoma, and metastatic carcinomas (adenocarcinma of the colon, small cell carcinoma of the lung, neruroendocrine carcinoma). False-negative results have been also reported rarely except for small hemagniomas that are below the limits of spatial resolution of gamma camera.

  18. Evaluation of hepatic hemangioma by Tc-99 m red blood cell hepatic blood pool scan

    International Nuclear Information System (INIS)

    Sohn, Myung Hee

    2005-01-01

    Hemangioma is the most common benign tumor of the liver, with a prevalence estimated as high as 7%. Tc-99m red blood cell (RBC) hepatic blood pool scan with single photon emission computed tomography (SPECT) imaging is extremely useful for the confirmation or exclusion of hepatic hemangiomas. The classic finding of absent or decreased perfusion and increased blood pooling ('perfusion/blood pool mismatch') is the key diagnostic element in the diagnosis of hemangiomas. The combination of early arterial flow and delayed blood pooling ('perfusion/blood pool match') is shown uncommonly. In giant hemangioma, filling with radioactivity appears first in the periphery, with progressive central fill-in on sequential RBC blood pool scan. However, the reverse filling pattern, which begins first in the center with progressive peripheral filling, is also rarely seen. Studies with false-positive blood pooling have been reported infrequently in nonhemangiomas, including hemangiosarcoma, hepatocellular carcinoma, hepatic adenoma, and metastatic carcinomas (adenocarcinma of the colon, small cell carcinoma of the lung, neruroendocrine carcinoma). False-negative results have been also reported rarely except for small hemagniomas that are below the limits of spatial resolution of gamma camera

  19. Abdominal blood pool scintigraphy in the management of acute or intermittent gastrointestinal bleeding

    International Nuclear Information System (INIS)

    Kalff, V.; Kelly, M.J.; Dudley, F.; Metz, G.

    1983-01-01

    Gastrointestinal blood pool scintigraphy, using a modified in-vivo blood cell labelling technique with technetium-99, is a new, easily performed, non-invasive procedure. It is valuable in screening patients with acute or intermittent gastrointestinal blood loss in whom duodenoscopic and sigmoidoscopic findings are unhelpful. This paper reviews the value of this scintigraphic technique over the first eight months of its use in a major teaching hospital, and compares the results with other published data. If used and interpreted appropriately, scintigraphy is sensitive in detecting and localizing the bleeding site, and is very helpful in indicating the optimal timing of emergency contrast angiography

  20. Dried blood spots of pooled samples for RHD gene screening in blood donors of mixed ancestry.

    Science.gov (United States)

    Silva-Malta, M C F; Araujo, N C Fidélis; Vieira, O V Neves; Schmidt, L Cayres; Gonçalves, P de Cassia; Martins, M Lobato

    2015-10-01

    In this study, we present a strategy for RHD gene screening based on real-time polymerase chain reaction (PCR) using dried blood spots of pooled samples. Molecular analysis of blood donors may be used to detect RHD variants among the presumed D-negative individuals. RHD genotyping using pooled samples is a strategy to test a large number of samples at a more reasonable cost. RHD gene detection based on real-time PCR using dried blood spots of pooled samples was standardised and used to evaluate 1550 Brazilian blood donors phenotyped as RhD-negative. Positive results were re-evaluated by retesting single samples using real-time PCR and conventional multiplex PCR to amplify five RHD-specific exons. PCR-sequence-specific primers was used to amplify RHDψ allele. We devised a strategy for RHD gene screening using dried blood spots of five pooled samples. Among 1550 serologically D-negative blood donors, 58 (3.74%) had the RHD gene. The non-functional RHDψ allele was detected in 47 samples (3.02%). The present method is a promising strategy to detect the RHD gene among presumed RhD-negative blood donors, particularly for populations with African ancestry. © 2015 British Blood Transfusion Society.

  1. Cardiac tumours: non invasive detection and assessment by gated cardiac blood pool radionuclide imaging

    International Nuclear Information System (INIS)

    Pitcher, D.; Wainwright, R.; Brennand-Roper, D.; Deverall, P.; Sowton, E.; Maisey, M.

    1980-01-01

    Four patients with cardiac tumours were investigated by gated cardiac blood pool radionuclide imaging and echocardiography. Contrast angiocardiography was performed in three of the cases. Two left atrial tumours were detected by all three techniques. In one of these cases echocardiography alone showed additional mitral valve stenosis, but isotope imaging indicated tumour size more accurately. A large septal mass was detected by all three methods. In this patient echocardiography showed evidence of left ventricular outflow obstruction, confirmed at cardiac catheterisation, but gated isotope imaging provided a more detailed assessment of the abnormal cardiac anatomy. In the fourth case gated isotope imaging detected a large right ventricular tumour which had not been identified by echocardiography. Gated cardiac blood pool isotope imaging is a complementary technique to echocardiography for the non-invasive detection and assessment of cardiac tumours. (author)

  2. Nonstationary temporal Wiener filtering of gated blood pool studies

    International Nuclear Information System (INIS)

    King, M.A.; Miller, T.R.; Doherty, P.W.; Bianco, J.A.

    1985-01-01

    Temporal filtering of dynamic images can significantly improve the image quality of gated blood pool (GBP) studies and serves as a necessary preprocessing step in the formation of cardiac functional images based on derivatives of pixel time activity curves. Generally, either linear combination of the frames, or a simple frequency domain low pass filter have been employed. The work described in this paper introduces the Wiener temporal filter which adjusts to match the temporal characteristic of the image at each pixel. For temporal data degraded by signal-dependent Poisson noise, the frequency domain form of the filter is presented. Use of nonstationary temporal Wiener filtering was found to improve the quality of cines formed from GBP studies and yielded better separation of cardiac from non-cardiac regions in functional images the peak ejection and filling rates

  3. Spatially pooled contrast responses predict neural and perceptual similarity of naturalistic image categories.

    Directory of Open Access Journals (Sweden)

    Iris I A Groen

    Full Text Available The visual world is complex and continuously changing. Yet, our brain transforms patterns of light falling on our retina into a coherent percept within a few hundred milliseconds. Possibly, low-level neural responses already carry substantial information to facilitate rapid characterization of the visual input. Here, we computationally estimated low-level contrast responses to computer-generated naturalistic images, and tested whether spatial pooling of these responses could predict image similarity at the neural and behavioral level. Using EEG, we show that statistics derived from pooled responses explain a large amount of variance between single-image evoked potentials (ERPs in individual subjects. Dissimilarity analysis on multi-electrode ERPs demonstrated that large differences between images in pooled response statistics are predictive of more dissimilar patterns of evoked activity, whereas images with little difference in statistics give rise to highly similar evoked activity patterns. In a separate behavioral experiment, images with large differences in statistics were judged as different categories, whereas images with little differences were confused. These findings suggest that statistics derived from low-level contrast responses can be extracted in early visual processing and can be relevant for rapid judgment of visual similarity. We compared our results with two other, well- known contrast statistics: Fourier power spectra and higher-order properties of contrast distributions (skewness and kurtosis. Interestingly, whereas these statistics allow for accurate image categorization, they do not predict ERP response patterns or behavioral categorization confusions. These converging computational, neural and behavioral results suggest that statistics of pooled contrast responses contain information that corresponds with perceived visual similarity in a rapid, low-level categorization task.

  4. Brain magnetic resonance imaging with contrast dependent on blood oxygenation

    International Nuclear Information System (INIS)

    Ogawa, S.; Lee, T.M.; Kay, A.R.; Tank, D.W.

    1990-01-01

    Paramagnetic deoxyhemoglobin in venous blood is a naturally occurring contrast agent for magnetic resonance imaging (MRI). By accentuating the effects of this agent through the use of gradient-echo techniques in high yields, the authors demonstrate in vivo images of brain microvasculature with image contrast reflecting the blood oxygen level. This blood oxygenation level-dependent (BOLD) contrast follows blood oxygen changes induced by anesthetics, by insulin-induced hypoglycemia, and by inhaled gas mixtures that alter metabolic demand or blood flow. The results suggest that BOLD contrast can be used to provide in vivo real-time maps of blood oxygenation in the brain under normal physiological conditions. BOLD contrast adds an additional feature to magnetic resonance imaging and complement other techniques that are attempting to provide position emission tomography-like measurements related to regional neural activity

  5. Gated blood pool studies with a single probe - clinical validity

    International Nuclear Information System (INIS)

    Loesel, E.; Hoffmann, G.

    1981-01-01

    The global volume alterations of the heart can be estimated non-invasively by means of the radiocardiographic function analysis developed by Hoffmann and Kleine. Since the failing heart with its functional disturbances demonstrates a pathological volume behaviour under physical exercise, it is possible to use these characteristics to differentiate between the intact heart and the failing heart by registration of the global volume alterations. The gated blood pool technique combined with the registration of the intraventricular pressure pulse by means of a Swan-Ganz flow-directed catheter enables demonstration of ventricular stroke work as a pressure-volume loop (work diagram). Its shape indicates whether the ventricle has to perform mainly pressure work or volume work. Myocardial failure is altering the basic conditions of the heart. The work diagram of the failing heart is significantly different from that of the intact human heart. It is shifted in its pressure-volume coordinates according to an increase of EDV and ESV and the rise of the filling pressure. Case demonstrations reveal the global volume behaviour of the heart under varying conditions: resting and physical exercise, drug influence on the intact and failing heart. (orig.) [de

  6. Evaluation of portable blood glucose meters using canine and feline pooled blood samples.

    Science.gov (United States)

    Mori, A; Oda, H; Onozawa, E; Shono, S; Takahashi, T; Yamashita, S; Fujimoto, H; Sako, T

    2016-12-01

    This study evaluated the accuracy and reproducibility of a human portable blood glucose meter (PBGM) for canine and feline whole blood. Reference plasma glucose values (RPGV) were concurrently measured using glucose oxidation methods. Fifteen healthy dogs and 6 healthy cats were used for blood sampling. Blood glucose concentrations and hematocrits were adjusted using pooled blood samples for our targeted values. A positive correlation between the PBGM and RPGV was found for both dogs (y = 0.877, x = -24.38, r = 0.9982, n = 73) and cats (y = 1.048, x = -27.06, r = 0.9984, n = 69). Acceptable results were obtained in error grid analysis between PBGM and RPGV in both dogs and cats; 100% of these results were within zones A and B. Following ISO recommendations, a PBGM is considered accurate if 95% of the measurements are within ± 15 mg/dl of the RPGV when the glucose concentration is cats (39%, 27 of 69 cats). Blood samples with high hematocrits induced lower whole blood glucose values measured by the PBGM than RPGV under hypoglycemic, normoglycemic, and hyperglycemic conditions in both dogs and cats. Therefore, this device is not clinically useful in dogs and cats. New PBGMs which automatically compensate for the hematocrit should be developed in veterinary practice.

  7. ECG-gated blood pool tomography in the determination of left ventricular volume, ejection fraction, and wall motion

    International Nuclear Information System (INIS)

    Underwood, S.R.; Ell, P.J.; Jarritt, P.H.; Emanuel, R.W.; Swanton, R.H.

    1984-01-01

    ECG-gated blood pool tomography promises to provide a ''gold standard'' for noninvasive measurement of left ventricular volume, ejection fraction, and wall motion. This study compares these measurements with those from planar radionuclide imaging and contrast ventriculography. End diastolic and end systolic blood pool images were acquired tomographically using an IGE400A rotating gamma camera and Star computer, and slices were reconstructed orthogonal to the long axis of the heart. Left ventricular volume was determined by summing the areas of the slices, and wall motion was determined by comparison of end diastolic and end systolic contours. In phantom experiments this provided an accurate measurement of volume (r=0.98). In 32 subjects who were either normal or who had coronary artery disease left ventricular volume (r=0.83) and ejection fraction (r=0.89) correlated well with those using a counts based planar technique. In 16 of 18 subjects who underwent right anterior oblique X-ray contrast ventriculography, tomographic wall motion agreed for anterior, apical, and inferior walls, but abnormal septal motion which was not apparent by contrast ventriculography, was seen in 12 subjects tomographically. All 12 had disease of the left anterior descending coronary artery and might have been expected to have abnormal septal motion. ECG-gated blood pool tomography can thus determine left ventricular volume and ejection fraction accurately, and provides a global description of wall motion in a way that is not possible from any single planar image

  8. Right-sided phase abnormalities on gated blood pool ventriculography: Demonstration of six different patterns

    International Nuclear Information System (INIS)

    Bahar, R.H.; Abdel-Dayem, H.M.; Ziada, G.; Al-Suhali, A.; Constantinides, C.; Nair, K.M.

    1986-01-01

    Phase pattern abnormalities on multiple gated blood pool ventriculography are better reported for the left ventricle (LV) than for the right side of the heart. In a study of 92 patients who also underwent contrast ventriculography, the authors identified six different patterns of right-sided phase abnormalities and their causes: right bundle-branch block, causing delayed phase in the entire right ventricle (RV); ischemic right coronary artery disease, causing delayed phase in the inferior RV wall; pericardial effusion, causing an L-shaped area of delayed phase to the right of the septum and below the LV; pulmonary hypertension, causing delayed phase in the pulmonary infundibulum; tricuspid regurgitation, causing a crescentic area of delayed phase around and below the right RV and extending below the LV as well, and atrial septal defect causing an abnormally large auricular phase

  9. Volume of distribution of contrast media in blood

    International Nuclear Information System (INIS)

    Kormano, M.

    1979-01-01

    The volume of distribution of diatrizoate and iodipamide in blood in relation to hematocrit and contrast concentration was measured using 125 I-labeled compounds. In concentration obtained after intravenous injection, the percentage volume of distribution of both contrast media is 100 minus hematocrit, except for high hematocrit values, which may cause uneven distribution of contrast media in smaller concentrations. No evidence of intracellular penetration was obtained. (Auth.)

  10. [Reference values for the blood coagulation tests in Mexico: usefulness of the pooled plasma from blood donors].

    Science.gov (United States)

    Calzada-Contreras, Adriana; Moreno-Hernández, Manuel; Castillo-Torres, Noemi Patricia; Souto-Rosillo, Guadalupe; Hernández-Juárez, Jesús; Ricardo-Moreno, María Tania; Sánchez-Fernández, Maria Guadalupe de Jesús; García-González, América; Majluf-Cruz, Abraham

    2012-01-01

    The blood coagulation system maintains the blood in a liquid state and bleeding and thrombosis are the manifestations of its malfunction. Blood coagulation laboratory evaluates the physiology of this system. To establish both, the reference values for several tests performed at the blood coagulation laboratory as well as the utility of the pooled plasma to perform these assays. MATERIAL AND: In this descriptive, cross-sectional, randomized study, we collected plasma from Mexican Mestizos. Each pooled plasma was prepared with the plasma from at least 20 blood donors. We performed screening and special tests and the Levey-Jennings graphs were built and interpreted after each pass. Results of the tests were analyzed and their distribution was established using the Kolmogorov-Smirnov test. To establish the reference values we used 95% confidence intervals. We collected 72 pooled plasmas. The distribution for PT, APTT, and TT tests was abnormal. Although the PT test showed a bimodal distribution it was normal for factor VII. The reference values for the hemostatic, anticoagulant, and fibrinolytic factors were different from those suggested by the manufacturers. We established the reference values for the blood coagulation tests in the adult Mexican population. We have shown that the pooled plasma must be used for the screening tests. We suggest that each clinical laboratory should establish its own reference values (at least for the screening tests). To reach this objective, we encourage the use of the pooled plasma.

  11. Slower lower limb blood pooling in young women with orthostatic intolerance.

    Science.gov (United States)

    Lindenberger, Marcus; Länne, Toste

    2015-01-01

    What is the central question of this study? Orthostatic stress is mostly caused by venous blood pooling in the lower limbs. Venous distension elicits sympathetic responses, and increased distension speed enhances the cardiovascular response. We examine whether lower limb blood pooling rate during lower body negative pressure is linked to orthostatic intolerance. What is the main finding and its importance? A similar amount of blood was pooled in the lower limb, but at a slower rate in women who developed signs of orthostatic intolerance. The difference in blood pooling rate increased with orthostatic stress and was most prominent at a presyncope-inducing level of lower body negative pressure. The findings have implications for the pathophysiology as well as treatment of orthostatic intolerance. Vasovagal syncope is common in young women, but its aetiology remains elusive. Orthostatic stress-induced lower limb blood pooling is linked with central hypovolaemia and baroreceptor unloading. Venous distension in the arm elicits a sympathetic response, which is enhanced with more rapid distension. Our aim was to study both the amount and the speed of lower limb pooling during orthostatic stress and its effects on compensatory mechanisms to maintain cardiovascular homeostasis in women with orthostatic intolerance. Twenty-seven healthy women, aged 20-27 years, were subjected to a lower body negative pressure (LBNP) of 11-44 mmHg. Five women developed symptoms of vasovagal syncope (orthostatic intolerant) and were compared with the remaining women, who tolerated LBNP well (orthostatic tolerant). Lower limb blood pooling, blood flow and compensatory mobilization of venous capacitance blood were measured. Lower body negative pressure induced equal lower limb blood pooling in both groups, but at a slower rate in orthostatic intolerant women (e.g. time to 50% of total blood pooling, orthostatic intolerant 44 ± 7 s and orthostatic tolerant 26 ± 2 s; P intolerant women (P = 0

  12. Whole-body magnetic resonance angiography with blood-pool agents

    International Nuclear Information System (INIS)

    Kramer, H.; Morana, G.

    2007-01-01

    Although often asymptomatic, peripheral arterial disease (PAD) is associated with significant morbidity in a large proportion of patients. Atherosclerosis is the underlying pathology in many instances, involving the whole arterial tree. Whole-body magnetic resonance angiography (MRA) permits rapid, non-invasive and accurate evaluation of the entire vascular system and can be used for both diagnostic purposes and monitoring of vascular involvement in diseases such as diabetes, Marfan's syndrome and Takayasu arteritis. MRA has been used successfully in the identification of high-grade stenosis in PAD, abnormalities of the ileocaval veins and carotid plaque imaging. Carotid disease is significantly correlated with severe coronary artery disease and renal artery atherosclerosis. Symptomatic lesions in one vascular bed are often related to additional asymptomatic atherosclerotic lesions in other vascular regions. MRA may be advantageous over computed tomographic angiography because it can be performed with contrast media virtually devoid of serious toxicity and without utilization of ionizing radiation. Display of the entire arterial vasculature can be achieved in < 90 s, with excellent sensitivity and specificity. Recent technological advances, such as parallel imaging and the implementation of dedicated matrix coils, have further increased image quality, and in combination with the blood-pool contrast agents, such as gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany), extended imaging time, higher spatial resolution and larger anatomical coverage can be achieved. (orig.)

  13. Whole-body magnetic resonance angiography with blood-pool agents

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, H. [Inst. for Clinical Radiology, Univ. Hospital Munich, Munich (Germany); Morana, G. [Radiological Dept., Hospital Ca' Foncello, Treviso (Italy)

    2007-03-15

    Although often asymptomatic, peripheral arterial disease (PAD) is associated with significant morbidity in a large proportion of patients. Atherosclerosis is the underlying pathology in many instances, involving the whole arterial tree. Whole-body magnetic resonance angiography (MRA) permits rapid, non-invasive and accurate evaluation of the entire vascular system and can be used for both diagnostic purposes and monitoring of vascular involvement in diseases such as diabetes, Marfan's syndrome and Takayasu arteritis. MRA has been used successfully in the identification of high-grade stenosis in PAD, abnormalities of the ileocaval veins and carotid plaque imaging. Carotid disease is significantly correlated with severe coronary artery disease and renal artery atherosclerosis. Symptomatic lesions in one vascular bed are often related to additional asymptomatic atherosclerotic lesions in other vascular regions. MRA may be advantageous over computed tomographic angiography because it can be performed with contrast media virtually devoid of serious toxicity and without utilization of ionizing radiation. Display of the entire arterial vasculature can be achieved in < 90 s, with excellent sensitivity and specificity. Recent technological advances, such as parallel imaging and the implementation of dedicated matrix coils, have further increased image quality, and in combination with the blood-pool contrast agents, such as gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany), extended imaging time, higher spatial resolution and larger anatomical coverage can be achieved. (orig.)

  14. Blood pooling in extrathoracic veins after glossopharyngeal insufflation

    DEFF Research Database (Denmark)

    Mijacika, Tanja; Frestad, Daria; Kyhl, Kasper

    2017-01-01

    Purpose: Trained breath-hold divers hyperinflate their lungs by glossopharyngeal insufflation (GPI) to prolong submersion time and withstand lung collapse at depths. Pulmonary hyperinflation leads to profound hemodynamic changes. Methods: Thirteen divers performed preparatory breath-holds followed...... fluid extravasation. Conclusions: GPI leads to heart and pulmonary vessel compression, resulting in redistribution of blood to extrathoracic capacitance veins proximal to venous valves. This is partially reversed by the onset of involuntary breathing movements....

  15. Color contrast of red blood cells on solid substrate

    Science.gov (United States)

    Paiziev, Adkham A.

    2013-02-01

    In present study we developed the new method of colour visualization of red blood cells without using any chemical staining. The method based on physical phenomena a white light interference on thin transparent films. It is shown that in the case of thin human blood smears colour interference contrast occurs on solid polished substrates. The best contrast shows substrates with maximal refractive index (Mo, W, Si). These materials have been selected as substrate instead of ordinary microscopic slide in reflected light microscopy. It is shown that reflection of incident white light from blood cell surface and boundary cell-substrate generate two coherent lights. The second one (object signal) after passing through red blood cell gathers additional phase and after interference interaction with reference signal (light reflected from outer cell surface) enables cell image in colour. Number of blood smears of healthy persons (control) and patients who were diagnosed with cancer are presented. It is concluded that the offered method may be used as an effective diagnostic tool to detect early stage blood cells lesion by its interference painting in white light. Offered method may be used in research laboratories, hospitals, diagnostic centres, emergency medicine and other as complementary diagnostic tool to present convenient optical and electron microscopy technique.

  16. Effects of iodinated contrast media on blood and endothelium

    International Nuclear Information System (INIS)

    Aspelin, Peter; Stacul, Fulvio; Thomsen, Henrik S.; Morcos, Sameh K.; Molen, Aart J. van der

    2006-01-01

    The aim of the study was to assess the effects of iodinated contrast media on blood components and endothelium based on experimental and clinical studies and to produce clinically relevant guidelines for reducing thrombotic and hematologic complications following the intravascular use of contrast media. A report was drafted after review of the literature and discussions among the members of the Contrast Media Safety Committee of the European Society of Urogenital Radiology. The final report was produced following discussion at the 12th European Symposium on Urogenital Radiology in Ljubljana, Slovenia (2005). Experimental data indicate that all iodinated contrast media produce an anticoagulant effect and that this effect is greater with ionic contrast media. Several of the in vitro and experimental in vivo studies on haematological effects of contrast media have not been confirmed by clinical studies. Low- or iso-osmolar contrast media should be used for diagnostic and interventional angiographic procedures, including phlebography. Meticulous angiographic technique is the most important factor for reducing the thrombotic complications associated with angiographic procedures. Drugs and interventional devices that decrease the risk of thromboembolic complications during interventional procedures minimize the importance of the effects of contrast media. (orig.)

  17. Clinical usefullness of ECG-triggered single photon emission comuter tomography of blood-pool

    International Nuclear Information System (INIS)

    Eilles, Chr.; Boerner, W.; Strauss, P.; Gerhards, W.; Reiners, Ch.

    1982-01-01

    ECT allows direct measurement of the volume of an organ and imaging without disturbing background-superposition. This makes ECT to an useful instrument for ECG-gated blood-pool imaging. Acquisition is made after the injection of 25 mCi Tc-99m HSA with a rotating Anger-Camera-System. ECG-gated imaging is done for each projection; herewith 50-70 cycles per projection are added according to the phase of the heart-cycle. Transversal-Sections of the heart are reconstructed with filtered-back-projection. For each slice a representative cycle, consisting of 10-16 frames, is computed. As shown by our group before a good quality of the reconstructed images can be obtained. Comparison is made with the results of the ECG-gated blood-pool-ECT, the results of the conventional blood-pool-studies and with the results of Laevo-Cardiography. (Author)

  18. Radiological contrast media and pancreatic blood perfusion in anesthetized rats.

    Science.gov (United States)

    Linder, G; Carlsson, P O; Källskog, Ö; Hansell, P; Jansson, L; Riesenfeld Källskog, V

    2007-12-01

    Radiological contrast media (CM) have been suggested to be able to impair pancreatic microcirculation. To evaluate the effects of an iso-osmolar (iodixanol, 290 mOsm/kg H2O) and a low-osmolar (iopromide, 660 mOsm/kg H2O) CM on total pancreatic and islet blood perfusion. Thiobutabarbital-anesthetized rats were injected with iodine equivalent doses (600 mg I/kg body weight) of iodixanol or iopromide. Saline or low-osmolar mannitol (660 mOsm/kg H2O) solutions served as control substances. Blood perfusion measurements were then carried out with a microsphere technique. Iso-osmolar iodixanol had no effects on blood perfusion. Low-osmolar iopromide increased total pancreatic blood perfusion, whereas islet blood perfusion was unchanged. No differences were seen when mannitol solutions were given. Neither an iso-osmolar nor a low-osmolar CM affected pancreatic islet blood perfusion, whereas the low-osmolar CM increased total pancreatic blood perfusion. The absence of hemodynamic effect of low-osmolar mannitol suggests that the hyperosmolality per se of iopromide versus iodixanol does not induce the hemodynamic effect. The consequences of the effect of iopromide for pancreatic function remain to be established.

  19. Use of blood-pool imaging in evaluation of diffuse activity patterns in technetium-99m pyrophosphate myocardial scintigraphy.

    Science.gov (United States)

    Cowley, M J; Mantle, J A; Rogers, W J; Russell, R O; Rackley, C E; Logic, J R

    1979-06-01

    It has been suggested that diffuse Tc-99m pyrophosphate precordial activity may be due to persistent blood-pool activity in routine delayed views during myocardial imaging. To answer this question, we reviewed myocardial scintigrams recorded 60--90 min following the injection of 12--15 mCi of Tc-99m pyrophosphate for the presence of diffuse precordial activity, and compared these with early images of the blood pool in 265 patients. Diffuse activity in the delayed images was identified in 48 patients: in 20 with acute myocardial infarction and in 28 with no evidence of it. Comparison of these routine delayed images with early views of the blood pool revealed two types of patterns. In patients with acute infarction, 95% had delayed images that were distinguishable from blood pool either because the activity was smaller than the early blood pool, or by the presence of localized activity superimposed on diffuse activity identical to blood pool. In those without infarction, 93% had activity distribution in routine delayed views matching that in the early blood-pool images. The usefulness of the diffuse TcPPi precordial activity in myocardial infarction is improved when early blood-pool imaging is used to exclude persistence of blood-pool activity as its cause. Moreover, it does not require additional amounts of radioactivity nor complex computer processing, a feature that may be of value in the community hospital using the technique to "rule out" infarction 24--72 hr after onset of suggestive symptoms.

  20. Use of blood-pool imaging in evaluation of diffuse activity patterns in technetium-99m pyrophosphate myocardial scintigraphy

    International Nuclear Information System (INIS)

    Cowley, M.J.; Mantle, J.A.; Rogers, W.J.; Russell, R.O. Jr.; Rackley, C.E.; Logic, J.R.

    1979-01-01

    It has been suggested that diffuse 99m Tc pyrophosphate precordial activity may be due to persistent blood-pool activity in routine delayed views during myocardial imaging. To answer this question, we reviewed myocardial scintigrams recorded 60 to 90 min following the injection of 12 to 15 mCi of 99m Tc pyrophosphate for the presence of diffuse precordial activity, and compared these with early images of the blood pool in 265 patients. Diffuse activity in the delayed images was identified in 48 patients: in 20 with acute myocardial infarction and in 28 with no evidence of it. Comparison of these routine delayed images with early views of the blood pool revealed two types of patterns. In patients with acute infarction, 95% had delayed images that were distinguishable from blood pool either because the activity was smaller than the early blood pool, or by the presence of localized activity superimposed on diffuse activity identical to blood pool. In those without infarction, 93% had activity distribution in routine delayed views matching that in the early blood-pool images. The usefulness of the diffuse TcPPi precordial activity in myocardial infarction is improved when early blood-pool imaging is used to exclude persistence of blood-pool activity as its cause. Moreover, it does not require additional amounts of radioactivity nor complex computer processing, a feature that may be of value in the community hospital using the technique to rule out infarction 24 to 72 hr after onset of suggestive symptoms

  1. Nephron blood flow dynamics measured by laser speckle contrast imaging

    DEFF Research Database (Denmark)

    von Holstein-Rathlou, Niels-Henrik; Sosnovtseva, Olga V; Pavlov, Alexey N

    2011-01-01

    Tubuloglomerular feedback (TGF) has an important role in autoregulation of renal blood flow and glomerular filtration rate (GFR). Because of the characteristics of signal transmission in the feedback loop, the TGF undergoes self-sustained oscillations in single-nephron blood flow, GFR, and tubular...... simultaneously. The interacting nephron fields are likely to be more extensive. We have turned to laser speckle contrast imaging to measure the blood flow dynamics of 50-100 nephrons simultaneously on the renal surface of anesthetized rats. We report the application of this method and describe analytic...... techniques for extracting the desired data and for examining them for evidence of nephron synchronization. Synchronized TGF oscillations were detected in pairs or triplets of nephrons. The amplitude and the frequency of the oscillations changed with time, as did the patterns of synchronization...

  2. 18F-FDG-labeled red blood cell PET for blood-pool imaging: preclinical evaluation in rats.

    Science.gov (United States)

    Matsusaka, Yohji; Nakahara, Tadaki; Takahashi, Kazuhiro; Iwabuchi, Yu; Nishime, Chiyoko; Kajimura, Mayumi; Jinzaki, Masahiro

    2017-12-01

    Red blood cells (RBCs) labeled with single-photon emitters have been clinically used for blood-pool imaging. Although some PET tracers have been introduced for blood-pool imaging, they have not yet been widely used. The present study investigated the feasibility of labeling RBCs with 18 F-2-deoxy-2-fluoro-D-glucose ( 18 F-FDG) for blood-pool imaging with PET. RBCs isolated from venous blood of rats were washed with glucose-free phosphate-buffered saline and labeled with 18 F-FDG. To optimize labeling efficiency, the effects of glucose deprivation time and incubation (labeling) time with 18 F-FDG were investigated. Post-labeling stability was assessed by calculating the release fraction of radioactivity and identifying the chemical forms of 18 F in the released and intracellular components of 18 F-FDG-labeled RBCs incubated in plasma. Just after intravenous injection of the optimized autologous 18 F-FDG-labeled RBCs, dynamic PET scans were performed to evaluate in vivo imaging in normal rats and intraabdominal bleeding models (temporary and persistent bleeding). The optimal durations of glucose deprivation and incubation (labeling) with 18 F-FDG were 60 and 30 min, respectively. As low as 10% of 18 F was released as the form of 18 F-FDG from 18 F-FDG-labeled RBCs after a 60-min incubation. Dynamic PET images of normal rats showed strong persistence in the cardiovascular system for at least 120 min. In the intraabdominal bleeding models, 18 F-FDG-labeled RBC PET visualized the extravascular blood clearly and revealed the dynamic changes of the extravascular radioactivity in the temporary and persistent bleeding. RBCs can be effectively labeled with 18 F-FDG and used for blood-pool imaging with PET in rats.

  3. Effect of solvent/detergent-treated pooled plasma on fibrinolysis in reconstituted whole blood.

    Science.gov (United States)

    Saadah, Nicholas H; van der Meer, Pieter F; Brinkman, Herm Jan M; de Korte, Dirk; Bontekoe, Ido J; Korsten, Herbert H; Middelburg, Rutger A; van der Bom, Johanna G; Schipperus, Martin R

    2017-10-01

    Hyperfibrinolysis has been observed in patients heavily transfused with solvent/detergent-treated pooled plasma (S/D plasma). We compared coagulation and fibrinolytic variables in blood containing S/D plasma with blood containing fresh-frozen plasma (FFP), with and without α2-antiplasmin or tranexamic acid (TXA) supplementation. Whole blood samples were reconstituted from red blood cells, platelet (PLT) concentrates, and varying mixtures of FFP and S/D plasma. Hematocrit and PLT count of reconstituted whole blood samples were varied. For a subset of runs, α2-antiplasmin or TXA was added to S/D plasma whole blood samples. Thromboelastography (TEG) analysis was performed to assess 50% clot lysis time (CLT 50% ), maximum amplitude (MA), and initial clotting time (R-time). The change in CLT 50% of whole blood as the plasma compartment transitions from FFP to S/D plasma was -52% (95% confidence interval [CI], -60% to -45%; p plasma in whole blood. α2-Antiplasmin and TXA restored clot lysis time in S/D plasma whole blood. Whole blood with S/D plasma has shorter clot lysis times in vitro compared to whole blood with FFP. α2-Antiplasmin and TXA restore clot lysis time of S/D plasma whole blood to that of FFP whole blood. Clinicians should be aware of the decreased clot lysis time associated with S/D plasma transfusion. © 2017 AABB.

  4. Effect of pool length on blood lactate, heart rate, and velocity in swimming.

    Science.gov (United States)

    Keskinen, O P; Keskinen, K L; Mero, A A

    2007-05-01

    Exercise testing in water has been used to follow the progression of conditioning during regular training in swimmers. The present study examined the effects of pool length in eleven male swimmers on a set of 5 x 200-m freestyle swims with increasing speed from submaximal to maximal. Mean velocity of swimming, blood lactate and heart rate were examined in both 25-m and 50-m pools. Turning benefit as a marker for turning skill was measured separately by a underwater video system (speed difference between pre- and post-turning) during short all-out swims. Maximum force during swimming was measured in tethered swimming and explosive strength of leg extensor muscles was evaluated by a counter movement jump. The significantly higher (p=0.033 - 0.000) blood lactate values for the 50-m pool as compared to the 25-m pool were found at each point of swimming velocity versus blood lactate curve. The highest post-test lactate level was 7.36 +/- 1.47 mmol x l (-1) in the short course and 8.24 +/- 1.55 mmol x l (-1) (p=0.033) in the long course. The maximum swimming velocity was significantly greater (4.5 %) in the 25-m pool swimming (1.38 +/- 0.11 m x s (-1) vs. 1.32 +/- 0.12 m x s (-1); p=0.000). The heart rate values were significantly (p=0.020 - 0.000) lower in the short course than in the long course at all points of submaximal velocity with a mean difference of 7.3 +/- 0.7 bpm. Heart rate was equal (172 +/- 14 vs. 172 +/- 14 bpm) after the maximum swims in both short and long course. The turning benefit in the short maximum swim was 0.12 +/- 0.05 m x s (-1) (8.1 +/- 3.2 %), correlating positively with the difference in maximal swimming velocity between the short and long-pool swims (r = 0.59; p = 0.029), with the maximum force during tethered swimming (r=0.75; p=0.004) and with the vertical jumping height in the counter movement jump (r=0.55; p=0.039). We conclude that the pool length has a strong effect on blood lactate concentration and heart rate with greater swimming

  5. Preliminary estimation of bryophyte biomass and carbon pool from three contrasting different vegetation types

    Czech Academy of Sciences Publication Activity Database

    Singh, M.K.; Juhász, A.; Csintalan, Z.; Kaligaric, M.; Marek, Michal V.; Urban, Otmar; Tuba, Z.

    2005-01-01

    Roč. 33, č. 1 (2005), s. 267-270 ISSN 0133-3720 Grant - others:EU(CZ) HPRI-CT-2002-00197 Institutional research plan: CEZ:AV0Z60870520 Keywords : bryophyte * carbon pool * rain forest Subject RIV: EH - Ecology, Behaviour Impact factor: 0.320, year: 2005

  6. Ventricular function during the acute rejection of heterotopic transplanted heart: Gated blood pool studies

    International Nuclear Information System (INIS)

    Valette, H.; Bourguignon, M.H.; Desruennes, M.; Merlet, P.; Le Guludec, D.; Syrota, A.

    1991-01-01

    Twenty patients who had undergone a heterotopic heart transplant were studied prospectively to determine the relationship between rejection and ventricular dysfunction assessed from gated blood pool studies. A fully automated method for detecting ventricular edges was implemented; its success rate for the grafted left and right ventricles was 94% and 77%, respectively. The parameters, peak ejection and filling rates, were calculated pixel per pixel using a two-harmonic Fourier algorithm and then averaged over the ventricular region of interest. Peak filling and ejection rates were closely related with the severity of the rejection, while the left ventricular ejection fraction was not. Peak filling rates of both ventricles were the indices closely related to the presence of moderate rejection. Despite the low number of patients, these data suggested that gated blood pool derived indices of ventricular function are associated with ventricular dysfunction resulting from myocarditis rejection. Radionuclide ventriculography provides parametric data which are accurate and reliable for the diagnosis of rejection. (orig.)

  7. Alterations of the blood pool in the femoral head before and after renal transplantation

    International Nuclear Information System (INIS)

    Hamaguchi, Hiroyuki; Fujioka, Mikihiro; Inoue, Shigehiro; Shibatani, Masahiko; Kubo, Toshikazu; Kubota, Takao; Ushijima, Yo; Nishimura, Tsunehiko

    2003-01-01

    The pathogenesis of idiopathic osteonecrosis of the femoral head (ION) is thought to be an ischemic event. The purpose of this study is to investigate alterations of the blood pool in the femoral head before and after renal transplantation. After renal transplantation, all patients received the same immunosuppressive therapy: corticosteroids, cyclosporin-A, and azathioprine. We performed 3-phase bone scintigraphy on 16 renal allograft recipients within 1 week before renal transplantation, and between week 4 and 9 after renal transplantation. Regions of interest (ROI) were assigned bilaterally in the femoral head, diaphysis, and soft tissue. The head-to-diaphysis ratios (HD ratios) were then calculated. Idiopathic osteonecrosis of the femoral head occurred in 2 femoral heads of 1 patient. The HD ratio before renal transplantation (mean HD±SD, 1.52±0.30) and the HD ratio after renal transplantation (1.28±0.30) were significantly different (P=0.000024). The HD ratios before and after renal transplantation were significantly different, indicating that the administration of steroids diminished the blood pool in the femoral head. A low HD ratio before renal transplantation revealed a poor blood pool in the femoral head, which may be a risk factor for ION. (author)

  8. Gene expression changes in blood RNA after swimming in a chlorinated pool.

    Science.gov (United States)

    Salas, Lucas A; Font-Ribera, Laia; Bustamante, Mariona; Sumoy, Lauro; Grimalt, Joan O; Bonnin, Sarah; Aguilar, Maria; Mattlin, Heidi; Hummel, Manuela; Ferrer, Anna; Kogevinas, Manolis; Villanueva, Cristina M

    2017-08-01

    Exposure to disinfection by-products (DBP) such as trihalomethanes (THM) in swimming pools has been linked to adverse health effects in humans, but their biological mechanisms are unclear. We evaluated short-term changes in blood gene expression of adult recreational swimmers after swimming in a chlorinated pool. Volunteers swam 40min in an indoor chlorinated pool. Blood samples were drawn and four THM (chloroform, bromodichloromethane, dibromochloromethane and bromoform) were measured in exhaled breath before and after swimming. Intensity of physical activity was measured as metabolic equivalents (METs). Gene expression in whole blood mRNA was evaluated using IlluminaHumanHT-12v3 Expression-BeadChip. Linear mixed models were used to evaluate the relationship between gene expression changes and THM exposure. Thirty-seven before-after pairs were analyzed. The median increase from baseline to after swimming were: 0.7 to 2.3 for MET, and 1.4 to 7.1μg/m 3 for exhaled total THM (sum of the four THM). Exhaled THM increased on average 0.94μg/m 3 per 1 MET. While 1643 probes were differentially expressed post-exposure. Of them, 189 were also associated with exhaled levels of individual/total THM or MET after False Discovery Rate. The observed associations with the exhaled THM were low to moderate (Log-fold change range: -0.17 to 0.15). In conclusion, we identified short-term gene expression changes associated with swimming in a pool that were minor in magnitude and their biological meaning was unspecific. The high collinearity between exhaled THM levels and intensity of physical activity precluded mutually adjusted models with both covariates. These exploratory results should be validated in future studies. Copyright © 2017. Published by Elsevier B.V.

  9. Cardiac cine MRI: Comparison of 1.5 T, non-enhanced 3.0 T and blood pool enhanced 3.0 T imaging

    International Nuclear Information System (INIS)

    Gerretsen, S.C.; Versluis, B.; Bekkers, S.C.A.M.; Leiner, T.

    2008-01-01

    Introduction: Cardiac cine imaging using balanced steady state free precession sequences (bSSFP) suffers from artefacts at 3.0 T. We compared bSSFP cardiac cine imaging at 1.5 T with gradient echo imaging at 3.0 T with and without a blood pool contrast agent. Materials and methods: Eleven patients referred for cardiac cine imaging underwent imaging at 1.5 T and 3.0 T. At 3.0 T images were acquired before and after administration of 0.03 mmol/kg gadofosveset. Blood pool signal-to-noise ratio (SNR), temporal variations in SNR, ejection fraction and myocardial mass were compared. Subjective image quality was scored on a four-point scale. Results: Blood pool SNR increased with more than 75% at 3.0 T compared to 1.5 T (p < 0.001); after contrast administration at 3.0 T SNR increased with 139% (p < 0.001). However, variations in blood pool SNR at 3.0 T were nearly three times as high versus those at 1.5 T in the absence of contrast medium (p < 0.001); after contrast administration this was reduced to approximately a factor 1.4 (p = 0.21). Saturation artefacts led to significant overestimation of ejection fraction in the absence of contrast administration (1.5 T: 44.7 ± 3.1 vs. 3.0 T: 50.7 ± 4.2 [p = 0.04] vs. 3.0 T post contrast: 43.4 ± 2.9 [p = 0.55]). Subjective image quality was highest for 1.5 T (2.8 ± 0.3), and lowest for non-enhanced 3.0 T (1.7 ± 0.6; p = 0.006). Conclusions: GRE cardiac cine imaging at 3.0 T after injection of the blood pool agent gadofosveset leads to improved objective and subjective cardiac cine image quality at 3.0 T and to the same conclusions regarding cardiac ejection fraction compared to bSSFP imaging at 1.5 T

  10. Clinical comparison of cardiac blood pool visualization with technetium-99m red blood cells labeled in vivo and with technetium-99m human serum albumin

    International Nuclear Information System (INIS)

    Thrall, J.H.; Freitas, J.E.; Swanson, D.; Rogers, W.L.; Clare, J.M.; Brown, M.L.; Pitt, B.

    1978-01-01

    Technetium-99m red blood cells (Tc-RBC) labeled by an in vivo technique were compared with two preparations of Tc-99m human serum albumin (HSA) for cardiac blood-pool imaging. Relative distribution of the tracers was analyzed on end-diastolic frames of gated blood-pool studies and on whole-body (head to mid-thigh) anterior pinhole images. The Tc-RBC demonstrated greater relative percentage localization in the cardiac blood pool, higher target-to-background ratios in the left ventricle, and less liver concentration. For cardiac blood-pool imaging, Tc-RBC labeled by the in vivo approach appears to be superior to the two Tc-HSA preparations studied

  11. Detection of soft tissue pathology on the blood pool phase of bone scans

    International Nuclear Information System (INIS)

    Raimondo, A.J.; Turner, H.A.; Kitchener, M.I.

    1999-01-01

    Full text: It is important to optimize information obtained from isotope bone scanning in musculoskeletal imaging. Although important at all times, it is especially imperative in the current climate of health services rationalization, capping of imaging expenditure and the promotion of newer modalities that are increasingly versatile and sensitive for imaging the musculoskeletal system. Careful attention must be paid to the blood flow and blood pool images, to visualize soft tissue as well as bony pathology. A series of cases and images will be presented that demonstrated blood pool pathology that was not appreciated on delayed imaging, or where reliance only on the delayed images would have led to an incorrect diagnosis. These include the detection of tendonitis, tenosynovitis, bursitis, muscle tears and soft tissue neoplasms, including neuromas. In cases where the bone scan cannot provide a definitive diagnosis, it will at least direct the referring clinician to the most appropriate confirmatory diagnostic imaging modality, thus reinforcing the value that isotope imaging provides in musculoskeletal medicine

  12. Dynamic circular buffering: a technique for equilibrium gated blood pool imaging.

    Science.gov (United States)

    Vaquero, J J; Rahms, H; Green, M V; Del Pozo, F

    1996-03-01

    We have devised a software technique called "dynamic circular buffering" (DCB) with which we create a gated blood pool image sequence of the heart in real time using the best features of LIST and FRAME mode methods of acquisition/processing. The routine is based on the concept of independent "agents" acting on the timing and position data continuously written into the DCB. This approach allows efficient asynchronous operation on PC-type machines and enhanced capability on systems capable of true multiprocessing and multithreading.

  13. Left ventricular function assessed by multi-gated blood pool single photon emission computed tomography with [sup 99m]Tc

    Energy Technology Data Exchange (ETDEWEB)

    Murano, Ken-ichi; Narita, Michihiro; Kurihara, Tadashi (Sumitomo Hospital, Osaka (Japan))

    1992-01-01

    To evaluate the usefulness of gated blood pool single photon emission computed tomography with [sup 99m]Tc (gated SPECT) for assessing left ventricular (LV) function, we performed gated SPECT in 2 normal subjects and 18 patients including 13 with ischemic heart disease, 3 with hypertrophic cardiomyopathy and 2 with dilated cardiomyopathy. LV end-diastolic volume (LVEDV), LV ejection fraction (LVEF) and regional wall motion obtained by gated SPECT were compared with the results of contrast left ventriculography (contrast LVG), echocardiography and planar multigated blood pool imaging (planar blood pool). After the patients' red blood cells were labelled with 30 mCi (1,110 MBq) [sup 99m]Tc in vivo, gated SPECT was performed in each of 32 projections through a 360 degree arc for each of the cardiac cycle divided into 16. From these images, the left ventricular vertical long-axis image, the horizontal long-axis and short-axis images were reconstructed. To calculate LVEDV, we used serial short-axis images which were composed of LV. To define LV and left atrial borders, we used amplitude images and cinematic displays of the vertical long-axis image. The level of the optimal cut for delineating the LV border was determined from the volume-cut-level-graph at each background activity, which was constructed by a phantom study. LV wall motion by gated SPECT was compared with the results of contrast LVG according to segmental analysis. LVEDV obtained by gated SPECT showed an excellent linear correlation with LVEDV calculated by echocardiography (r=0.98) and by contrast LVG (r=0.89). LVEF as determined by gated SPECT correlated well with the results obtained by the planar blood pool (r=0.94) and by contrast LVG (r=0.94). The visual interpretation of regional wall motion according to gated SPECT agreed with that determined by contrast LVG. We concluded that gated SPECT is a reliable method for assessing LV function. (author).

  14. Comparison of blood pool and extracellular gadolinium chelate for functional MR evaluation of vascular thoracic outlet syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Ruth P., E-mail: ruthplim74@gmail.com [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Austin Health, Department of Radiology, Heidelberg, Victoria 3084 (Australia); The University of Melbourne, School of Medicine, Parkville, Victoria 3010 (Australia); Bruno, Mary, E-mail: mary.bruno@nyumc.org [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Rosenkrantz, Andrew B., E-mail: Andrew.rosenkrantz@nyumc.org [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Kim, Danny C., E-mail: danny.kim@nyumc.org [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Mulholland, Thomas, E-mail: Thomas.mulholland@nyumc.org [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Kwon, Jane, E-mail: jane.kwon@nyumc.org [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Palfrey, Amy P., E-mail: amy.pastva10@stjohns.edu [St John' s University, Department of Psychology, 8000 Utopia Parkway, Jamaica-Queens, NY 11439 (United States); Ogedegbe, Olugbenga, E-mail: Olugbenga.Ogedegbe@nyumc.org [New York University School of Medicine, Clinical and Translational Science Institute, 227 E30th St, 8th Floor, New York, NY 10016 (United States)

    2014-07-15

    Objective: To compare performance of single-injection blood pool agent (gadofosveset trisodium, BPA) against dual-injection extracellular contrast (gadopentetate dimeglumine, ECA) for MRA/MRV in assessment of suspected vascular TOS. Materials and methods: Thirty-one patients referred for vascular TOS evaluation were assessed with BPA (n = 18) or ECA (n = 13) MRA/MRV in arm abduction and adduction. Images were retrospectively assessed for: image quality (1 = non-diagnostic, 5 = excellent), vessel contrast (1 = same signal as muscle, 4 = much brighter than muscle) and vascular pathology by two independent readers, with a separate experienced reader providing reference assessment of vascular pathology. Results: Median image quality was diagnostic or better (score ≥3) for ECA and BPA at all time points, with BPA image quality superior at abduction late (BPA 4.5, ECA 4, p = 0.042) and ECA image quality superior at adduction-early (BPA 4.5; ECA 4.0, p = 0.018). High qualitative vessel contrast (mean score ≥3) was observed at all time points with both BPA and ECA, with superior BPA vessel contrast at abduction-late (BPA 3.97 ± 0.12; ECA 3.73 ± 0.26, p = 0.007) and ECA at adduction-early (BPA 3.42 ± 0.52; ECA 3.96 ± 0.14, p < 0.001). Readers readily identified arterial and venous pathology with BPA, similar to ECA examinations. Conclusion: Single-injection BPA MRA/MRV for TOS evaluation demonstrated diagnostic image quality and high vessel contrast, similar to dual-injection ECA imaging, enabling identification of fixed and functional arterial and venous pathology.

  15. Influence of circulating antigen on blood pool activity of a radioiodinated monoclonal antibody

    International Nuclear Information System (INIS)

    Zalutsky, M.R.; Knapp, R.C.; Bast, R.C. Jr.

    1988-01-01

    Athymic mice with and without circulating CA 125 antigen were injected with 0.1-100 μg of 131 I-labeled OC 125 F(ab') 2 antibody fragment. Both the blood clearance of 131 I activity and the change in serum CA 125 were monitored over 24 h. Influence of CA 125 on blood pool activity could be avoided only at the 100 μg dose. In patient studies, circulating CA 125 levels decreased for the first 2 h after injection of OC 125 F(ab') 2 but generally returned to preinjection levels shortly thereafter. In vitro binding studies using the sera from patients injected with 131 I-labeled OC 125 F(ab') 2 suggest that circulating CA 125 could interfere with the tumor uptake of the labeled antibody. (author)

  16. Nitrogen Reserve Pools in Two Miscanthus × giganteus Genotypes under Contrasting N Managements

    Directory of Open Access Journals (Sweden)

    Ryan M. Dierking

    2017-09-01

    Full Text Available Nitrogen (N reserves in vegetative tissues contribute N to regrowth of Miscanthus × giganteus shoots in spring, but our understanding of how N fertilization and plant genotype affect this process is incomplete. Our specific objectives were to: (1 determine how N fertilizer management impacts accumulation of dry matter and N among aboveground and belowground tissues and organs; (2 understand how changes in N management and tissue N concentration influence seasonal fluctuations in concentrations of buffer-soluble proteins and amino acids in putative storage organs including rhizomes and roots; and (3 characterize genotypic variability and genotype × N interactions for N reserve accumulation and use among Miscanthus × giganteus genotypes. Established plots of the IL Clone and Nagara-sib population were fertilized with 0–0, 0–150, 75–75, 150–0, and 150–150 kg N ha-1 where the first numeral denotes the N rate applied in 2011 (Year 1 and the second number denotes the N rate applied in 2012 (Year 2. Rhizomes, roots, stembases, and shoots were sampled at 6-week intervals between March and August and then in November at dormancy. Concentrations of N, soluble protein and amino-N increased in all tissues with fertilizer N application. With the exception of rhizome amino-N, concentrations of these N pools in roots and rhizomes declined as plants resumed growth in spring and increased sharply between August and November as growth slowed. Losses in shoot and stembase N mass between August and November were similar to total N accumulation in roots and rhizomes during this interval. Compared to the unfertilized control, specific N managements enhanced growth of above- and belowground tissues. The IL Clone generally had greater biomass yield of all organs than the Nagara-sib; the exception being shoot biomass in November when extensive leaf senescence reduce yield of the IL Clone. High biomass yields were obtained with 75 kg N ha-1 applied annually

  17. Automatic measurements of local ventricular parameters using gated blood-pool emission tomography

    International Nuclear Information System (INIS)

    Mariano-Goulart, D.; Caderas de Kerleau, C.; Rossi, M.

    2005-01-01

    This paper describes a new method designed to improve the accuracy of the assessment of systolic and diastolic parameters from noisy regional time-activity curves, both for the right and the left ventricle. First, we explain how it is possible to derive local time-activity curves from segmented gated-blood pool tomographic acquisitions. The new method is based on the computation of a suitable deformation of a reference time-activity-curve. This paper describes how this reference curve is transformed to approximate the acquired data with a smooth, noise-free time-activity curve from which relevant clinical parameters can be derived. One may remind and illustrate the main results dealing with the validation studies of this new method achieved on simulated data and by comparison with multi-harmonic reconstructions. Last, some clinical examples are proposed to illustrate the potentials of this method. The deformable model used in this paper provides accurate assessment of systolic (time of end systole, amplitude, peak ejection rate) or diastolic parameters (peak filling rate) both for planar and tomographic gated blood pool studies. Further clinical studies are now necessary to compare the results of this model with those achieved with usual multi-harmonic fits, and to evaluate its interest in the assessment of rhythmic heart diseases or in the prognosis of heart failure. (author)

  18. Evaluation of factor analysis and other functional images in exercise gated blood-pool study

    International Nuclear Information System (INIS)

    Matsunari, Ichiro; Bunko, Hisashi; Nakajima, Kenichi; Taki, Junichi; Shiire, Yasushi; Hisada, Kinichi

    1990-01-01

    Factor analysis, a new method of functional imaging, has been applied to cardiovascular nuclear medicine. Because of the difficulty of its interpretation, it has not been popular as a method for detecting abnormal wall motion. The purpose of this study was to evaluate the usefulness of factor analysis in exercise gated blood-pool study in patients with ischemic heart disease. In our factor analysis, left ventricular region of interest (LVROI) was extracted to exclude the surrounding radioactivities. The new method was compared with the conventional factor analysis using whole region (whole ROI method), and the other functional images, i.e. stroke volume, ejection fraction and phase images. At first we tried 3-factor analysis of the LVROI method, which resulted in many uninterpretable factors. Whereas in 2-factor analysis no uninterpretable factors were extracted. In comparison with cine-mode display, the LVROI method with 2-factor analysis showed the best sensitivity (85%) and specificity (100%). In exercise gated blood-pool study, it became easier to detect abnormal wall motion by comparing the factor image at exercise with resting image. In conclusion, the 2-factor analysis using the LVROI method greatly improved the limitation of conventional factor analysis, and will be useful in detecting wall motion abnormality in patients with ischemic heart disase. (author)

  19. Hypertrophic cardiomyopathy. Evaluation by gated cardiac blood pool scanning. [/sup 99m/Tc tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Pohost, G.M.; Vignola, P.A.; McKusick, K.E.; Block, P.C.; Myers, G.S.; Walker, H.J.; Copen, D.L.; Dinsmore, T.E.

    1977-01-01

    The gated radionuclide cardiac blood pool scan (GCS) can be used to visualize the entire profile of the interventricular septum and left ventricular contraction. Twenty-two patients with hypertrophic cardiomyopathy, nine with valvular aortic stenosis and six normals, underwent echocardiography and GCS. All patients with hypertrophic cardiomyopathy had asymmetric septal hypertrophy and 14 of 22 had resting systolic anterior motion of the anterior leaflet of the mitral valve on echocardiogram. In eight patients with aortic stenosis with adequate echocardiograms, two had asymmetric septal hypertrophy and none had systolic anterior motion. The GCS demonstrated disproportionate upper septal thickening in 11; septal flattening in 16; cavity obliteration in 17; and a filling defect in the region of the left ventricular outflow tract in 16 of the 22 patients with hypertrophic cardiomyopathy. In the nine patients with valvular aortic stenosis, two demonstrated septal flattening, two cavity obliteration, two an outflow tract defect, and none disproportionate upper septal thickening. Both patients with cavity obliteration demonstrated asymmetric septal hypertrophy on echocardiogram. One normal control patient had septal flattening. Thus the gated cardiac blood pool scan provides an atraumatic technique for the evaluation of patients with hypertrophic cardiomyopathy which complements the echocardiogram.

  20. Chemical contrast observed in thermal images of blood-stained fabrics exposed to steam.

    Science.gov (United States)

    O'Brien, Wayne L; Boltin, Nicholas D; Lu, Zhenyu; Cassidy, Brianna M; Belliveau, Raymond G; Straub, Emory J; DeJong, Stephanie A; Morgan, Stephen L; Myrick, M L

    2015-09-21

    Thermal imaging is not ordinarily a good way to visualize chemical contrast. In recent work, however, we observed strong and reproducible images with chemical contrasts on blood-stained fabrics, especially on more hydrophobic fabrics like acrylic and polyester.

  1. Blood Pool Segmentation Results in Superior Virtual Cardiac Models than Myocardial Segmentation for 3D Printing.

    Science.gov (United States)

    Farooqi, Kanwal M; Lengua, Carlos Gonzalez; Weinberg, Alan D; Nielsen, James C; Sanz, Javier

    2016-08-01

    The method of cardiac magnetic resonance (CMR) three-dimensional (3D) image acquisition and post-processing which should be used to create optimal virtual models for 3D printing has not been studied systematically. Patients (n = 19) who had undergone CMR including both 3D balanced steady-state free precession (bSSFP) imaging and contrast-enhanced magnetic resonance angiography (MRA) were retrospectively identified. Post-processing for the creation of virtual 3D models involved using both myocardial (MS) and blood pool (BP) segmentation, resulting in four groups: Group 1-bSSFP/MS, Group 2-bSSFP/BP, Group 3-MRA/MS and Group 4-MRA/BP. The models created were assessed by two raters for overall quality (1-poor; 2-good; 3-excellent) and ability to identify predefined vessels (1-5: superior vena cava, inferior vena cava, main pulmonary artery, ascending aorta and at least one pulmonary vein). A total of 76 virtual models were created from 19 patient CMR datasets. The mean overall quality scores for Raters 1/2 were 1.63 ± 0.50/1.26 ± 0.45 for Group 1, 2.12 ± 0.50/2.26 ± 0.73 for Group 2, 1.74 ± 0.56/1.53 ± 0.61 for Group 3 and 2.26 ± 0.65/2.68 ± 0.48 for Group 4. The numbers of identified vessels for Raters 1/2 were 4.11 ± 1.32/4.05 ± 1.31 for Group 1, 4.90 ± 0.46/4.95 ± 0.23 for Group 2, 4.32 ± 1.00/4.47 ± 0.84 for Group 3 and 4.74 ± 0.56/4.63 ± 0.49 for Group 4. Models created using BP segmentation (Groups 2 and 4) received significantly higher ratings than those created using MS for both overall quality and number of vessels visualized (p 3D printers with good quality and accurate representation of the virtual 3D models. We recommend using BP segmentation with either MRA or bSSFP source datasets to create virtual 3D models for 3D printing. Desktop 3D printers can offer good quality printed models with accurate representation of anatomic detail.

  2. Detecting early cardiac dysfunction with radionuclide cardiac blood-pool imaging

    International Nuclear Information System (INIS)

    Wu Kegui; Chen Daguang; Lin Haoxue

    1992-01-01

    Cardiac function was measured by radionuclide cardiac blood-pool imaging in 15 normal persons, 19 cases of hypertension, 32 cases of coronary heart disease, 35 cases of coronary heart disease combined with hypertension and 44 cases of myocardial infarction. Significant differences have been found in indices of cardiac function between normal subjects and patients with coronary heart disease and coronary heart disease combined with hypertension, even though the patients were without any clinical sin of cardiac failure. Lowered regional EF and decreased ventricular was motion were found in 38.8% of patients, while 65.7%of patients revealed marked abnormality in MFR. The results indicate that latent cardiac dysfunction is common in patients with coronary heart disease. The earliest change is diastolic function abnormalities

  3. Patterns of ventricular dysfunction in patients receiving cardiotoxic chemotherapy as assessed with gated blood pool imaging

    International Nuclear Information System (INIS)

    Spies, S.M.; Parikh, S.R.; Spies, W.G.; Zimmer, A.M.; Silverstein, E.A.

    1989-01-01

    Clinical concern over significant cardiotoxicity of commonly employed chemotherapeutic regimens is a common indication for gated blood pool imaging. The authors have undertaken a review of 102 patients referred for such evaluation during a 14-month period. Ventricular ejection fractions, cine displays, and phase analysis were performed on each patient study. Approximately one-third of the cases showed significant abnormalities in wall motion or global ejection fraction. Many abnormal cases had isolated left ventricular findings, while fewer had isolated right ventricular findings. Left ventricular wall motion abnormalities were often focal. The patterns of ventricular dysfunction in patients receiving cardiotoxic chemotherapy are diverse, and awareness of the various possibilities is important for accurate clinical assessment of these patients

  4. Evaluation of Various Cardiac Indices and ROC Analysis in Coronary Artery Disease Employing Resting ECG Gated Blood Pool Scan

    International Nuclear Information System (INIS)

    Choi, Chang Woon; Lee, Dong Soo; Kim, Sang Eun; Chung, June Key; Lee, Myung Chul; Park, Young Bae; Seo, Jung Don; Lee, Young Woo; Koh, Chang Soon

    1992-01-01

    Gated blood pool scan is frequently used for evaluating the change in cardiac function in various cardiac diseases. But resting gated blood pool scan using only LVEF as a cardiac index has been consistently shown to have a low sensitivity, which is about 50%, in detecting coronary artery disease. So it is recommended to compare exercise gated blood pool scan to resting gated blood pool scan. Exercise tests, however, are not always possible, especially in patients with musculoskeletal diseases, recent myocardial infarction and in elderly persons. We studied the usefulness of resting gated blood pool scan using multiple indices in evaluating the patients with coronary artery disease. Studied cases were 185 patients with coronary artery disease (angina pectoris 31, myocardial infarction 154) and 25 normals with low likelihood of coronary artery disease. We used 99m Tc-labeled RBC, 740 MBq labeled by in vivo method. The data were evaluated by Micro DELTA computer program. The results were as following: 1) The ejection rates (PER, AER) and filling rates (PFR, AFR) were different in normals and patients with angina pectoris or myocardial infarction. 2) Mean phase angle, ejection rates and filling rates could separate normals from coronary artery disease patients with normal LVEF. 3) Regional ejection fraction was decreased at the site of the infarct in patients with myocardial infarction. 4) Peak filling rate was the most detectable index in evaluation of cardiac function in patients with coronary artery disease. 5) The threshold at 1.5 standard deviation of normal range was considered as the most reliable cut-off value from ROC analysis. These data suggest that the resting gated blood pool scan has an important role in the evaluation of cardiac functional changes using various cardiac indices in patients with coronary artery disease.

  5. The values of myocardial tomography imaging and gated cardiac blood pool imaging in detecting left ventricular aneurysm

    International Nuclear Information System (INIS)

    Zhu Mei; Pan Zhongyun; Li Jinhui

    1992-01-01

    The sensitivity and specificity of myocardial tomography imaging and gated cardiac blood-pool imaging in detecting LVA were studied in 36 normal subjects and 68 patients with myocardial infarction. The sensitivities of exercise and rest myocardial imaging in detecting LVA were 85% and 77.3% respectively. The specificity of both is 95.5%. The sensitivity of cinema display, phase analysis and left ventricular phase shift in evaluating LVA were 86.7%, 86.7%, 100% respectively. Their specificity were all 100%. It is concluded that blood pool imaging is of choice for the diagnosis of LVA, and that myocardial imaging could also demonstrate LVA during diagnosing myocardial infarction

  6. Identification of cytoskeletal elements enclosing the ATP pools that fuel human red blood cell membrane cation pumps.

    Science.gov (United States)

    Chu, Haiyan; Puchulu-Campanella, Estela; Galan, Jacob A; Tao, W Andy; Low, Philip S; Hoffman, Joseph F

    2012-07-31

    The type of metabolic compartmentalization that occurs in red blood cells differs from the types that exist in most eukaryotic cells, such as intracellular organelles. In red blood cells (ghosts), ATP is sequestered within the cytoskeletal-membrane complex. These pools of ATP are known to directly fuel both the Na(+)/K(+) and Ca(2+) pumps. ATP can be entrapped within these pools either by incubation with bulk ATP or by operation of the phosphoglycerate kinase and pyruvate kinase reactions to enzymatically generate ATP. When the pool is filled with nascent ATP, metabolic labeling of the Na(+)/K(+) or Ca(2+) pump phosphoproteins (E(Na)-P and E(Ca)-P, respectively) from bulk [γ-(32)P]-ATP is prevented until the pool is emptied by various means. Importantly, the pool also can be filled with the fluorescent ATP analog trinitrophenol ATP, as well as with a photoactivatable ATP analog, 8-azido-ATP (N(3)-ATP). Using the fluorescent ATP, we show that ATP accumulates and then disappears from the membrane as the ATP pools are filled and subsequently emptied, respectively. By loading N(3)-ATP into the membrane pool, we demonstrate that membrane proteins that contribute to the pool's architecture can be photolabeled. With the aid of an antibody to N(3)-ATP, we identify these labeled proteins by immunoblotting and characterize their derived peptides by mass spectrometry. These analyses show that the specific peptides that corral the entrapped ATP derive from sequences within β-spectrin, ankyrin, band 3, and GAPDH.

  7. Relaxivity of blood pool contrast agent depends on the host tissue as suggested by semianalytical simulations

    DEFF Research Database (Denmark)

    Kjølby, Birgitte Fuglsang; Østergaard, Leif; Kiselev, Valerij

    simulations and analytical theory to describe this effect and created a program for fast, realistic simulation of transverse relaxation in perfused tissues. We performed simulations for gray matter and white matter. The predicted values of the relaxivity are in agreement with the relaxivity found in animal...

  8. Frequency characteristics of temporal filters used in ECG gated blood pool scintigraphy

    International Nuclear Information System (INIS)

    Futamura, Yoshihiro; Furuta, Toshiya; Shimokata, Tatsuyuki; Sakakura, Kazuyoshi; Sakurai, Junichi; Senda, Minoru

    1984-01-01

    The purpose of this study is to assess the frequency characteristics of several temporal filters used in ECG gated blood pool scintigraphy and to apply the temporal filters to the image processing. The three following filters were analyzed; (1) X'sub(n) = 1/4.Xsub(n-1) + 1/2.Xsub(n) + 1/4.Xsub(n+1) (2) X'sub(n) = 1/10.Xsub(n-2) + 1/5.Xsub(n-1) + 2/5.Xsub(n) + 1/5.Xsub(n+1) + 1/10.Xsub(n+2) (3) f(x) = a 0 + Σsub(m=1)sup(j)asub(m)sin(mx+αsub(m)) where X'n is the averaged pixel count of the n-th frame and Xn is a pixel count of n-th frame. The last equation is Fourier transformation. Sinusoidal waves were generated in the digital computer in order to assess the frequency characteristics of the filters. The sinusoidal waves were sampled by 3,200 Hz and one frame was created by one hundred sampling points. One cycle was composed of thirty two frames as usually used in the gated blood pool study. At the discrete sampling of the sinusoidal waves, the amplitude ratio of input to output signal was almost flat up to 3 Hz. But the ratio oscillated above 3 Hz. This oscillation was created by the discrete sampling and was regarded as the newly produced noise. By using the first filter, the amplitude ratio of input to output was almost flat up to 2 Hz. But above 3 Hz, the amplitude ratio was less than 1 and the cut-off frequency was 7 Hz. By using the second filter the amplitude ratio was already less than 1 at 1 Hz and the cut-off frequency was 5 Hz. By the third filter, the amplitude ratio was almost flat up to 5 Hz and then gradually decreased above 5 Hz. All filters damped the noises created by the discrete sampling of the sinusoidal waves. The third filter had the excellent frequency characteristics. The reasons were (1) the distortion of the output wave was small because of the flat amplitude ratio, and (2) the noises were eliminated by filtering with an abrupt high frequency cut-off. (J.P.N.)

  9. Frequency characteristics of temporal filters used in ECG gated blood pool scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Futamura, Yoshihiro; Furuta, Toshiya; Shimokata, Tatsuyuki; Sakakura, Kazuyoshi; Sakurai, Junichi; Senda, Minoru (Meitetsu Hospital, Nagoya (Japan))

    1984-07-01

    The purpose of this study is to assess the frequency characteristics of several temporal filters used in ECG gated blood pool scintigraphy and to apply the temporal filters to the image processing. The three following filters were analyzed; (1) X'sub(n) = 1/4.Xsub(n-1) + 1/2.Xsub(n) + 1/4.Xsub(n+1) (2) X'sub(n) = 1/10.Xsub(n-2) + 1/5.Xsub(n-1) + 2/5.Xsub(n) + 1/5.Xsub(n+1) + 1/10.Xsub(n+2) (3) f(x) = a/sub 0/ + ..sigma..sub(m=1)sup(j)asub(m)sin(mx+..cap alpha..sub(m)) where X'n is the averaged pixel count of the n-th frame and Xn is a pixel count of n-th frame. The last equation is Fourier transformation. Sinusoidal waves were generated in the digital computer in order to assess the frequency characteristics of the filters. The sinusoidal waves were sampled by 3,200 Hz and one frame was created by one hundred sampling points. One cycle was composed of thirty-two frames as usually used in the gated blood pool study. At the discrete sampling of the sinusoidal waves, the amplitude ratio of input to output signal was almost flat up to 3 Hz. But the ratio oscillated above 3 Hz. This oscillation was created by the discrete sampling and was regarded as the newly produced noise. By using the first filter, the amplitude ratio of input to output was almost flat up to 2 Hz. But above 3 Hz, the amplitude ratio was less than 1 and the cut-off frequency was 7 Hz. By using the second filter the amplitude ratio was already less than 1 at 1 Hz and the cut-off frequency was 5 Hz. By the third filter, the amplitude ratio was almost flat up to 5 Hz and then gradually decreased above 5 Hz. All filters damped the noises created by the discrete sampling of the sinusoidal waves. The third filter had the excellent frequency characteristics. The reasons were (1) the distortion of the output wave was small because of the flat amplitude ratio, and (2) the noises were eliminated by filtering with an abrupt high frequency cut-off.

  10. Dynamic arrythmia filtration for gated blood pool imaging: Validation against list - Mode technique

    International Nuclear Information System (INIS)

    Juni, J.E.; Wallis, J.; Rocchini, A.; Wu-Connolly, L.

    1985-01-01

    Normal resting heart rate variation distort the diastolic portions of time-activity curves (TACs) generated from gated blood pool (GBP) images. This alters calculated measures of diastolic function e.g. peak filling rate (PFR). The authors compared diastolic filling parameters obtained by two methods of arrythmia removal, list-mode (LM) acquisition and a new approach, dynamic arrythima filtration (DAF). LM acquisition techniques reject beats of unusual cycle length, thus reducing the TAC distortions caused by heart rate variation but is time consuming and requires large amounts of disk storage. In DAF systems data is evaluated for cycle length in real-time and accepted or rejected immediately according to preset, operator determined cycle-length criteria, thus eliminating the need for post-processing of data and for large mass data storage. The authors prospectively determined EF, time to end-systole (TES), PFR, ad TPFR on 25 GBP patients. Camera and ECG data were sent simultaneously to 2 computers. One acquired data via LM and the other by DAF. Fluctuations in heart rate during GBP acquisition may cause errors in calculation of filling parameters. Both LM and DAF remove cycles of unusual length. DAF is less time consuming and technically demanding than LM and provides results which correlate closely with those obtained by LM

  11. Pulmonary capillary wedge pressure, as inferred from lung areas in gated blood-pool scintigrams: concise communication

    International Nuclear Information System (INIS)

    Urbina, A.; Okada, R.D.; Palacios, I.; Osbakken, M.; Strauss, H.W.

    1981-01-01

    To determine whether the apex-to-base distribution of pulmonary blood volume, as obtained from gated cardiac blood-pool scans, could be used as a noninvasive method to estimate mean pulmonary capillary wedge pressure (PCWP), gated blood-pool scans were analyzed in 77 patients who also had PCWP measurements at cardiac catheterization. Ten of these patients had gated cardiac blood-pool scans and PCWP measurements both at rest and during exercise. The apex-to-base distribution of pulmonary blood volume was determined from the end-systolic frame of the left anterior oblique view by placing equal-sized regions of interest over the apex and base of the right lung. The ratio of apex counts over base counts (A/B ratio) was considered abnormal if greater than unity. The mean A/B ratio was 1.15 +/- 0.27 (1 s.d.) for the 32 studies associated with an abnormal mean PCWP (greater than 12 mm Hg). The mean A/B ratio was 0.85 +/- 0.23 for the 55 studies associated with a normal mean PCWP (p less than 0.01 comparing normal group with abnormal). The sensitivity of the A/B ratio for a mean PCWP greater than 12 mm Hg was 81%R (26/32). The specificity of the A/B ratio for a mean PCWP greater than or equal to 12 mm Hg was 89% (49/55). Thus, noninvasive determination of the pulmonary apex-to-base ratio from gated cardiac blood-pool scans appears to differentiate subjects with normal and abnormal mean pulmonary capillary wedge pressures

  12. Hepatic blood perfusion estimated by dynamic contrast-enhanced computed tomography in pigs

    DEFF Research Database (Denmark)

    Winterdahl, Michael; Sørensen, Michael; Keiding, Inger Susanne

    2012-01-01

    The aim of this study was to determine whether dynamic contrast-enhanced computed tomography (DCE-CT) and the slope method can provide absolute measures of hepatic blood perfusion from the hepatic artery (HA) and portal vein (PV) at experimentally varied blood flow rates....

  13. Laser speckle contrast imaging for monitoring changes in microvascular blood flow

    DEFF Research Database (Denmark)

    Ambrus, Rikard; Strandby, Rune B.; Svendsen, Lars Bo

    2016-01-01

    BACKGROUND/AIMS: Microvascular blood flow is essential for healing and predicts surgical outcome. The aim of the current study was to investigate the relation between fluxes measured with the laser speckle contrast imaging (LSCI) technique and changes in absolute blood flow. In addition, we studied...

  14. Prediction of cardiac sympathetic nerve activity and cardiac functional outcome after treatment in patients with dilated cardiomyopathy. Examination using dobutamine gated blood pool scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Kasama, Shu; Toyama, Takuji; Iwasaki, Tsutomu; Suzuki, Tadashi [Gunma Univ., Maebashi (Japan). School of Medicine; Hoshizaki, Hiroshi; Oshima, Shigeru; Taniguchi, Koichi; Nagai, Ryozo

    2000-07-01

    This study evaluated whether dobutamine gated blood pool scintigraphy can predict improvement of cardiac sympathetic nerve activity and cardiac function. Sixteen patients (10 men and 6 women, mean age 59{+-}13 years) with dilated cardiomyopathy underwent dobutamine gated blood pool scintigraphy to measure left ventricular ejection fraction (LVEF) using tracer at 0, 5, 10 and 15 {mu}g/kg/min before treatment. Patients were divided into good responders (LVEF increase {>=}15%) 8 patients (GR Group) and poor responders (LVEF increase <15%) 8 patients (PR Group) after treatment with {beta}-blocker or amiodarone with a background treatment of digitalis, diuretics and angiotensin converting enzyme inhibitor. I-123 metaiodobenzylguanidine (MIBG) imaging to evaluate cardiac sympathetic nerve activity and echocardiography were performed before and at one year after treatment. MIBG imaging was obtained 4 hours after tracer injection, and the heart/mediastinum count ratio (H/M ratio) calculated from the anterior planar image and the total defect score (TDS) from the single photon emission computed tomography image. LVEF and left ventricular endo-diastolic dimension (LVDd) were measured by echocardiography and New York Heart Association (NYHA) functional class was evaluated. The GR Group showed TDS decreased from 28{+-}6 to 17{+-}12 (p<0.05), H/M ratio increased from 1.79{+-}0.26 to 2.07{+-}0.32 (p<0.05), LVEF increased from 29{+-}8% to 48{+-}10% (p<0.01), and LVDd decreased from 65{+-}4 mm to 58{+-}5 mm (p<0.05). In contrast, the PR group showed no significant changes in TDS. H/M ratio, LVEF and LVDd. NYHA functional class improved in both groups. The improvement was better in the GR Group than in the PR group. Dobutamine gated blood pool scintigraphy is useful to predict the improvement of the cardiac sympathetic nerve activity and cardiac function, and symptoms after treatment in patients with dilated cardiomyopathy. (author)

  15. 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....

  16. Evaluation of latent cardiac disease in diabetic patients with Tl-201 exercise myocardial scintigram and blood pool scintigram

    International Nuclear Information System (INIS)

    Miyashita, Takeo; Kasai, Ryutaro; Ikebe, Nobuhiko; Nagai, Yoshikazu; Yamasawa, Ikuhiro; Ibukiyama, Chiharu; Notoya, Yoko

    1990-01-01

    To find latent heart disease in diabetic patients, 142 diabetic patients were divided into 4 groups: (1) no hypertension and normal ECG (DM group); (2) hypertension recognized clinically (HT group); (3) myocardial damage on ECG (MD group); (4) group associated with the previous 2 (HT+MD group). In all groups Tl-201 exercise myocardial scintigrams and blood pool scintigrams were taken for comparative analysis. Positive rates of SPECT were 27.7% (23/83) in the DM group, 30.0% (9/30) in the HT group, 50.0% (6/12) in the MD group, and 70.6% (12/17) in the HT+MD group. The rate in the HT+MD group was significantly higher than in that of the DM and HT groups (p<0.001, p<0.01). Blood pool scintigrams revealed that in the HT+MD group, as compared with the normal control group, both 1/3 FF and PFR were significantly depressed, in addition to significant TPF prolongation in the former (p<0.001, p<0.05, p<0.05). These findings suggest that in diabetic patients hypertension and myocardial damage would lead to a high incidence of abnormality in SPECT and left ventricular rapid filling dysfunction. This indicate a high incidence of latent cardiac disease which can be recognized in diabetic patients by stress myocardial and blood pool scintigrams. (author)

  17. Assessment of cardiac blood pool imaging in patients with left ventricular outflow tract stenosis

    International Nuclear Information System (INIS)

    Nakamura, Yutaka; Ono, Yasuo; Kohata, Tohru; Tsubata, Shinichi; Kamiya, Tetsuroh.

    1993-01-01

    We performed cardiac blood pool imagings with Tc-99m at rest and during supine ergometer exercise to evaluate left ventricular performance in 14 patients with left ventricular outflow tract stenosis. All catheterized patients were divided into two subgroups: 8 patients with peak systolic left ventricular to descending aortic pressure gradients of less than 50 mmHg (LPG group) and 6 patients with peak systolic gradients of more than 50 mmHg (HPG group). Control group included 10 patients without stenotic coronary lesions after Kawasaki disease. Left ventricular ejection fraction (LVEF) was obtained as systolic index; both filling fraction during the first third of diastole (1/3FF) and mean filling rate during the first third of diastole (1/3FR mean) were obtained as diastolic indices. None of the patients had abnormal findings on 201 Tl imaging. LVEF at rest in HPG group was significantly higher than those in control group, but LVEF in HPG group did not increase after exercise. It increased significantly in control group and LPG group. 1/3 FF in HPG group was significantly lower not only at rest but also during exercise. 1/3 FR mean at rest was not different significantly among the 3 groups. However, 1/3FR mean during exercise in LPG group was significantly lower; and 1/3 FR mean during exercise was significantly lower in HPG group than LPG group. The ratio of left ventricular muscular mass to left ventricular end-diastolic volume (M/V) calculated from left ventricular cineangiograms was different significantly among the 3 groups. The M/V ratio showed a correlation with LVEF and 1/3 FF both at rest and during exercise. These results would indicate that systolic function was impaired on exercise in severe left ventricular outflow tract stenosis and diastolic function was impaired on exercise in mild and severe left ventricular outflow tract stenosis. This may correlate with left ventricular hypertrophy and interaction of systolic function. (author)

  18. Assessment of cardiac blood pool imaging in patients with left ventricular outflow tract stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Yutaka (Tajimi City Hospital, Gifu (Japan)); Ono, Yasuo; Kohata, Tohru; Tsubata, Shinichi; Kamiya, Tetsuroh

    1993-09-01

    We performed cardiac blood pool imagings with Tc-99m at rest and during supine ergometer exercise to evaluate left ventricular performance in 14 patients with left ventricular outflow tract stenosis. All catheterized patients were divided into two subgroups: 8 patients with peak systolic left ventricular to descending aortic pressure gradients of less than 50 mmHg (LPG group) and 6 patients with peak systolic gradients of more than 50 mmHg (HPG group). Control group included 10 patients without stenotic coronary lesions after Kawasaki disease. Left ventricular ejection fraction (LVEF) was obtained as systolic index; both filling fraction during the first third of diastole (1/3FF) and mean filling rate during the first third of diastole (1/3FR mean) were obtained as diastolic indices. None of the patients had abnormal findings on [sup 201]Tl imaging. LVEF at rest in HPG group was significantly higher than those in control group, but LVEF in HPG group did not increase after exercise. It increased significantly in control group and LPG group. 1/3 FF in HPG group was significantly lower not only at rest but also during exercise. 1/3 FR mean at rest was not different significantly among the 3 groups. However, 1/3FR mean during exercise in LPG group was significantly lower; and 1/3 FR mean during exercise was significantly lower in HPG group than LPG group. The ratio of left ventricular muscular mass to left ventricular end-diastolic volume (M/V) calculated from left ventricular cineangiograms was different significantly among the 3 groups. The M/V ratio showed a correlation with LVEF and 1/3 FF both at rest and during exercise. These results would indicate that systolic function was impaired on exercise in severe left ventricular outflow tract stenosis and diastolic function was impaired on exercise in mild and severe left ventricular outflow tract stenosis. This may correlate with left ventricular hypertrophy and interaction of systolic function. (author).

  19. Trial on MR portal blood flow measurement with phase contrast technique

    International Nuclear Information System (INIS)

    Tsunoda, Masatoshi; Kimoto, Shin; Togami, Izumi

    1991-01-01

    Portal blood flow measurement is considered to be important for the analysis of hemodynamics in various liver diseases. The Doppler ultrasound method has been used extensively during the past several years for measuring portal blood flow, as a non-invasive method. However, the Doppler ultrasound technique do not allow the portal blood flow to be measured in cases of obesity, with much intestinal gas, and so on. In this study, we attempted to measure the blood flow in the main trunk of portal vein as an application of MR phase contrast technique to the abdominal region. In the flow phantom study, the flow volumes and the velocities measured by phase contrast technique showed a close correlation with those measured by electromagnetic flowmeter. In the clinical study with 10 healthy volunteers, various values of portal blood flow were obtained. Mean portal blood flow could be measured within the measuring time (about 8 minutes) under natural breathing conditions. Phase contrast technique is considered to be useful for the non-invasive measurement of portal blood flow. (author)

  20. Effects of Contrast Media on Blood Rheology: Comparison in Humans, Pigs, and Sheep

    International Nuclear Information System (INIS)

    Laurent, Alexandre; Durussel, Jean Jacques; Dufaux, Jacques; Penhouet, Laurence; Bailly, Anne Laure; Bonneau, Michel; Merland, Jean Jacques

    1999-01-01

    Purpose: To compare whole blood viscosity and erythrocyte aggregation in humans, pigs, and sheep, before and after adding water-soluble iodinated contrast medium (CM). Methods: Two CMs were studied: iopromide (nonionic) and ioxaglate (ionic). The blood-CM viscosity was measured with a Couette viscometer. Erythrocyte aggregation was measured with an erythroaggregometer. Results: The blood-CM viscosity was increased up to +20% (relative to pure blood) with a CM concentration of 0%-10%. At CM concentrations from 10% to 50%, the viscosity decreased. The disaggregation shear stress was increased (relative to pure blood) at low CM concentration (0%-10%). When the CM concentration increased from 10% to 20%, the disaggregation shear stress was decreased, except with the pig blood-ioxaglate mixture. Conclusion: At low CM concentration the blood viscosity was increased in pig, sheep, and humans and the disaggregation shear stress was increased in pig and humans. The aggregation of sheep blood was too low to be detected by the erythroaggregometer. This rise can be explained by the formation of poorly deformable echinocytes. At higher CM concentration, the viscosity and the disaggregation shear stress decreased in relation to the blood dilution. We conclude that pig blood and sheep blood can both be used to study the effect of CM injection on blood viscosity. Nevertheless, the rheologic behavior of pig blood in terms of erythrocyte aggregation is closer to that of human blood than is sheep blood when mixed with CM. Pigs could thus be more suitable than sheep for in vivo studies of CM miscibility with blood during selective cannulation procedures

  1. Susceptibility contrast imaging of CO2-induced changes in the blood volume of the human brain

    DEFF Research Database (Denmark)

    Rostrup, Egill; Larsson, H B; Toft, P B

    1996-01-01

    PURPOSE: To investigate changes in the regional cerebral blood volume (rCBV) in human subjects during rest and hypercapnia by MR imaging, and to compare the results from contrast-enhanced and noncontrast-enhanced susceptibility-weighted imaging. MATERIAL AND METHODS: Five healthy volunteers (aged...

  2. Heat as a contrast agent to enhance thermal imaging of blood vessels

    Science.gov (United States)

    Case, Jason R.; Trammell, Susan R.; Young, Madison A.; Israel, Uriah; Crown, Michael X.

    2013-03-01

    In this study we test the feasibility of using low-cost LEDs to selectivity heat blood for enhanced thermal imaging of vascular structures. Applications of this new imaging technique include mapping blood vessels during surgeries such as tumor removal and vascular repair. In addition, this technique could potentially be used to determine the location of increased vascular density, and thus breast cancer tumors. Porcine blood, skeletal muscle, skin and fat were illuminated with LEDs that emit at 405 nm and 530 nm (near the blood absorption peaks) and the increase in temperature as a function of time was recorded using a thermal camera. In the studies with the 530 nm LED, blood heated more than other tissue types and the heating rate for the blood was significantly faster than other tissues. Illumination of blood with the 530 nm LED at low powers (tissue irradiance tissue. Illumination with the 405 nm LED produced large temperature changes (up to 15°C) at low LED powers (tissue irradiance muscle tissue was dependent on the skeletal muscle type, but most samples showed heating comparable to or larger than blood. This LED was not effective at selectively heating blood relative to the other tissue types. The results of the preliminary studies suggest that the best contrast can be achieved with pulsed 530 nm LED illumination and an image analysis method that highlights rapid changes in temperature.

  3. [Single-donor (apheresis) platelets and pooled whole-blood-derived platelets--significance and assessment of both blood products].

    Science.gov (United States)

    Hitzler, Walter E

    2014-01-01

    The transfusion efficacy of ATK, which contain fully functional platelets, is beyond all doubt. The equivalence of ATK and PTK has been subject of many studies. Some of those studies show the superiority of ATK's, while others do not, but there have been no studies that demonstrated a superiority of PTK's. The superiority of platelets stored in plasma and in third generation additive solution was demonstrated in clinical studies; therefore, it cannot be said that all the platelet concentrates on the German market are equivalent in efficacy. Of decisive importance, above all, is the risk of transfusion-transmitted infections with known pathogens, or those not yet discovered. This risk is different for ATK compared to PTK. Taking this difference in risk and the difference in donor exposure of transfused patients into account, it can definitely be said that ATK and PTK are not equivalent. In 2012, the Robert-Koch-Institute (RKI) published a mathematical risk model for different platelet concentrates and assessed the risk of transmitting known pathogens such as HIV, HCV, and HBV. The risk was higher for PTK compared to ATK. The relative risks for PTK derived from 4BCs were 2.2 (95%--CI: 2.1-2.4) for HIV, 2.7 (95%--CI: 2.5-3.0) for HCV, and 2.2 (95%--CI: 2.8-3.7) for HBV. At the present time, these are the relative risks of transfusion-transmitted infections with the traditional pathogens for PTK compared to ATK. In addition to the RKI assessed risks, there is the theoretical risk of a new, unknown agent, transmitted through blood exposure. The magnitude of this risk is hardly predictable for PTK. The experience gathered so far, especially in the last three decades, with the emergence of HIV, prions, and West Nil virus, shows that the biological nature of a next transfusion-transmissible infectious agent cannot be predictable. This agent, if we think at a conventional sexually transmissible agent with nucleic acid and long latent period, would spread first in areas with

  4. Radionuclide-determined change in pulmonary blood volume with exercise. Improved sensitivity of multigated blood-pool scanning in detecting coronary-artery disease

    International Nuclear Information System (INIS)

    Okada, R.D.; Pohost, G.M.; Kirshenbaum, H.D.; Kushner, F.G.; Boucher, C.A.; Block, P.C.; Strauss, H.W.

    1979-01-01

    To assess the clinical usefulness of radionuclide-determined changes in pulmonary blood volume in patients with or without substantial coronary-artery disease, we determined the ratio of pulmonary blood volume at rest as compared with that during exercise. We used multigated blood-pool images obtained at rest and during supine exercise to determine the blood-volume ratio in patients subsequently undergoing coronary arteriography for evaluation of chest pain. Exercise tests were performed by use of a submaximal-workload protocol, although all tests were limited according to each patient's symptoms. The mean exercise/rest pulmonary-blood-volume ratios were lower for persons without coronary-artery disease (0.94 +- 0.06 [S.D.], 10 patients) and for those with disease confined to the right coronary artery (0.99 +- 0.12, five patients), as compared with all others with coronary-artery disease (1.14 +- 0.15, 37 patients) (P < 0.01). A pulmonary-blood-volume ratio equal to or greater than 1.06 had a sensitivity of 79%. Patients with coronary-artery disease not confined to the right coronary artery usually show an increase in pulmonary blood volume during supine exercise. No such change occurs in persons without coronary-artery disease

  5. Subharmonic response from ultrasound contrast microbubbles for noninvasive blood pressure estimation

    Science.gov (United States)

    Katiyar, Amit; Sarkar, Kausik; Forsberg, Flemming

    2010-11-01

    Estimation of local organ-level blood pressure can help in diagnosing and monitoring heart and vascular diseases. Subharmonic signals from ultrasound contrast microbubbles have been proposed as a noninvasive alternative to the current practice of using manometer-tipped catheter. Approximately 10dB linear decrease in subharmonic component with 25 kPa pressure increase (typical blood pressure variation) has been reported for several contrast microbubbles. Here we report a theoretical investigation of the underlying phenomenon. We first study the well established model of a free microbubble to show that reduction of subharmonic with ambient pressure increase occurs only below a certain excitation frequency. Above this critical frequency, subharmonic signal increases with ambient pressure. Furthermore, where it decreases with ambient pressure, the relationship is linear only above certain excitation pressure. The dependence of the critical frequency on bubble radius and possibly bubble size distribution is discussed. We also report similar behavior for several models for encapsulated contrast microbubbles.

  6. Half a decade of mini-pool nucleic acid testing: Cost-effective way for improving blood safety in India

    Directory of Open Access Journals (Sweden)

    Shivaram Chandrashekar

    2014-01-01

    Full Text Available Background and Objectives: It is well established that Nucleic acid testing (NAT reduces window phase of transfusion transmissible infections (TTI and helps improve blood safety. NAT testing can be done individually or in pools. The objectives of this study were to determine the utility, feasibility and cost effectiveness of an in-house minipool-NAT(MP-NAT. Materials and Methods: Blood donors were screened by history, tested by ELISA and sero-negative samples were subjected to an in-house NAT by using reverse transcriptase-polymerase chain reaction (RT-PCR. Testing was done in mini-pools of size eight (8. Positive pools were repeated with individual samples. Results: During the study period of Oct 2005-Sept 2010 (5 years all blood donors (n=53729 were screened by ELISA. Of which 469 (0.87% were positive for HIV-1, HBV or HCV. Sero-negative samples (n=53260 were screened by in-house MP-NAT. HIV-NAT yield was 1/53260 (n=1 and HBV NAT yield (n=2 was 1/26630. Conclusion: NAT yield was lower than other India studies possibly due to the lower sero-reactivity amongst our donors. Nevertheless it intercepted 9 lives including the components prepared. The in-house assay met our objective of improving blood safety at nominal cost and showed that it is feasible to set up small molecular biology units in medium-large sized blood banks and deliver blood within 24-48 hours. The utility of NAT (NAT yield will vary based on the donor population, the type of serological test used, the nature of kit employed and the sensitivity of NAT test used. The limitations of our in-house MP-NAT consisted of stringent sample preparation requirements, with labor and time involved. The benefits of our MP-NAT were that it acted as a second level of check for ELISA tests, was relatively inexpensive compared to ID-NAT and did not need sophisticated equipment.

  7. 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.

  8. Jugular venous pooling during lowering of the head affects blood pressure of the anesthetized giraffe

    DEFF Research Database (Denmark)

    Brøndum, E.; Hasenkam, John Michael; Secher, Niels H.

    2009-01-01

    How blood flow and pressure to the giraffe's brain are regulated when drinking remains debated. We measured simultaneous blood flow, pressure, and cross-sectional area in the carotid artery and jugular vein of five anesthetized and spontaneously breathing giraffes. The giraffes were suspended...... unchanged. Cardiac output was reduced by 30%, CVP decreased to -1 +/- 2 mmHg (P blood in the veins. When the head was raised, the jugular...... veins collapsed and blood was returned to the central circulation, and CVP and cardiac output were restored. The results demonstrate that in the upright-positioned, anesthetized giraffe cerebral blood flow is governed by arterial pressure without support of a siphon mechanism and that when the head...

  9. Contrast sensitivity, ocular blood flow and their potential role in assessing ischaemic retinal disease.

    Science.gov (United States)

    Shoshani, Yochai Z; Harris, Alon; Rusia, Deepam; Spaeth, George L; Siesky, Brent; Pollack, Ayala; Wirostko, Barbara

    2011-08-01

    To examine the definition, evaluation methodology, association to ocular blood flow and potential clinical value of contrast sensitivity (CS) testing in clinical and research settings, focusing in patients with ischemic retinal disease. A review of the medical literature focusing on CS and ocular blood flow in ischemic retinal disease. CS may be more sensitive than other methods at detecting subtle defects or improvements in primarily central retinal ganglion cell function early on in a disease process. CS testing attempts to provide spatial detection differences which are not directly assessed with standard visual acuity chart testing. Analyzing all studies that have assessed both CS change and ocular blood flow, it is apparent that both choroidal circulation and retinal circulation may have an important role in influencing CS. The concept that CS is directly influenced by ocular blood flow is supported by reviewing the studies involving both. Although the studies in the literature have not established a direct cause and effect relationship per se, the literature review makes it logical to assume that changes in retinal and choroidal blood flow influence CS. This raises the possibility that a subjective visual characteristic, specifically CS, may be able to be evaluated more objectively by studying blood flow. It appears appropriate to study the relationship between blood flow and CS more extensively to develop improved ways of measuring various aspects of blood flow to the eye and to best quantify early changes in visual function. © 2011 The Authors. Acta Ophthalmologica © 2011 Acta Ophthalmologica Scandinavica Foundation.

  10. Laser speckle contrast imaging of skin blood perfusion responses induced by laser coagulation

    Energy Technology Data Exchange (ETDEWEB)

    Ogami, M; Kulkarni, R; Wang, H; Reif, R; Wang, R K [University of Washington, Department of Bioengineering, Seattle, Washington 98195 (United States)

    2014-08-31

    We report application of laser speckle contrast imaging (LSCI), i.e., a fast imaging technique utilising backscattered light to distinguish such moving objects as red blood cells from such stationary objects as surrounding tissue, to localise skin injury. This imaging technique provides detailed information about the acute perfusion response after a blood vessel is occluded. In this study, a mouse ear model is used and pulsed laser coagulation serves as the method of occlusion. We have found that the downstream blood vessels lacked blood flow due to occlusion at the target site immediately after injury. Relative flow changes in nearby collaterals and anastomotic vessels have been approximated based on differences in intensity in the nearby collaterals and anastomoses. We have also estimated the density of the affected downstream vessels. Laser speckle contrast imaging is shown to be used for highresolution and fast-speed imaging for the skin microvasculature. It also allows direct visualisation of the blood perfusion response to injury, which may provide novel insights to the field of cutaneous wound healing. (laser biophotonics)

  11. Jugular venous pooling during lowering of the head affects blood pressure of the anesthetized giraffe.

    Science.gov (United States)

    Brøndum, E; Hasenkam, J M; Secher, N H; Bertelsen, M F; Grøndahl, C; Petersen, K K; Buhl, R; Aalkjaer, C; Baandrup, U; Nygaard, H; Smerup, M; Stegmann, F; Sloth, E; Ostergaard, K H; Nissen, P; Runge, M; Pitsillides, K; Wang, T

    2009-10-01

    How blood flow and pressure to the giraffe's brain are regulated when drinking remains debated. We measured simultaneous blood flow, pressure, and cross-sectional area in the carotid artery and jugular vein of five anesthetized and spontaneously breathing giraffes. The giraffes were suspended in the upright position so that we could lower the head. In the upright position, mean arterial pressure (MAP) was 193 +/- 11 mmHg (mean +/- SE), carotid flow was 0.7 +/- 0.2 l/min, and carotid cross-sectional area was 0.85 +/- 0.04 cm(2). Central venous pressure (CVP) was 4 +/- 2 mmHg, jugular flow was 0.7 +/- 0.2 l/min, and jugular cross-sectional area was 0.14 +/- 0.04 cm(2) (n = 4). Carotid arterial and jugular venous pressures at head level were 118 +/- 9 and -7 +/- 4 mmHg, respectively. When the head was lowered, MAP decreased to 131 +/- 13 mmHg, while carotid cross-sectional area and flow remained unchanged. Cardiac output was reduced by 30%, CVP decreased to -1 +/- 2 mmHg (P blood in the veins. When the head was raised, the jugular veins collapsed and blood was returned to the central circulation, and CVP and cardiac output were restored. The results demonstrate that in the upright-positioned, anesthetized giraffe cerebral blood flow is governed by arterial pressure without support of a siphon mechanism and that when the head is lowered, blood accumulates in the vein, affecting MAP.

  12. A new 99mTc-red blood cell labeling procedure for cardiac blood pool imaging: Clinical results

    International Nuclear Information System (INIS)

    Kelbaek, H.; Buelow, K.; Aldershvile, J.; Moegelyang, J.; Nielsen, S.L.; Copenhagen Univ.

    1989-01-01

    The first clinical results of a new 99m Tc-red blood cell labeling procedure avoiding cell centrifugation are presented. One ml heparinized blood samples were incubated with small amounts of a stannous kit. By titration studies, ideal quantities of sodium hypochlorite for oxidation of extracellular tin and of EDTA as stabilizer of the label were found. The Cl - concentration and pH of the labeled blood were acceptable, and EDTA increased labeling yield and stability determined in vitro by a few percent. The new procedure gave a slightly higher labeling yield than a current technique using centrifugation of cells. Labeling efficiency expressed as cell bound/total activity was 96.6%±1.3% in healthy subjects and 95.5%±2.2% in cardiac patients and remained high for 2 h after reinjection. The biological halflife of labeled cells following the new procedure was 11-12 h rendering it suitable for serial determinations of radionuclide cardiography. (orig.)

  13. 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.)

  14. 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)

  15. 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.)

  16. Use of pooled blood plasmas in the assessment of fouling resistance

    Czech Academy of Sciences Publication Activity Database

    de los Santos Pereira, Andres; Rodriguez-Emmenegger, Cesar; Surman, František; Riedel, Tomáš; Bologna Alles, A.; Brynda, Eduard

    2014-01-01

    Roč. 4, č. 5 (2014), s. 2318-2321 ISSN 2046-2069 R&D Projects: GA MŠk EE2.3.30.0029; GA ČR GAP106/12/1451; GA ČR GAP205/12/1702; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:61389013 Keywords : blood plasma * fouling * biomaterials Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.840, year: 2014

  17. Contrast-enhanced ultrasonography to assess blood perfusion of skeletal muscles in normal dogs

    Science.gov (United States)

    OH, Juyeon; JEON, Sunghoon; CHOI, Jihye

    2015-01-01

    This study evaluated perfusion of skeletal muscle using contrast enhanced ultrasonography in humerus, radius, femur and tibia in normal dogs. Contrast enhanced ultrasonography for each region was performed after injecting 0.5 mL and 1 mL of contrast medium (SonoVue) in every dog. Blood perfusion was assessed quantitatively by measuring the peak intensity, time to the peak intensity and area under the curve from the time–intensity curve. Vascularization in skeletal muscle was qualitatively graded with a score of 0–3 according to the number of vascular signals. A parabolic shape of time–intensity curve was observed from muscles in normal dogs, and time to the peak intensity, the peak intensity and area under the curve of each muscle were not significantly different according to the appendicular regions examined and the dosage of contrast agent administered. This study reports that feasibility of contrast enhanced ultrasonography for assessment of the muscular perfusion in canine appendicular regions. PMID:25754794

  18. Non invasive blood flow assessment in diabetic foot ulcer using laser speckle contrast imaging technique

    Science.gov (United States)

    Jayanthy, A. K.; Sujatha, N.; Reddy, M. Ramasubba; Narayanamoorthy, V. B.

    2014-03-01

    Measuring microcirculatory tissue blood perfusion is of interest for both clinicians and researchers in a wide range of applications and can provide essential information of the progress of treatment of certain diseases which causes either an increased or decreased blood flow. Diabetic ulcer associated with alterations in tissue blood flow is the most common cause of non-traumatic lower extremity amputations. A technique which can detect the onset of ulcer and provide essential information on the progress of the treatment of ulcer would be of great help to the clinicians. A noninvasive, noncontact and whole field laser speckle contrast imaging (LSCI) technique has been described in this paper which is used to assess the changes in blood flow in diabetic ulcer affected areas of the foot. The blood flow assessment at the wound site can provide critical information on the efficiency and progress of the treatment given to the diabetic ulcer subjects. The technique may also potentially fulfill a significant need in diabetic foot ulcer screening and management.

  19. Predictive value of T2-weighted imaging and contrast-enhanced MR imaging in assessing myometrial invasion in endometrial cancer: a pooled analysis of prospective studies

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Lian-Ming [Shanghai Jiao Tong University School of Medicine, Department of Radiology, Renji Hospital, Shanghai (China); Wayne State University, Department of Radiology, Detroit, MI (United States); Xu, Jian-Rong; Gu, Hai-Yan; Hua, Jia [Shanghai Jiao Tong University School of Medicine, Department of Radiology, Renji Hospital, Shanghai (China); Haacke, E.M.; Hu, Jiani [Wayne State University, Department of Radiology, Detroit, MI (United States)

    2013-02-15

    To obtain diagnostic performance values of T2-weighted imaging (T2WI) and contrast-enhanced magnetic resonance imaging (CE-MRI) in the prediction of myometrial invasion in patients with endometrial cancer. Databases including MEDLINE and EMBASE were searched for relevant original articles published from January1995 to March 2012. Pooled estimation data were obtained by statistical analysis. Eleven articles (548 patients) were included. For assessing any myometrial involvement, the pooled sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for CE-MRI were 0.81 (95% CI, 0.72, 0.88), 0.72 (95% CI, 0.64, 0.79), 0.65 (95% CI, 0.56, 0.73) and 0.85 (95% CI, 0.78, 0.91); for T2WI, they were 0.87 (95% CI, 0.78, 0.94), 0.58 (95% CI, 0.47, 0.69), 0.64 (95% CI, 0.54, 0.73), 0.84 (95% CI, 0.73, 0.92) respectively. The pooled specificity of CE-MRI (0.72) was significantly higher than T2WI (0.58) (P < 0.05). For assessing deep myometrial involvement, there was no statistically significant difference between CE-MRI and T2WI, (P > 0.05). CE-MRI has a good diagnostic performance in the prediction of any myometrial invasion and is superior to T2WI. But its PPV is somewhat suboptimal. For assessing deep myometrial involvement, its NPV appears relative high and negative findings strongly suggest an absence of deep myometrial involvement, which can guide therapeutic decision-making. (orig.)

  20. The effect of low-osmolar ionic and nonionic contrast media on human blood viscosity, erythrocyte morphology, and aggregation behavior

    NARCIS (Netherlands)

    Hardeman, M. R.; Goedhart, P.; Koen, I. Y.

    1991-01-01

    The effects of three low-osmolar radiographic contrast media (CM)--two nonionic (iohexol, iopamidol) and one ionic (ioxaglate)--on red blood cell (RBC) morphology and aggregation behavior, as well as on blood and plasma viscosity, have been studied. Blood taken from normal, healthy individuals and

  1. Enhanced conjugation stability and blood circulation time of macromolecular gadolinium-DTPA contrast agent

    Energy Technology Data Exchange (ETDEWEB)

    Jenjob, Ratchapol [Department of New Drug Development, School of Medicine, Inha University, 2F A-dong, Jeongseok Bldg., Sinheung-dong 3-ga, Jung-gu, Incheon 400-712 (Korea, Republic of); Kun, Na [Department of Biotechnology, The Catholic University of Korea, 43 Jibong-ro, Wonmi-gu, Bucheon-si, Gyeonggi-do 420-743 (Korea, Republic of); Ghee, Jung Yeon [Utah-Inha DDS and Advanced Therapeutics, B-403 Meet-You-All Tower, SongdoTechnopark, 7–50, Songdo-dong, Yeonsu-gu, Incheon 406-840 (Korea, Republic of); Shen, Zheyu; Wu, Xiaoxia [Division of Functional Materials and Nano-Devices, Ningbo Institute of Materials Technology & Engineering (NIMTE), Chinese Academy of Sciences, 519 Zhuangshi Street, Zhenhai District, Ningbo, Zhejiang 315201 (China); Cho, Steve K., E-mail: scho@gist.ac.kr [Division of Liberal Arts and Science, GIST College, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Lee, Don Haeng [Utah-Inha DDS and Advanced Therapeutics, B-403 Meet-You-All Tower, SongdoTechnopark, 7–50, Songdo-dong, Yeonsu-gu, Incheon 406-840 (Korea, Republic of); Department of Internal Medicine, School of Medicine, Inha University Hospital, Incheon 420-751 (Korea, Republic of); Yang, Su-Geun, E-mail: Sugeun.Yang@Inha.ac.kr [Department of New Drug Development, School of Medicine, Inha University, 2F A-dong, Jeongseok Bldg., Sinheung-dong 3-ga, Jung-gu, Incheon 400-712 (Korea, Republic of)

    2016-04-01

    In this study, we prepared macromolecular MR T1 contrast agent: pullulan-conjugated Gd diethylene triamine pentaacetate (Gd-DTPA-Pullulan) and estimated residual free Gd{sup 3+}, chelation stability in competition with metal ions, plasma and tissue pharmacokinetics, and abdominal MR contrast on rats. Residual free Gd{sup 3+} in Gd-DTPA-Pullulan was measured using colorimetric spectroscopy. The transmetalation of Gd{sup 3+} incubated with Ca{sup 2+} was performed by using a dialysis membrane (MWCO 100–500 Da) and investigated by ICP-OES. The plasma concentration profiles of Gd-DTPA-Pullulan were estimated after intravenous injection at a dose 0.1 mmol/kg of Gd. The coronal-plane abdominal images of normal rats were observed by MR imaging. The content of free Gd{sup 3+}, the toxic residual form, was less than 0.01%. Chelation stability of Gd-DTPA-Pullulan was estimated, and only 0.2% and 0.00045% of Gd{sup 3+} were released from Gd-DTPA-Pullulan after 2 h incubation with Ca{sup 2+} and Fe{sup 2+}, respectively. Gd-DTPA-Pullulan displayed the extended plasma half-life (t{sub 1/2,α} = 0.43 h, t{sub 1/2,β} = 2.32 h), much longer than 0.11 h and 0.79 h of Gd-EOB-DTPA. Abdominal MR imaging showed Gd-DTPA-Pullulan maintained initial MR contrast for 30 min. The extended plasma half-life of Gd-DTPA-Pullulan probably allows the prolonged MR acquisition time in clinic with enhanced MR contrast. - Highlights: • Macromolecule (pullulan) conjugated Gd contrast agent (Gd-DTPA-Pullulan) showed the extended plasma half-life (t{sub 1/2,α} = 0.43 h, t{sub 1/2,β} = 2.32 h) in comparison with Gd-EOB-DTPA • Gd-DTPA-pullulan T1 contrast agent exhibited strong chelation stability against Gd. • The extended blood circulation attributed the enhanced and prolonged MR contrast on abdominal region of rats. • The extended blood circulation may provide prolonged MR acquisition time window in clinics.

  2. A Giant Hepatic Hemangioma Complicated by Kasabach-Merritt Syndrome: Findings of Tc-99m RBC Scintigraphy and SPECT Including a Total Body Blood Pool Imaging Study

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Myung Hee; Jeong, Hwan Jeong; Lim, Seok Tae; Kim, Dong Wook; Yim, Chang Yeol [Chonbuk National University Medical School, Jeonju (Korea, Republic of)

    2009-02-15

    Kasabach-Merritt syndrome (KMS) consists of thrombocytopenia, microangiopathic hemolytic anemia, and localized consumption coagulopathy that develops within vascular hemangioma. This syndrome may also be associated with occult hemangiomas located at various sites. Tc-99m RBC scintigraphy and SPECT have proven to be reliable for confirming or excluding hemangioma. Total body blood pool imaging study during the scintigraphy also provides a means of screening for occult lesions. The authors report the case of a 29-year-old man who presented with a giant hepatic hemangioma complicated by KMS, and underwent Tc-99m RBC scintigraphy and SPECT including a total body blood pool imaging study.

  3. Assessing the performance of multiplexed tandem PCR for the diagnosis of pathogenic genotypes of Theileria orientalis using pooled blood samples from cattle.

    Science.gov (United States)

    Gebrekidan, Hagos; Gasser, Robin B; Stevenson, Mark A; McGrath, Sean; Jabbar, Abdul

    2017-02-01

    Oriental theileriosis caused by multiple genotypes of Theileria orientalis is an important tick-borne disease of bovines. Here, we assessed the performance of an established multiplexed tandem PCR (MT-PCR) for the diagnosis of the two recognized, pathogenic genotypes (chitose and ikeda) of T. orientalis in cattle using pooled blood samples. We used a total of 265 cattle blood samples, which were divided into two groups according to previous MT-PCR results for individual samples. Samples in group 1 (n = 155) were from a herd with a relatively high prevalence of T. orientalis infection; and those in group 2 (n = 110) were from four herds with a low prevalence. For group 1, 31 and 15 batches of five- and ten-pooled samples (selected at random), respectively, were formed. For group 2, 22 and 11 batches of five- and ten-pooled samples (selected at random), respectively, were formed. DNAs from individual pooled samples in each batch and group were then tested by MT-PCR. For group 1, the apparent prevalences estimated using the 31 batches of five-pooled samples (97%) and 15 batches of ten-pooled samples (100%) were significantly higher compared with individual samples (75%). For group 2, higher apparent prevalences (9% and 36%) were also recorded for the 22 and 11 batches of pooled samples, respectively, compared with individual samples (7%). Overall, the average infection intensity recorded for the genotypes of chitose and ikeda were considerably lower in pooled compared with individual samples. The diagnostic specificities of MT-PCR were estimated at 95% and 94%, respectively, when batches of five- and ten-pooled samples were tested, and 94% for individual samples. The diagnostic sensitivity of this assay was estimated at 98% same for all individual, five- and ten-pooled samples. This study shows that screening batches of five- and ten-pooled blood samples from cattle herds are similar to those obtained for individual samples, and, importantly, that the reduced cost

  4. Restoration of the contrast of cerebral blood flows by the spatial deconvolution method

    International Nuclear Information System (INIS)

    Compingt, D.L.; Philippon, B.L.

    1982-01-01

    The measurement of regional cerebral blood flows (rCBF) with a gamma camera during xenon-133 inhalation necessitates collimators with high efficiency. Their spatial resolutions are weak: on the images given by a F.W.H.M. collimator (25 mm to 5 cm depth of water), the contrast restoration method by the ponctual dispersion function (P.D.F.) is used. The convolution product (Image)=(Object)*(P.D.F.) is resolved by a bidimensional Fast Fourier Transform treatment. The high frequencies are eliminated by a progressive filtration. The rCBF is calculated with Obrist's method. The Initial Slope Index is only used. A rCBF image with the calculator is also realized. The numerical values are compared with the normal treatment (N) without contrast restoration and after restoration. 22 patients are so treated after severe cerebral strokes. The hemispheric average of the flows according to the 2 treatments is unchanged (difference: 1.1%). The contrast between higher and lower flow areas is increasing by 73% after contrast restoration (significant difference: p [fr

  5. Susceptibility contrast imaging of CO2-induced changes in the blood volume of the human brain

    DEFF Research Database (Denmark)

    Rostrup, Egill; Larsson, H B; Toft, P B

    1996-01-01

    PURPOSE: To investigate changes in the regional cerebral blood volume (rCBV) in human subjects during rest and hypercapnia by MR imaging, and to compare the results from contrast-enhanced and noncontrast-enhanced susceptibility-weighted imaging. MATERIAL AND METHODS: Five healthy volunteers (aged...... by fitting a gamma-variate function to the data. The tissue concentration vs time curves were deconvoluted using an input function obtained by arterial sampling. RESULTS: The ratio of gray to white matter CBV (1.9-2.5) as well as the fractional increase in rCBV during hypercapnia (about 30%) was found...

  6. Dynamic measurements of total hepatic blood flow with Phase Contrast MRI

    Energy Technology Data Exchange (ETDEWEB)

    Yzet, Thierry [Department of Radiology, University Hospital, Place Victor Pauchet, 80054 Amiens cedex 1 (France)], E-mail: Yzet.Thierry@chu-amiens.fr; Bouzerar, Roger [Department of Imaging and Biophysics, University Hospital, Jules Verne University of Picardie, Place Victor Pauchet, 80054 Amiens cedex 1 (France)], E-mail: bouzerar.roger@chu-amiens.fr; Baledent, Olivier [Department of Imaging and Biophysics, University Hospital, Jules Verne University of Picardie, Place Victor Pauchet, 80054 Amiens cedex 1 (France)], E-mail: Olivier.Baledent@chu-amiens.fr; Renard, Cedric [Department of Radiology, University Hospital, Place Victor Pauchet, 80054 Amiens cedex 1 (France)], E-mail: Renard.Cedric@chu-amiens.fr; Lumbala, Didier Mbayo [Department of Radiology, University Hospital, Place Victor Pauchet, 80054 Amiens cedex 1 (France)], E-mail: MbayoLumbala.Didier@chu-amiens.fr; Nguyen-Khac, Eric [Mobile Unit of Alcoology, University Hospital, Place Victor Pauchet, 80054 Amiens cedex 1 (France)], E-mail: Nguyen-Khac.Eric@chu-amiens.fr; Regimbeau, Jean-Marc [Department of Visceral and Digestive General Surgery, University Hospital, Place Victor Pauchet, 80054 Amiens cedex 1 (France)], E-mail: regimbeau.jean-marc@chu-amiens.fr; Deramond, H. [Department of Radiology, University Hospital, Place Victor Pauchet, 80054 Amiens cedex 1 (France)], E-mail: deramond.herve@chu-amiens.fr; Meyer, Marc-Etienne [Department of Imaging and Biophysics, University Hospital, Jules Verne University of Picardie, Place Victor Pauchet, 80054 Amiens cedex 1 (France)], E-mail: Meyer.Marc-Etienne@chu-amiens.fr

    2010-01-15

    Background/Aims: To measure total hepatic blood flow including portal and proper hepatic artery flows as well as the temporal evolution of the vessel's section during a cardiac cycle. Methods: Twenty healthy subjects, with a mean age of 26 years, were explored. Magnetic resonance imaging blood flow measurements were carried out in the portal vein and the proper hepatic artery. MR studies were performed using a 1.5T imager (General Electric Medical Systems). Gradient-echo 2D Fast Cine Phase Contrast sequences were used with both cardiac and respiratory gatings. Data analysis was performed using a semi-automatic software built in our laboratory. Results: The total hepatic flow rate measured was 1.35 {+-} 0.18 L/min or 19.7 {+-} 4.6 mL/(min kg). The proper hepatic artery provided 19.1% of the total hepatic blood flow entering the liver. Those measurements were in agreement with earlier studies using direct measurements. Mean and maximum velocities were also assessed and a discrepancy between our values and the literature's Doppler data was found. Measurements of the portal vein area have shown a mean variation, defined as a 'pulsatility' index of 18% over a cardiac cycle. Conclusions: We report here proper hepatic artery blood flow rate measurements using MRI. Associated with portal flow measurements, we have shown the feasibility of total hepatic flowmetry using a non-invasive and harmless technique.

  7. Evaluation of left ventricular function during exercise in patients with ischemic heart disease using multigated blood pool scintigraphy

    International Nuclear Information System (INIS)

    Ohmori, Yoshiaki; Kanoh, Yasushi; Shiotani, Hideyuki; Fujitani, Kazuhiro; Fukuzaki, Hisashi; Kajiya, Teishi; Nakashima, Yoshiharu; Maeda, Kazumi.

    1985-01-01

    Multigated blood pool scintigraphy (exercise RI ventriculography) and exercise stress thallium-201 myocardial scintigraphy were performed in 44 ischemic heart disease (IHD) patients (16 with angina pectoris and 28 with old myocardial infarction) and 11 healthy persons. Furthermore, blood circulation was examined in 38 of the subjects. Work load was significantly greater, and the number of diseased vessels and the incidence of indicators for transient ischemia during exercise were significantly lower in the group with a remarkably increased left ventricular ejection fraction (EF) during exercise than in the group with a remarkably decreased EF. In the group with unchanged EF, reginal left ventricular wall movement could be assessed using phase analysis. In IHD patients with a remarkably decreased EF at rest, EF was scarcely changed during exercise, and indicators for transient ischemia were not observed frequently. There was a highly significnat correlation between EF during exercise and pulmonary artery wedge pressure or cardiac index during exercise, suggesting that EF is a noninvasive indicator for coronary circulation during exercise. Exercise RI ventriculography was considered useful for evaluating the physiology of IHD. (Namekawa, K.)

  8. PCR-based pooling of dried blood spots for detection of malaria parasites: optimization and application to a cohort of Ugandan children.

    Science.gov (United States)

    Hsiang, Michelle S; Lin, Michael; Dokomajilar, Christian; Kemere, Jordan; Pilcher, Christopher D; Dorsey, Grant; Greenhouse, Bryan

    2010-10-01

    Sensitive, high-throughput methods to detect malaria parasites in low-transmission settings are needed. PCR-based pooling strategies may offer a solution. We first used laboratory-prepared samples to compare 2 DNA extraction and 4 PCR detection methods across a range of pool sizes and parasite densities. Pooled Chelex extraction of DNA, followed by nested PCR of cytochrome b, was the optimal strategy, allowing reliable detection of a single low-parasitemic sample (100 parasites/μl) in pool sizes up to 50. This PCR-based pooling strategy was then compared with microscopy using 891 dried blood spots from a cohort of 77 Ugandan children followed for 2 years in an urban setting of low endemicity. Among 419 febrile episodes, 35 cases of malaria were detected using the PCR-based pooling strategy and 40 cases using microscopy. All five cases of malaria not detected by PCR were from samples stored for >2 years with parasitemia of parasites using dried blood spots offers a sensitive and efficient approach for malaria surveillance in low-transmission settings, enabling improved detection of asymptomatic submicroscopic infections and dramatic savings in labor and costs.

  9. Usefulness of diastolic phase index by gated cardiac blood pool imaging in patients with left ventricular hypertrophy

    Energy Technology Data Exchange (ETDEWEB)

    Narita, Michihiro; Kurihara, Tadashi; Murano, Kenichi; Usami, Masahisa; Honda, Minoru

    1983-09-01

    To assess the left ventricular (LV) diastolic filling rate in patients with LV hypertrophy, we analyzed LV time activity curves obtained from gated cardiac blood pool imaging. Gated cardiac blood pool imaging with Tc-99m were obtained at rest in 20 normal subjects, 20 patients with hypertrophic cardiomyopathy (HCM) and 10 patients with hypertensive hypertrophy (HT). As systolic indices we obtained LV ejection fraction (EF) and mean first third ejection rate (1/3 ER/sub mean/). And as diastolic indices, mean filling rate during the first third of diastole (1/3 FR/sub mean/) and maximal filling rate during the whole diastole (FRmax) were calculated. LVEF and 1/3 ER/sub mean/ in patients with HT were not different significantly from normal, but those in patients with HCM were significantly greater than normal, besides 1/3 ER/sub mean/ in patients with HCM was greater than that in HT. Among diastolic phase indices, FRmax was not different significantly between 3 groups, but 1/3 FR/sub mean/ in HCM (1.47 +- 0.30 sec/sup 1/) and HT (1.34 +- 0.38 sec/sup 1/) was significantly lower than normal (2.10 +- 0.27 sec/sup 1/). Abnormal 1/3 FR/sub mean/ (<1.56 sec/sup 1/) was found in 65% of HCM and 80% of HT. Besides, in patients with HCM, 10 patients who had exertional dyspnea and anginal chest pain (NYHA Class II or III) showed significantly lower 1/3 FR/sub mean/ values than 10 patients without symptoms (1.25 +- 0.15 sec/sup 1/ vs 1.70 +- 0.25 sec/sup 1/. 1/3 FR/sub mean/ did not correlated well with LV wall thickness (summation of septal and posterior wall thickness) which was measured by ecohocardiography. But the ratio of 1/3 FR/sub mean/ to 1/3 ER/sub mean/ correlated well (r=-0.77 wall thickness in patients with LV hypertrophy. (J.P.N.).

  10. A reduced gastric corpus microvascular blood flow during Ivor-Lewis esophagectomy detected by laser speckle contrast imaging technique

    DEFF Research Database (Denmark)

    Ambrus, Rikard; Svendsen, Lars Bo; Secher, Niels H.

    2017-01-01

    BACKGROUND: Reduced microvascular blood flow is related to anastomotic insufficiency following esophagectomy, emphasizing a need for intraoperative monitoring of the microcirculation. This study evaluated if laser speckle contrast imaging (LSCI) was able to detect intraoperative changes in gastric...

  11. Multifunctional polyelectrolyte microcapsules as a contrast agent for photoacoustic imaging in blood.

    Science.gov (United States)

    Yashchenok, Alexey M; Jose, Jithin; Trochet, Philippe; Sukhorukov, Gleb B; Gorin, Dmitry A

    2016-08-01

    The polyelectrolyte microcapsules that can be accurate either visualized in biological media or in tissue would enhance their further in vivo application both as a carrier of active payloads and as a specific sensor. The immobilization of active species, for instance fluorescent dyes, quantum dots, metal nanoparticles, in polymeric shell enables visualization of capsules by optical imaging techniques in aqueous solution. However, for visualization of capsules in complex media an instrument with high contrast modality requires. Herein, we show for the first time photoacoustic imaging (PAI) of multifunctional microcapsules in water and in blood. The microcapsules exhibit greater photoacoustic intensity compare to microparticles with the same composition of polymeric shell presumably their higher thermal expansion. Photoacoustic intensity form microcapsules dispersed in blood displays an enhancement (2-fold) of signal compare to blood. Photoacoustic imaging of microcapsules might contribute to non-invasive carrier visualization and further their in vivo distribution. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Dynamics of phytoplankton productivity and exopolysaccharides (EPS and TEP) pools in the Seine Estuary (France, Normandy) over tidal cycles and over two contrasting seasons.

    Science.gov (United States)

    Morelle, Jérôme; Schapira, Mathilde; Claquin, Pascal

    2017-10-01

    Exopolysaccharides (EPS) play an important role in the carbon flux and may be directly linked to phytoplankton and microphytobenthos production, most notably in estuarine systems. However the temporal and spatial dynamics of estuarine EPS are still not well understood, nor how primary productivity triggers this variability at these different scales. The aim of this study was to investigate the primary productivity of phytoplankton and EPS dynamics in the Seine estuary over a tidal cycle in three different haline zones over two contrasted seasons. The other objectives was to investigate the origin of pools of soluble carbohydrates (S-EPS) and transparent exopolymeric particles (TEP) in phytoplankton, microphytobenthos or other compartments. High frequency measurements of productivity were made in winter and summer 2015. Physical and chemical parameters, biomass and EPS were measured at hourly intervals in sub-surface waters and just above the water sediment-interface. Our results confirmed that high frequency measurements improve the accuracy of primary productivity estimations and associated carbon fluxes in estuaries. The photosynthetic parameters were shown to be strongly controlled by salinity and by the concentrations of suspended particle matter at the smallest temporal and at spatial scales. At these scales, our results showed an inverse relationship between EPS concentrations and biomass and productivity, and a positive relationship with sediment resuspension. Additionally, the distribution of EPS appears to be linked to hydrodynamics with the tide at daily scale and with the winter at seasonal scale. At spatial scale, the maximum turbidity zone played an important role in the distribution of TEP. Our results suggest that, in the Seine estuary, between 9% and 33% of the S-EPS pool in the water column can be attributed to phytoplankton excretion, while only 0.4%-1.6% (up to 6.14% in exceptional conditions) originates from the microphytobenthos compartments

  13. Ventricular emptying performance in patients with tetralogy of Fallot; Assessment with Fourier analysis of gated blood-pool data

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Kan; Maeda, Hisato; Nakagawa, Tsuyoshi; Ito, Tsunao; Yamaguchi, Nobuo; Matsuda, Akira (Mie Univ., Tsu (Japan). School of Medicine)

    1989-12-01

    Comparison of emptying patterns between left and right ventricles (LV, RV) was performed with Fourier analysis of gated blood-pool data in patients with tetralogy of Fallot (TF). Using global time-activity curves, the phase and amplitude at the first-harmonic component of Fourier series were calculated and emptying patterns of both ventricles were evaluated by phase difference {l brace}D(phase)=RV phase minus LV phase{r brace} and RV/LV amplitude ratio {l brace}R(amp){r brace}. In 20 patients with normal cardiac function, D(phase) was minimal (mean 2.0{plus minus}6.6 degrees) and R(amp) was less than 1.0 (mean 0.60{plus minus}0.19). In 11 patients with TF, D(phase) was significantly larger than normal, with a mean value of 24.3{plus minus}10.0 degrees (p<0.01) and became greater in a reversed proportion to the ratio of the pulmonary-to-systemic blood flow (p<0.01). In all but one cases with TF, R(amp) was greater than 1.0 with a mean value of 1.4{plus minus}0.4, significantly larger than normal (p<0.001). Furthermore, using time-activity curves approximated by terms up to the 3rd-harmonic component, the temporal difference in emptying patterns between both ventricles was investigated. In TF cases, the time from end-diastole to minimum count (T2) was significantly larger in RV than in LV (p<0.001). The elongated T2 interval of RV seemed to play an important role in producing RV phase lag. Thus, this non-invasive method is valuable for pathophysiologic investigation of patients with TF and can be of help in estimating the severity of their disease. (author).

  14. Integrating atlas and graph cut methods for right ventricle blood-pool segmentation from cardiac cine MRI

    Science.gov (United States)

    Dangi, Shusil; Linte, Cristian A.

    2017-03-01

    Segmentation of right ventricle from cardiac MRI images can be used to build pre-operative anatomical heart models to precisely identify regions of interest during minimally invasive therapy. Furthermore, many functional parameters of right heart such as right ventricular volume, ejection fraction, myocardial mass and thickness can also be assessed from the segmented images. To obtain an accurate and computationally efficient segmentation of right ventricle from cardiac cine MRI, we propose a segmentation algorithm formulated as an energy minimization problem in a graph. Shape prior obtained by propagating label from an average atlas using affine registration is incorporated into the graph framework to overcome problems in ill-defined image regions. The optimal segmentation corresponding to the labeling with minimum energy configuration of the graph is obtained via graph-cuts and is iteratively refined to produce the final right ventricle blood pool segmentation. We quantitatively compare the segmentation results obtained from our algorithm to the provided gold-standard expert manual segmentation for 16 cine-MRI datasets available through the MICCAI 2012 Cardiac MR Right Ventricle Segmentation Challenge according to several similarity metrics, including Dice coefficient, Jaccard coefficient, Hausdorff distance, and Mean absolute distance error.

  15. The effect of varying the acquisition angle on processing and ejection fractions in gated blood pool studies

    International Nuclear Information System (INIS)

    Hughes, K.; Schults, C.G.; Trinh, T.

    2002-01-01

    Full text: Suboptimal ventricular definition has been blamed for difficulties in processing and variations in Ejection Fraction (EF). Clinical patients had Gated Blood Pool Studies (GBPS) performed by one of two operators, ensuring good left ventricular separation and definition. With patient consent, another study was acquired with the camera angle altered in the caudal or septal plane. Using GE Entegra GBPS Software, which allows some operator involvement in modifying the automated systolic and diastolic regions, the studies were analysed by eight 'blinded' technologists. Analyses of optimal and suboptimal acquisitions were compared. The mean, standard deviation (SD) and coefficient of variation (CV%) were determined for each patient's set of EFs. There was no significant difference in the means of the optimal and suboptimal groups (61.2% and 61.7%). One third of the suboptimal studies acquired gave a mean EF that differed by more than 5% from the Optimal' mean. The average CV of all analyses was 4.5%. The optima] group CV 4.7% (septal 4.6%/caudal 4.8%) and the suboptimal group CV 4.3% (septal 4.5%/caudal 4.2%). The analysis demonstrates that precision of processing GBPS is not affected when the study is acquired at a suboptimal angle. Although most EF results are reliable when acquired at a suboptimal angle, approximately one third will produce an EF that varies from the optimal result by more than 5%. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  16. Functional imaging of the nonhuman primate Placenta with endogenous blood oxygen level-dependent contrast.

    Science.gov (United States)

    Schabel, M C; Roberts, V H J; Lo, J O; Platt, S; Grant, K A; Frias, A E; Kroenke, C D

    2016-11-01

    To characterize spatial patterns of T2* in the placenta of the rhesus macaque (Macaca mulatta), to correlate these patterns with placental perfusion determined using dynamic contrast-enhanced MRI (DCE-MRI), and to evaluate the potential for using the blood oxygen level-dependent effect to quantify placental perfusion without the use of exogenous contrast reagent. MRI was performed on three pregnant rhesus macaques at gestational day 110. Multiecho spoiled gradient echo measurements were used to compute maps of T2*. Spatial maxima in these maps were compared with foci of early enhancement determined by DCE-MRI. Local maxima in T2* maps were strongly correlated with spiral arteries identified by DCE-MRI, with mean spatial separations ranging from 2.34 to 6.11 mm in the three animals studied. Spatial patterns of R2* ( = 1/ T2*) within individual placental lobules can be quantitatively analyzed using a simple model to estimate fetal arterial oxyhemoglobin concentration [Hbo,f] and a parameter viPS/Φ, reflecting oxygen transport to the fetus. Estimated mean values of [Hbo,f] ranged from 4.25 mM to 4.46 mM, whereas viPS/Φ ranged from 2.80 × 10 5 cm -3 to 1.61 × 10 6 cm -3 . Maternal spiral arteries show strong spatial correlation with foci of extended T2* observed in the primate placenta. A simple model of oxygen transport accurately describes the spatial dependence of R2* within placental lobules and enables assessment of placental function and oxygenation without requiring administration of an exogenous contrast reagent. Magn Reson Med 76:1551-1562, 2016. © 2015 International Society for Magnetic Resonance in Medicine. © 2015 International Society for Magnetic Resonance in Medicine.

  17. 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

  18. Gated blood-pool SPECT assessment of Wolff-Parkinson-White syndromes before and after radiofrequency ablation of accessory pathways

    International Nuclear Information System (INIS)

    Bontemps, L.; Ben Brahim, H.; Kraiem, T.; Chevalier, P.; Kirkorian, G.; Touboul, P.; Itti, R.

    1997-01-01

    Radiofrequency (RF) ablation of accessory pathways in Wolff-Parkinson-White (WPW) syndrome is supposed to be less aggressive than fulguration while providing excellent results. The aims of our study were therefore the evaluation of the functional results of this therapy in terms of left or right ejection fractions and its effects on the contraction synchronism between both ventricular chambers, derived from bi-ventricular Fourier phase histograms. A consecutive series of 44 patients has been investigated within 48 hours before and after RF therapy: 14 patients had right sided WPW and 30 patients left sided WPW. Only patients for whom RF treatment was considered as a success have been included in the study. Gated blood pool tomography has been performed in order to localize the site of pre-excitation and to build-up the phase histograms for both ventricles, and planar gated imaging has been used for right and left ejection fraction determination. Functional results demonstrate the absence of deleterious effect of RF on ventricular contraction and rather a slight increase of ejection fractions, with a more statistically significant difference for left WPW (LVEF = 62.2 % before RF vs 64.4 % after RF; p = 0.02) than for right WPW (RVEF = 36.3 % before RF vs 39.7 after RF; p = 0.16). Phase analysis, on the contrary, show only significant differences for right WPW, with a noticeable decrease of the pre-excitation (left-to-right phase difference 14.4 deg before RF vs 7.5 deg after RF; p = 0.03) and a significant reduction of the right ventricular phase dispersion (right phase standard deviation 26.5 deg before RF vs 19.0 deg after RF; p = 0.03). For left WPW no measurable differences can be demonstrated in the basal state and it is suggested to use stimulation techniques in order to enhance the competition between the normal and accessory conduction pathways. (authors)

  19. Hypotension Risk Prediction via Sequential Contrast Patterns of ICU Blood Pressure.

    Science.gov (United States)

    Ghosh, Shameek; Feng, Mengling; Nguyen, Hung; Li, Jinyan

    2016-09-01

    Acute hypotension is a significant risk factor for in-hospital mortality at intensive care units. Prolonged hypotension can cause tissue hypoperfusion, leading to cellular dysfunction and severe injuries to multiple organs. Prompt medical interventions are thus extremely important for dealing with acute hypotensive episodes (AHE). Population level prognostic scoring systems for risk stratification of patients are suboptimal in such scenarios. However, the design of an efficient risk prediction system can significantly help in the identification of critical care patients, who are at risk of developing an AHE within a future time span. Toward this objective, a pattern mining algorithm is employed to extract informative sequential contrast patterns from hemodynamic data, for the prediction of hypotensive episodes. The hypotensive and normotensive patient groups are extracted from the MIMIC-II critical care research database, following an appropriate clinical inclusion criteria. The proposed method consists of a data preprocessing step to convert the blood pressure time series into symbolic sequences, using a symbolic aggregate approximation algorithm. Then, distinguishing subsequences are identified using the sequential contrast mining algorithm. These subsequences are used to predict the occurrence of an AHE in a future time window separated by a user-defined gap interval. Results indicate that the method performs well in terms of the prediction performance as well as in the generation of sequential patterns of clinical significance. Hence, the novelty of sequential patterns is in their usefulness as potential physiological biomarkers for building optimal patient risk stratification systems and for further clinical investigation of interesting patterns in critical care patients.

  20. Dynamic Contrast-Enhanced Computed Tomography-Derived Blood Volume and Blood Flow Correlate With Patient Outcome in Metastatic Renal Cell Carcinoma

    DEFF Research Database (Denmark)

    Mains, Jill Rachel; Donskov, Frede; Pedersen, Erik Morre

    2017-01-01

    = 7). Using a prototype software program (Advanced Perfusion and Permeability Application, Philips Healthcare, Best, the Netherlands), blood volume (BV), blood flow (BF), and permeability surface area product (PS) were calculated for each tumor at baseline, week 5, and week 10. These parameters......OBJECTIVES: The aim was to explore the potential for using dynamic contrast-enhanced computed tomography as a noninvasive functional imaging biomarker before and during the early treatment of metastatic renal cell carcinoma (mRCC). MATERIALS AND METHODS: Dynamic contrast-enhanced computed...

  1. Quantification of blood flow in the middle cerebral artery with phase-contrast MR imaging

    International Nuclear Information System (INIS)

    Stock, K.W.; Wetzel, S.G.; Radue, E.W.; Lyrer, P.A.

    2000-01-01

    The aim of this study was to assess blood flow in the middle cerebral artery (MCA) according to age, gender, and side. Eighty-eight subjects without carotid obstruction were measured for mean velocity, vessel area, and volume flow rates of both MCA with phase-contrast MR. A high-resolution sequence with a matrix of 300 x 512 and a double oblique localizing strategy was used for measurement. A mean velocity of 33 ± 6.8 cm/s, a mean vessel area of 6.2 ± 1.2 mm 2 and a mean flow rate of 121 ± 28 ml/min were measured in the MCA. Lower volume flow rates were seen in subjects aged over 50 years (p < 0.01). When comparing women with men, a lower vessel area (p < 0.05) of the MCA was counterbalanced by a higher velocity, resulting in no significant difference of the volume flow rate. No difference occurred between the right and the left side. Flow reduction occurs in the elderly. A lower vessel area of the MCA in women is compensated by a higher velocity. (orig.)

  2. Streaming flow from ultrasound contrast agents by acoustic waves in a blood vessel model.

    Science.gov (United States)

    Cho, Eunjin; Chung, Sang Kug; Rhee, Kyehan

    2015-09-01

    To elucidate the effects of streaming flow on ultrasound contrast agent (UCA)-assisted drug delivery, streaming velocity fields from sonicated UCA microbubbles were measured using particle image velocimetry (PIV) in a blood vessel model. At the beginning of ultrasound sonication, the UCA bubbles formed clusters and translated in the direction of the ultrasound field. Bubble cluster formation and translation were faster with 2.25MHz sonication, a frequency close to the resonance frequency of the UCA. Translation of bubble clusters induced streaming jet flow that impinged on the vessel wall, forming symmetric vortices. The maximum streaming velocity was about 60mm/s at 2.25MHz and decreased to 15mm/s at 1.0MHz for the same acoustic pressure amplitude. The effect of the ultrasound frequency on wall shear stress was more noticeable. Maximum wall shear stress decreased from 0.84 to 0.1Pa as the ultrasound frequency decreased from 2.25 to 1.0MHz. The maximum spatial gradient of the wall shear stress also decreased from 1.0 to 0.1Pa/mm. This study showed that streaming flow was induced by bubble cluster formation and translation and was stronger upon sonication by an acoustic wave with a frequency near the UCA resonance frequency. Therefore, the secondary radiant force, which is much stronger at the resonance frequency, should play an important role in UCA-assisted drug delivery. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Laser speckle contrast reveals cerebral blood flow dynamics evoked by optogenetically controlled neuronal activity

    Science.gov (United States)

    Li, Nan; Thakor, Nitish V.; Pelled, Galit

    2013-03-01

    As a critical basis of functional brain imaging, neurovascular coupling describes the link between neuronal and hemodynamic changes. The majority of in vivo neurovascular coupling studies was performed by inducing sensory stimulation via afferent inputs. Unfortunately such an approach results in recruiting of multiple types of cells, which confounds the explanation of neuronal roles in stimulus evoked hemodynamic changes. Recently optogenetics has emerged to provide immediate control of neurons by exciting or inhibiting genetically engineered neurons expressing light sensitive proteins. However, there is a need for optical methods capable of imaging the concurrent hemodynamic changes. We utilize laser speckle contrast imaging (LSCI) to obtain high resolution display of cerebral blood flow (CBF) in the vicinity of the targeted neural population. LSCI is a minimally invasive method for imaging CBF in microvessels through thinned skull, and produces images with high spatiotemporal resolution, wide field of view. In the integrated system light sources with different wavelengths and band-passing/blocking filters were used to allow simultaneous optical manipulation of neuronal activities and optical imaging of corresponding CBF. Experimental studies were carried out in a rodent model expressing channalrhodopsin (ChR2) in excitatory neurons in the somatosensory cortex (S1). The results demonstrated significant increases of CBF in response to ChR2 stimulation (exciting neuronal firing) comparable to the CBF response to contralateral forepaw stimulation. The approach promises to be an exciting minimally invasive method to study neurovascular coupling. The complete system provides a novel approach for broad neuroscience applications.

  4. Impact of physiological noise correction on detecting blood oxygenation level-dependent contrast in the breast

    Science.gov (United States)

    Wallace, Tess E.; Manavaki, Roido; Graves, Martin J.; Patterson, Andrew J.; Gilbert, Fiona J.

    2017-01-01

    Physiological fluctuations are expected to be a dominant source of noise in blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) experiments to assess tumour oxygenation and angiogenesis. This work investigates the impact of various physiological noise regressors: retrospective image correction (RETROICOR), heart rate (HR) and respiratory volume per unit time (RVT), on signal variance and the detection of BOLD contrast in the breast in response to a modulated respiratory stimulus. BOLD MRI was performed at 3 T in ten volunteers at rest and during cycles of oxygen and carbogen gas breathing. RETROICOR was optimized using F-tests to determine which cardiac and respiratory phase terms accounted for a significant amount of signal variance. A nested regression analysis was performed to assess the effect of RETROICOR, HR and RVT on the model fit residuals, temporal signal-to-noise ratio, and BOLD activation parameters. The optimized RETROICOR model accounted for the largest amount of signal variance ( Δ R\\text{adj}2   =  3.3  ±  2.1%) and improved the detection of BOLD activation (P  =  0.002). Inclusion of HR and RVT regressors explained additional signal variance, but had a negative impact on activation parameter estimation (P  <  0.001). Fluctuations in HR and RVT appeared to be correlated with the stimulus and may contribute to apparent BOLD signal reactivity.

  5. Non-contrast enhanced MR venography using 3D fresh blood imaging (FBI). Initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Kenichi; Nitatori, Toshiaki; Inaoka, Sayuki; Takahara, Taro; Hachiya, Junichi [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine

    2001-10-01

    This study examined the efficacy of 3D-fresh blood imaging (FBI) in patients with venous disease in the iliac region to lower extremity. Fourteen patients with venous disease were examined [8 deep venous thrombosis (DVT) and 6 varix] by 3D-FBI and 2D-TOF MRA. ALL FBI images and 2D-TOF images were evaluated in terms of visualization of the disease and compared with conventional X-ray venography (CV). The total scan time of 3D-FBI ranged from 3 min 24 sec to 4 min 52 sec. 3D-FBI was positive in all 23 anatomical levels in which DVT was diagnosed by CV (100% sensitivity) as well as 2D-TOF. The delineation of collateral veins was superior or equal to that of 2D-TOF. 3D-FBI allowed depiction of varices in five of six cases; however, in one case, the evaluation was limited because the separation of arteries from veins was difficult. The 3D-FBI technique, which allows iliac to peripheral MR venography without contrast medium within a short acquisition time, is considered clinically useful. (author)

  6. Gadolinium-based magnetic resonance contrast agents at 7 Tesla: in vitro T1 relaxivities in human blood plasma.

    Science.gov (United States)

    Noebauer-Huhmann, Iris M; Szomolanyi, Pavol; Juras, Vladimír; Kraff, Oliver; Ladd, Mark E; Trattnig, Siegfried

    2010-09-01

    PURPOSE/INTRODUCTION: The aim of this study was to determine the T1 relaxivities (r1) of 8 gadolinium (Gd)-based MR contrast agents in human blood plasma at 7 Tesla, compared with 3 Tesla. Eight commercially available Gd-based MR contrast agents were diluted in human blood plasma to concentrations of 0, 0.25, 0.5, 1, and 2 mmol/L. In vitro measurements were performed at 37 degrees C, on a 7 Tesla and on a 3 Tesla whole-body magnetic resonance imaging scanner. For the determination of T1 relaxation times, Inversion Recovery Sequences with inversion times from 0 to 3500 ms were used. The relaxivities were calculated. The r1 relaxivities of all agents, diluted in human blood plasma at body temperature, were lower at 7 Tesla than at 3 Tesla. The values at 3 Tesla were comparable to those published earlier. Notably, in some agents, a minor negative correlation of r1 with a concentration of up to 2 mmol/L could be observed. This was most pronounced in the agents with the highest protein-binding capacity. At 7 Tesla, the in vitro r1 relaxivities of Gd-based contrast agents in human blood plasma are lower than those at 3 Tesla. This work may serve as a basis for the application of Gd-based MR contrast agents at 7 Tesla. Further studies are required to optimize the contrast agent dose in vivo.

  7. Assessment of myocardial perfusion abnormality and hibernating myocardium by gated blood pool and exercise-stress thallium tomographies after successful coronary angioplasty

    International Nuclear Information System (INIS)

    Hashimoto, Akiyoshi; Nakata, Tomoaki; Tsuchihashi, Kazufumi

    1993-01-01

    Cardiac function and myocardial perfusion were assessed by exercise-stress thallium SPECT and resting gated blood pool SPECT techniques before and after 47 successful coronary angioplasties. Thallium perfusion was analyzed visually and quantitatively in stress and resting studies. Left ventricular ejection fraction (LVEF) and peak filling rate (PFR) were calculated and regional wall motion was scored by amplitude and phase images in radionuclide planar and tomographic imagings. The thallium redistribution in delayed or resting SPECTs was more sensitive (87%) for detecting myocardial ischemia compared to symptoms (36%) and ECG changes (60%). An exercise capacity, LVEF, PFR, and the scores of perfusion and regional wall motion were improved significantly after coronary angioplasty. Stress thallium and gated blood pool SPECTs showed the improvements of myocardial perfusion in 159 (79%) of 201 segments and regional wall motion in 47 (51%) of 92 segments, respectively. These results suggest that the combined use of stress thallium SPECT, gated blood pool planar and SPECT techniques can contribute not only to the assessment of the efficacy of coronary angioplasty but also to detecting the mismatching of myocardial perfusion and contraction ('myocardial hibernation') in infarct-related myocardial lesions. (author)

  8. Clinical Significance of Intraluminal Contrast Enhancement in Patients with Spontaneous Cervical Artery Dissection: A Black-Blood MRI Study.

    Science.gov (United States)

    Coppenrath, Eva; Lenz, Olga; Sommer, Nora; Lummel, Nina; Linn, Jennifer; Treitl, Karla; Bamberg, Fabian; Reiser, Maximilian; Pfefferkorn, Thomas; Saam, Tobias

    2017-07-01

    Purpose  Recent studies have suggested that intraluminal thrombi show contrast enhancement on carotid black-blood T1w MRI. The aim of this study was to evaluate the significance of intraluminal contrast enhancement (iCE) regarding symptom status in patients with spontaneous cervical artery dissection (sCAD). Methods  33 consecutive patients (19 men) with sCAD received a brain MRI (DIFF, T2w, T2*w, FLAIR) and a multi-sequence 3T-MRI with fat-saturated high-resolution black-blood T1w-sequences pre- and post-contrast, contrast-enhanced MR angiography and TOF images of carotid and vertebral arteries. Presence/absence of iCE, vessel occlusion and vessel wall hematoma (hyperintense in T1w pre-contrast) were analysed by two radiologists in consensus decision. Results  44 of 132 analysed vessels had a vessel wall hematoma, consistent with sCAD. In 17 of 44 dissected vessels an acute ischemic stroke was found. 16 of 17 (94.1 %) vessels ipsilateral to ischemic stroke demonstrated iCE, compared to 9 of 44 (20.4 %) dissected vessels without stroke (PsCAD. Key points   · Intraluminal contrast enhancement is associated with cerebral ischemia in corresponding vessel territories in patients with cervical artery dissection.. · Our results suggest that intraluminal contrast enhancement represents intraluminal thrombus formation.. · Black-blood imaging might be useful to identify those patients with cervical artery dissection at higher risk for initial or recurrent stroke.. Citation Format · Coppenrath E, Lenz O, Sommer N et al. Clinical Significance of Intraluminal Contrast Enhancement in Patients with Spontaneous Cervical Artery Dissection: A Black-Blood MRI Study. Fortschr Röntgenstr 2017; 189: 624 - 631. © Georg Thieme Verlag KG Stuttgart · New York.

  9. [Pooled Umbilical Cord Blood Plasma for Culturing UCMSC and Ex Vivo Expanding Umbilical Cord Blood CD34⁺ Cells].

    Science.gov (United States)

    Wu, Jie-Ying; Lu, Yan; Chen, Jin-Song; Wu, Shao-Qing; Tang, Xue-Wei; Li, Yan

    2015-08-01

    To investigate the feasibility of umbilical cord blood plasma (UCP) as a replacement for fetal bovine serum (FBS) for culturing mesenchymal stem cells (MSC) derived from umbilical cord, and to observe the supporting effects of these cells (served as a feeder layer) on ex vivo expanding of human umbilical cord blood CD34(+) cells. Umbilical cord blood (UCB) units were suitable if the Guangzhou cord blood bank donor selection criteria strictly were fulfilled. UCP were ready to use after the collection from the plasma depletion/reduction during the processing and pooling of suitable UCB units (at least 30 units were screened for pathogens and microorganisms, and qualified). Umbilical cord mesenchymal stem cells (UCMSC) were harvested from the umbilical cord tissue of health full-term newborns after delivery by enzyme digestion and divided into 3 groups: group 1 and 2 were cultured in the presence of DMEM/F12 containing either FBS or UCP; and group 3 was cultured in serum-free medium (StemPro® MSC SFM CTS™). Morphology, proliferation and surface marker expression were examined by flow cytometry, and the differentiation toward adipogenic and osteogenic lineages was used for investigating the effect of media on UCMSC after 3-5 passages. Next, the cells cultured in the three different media were cryopreserved and thawed, then prepared as feeder layers with the name of UCMSC(FBS), UCMSC(UCP), and UCMSC(SFM), respectively. The CD34⁺ cells were separated from UCB by magnetic activated cell sorting (MACS) and divided into 4 groups cultured in StemPro(-34) SFM medium added with hematopoietic cytokine combination (StemSpan® CC100). The control group included only CD34⁺ cells as group A (blank control) and experimental groups included UCMSC(FBS) + CD34⁺ cells as group B, UCMSC(UCP) + CD34⁺ cells as group C, UCMSC(SFM) + CD34⁺ cells as group D, and cells in all groups were cultured ex vivo for 7 days. The nucleated cell (NC) number was counted by cell counter, CD34

  10. 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

  11. ROC Analysis of Visual Assessments Made in Gated Blood Pool Scans of Patients with Coronary Artery Disease

    International Nuclear Information System (INIS)

    Lee, Kyung Han; Choi, Yoon Ho; Lee, Bum Woo; Moon, Dae Hyuk; Chung, June Key; Lee, Myung Chul; Koh, Chang Soon; Koong, Sung Soo

    1989-01-01

    Visual assessment of regional wall motion abnormality (RWMA) by gated blood pol scan (GBPS) serves as an useful parameter in thc diagnosis, functional evaluation, and follow up in various clinical settings, but are still subject to some inherent limitations. On important problem may be the interobserver as well as intraobsever variation that may well be present due to the subjective nature of the interpretations. This study was carried out to determine the reliability and reproducibility of visual assessments made in GBPSs, and to observe the degree to which the results would be influenced by observer variation. Fifty two patients with coronary heart disease had resting GBPS and contrast ventriculography within 4 days apart. Contrast ventriculography showed normal wall motion in 6 patients and the remaining 46 had RWMA in one or more segments. The anterior and left anterolateral views of all 52 GBPSs were analyzed by three independent observers, who selected from 5 scales, their level of confidence that there was RWMA in that segment. Receiver operating characteristic (ROC) curves for each analysis was plotted and the area under the curve (θ) was used as a parameter representing each observer's performance in his interpretations. The findings of contract ventriculographies were used as the standard for RWMA. The apical and inferoapical segments showed the best correlation with contrast ventriculography (θ=0.90-.094, 0.81-0.94, respectively), and the inferior wall showed the poorest correlation (θ=0.70-0.74). The interpretations of the inferior, septal, apical and posteroinferior, segments showed no difference between the observers, but there was significantly better performance in assessment by observer A compared to that by B or C for the anterolateral segments (θ=0.87, 0.78, 0.76, respectively, p<0.01 for A vs B, p<0,05 for A vs C), as well as when all segments were considered altogether (θ=0,88, 0.83, 0.82, respectively, both p<0 05). This was also true for

  12. Non-invasive estimation of blood pressure using ultrasound contrast agents

    Science.gov (United States)

    Andersen, Klaus Scheldrup; Jensen, Jørgen Arendt

    2010-01-01

    Local blood pressure measurements provide important information on the state of health of organs in the body and can be used to diagnose diseases in the heart, lungs, and kidneys. This paper presents an experimental setup for investigating the ambient pressure sensitivity of a contrast agent using diagnostic ultrasound. The setup resembles a realistic clinical setup utilizing a single array transducer for transmit and receive. The ambient pressure sensitivity of SonoVue (Bracco, Milano, Italy) was measured twice using two different acoustic driving pressures, which were selected based on a preliminary experiment. To compensate for variations in bubble response and to make the estimates more robust, the relation between the energy of the subharmonic and the fundamental component was chosen as a measure over the subharmonic peak amplitude. The preliminary study revealed the growth stage of the subharmonic component to occur at acoustic driving pressures between 300 and 500 kPa. Based on this, the pressure sensitivity was investigated using a driving pressure of 485 and 500 kPa. At 485 kPa, a linear pressure sensitivity of 0.42 dB/kPa was found having a linear correlation coefficient of 0.94. The second measurement series at 485 kPa showed a sensitivity of 0.41 dB/kPa with a correlation coefficient of 0.89. Based on the measurements at 500 kPa, this acoustic driving pressure was concluded to be too high causing the bubbles to be destroyed. The pressure sensitivity for these two measurement series were 0.42 and 0.25 dB/kPa with linear correlation coefficients of 0.98 and 0.93, respectively.

  13. Effect of ionic and non-ionic contrast media on aggregation of red blood cells in vitro

    International Nuclear Information System (INIS)

    Raininko, R.; Ylinen, S.L.

    1987-01-01

    Fresh human blood without additives, and contrast medium were mixed and examined immediately by light microscopy in a non-flowing state. Sodium meglumine diatrizoate, meglumine diatrizoate, meglumine iodamide, sodium meglumine ioxaglate, iopromide, iopamidol, iohexol, and metrizamide were tested in concentrations of 300 mgI/ml. Physiologic saline and 5% glucose were used as controls. All media were tested in a randomized order with blood samples from 23 volunteers. No aggregation was detected in physiologic saline, and few rouleaux were found in ionic contrast media. Irregular red cell aggregates were found in all low-osmolal contrast media: in 17% of the specimens in ioxaglate, in 52% in metrizamide, and in 78 to 100% in other non-ionic media. Irregular aggregates were seen in all specimens with glucose. It remains to be domonstrated whether or not the irregular aggregation of human red cells in non-ionic contrast media has clinical significance. Iohexol was also tested with blood samples from several laboratory animals, but in nearly every case no aggregates were found. Results of animal experiments or tests with animal blood seem to be poorly applicable to man. (orig.)

  14. Finite-element modeling of time-dependent sodium exchange across the hollow fiber of a hemodialyzer by coupling with a blood pool model.

    Science.gov (United States)

    Ravagli, Enrico; Grandi, Elena; Rovatti, Paolo; Severi, Stefano

    2016-11-11

    Hollow fiber models describe the exchange of solutes between blood and dialysate across the membrane of a single fiber of the hemodialysis filter (hemodialyzer). This work aims to develop a new approach to simulate the solute exchange in a hollow fiber in a dynamic and realistic way. Sodium was chosen as our solute of interest due to its importance in hemodialysis as an osmotic regulator. A 2-dimensional (2D) hollow fiber model based on the finite element method (FEM) is coupled to a simple blood pool model to dynamically update the concentration of the solute entering the dialyzer. The resulting coupled model maintains the geometrical detail of the 2D fiber representation and gains a dynamic, blood-side inlet solute concentration. In vitro dialysis sessions were carried out for model validation, by implementing a combination of blood volume loss and/or sodium concentration steps. Plasmatic sodium concentration was recorded by blood gas sampling. Dialysate inlet and outlet conductivities were continuously recorded. Simulated plasmatic sodium concentration was compared with data from the blood gas samples. A mean error of 1.76 ± 1.03 mM was found for the complete dataset, along with a 3.87 mM maximum error. The simulated outlet dialysate sodium concentration was compared with the recorded outlet dialysate conductivity: a very high correlation was found on the whole dataset (R2 = 0.992). Coupling our FEM hollow fiber model to a simple blood pool model proved to be an effective approach for dynamical analysis of the properties of the hemodialyzer.

  15. Effect of streptozotocin-induced diabetes on myocardial blood flow reserve assessed by myocardial contrast echocardiography in rats

    Directory of Open Access Journals (Sweden)

    Weytjens Caroline

    2008-09-01

    Full Text Available Abstract The role of structural and functional abnormalities of small vessels in diabetes cardiomyopathy remains unclear. Myocardial contrast echocardiography allows the quantification of myocardial blood flow at rest and during dipyridamole infusion. The aim of the study was to determine the myocardial blood flow reserve in normal rats compared with Streptozotocin-induced diabetic rats using contrast echocardiography. Methods We prospectively studied 40 Wistar rats. Diabetes was induced by intravenous streptozotocin in 20 rats. All rats underwent baseline and stress (dipyridamole: 20 mg/kg high power intermittent imaging in short axis view under anaesthesia baseline and after six months. Myocardial blood flow was determined and compared at rest and after dipyridamole in both populations. The myocardial blood flow reserve was calculated and compared in the 2 groups. Parameters of left ventricular function were determined from the M-mode tracings and histological examination was performed in all rats at the end of the study. Results At six months, myocardial blood flow reserve was significantly lower in diabetic rats compared to controls (3.09 ± 0.98 vs. 1.28 ± 0.67 ml min-1 g-1; p Conclusion In this animal study, diabetes induced a functional alteration of the coronary microcirculation, as demonstrated by contrast echocardiography, a decrease in capillary density and of the cardiac systolic function. These findings may offer new insights into the underlying mechanisms of diabetes cardiomyopathy.

  16. Proposta do uso de pool de sangue total como controle interno de qualidade em hematologia Proposal for the use of a pool of whole blood as internal quality control in hematology

    Directory of Open Access Journals (Sweden)

    Carina Daniele Schons

    2010-06-01

    Full Text Available INTRODUÇÃO: A confiabilidade dos resultados do laboratório é garantida pela realização do controle de qualidade, que tem como funções básicas análise, pesquisa e prevenção da ocorrência de erros laboratoriais por meio de programas que abrangem tanto o controle interno quanto o externo. OBJETIVO: Propor a padronização de utilização de pool de sangue total como controle interno de qualidade no setor de hematologia. MÉTODO: Foram selecionadas amostras de sangue total, colhidas com ácido etilenodiaminotetracético (EDTA, de mesmos grupo sanguíneo e fator Rh, livres de interferentes, como hemólise, lipemia e icterícia. De um total de 30 ml de sangue total, obtiveram-se três alíquotas de 10 ml cada, às quais foram adicionados, respectivamente, 0 ml (sem adição, 1 ml e 5 ml de glicerol (conservante. As amostras foram avaliadas em contador automático ADVIA® 60. Após determinação dos valores de média e DP, todas as amostras foram avaliadas por um período de 45 dias úteis para confecção do gráfico de Levey-Jennings e verificação da estabilidade da amostra. RESULTADO E CONCLUSÃO: Podemos verificar que o pool de sangue total, preparado de acordo com a metodologia proposta, não apresenta estabilidade necessária para sua utilização, como controle interno alternativo no setor de hematologia.INTRODUCTION: The reliability of laboratory results is ensured by the implementation of quality control, which has basic functions, such as analysis, research and prevention of laboratory errors through programs that encompass both internal and external control. OBJECTIVE: To propose a standard method to use pooled whole blood as internal quality control in the Hematology division. METHOD: The selected whole blood samples were collected with EDTA, belonged to the same blood group and Rh factor and did not present interfering factors, such as hemolysis, lipemia and icterus. From a total of 30 ml of whole blood it was obtained 3

  17. Non-contrast 3D black blood MRI for abdominal aortic aneurysm surveillance: comparison with CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Chengcheng; Leach, Joseph R.; Hope, Michael D. [University of California San Francisco, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Tian, Bing; Liu, Qi; Lu, Jianping; Chen, Luguang [Changhai Hospital, Department of Radiology, Shanghai (China); Saloner, David [University of California San Francisco, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Radiology Service, VA Medical Center, San Francisco, CA (United States)

    2017-05-15

    Management of abdominal aortic aneurysms (AAAs) is based on diameter. CT angiography (CTA) is commonly used, but requires radiation and iodinated contrast. Non-contrast MRI is an appealing alternative that may allow better characterization of intraluminal thrombus (ILT). This study aims to 1) validate non-contrast MRI for measuring AAA diameter, and 2) to assess ILT with CTA and MRI. 28 patients with AAAs (diameter 50.7 ± 12.3 mm) underwent CTA and non-contrast MRI. MRI was acquired at 3 T using 1) a conventional 3D gradient echo (GRE) sequence and 2) a 3D T{sub 1}-weighted black blood fast-spin-echo sequence. Two radiologists independently measured the AAA diameter. The ratio of signal of ILT and adjacent psoas muscle (ILT{sub r} = signal{sub ILT}/signal{sub Muscle}) was quantified. Strong agreement between CTA and non-contrast MRI was shown for AAA diameter (intra-class coefficient > 0.99). Both approaches had excellent inter-observer reproducibility (ICC > 0.99). ILT appeared homogenous on CTA, whereas MRI revealed compositional variations. Patients with AAAs ≥5.5 cm and <5.5 cm had a variety of distributions of old/fresh ILT types. Non-contrast 3D black blood MRI provides accurate and reproducible AAA diameter measurements as validated by CTA. It also provides unique information about ILT composition, which may be linked with elevated risk for disease progression. (orig.)

  18. Dynamic contrast enhanced CT measurement of blood flow during interstitial laser photocoagulation: comparison with an Arrhenius damage model

    International Nuclear Information System (INIS)

    Purdie, T.J.; Lee, T.J.; Iizuka, M.; Sherar, M.D.

    2000-01-01

    One effect of heating during interstitial laser photocoagulation (ILP) is to directly destroy the tumour vasculature resulting in a loss of viable blood supply. Therefore, blood flow measured during and after treatment can be a useful indicator of tissue thermal damage. In this study, the effect of ILP treatment on rabbit thigh tumours was investigated by measuring blood flow changes using dynamic contrast enhanced computed tomography (CT). The CT measured changes in blood flow of treated tumour tissue were fitted to an Arrhenius model assuming first order rate kinetics. Our results show that changes in blood flow of tumour tissue distant from surrounding normal tissue are well described by an Arrhenius model. By contrast, the temperature profile of tumour tissue adjacent to normal tissue must be modified to account for heat dissipation by the latter. Finally, the Arrhenius parameters derived in the study are similar to those derived by heating tumour tissue to a lower temperature (<47 deg. C) than the current study. In conclusion, CT can be used to monitor blood flow changes during ILP and these measurements are related to the thermal damage predicted by the Arrhenius model. (author)

  19. Prospective comparison of air-contrast barium enema and colonoscopy in patients with fecal occult blood: a pilot study.

    Science.gov (United States)

    Rockey, Don C; Koch, Johannes; Yee, Judy; McQuaid, Kenneth R; Halvorsen, Robert A

    2004-12-01

    The utility of air-contrast barium enema and colonoscopy for evaluation of the colon has been debated. Air-contrast barium enema is less expensive and invasive than colonoscopy, but it also is less sensitive and specific. Further, although air-contrast barium enema may be less painful than colonoscopy, it often is poorly tolerated by patients. Thus, this study compared the sensitivity and the specificity of air-contrast barium enema and colonoscopy for detection of colonic lesions in patients with fecal occult blood. Over a 30-month period, patients with fecal occult blood were recruited. Patients underwent standard air-contrast barium enema, followed by colonoscopy 7 to 14 days later. Colonoscopists were blinded to the results of air-contrast barium enema until the colonoscopy was completed, after which the results were disclosed. If the findings were discrepant, colonoscopy was repeated. A total of 100 patients were evaluated. Nine air-contrast barium enemas were reported to be inadequate, and the cecum was not intubated at colonoscopy in two patients. In the remaining patients, 5 cancers were identified (1 each cecum, transverse colon, descending colon, sigmoid colon, and rectum) by both studies. Sixty-six polypoid lesions were identified in 30 patients. Diverticula were identified in 42 patients by air-contrast barium enema and in 18 patients by colonoscopy. Air-contrast barium enema detected 3 of 36 polypoid lesions 5 mm or less in diameter, 5 of 15 adenomas 6 to 9 mm in size, and 4 of 15 adenomas 10 mm or greater in diameter (sensitivity 8%, 33%, and 27%, respectively). After excluding patients with diverticula, air-contrast barium enema detected 3 of 7 adenomas 10 mm or greater in size. Overall, 12 polypoid lesions or filling defects were identified by air-contrast barium enema that could not be verified by colonoscopy. The specificity of air-contrast barium enema for lesions 1.0 cm or greater in size was 100%; for those 6 mm or greater, it was 97%. Air-contrast

  20. Usage of CO2 microbubbles as flow-tracing contrast media in X-ray dynamic imaging of blood flows.

    Science.gov (United States)

    Lee, Sang Joon; Park, Han Wook; Jung, Sung Yong

    2014-09-01

    X-ray imaging techniques have been employed to visualize various biofluid flow phenomena in a non-destructive manner. X-ray particle image velocimetry (PIV) was developed to measure velocity fields of blood flows to obtain hemodynamic information. A time-resolved X-ray PIV technique that is capable of measuring the velocity fields of blood flows under real physiological conditions was recently developed. However, technical limitations still remained in the measurement of blood flows with high image contrast and sufficient biocapability. In this study, CO2 microbubbles as flow-tracing contrast media for X-ray PIV measurements of biofluid flows was developed. Human serum albumin and CO2 gas were mechanically agitated to fabricate CO2 microbubbles. The optimal fabricating conditions of CO2 microbubbles were found by comparing the size and amount of microbubbles fabricated under various operating conditions. The average size and quantity of CO2 microbubbles were measured by using a synchrotron X-ray imaging technique with a high spatial resolution. The quantity and size of the fabricated microbubbles decrease with increasing speed and operation time of the mechanical agitation. The feasibility of CO2 microbubbles as a flow-tracing contrast media was checked for a 40% hematocrit blood flow. Particle images of the blood flow were consecutively captured by the time-resolved X-ray PIV system to obtain velocity field information of the flow. The experimental results were compared with a theoretically amassed velocity profile. Results show that the CO2 microbubbles can be used as effective flow-tracing contrast media in X-ray PIV experiments.

  1. Magnetic Particle / Magnetic Resonance Imaging: In-Vitro MPI-Guided Real Time Catheter Tracking and 4D Angioplasty Using a Road Map and Blood Pool Tracer Approach.

    Science.gov (United States)

    Salamon, Johannes; Hofmann, Martin; Jung, Caroline; Kaul, Michael Gerhard; Werner, Franziska; Them, Kolja; Reimer, Rudolph; Nielsen, Peter; Vom Scheidt, Annika; Adam, Gerhard; Knopp, Tobias; Ittrich, Harald

    2016-01-01

    In-vitro evaluation of the feasibility of 4D real time tracking of endovascular devices and stenosis treatment with a magnetic particle imaging (MPI) / magnetic resonance imaging (MRI) road map approach and an MPI-guided approach using a blood pool tracer. A guide wire and angioplasty-catheter were labeled with a thin layer of magnetic lacquer. For real time MPI a custom made software framework was developed. A stenotic vessel phantom filled with saline or superparamagnetic iron oxide nanoparticles (MM4) was equipped with bimodal fiducial markers for co-registration in preclinical 7T MRI and MPI. In-vitro angioplasty was performed inflating the balloon with saline or MM4. MPI data were acquired using a field of view of 37.3×37.3×18.6 mm3 and a frame rate of 46 volumes/sec. Analysis of the magnetic lacquer-marks on the devices were performed with electron microscopy, atomic absorption spectrometry and micro-computed tomography. Magnetic marks allowed for MPI/MRI guidance of interventional devices. Bimodal fiducial markers enable MPI/MRI image fusion for MRI based roadmapping. MRI roadmapping and the blood pool tracer approach facilitate MPI real time monitoring of in-vitro angioplasty. Successful angioplasty was verified with MPI and MRI. Magnetic marks consist of micrometer sized ferromagnetic plates mainly composed of iron and iron oxide. 4D real time MP imaging, tracking and guiding of endovascular instruments and in-vitro angioplasty is feasible. In addition to an approach that requires a blood pool tracer, MRI based roadmapping might emerge as a promising tool for radiation free 4D MPI-guided interventions.

  2. Magnetic Particle / Magnetic Resonance Imaging: In-Vitro MPI-Guided Real Time Catheter Tracking and 4D Angioplasty Using a Road Map and Blood Pool Tracer Approach.

    Directory of Open Access Journals (Sweden)

    Johannes Salamon

    Full Text Available In-vitro evaluation of the feasibility of 4D real time tracking of endovascular devices and stenosis treatment with a magnetic particle imaging (MPI / magnetic resonance imaging (MRI road map approach and an MPI-guided approach using a blood pool tracer.A guide wire and angioplasty-catheter were labeled with a thin layer of magnetic lacquer. For real time MPI a custom made software framework was developed. A stenotic vessel phantom filled with saline or superparamagnetic iron oxide nanoparticles (MM4 was equipped with bimodal fiducial markers for co-registration in preclinical 7T MRI and MPI. In-vitro angioplasty was performed inflating the balloon with saline or MM4. MPI data were acquired using a field of view of 37.3×37.3×18.6 mm3 and a frame rate of 46 volumes/sec. Analysis of the magnetic lacquer-marks on the devices were performed with electron microscopy, atomic absorption spectrometry and micro-computed tomography.Magnetic marks allowed for MPI/MRI guidance of interventional devices. Bimodal fiducial markers enable MPI/MRI image fusion for MRI based roadmapping. MRI roadmapping and the blood pool tracer approach facilitate MPI real time monitoring of in-vitro angioplasty. Successful angioplasty was verified with MPI and MRI. Magnetic marks consist of micrometer sized ferromagnetic plates mainly composed of iron and iron oxide.4D real time MP imaging, tracking and guiding of endovascular instruments and in-vitro angioplasty is feasible. In addition to an approach that requires a blood pool tracer, MRI based roadmapping might emerge as a promising tool for radiation free 4D MPI-guided interventions.

  3. Dual-Wavelength Laser Speckle Contrast Imaging (dwLSCI Improves Chronic Measurement of Superficial Blood Flow in Hands

    Directory of Open Access Journals (Sweden)

    Lingke Zhang

    2017-12-01

    Full Text Available Laser speckle contrast imaging (LSCI has been widely used to determine blood flow and perfusion in biological tissues. The physical model of traditional LSCI ignores the effects of scattering property distribution in relation to speckle correlation time τc and blood flow v, which further results in biased estimation. In this study, we developed a dual-wavelength laser speckle contrast imaging (dwLSCI method and a portable device for imaging the blood flow and tissue perfusion in human hands. Experimental data showed that dwLSCI could retrieve the vein vasculatures under the surface skin, and it further provided accurate measurements of vein blood flow signals, tissue perfusion signals, and fingertip perfusion signals, which assist with assessments of rehabilitation therapy for stroke patients. Fingertip perfusion signals demonstrated better performance in early assessments, while vein blood flow signals assisted the Fugl–Meyer Assessment Scale (FMA and the Wolf Motor Function Test (WMFT behavior assessments. As a general noninvasive imaging method, dwLSCI can be applied in clinical studies related to hand functions combined with behavior assessments.

  4. Dual-Wavelength Laser Speckle Contrast Imaging (dwLSCI) Improves Chronic Measurement of Superficial Blood Flow in Hands

    Science.gov (United States)

    Zhang, Lingke; Ding, Li; Li, Miao; Zhang, Xiaoli; Su, Diansan; Jia, Jie; Miao, Peng

    2017-01-01

    Laser speckle contrast imaging (LSCI) has been widely used to determine blood flow and perfusion in biological tissues. The physical model of traditional LSCI ignores the effects of scattering property distribution in relation to speckle correlation time τc and blood flow v, which further results in biased estimation. In this study, we developed a dual-wavelength laser speckle contrast imaging (dwLSCI) method and a portable device for imaging the blood flow and tissue perfusion in human hands. Experimental data showed that dwLSCI could retrieve the vein vasculatures under the surface skin, and it further provided accurate measurements of vein blood flow signals, tissue perfusion signals, and fingertip perfusion signals, which assist with assessments of rehabilitation therapy for stroke patients. Fingertip perfusion signals demonstrated better performance in early assessments, while vein blood flow signals assisted the Fugl–Meyer Assessment Scale (FMA) and the Wolf Motor Function Test (WMFT) behavior assessments. As a general noninvasive imaging method, dwLSCI can be applied in clinical studies related to hand functions combined with behavior assessments. PMID:29206145

  5. 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...

  6. Myocardial blood flow estimates from dynamic contrast-enhanced magnetic resonance imaging: three quantitative methods

    Science.gov (United States)

    Borrazzo, Cristian; Galea, Nicola; Pacilio, Massimiliano; Altabella, Luisa; Preziosi, Enrico; Carnì, Marco; Ciolina, Federica; Vullo, Francesco; Francone, Marco; Catalano, Carlo; Carbone, Iacopo

    2018-02-01

    Dynamic contrast-enhanced cardiovascular magnetic resonance imaging can be used to quantitatively assess the myocardial blood flow (MBF), recovering the tissue impulse response function for the transit of a gadolinium bolus through the myocardium. Several deconvolution techniques are available, using various models for the impulse response. The method of choice may influence the results, producing differences that have not been deeply investigated yet. Three methods for quantifying myocardial perfusion have been compared: Fermi function modelling (FFM), the Tofts model (TM) and the gamma function model (GF), with the latter traditionally used in brain perfusion MRI. Thirty human subjects were studied at rest as well as under cold pressor test stress (submerging hands in ice-cold water), and a single bolus of gadolinium weighing 0.1  ±  0.05 mmol kg‑1 was injected. Perfusion estimate differences between the methods were analysed by paired comparisons with Student’s t-test, linear regression analysis, and Bland–Altman plots, as well as also using the two-way ANOVA, considering the MBF values of all patients grouped according to two categories: calculation method and rest/stress conditions. Perfusion estimates obtained by various methods in both rest and stress conditions were not significantly different, and were in good agreement with the literature. The results obtained during the first-pass transit time (20 s) yielded p-values in the range 0.20–0.28 for Student’s t-test, linear regression analysis slopes between 0.98–1.03, and R values between 0.92–1.01. From the Bland–Altman plots, the paired comparisons yielded a bias (and a 95% CI)—expressed as ml/min/g—for FFM versus TM, ‑0.01 (‑0.20, 0.17) or 0.02 (‑0.49, 0.52) at rest or under stress respectively, for FFM versus GF, ‑0.05 (‑0.29, 0.20) or  ‑0.07 (‑0.55, 0.41) at rest or under stress, and for TM versus GF, ‑0.03 (‑0.30, 0.24) or  ‑0.09 (‑0.43, 0

  7. In-vitro effects of tri-iodinated X-ray contrast media on blood coagulation, fibrinolysis and complement system

    International Nuclear Information System (INIS)

    Blanke, D.

    1982-01-01

    In-vitro experiments with Jodipamid, Jothalamat and Diatrizoat served the purpose of determining influences of contrast media on blood coagulation, fibrinolysis and the complement system. For all three contrast media investigated the effect noted was dose-dependent and was only brought about by concentrations higher than physiological ones. Liver-pathway Jodipamid was seen to have a much stronger effect than the two renal-pathway contrast media Jothalamat and Diatrizoat, which is probably due to the different protein binding capacities. In detail, the results with Jodipamid were as follows: a sharp fall in thrombinogen, a distinct decrease in fibrinogen both in the immunological and functional test, but only delayed decrease in complement factor C 4. Fibrinolytic fission products were found after applying the dose of 30 mM, as compared to 400 mM for the renal-pathway contrast media. Furthermore the functional tests (F I and F II) with Jothalamat and Diatrizoat showed only slight effects, the immunological ones (F I and C 4) none at all. The influence of the contrast media on factors I and II is interpreted by the author as an inhibition of fibrin polymerization. What seems to be the verification of fibrinolytic fission products is explained by a non-specific agglutination reaction, the decrease in C 4 by contrast-medium-induced protein denaturation. (orig./MG) [de

  8. 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.

  9. The predictive value of additional late blood pool imaging to the three-phase bone scan in the diagnosis of reflex sympathetic dystrophy in hemiplegic patients.

    Science.gov (United States)

    Okudan, Berna; Celik, Canan; Serttas, Seyfi; Ozgirgin, Neşe

    2005-12-01

    Reflex sympathetic dystrophy (RSD) is a relative common sequel after hemiplegia. The diagnosis of RSD in hemiplegic patients presents difficult clinical problems, as the symptoms and signs of RSD are not specific and RSD may be due to reasons other than hemiplegia. Bone scintigraphy has been routinely used for the diagnosis of RSD; however, the optimal acquisition protocols, diagnostic patterns and the utility of quantitation are controversial. This prospective study was conducted to demonstrate the higher predictive value of an additional late blood pool image to the three-phase bone scan compared to the regular three-phase bone scans in RSD patients associated with hemiplegia. Thirty-four RSD patients were enrolled into the study. Bone scans according to the new protocol were obtained for all patients. Those patients with either negative or positive bone scans with no evidence of RSD were followed for 6 months. The patients had positive bone scan findings and were symptomatic at the time of the study. Of these, seven patients (58.3%) subsequently became symptomatic and five patients (41.7%) remained asymptomatic at 6 months. None of the patients with negative bone scans had symptoms of RSD on presentation except one case. We conclude that the addition of a late blood pool image increases the predictive value and has an impact on initiating early treatment in asymptomatic patients.

  10. Automatic measurements of local ventricular parameters using gated blood-pool emission tomography; Extraction automatique des parametres fonctionnels ventriculaires locaux en tomoventriculographie isotopique

    Energy Technology Data Exchange (ETDEWEB)

    Mariano-Goulart, D.; Caderas de Kerleau, C.; Rossi, M. [Centre Hospitalier Universitaire Lapeyronie, 34 - Montpellier (France)

    2005-03-01

    This paper describes a new method designed to improve the accuracy of the assessment of systolic and diastolic parameters from noisy regional time-activity curves, both for the right and the left ventricle. First, we explain how it is possible to derive local time-activity curves from segmented gated-blood pool tomographic acquisitions. The new method is based on the computation of a suitable deformation of a reference time-activity-curve. This paper describes how this reference curve is transformed to approximate the acquired data with a smooth, noise-free time-activity curve from which relevant clinical parameters can be derived. One may remind and illustrate the main results dealing with the validation studies of this new method achieved on simulated data and by comparison with multi-harmonic reconstructions. Last, some clinical examples are proposed to illustrate the potentials of this method. The deformable model used in this paper provides accurate assessment of systolic (time of end systole, amplitude, peak ejection rate) or diastolic parameters (peak filling rate) both for planar and tomographic gated blood pool studies. Further clinical studies are now necessary to compare the results of this model with those achieved with usual multi-harmonic fits, and to evaluate its interest in the assessment of rhythmic heart diseases or in the prognosis of heart failure. (author)

  11. Influence of a hyperlipidic diet on the composition of the non-membrane lipid pool of red blood cells of male and female rats

    Directory of Open Access Journals (Sweden)

    Xavier Remesar

    2015-07-01

    Full Text Available Background and objectives. Red blood cells (RBC are continuously exposed to oxidative agents, affecting their membrane lipid function. However, the amount of lipid in RBCs is higher than the lipids of the cell membrane, and includes triacylglycerols, which are no membrane components. We assumed that the extra lipids originated from lipoproteins attached to the cell surface, and we intended to analyse whether the size and composition of this lipid pool were affected by sex or diet.Experimental design. Adult male and female Wistar rats were fed control or cafeteria diets. Packed blood cells and plasma lipids were extracted and analysed for fatty acids by methylation and GC-MS, taking care of not extracting membrane lipids.Results. The absence of ω3-PUFA in RBC extracts (but not in plasma suggest that the lipids extracted were essentially those in the postulated lipid surface pool and not those in cell membrane. In cells’ extracts, there was a marked depletion of PUFA (and, in general, of insaturation. Fatty acid patterns were similar for all groups studied, with limited effects of sex and no effects of diet in RBC (but not in plasma fatty acids. Presence of trans fatty acids was small but higher in RBC lipids, and could not be justified by dietary sources.Conclusions. The presence of a small layer of lipid on the RBC surface may limit oxidative damage to the cell outer structures, and help explain its role in the transport of lipophilic compounds. However, there may be other, so far uncovered, additional functions for this lipid pool.

  12. Effects of iodinated contrast media on common carotid and brachial artery blood flow and wall shear stress

    International Nuclear Information System (INIS)

    Irace, C.; Tamburini, S.; Bertucci, B.; Franceschi, M.S. de; Gnasso, A.

    2006-01-01

    The aim of our study was to evaluate the effect of the intravenous contrast media iomeprol on wall shear stress, blood flow and vascular parameters in the common carotid and brachial artery. Thirty outpatients undergoing thoracic or abdominal spiral CT scans were studied. The internal diameter and flow velocity of the common carotid and brachial artery were evaluated by ultrasound, and blood viscosity was measured before and after low osmolality iomeprol (Iomeron 350) injection. The wall shear stress, blood flow and pulsatility index were calculated. To test the differences between groups, the Wilcoxon rank test and Mann Whitney U test were applied. Blood viscosity decreased slightly, but significantly after contrast media (4.6±0.7 vs. 4.5±0.7 mPa.s, P=0.02). Contrarily, blood flow and wall shear stress did not change in the common carotid artery, but significantly decreased in the brachial artery (0.9±0.4 vs. 0.6±0.3 ml/s, P<0.0001, and 41.5±13.9 vs. 35.3±11.0 dynes/cm2, P<0.002, respectively), whereas the pulsatility index significantly increased in the brachial artery (5.0±3.3 vs. 7.5±5.3, P<0.001). Iomeprol injection causes blood flow and wall shear stress reduction of the brachial artery; the rise in the pulsatility index suggests an increase in peripheral vascular resistance. Further investigation is needed to evaluate whether these modifications can be clinically relevant. (orig.)

  13. Computational fluid dynamics simulations of blood flow regularized by 3D phase contrast MRI

    DEFF Research Database (Denmark)

    Rispoli, Vinicius C; Nielsen, Jon; Nayak, Krishna S

    2015-01-01

    BACKGROUND: Phase contrast magnetic resonance imaging (PC-MRI) is used clinically for quantitative assessment of cardiovascular flow and function, as it is capable of providing directly-measured 3D velocity maps. Alternatively, vascular flow can be estimated from model-based computation fluid dyn...

  14. Measurement of brain perfusion, blood volume, and blood-brain barrier permeability, using dynamic contrast-enhanced T(1)-weighted MRI at 3 tesla.

    Science.gov (United States)

    Larsson, Henrik B W; Courivaud, Frédéric; Rostrup, Egill; Hansen, Adam E

    2009-11-01

    Assessment of vascular properties is essential to diagnosis and follow-up and basic understanding of pathogenesis in brain tumors. In this study, a procedure is presented that allows concurrent estimation of cerebral perfusion, blood volume, and blood-brain permeability from dynamic T(1)-weighted imaging of a bolus of a paramagnetic contrast agent passing through the brain. The methods are applied in patients with brain tumors and in healthy subjects. Perfusion was estimated by model-free deconvolution using Tikhonov's method (gray matter/white matter/tumor: 72 +/- 16/30 +/- 8/56 +/- 45 mL/100 g/min); blood volume (6 +/- 2/4 +/- 1/7 +/- 6 mL/100 g) and permeability (0.9 +/- 0.4/0.8 +/- 0.3/3 +/- 5 mL/100 g/min) were estimated by using Patlak's method and a two-compartment model. A corroboration of these results was achieved by using model simulation. In addition, it was possible to generate maps on a pixel-by-pixel basis of cerebral perfusion, cerebral blood volume, and blood-brain barrier permeability. (c) 2009 Wiley-Liss, Inc.

  15. Clinical significance of intraluminal contrast enhancement in patients with spontaneous cervical artery dissection. A black-blood MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Coppenrath, Eva; Lenz, Olga; Sommer, Nora; Treitl, Karla; Reiser, Maximilian [Munich Univ. (Germany). Inst. of Clinical Radiology; Lummel, Nina [Univ. Hospital Klinikum rechts der Isar Munich, Munich (Germany). Inst. of Neuroradiology and Interventional Neuroradiology; Linn, Jennifer [Univ. Hospital Dresden (Germany). Inst. of Neuroradiology; Bamberg, Fabian [Tuebingen Univ. (Germany). Diagnostical and Interventional Radiology; Pfefferkorn, Thomas [Munich Univ. (Germany). Interdisciplinary Stroke Center Munich; Saam, Tobias [Radiology Center Rosenheim (Germany)

    2017-07-15

    Recent studies have suggested that intraluminal thrombi show contrast enhancement on carotid black-blood T1w MRI. The aim of this study was to evaluate the significance of intraluminal contrast enhancement (iCE) regarding symptom status in patients with spontaneous cervical artery dissection (sCAD). 33 consecutive patients (19 men) with sCAD received a brain MRI (DIFF, T2w, T2{sup *}w, FLAIR) and a multi-sequence 3T-MRI with fat-saturated high-resolution black-blood T1w-sequences pre- and post-contrast, contrast-enhanced MR angiography and TOF images of carotid and vertebral arteries. Presence/absence of iCE, vessel occlusion and vessel wall hematoma (hyperintense in T1w pre-contrast) were analysed by two radiologists in consensus decision. 44 of 132 analysed vessels had a vessel wall hematoma, consistent with sCAD. In 17 of 44 dissected vessels an acute ischemic stroke was found. 16 of 17 (94.1 %) vessels ipsilateral to ischemic stroke demonstrated iCE, compared to 9 of 44 (20.4 %) dissected vessels without stroke (P< 0.001). The presence/absence of iCE resulted in a sensitivity, specificity, positive and negative predictive value and accuracy for ischemic stroke of 0.94, 0.67, 0.64, 0.95, and 0.77, respectively, and an odds ratio of 32.0. iCE, which is suggestive of intraluminal thrombus formation, is strongly correlated with ischemic symptoms in patients with sCAD.

  16. Prognostic Significance of Hyponatremia in Acute Intracerebral Hemorrhage: Pooled Analysis of the Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial Studies.

    Science.gov (United States)

    Carcel, Cheryl; Sato, Shoichiro; Zheng, Danni; Heeley, Emma; Arima, Hisatomi; Yang, Jie; Wu, Guojun; Chen, Guofang; Zhang, Shihong; Delcourt, Candice; Lavados, Pablo; Robinson, Thompson; Lindley, Richard I; Wang, Xia; Chalmers, John; Anderson, Craig S

    2016-07-01

    To determine the association of hyponatremia at presentation with clinical and imaging outcomes in patients with acute intracerebral hemorrhage. Retrospective pooled analysis of prospectively collected data from 3,243 participants of the pilot and main phases of the Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trials 1 and 2 (international, multicenter, open, blinded endpoint, randomized controlled trials designed to assess the effects of early intensive blood pressure lowering in patients with acute intracerebral hemorrhage). Clinical hospital sites in 21 countries. Patients with predominantly mild-moderate severity of spontaneous intracerebral hemorrhage within 6 hours of onset and elevated systolic blood pressure (150-220 mm Hg) were included in the study. Patients were assigned to receive intensive (target systolic blood pressure, < 140 mm Hg within 1 hr) or guideline-recommended (target systolic blood pressure, < 180 mm Hg) blood pressure-lowering therapy. Presentation hyponatremia was defined as serum sodium less than 135 mEq/L. The primary outcome was death at 90 days. Multivariable logistic regression was used to assess the association of hyponatremia with important clinical events. Of 3,002 patients with available data, 349 (12%) had hyponatremia. Hyponatremia was associated with death (18% vs 11%; multivariable-adjusted odds ratio, 1.81; 95% CI, 1.28-2.57; p < 0.001) and larger baseline intracerebral hemorrhage volume (multivariable adjusted, p = 0.046) but not with baseline perihematomal edema volume nor with growth of intracerebral hemorrhage or perihematomal edema during the initial 24 hours. Hyponatremia at presentation is associated with increased mortality in patients with predominantly deep and modest volume intracerebral hemorrhage through mechanisms that seem independent of growth in intracerebral hemorrhage or perihematomal edema.

  17. 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.)

  18. Attempts to Improve Absolute Quantification of Cerebral Blood Flow in Dynamic Susceptibility Contrast Magnetic Resonance Imaging: A Simplified T1-Weighted Steady-State Cerebral Blood Volume Approach

    International Nuclear Information System (INIS)

    Wirestam, R.; Knutsson, L.; Risberg, J.; Boerjesson, S.; Larsson, E.M.; Gustafson, L.; Passant, U.; Staahlberg, F.

    2007-01-01

    Background: Attempts to retrieve absolute values of cerebral blood flow (CBF) by dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) have typically resulted in overestimations. Purpose: To improve DSC-MRI CBF estimates by calibrating the DSC-MRI-based cerebral blood volume (CBV) with a corresponding T1-weighted (T1W) steady-state (ss) CBV estimate. Material and Methods: 17 volunteers were investigated by DSC-MRI and 133Xe SPECT. Steady-state CBV calculation, assuming no water exchange, was accomplished using signal values from blood and tissue, before and after contrast agent, obtained by T1W spin-echo imaging. Using steady-state and DSC-MRI CBV estimates, a calibration factor K = CBV(ss)/CBV(DSC) was obtained for each individual. Average whole-brain CBF(DSC) was calculated, and the corrected MRI-based CBF estimate was given by CBF(ss) = KxCBF(DSC). Results: Average whole-brain SPECT CBF was 40.1±6.9 ml/min 100 g, while the corresponding uncorrected DSC-MRI-based value was 69.2±13.8 ml/mi 100 g. After correction with the calibration factor, a CBF(ss) of 42.7±14.0 ml/min 100 g was obtained. The linear fit to CBF(ss)-versus-CBF(SPECT) data was close to proportionality (R 0.52). Conclusion: Calibration by steady-state CBV reduced the population average CBF to a reasonable level, and a modest linear correlation with the reference 133Xe SPECT technique was observed. Possible explanations for the limited accuracy are, for example, large-vessel partial-volume effects, low post-contrast signal enhancement in T1W images, and water-exchange effects

  19. Blood flow in cerebral aneurysms: comparison of phase contrast magnetic resonance and computational fluid dynamics - preliminary experience

    International Nuclear Information System (INIS)

    Karmonik, C.; Benndorf, G.; Klucznik, R.

    2008-01-01

    Purpose: computational fluid dynamics (CFD) simulations are increasingly used to model cerebral aneurysm hemodynamics. We investigated the capability of phase contrast magnetic resonance imaging (pcMRI), guided by specialized software for optimal slice definition (NOVA, Vassol Inc.) as a non-invasive method to measure intra-aneurysmal blood flow patterns in-vivo. In a novel approach, these blood flow patterns measured with pcMRI were qualitatively compared to the ones calculated with CFD. Materials end methods: the volumetric inflow rates into three unruptured cerebral aneurysms and the temporal variations of the intra-aneurysmal blood flow patterns were recorded with pcMRI. Transient CFD simulations were performed on geometric models of these aneurysms derived from 3D digital subtraction angiograms. Calculated intra-aneurysmal blood flow patterns were compared at the times of maximum and minimum arterial inflow to the ones measured with pcMRI and the temporal variations of these patterns during the cardiac cycle were investigated. Results: in all three aneurysms, the main features of intra-aneurysmal flow patterns obtained with pcMRI consisted of areas with positive velocities components and areas with negative velocities components. The measured velocities ranged from approx. ±60 to ±100 cm/sec. Comparison with calculated CFD simulations showed good correlation with regard to the spatial distribution of these areas, while differences in calculated magnitudes of velocities were found. (orig.)

  20. Dynamic contrast-enhanced MRI assessment of hyperemic fractional microvascular blood plasma volume in peripheral arterial disease: initial findings.

    Directory of Open Access Journals (Sweden)

    Bas Versluis

    Full Text Available OBJECTIVES: The aim of the current study was to describe a method that assesses the hyperemic microvascular blood plasma volume of the calf musculature. The reversibly albumin binding contrast agent gadofosveset was used in dynamic contrast-enhanced magnetic resonance imaging (DCE MRI to assess the microvascular status in patients with peripheral arterial disease (PAD and healthy controls. In addition, the reproducibility of this method in healthy controls was determined. MATERIALS AND METHODS: Ten PAD patients with intermittent claudication and 10 healthy control subjects were included. Patients underwent contrast-enhanced MR angiography of the peripheral arteries, followed by one DCE MRI examination of the musculature of the calf. Healthy control subjects were examined twice on different days to determine normative values and the interreader and interscan reproducibility of the technique. The MRI protocol comprised dynamic imaging of contrast agent wash-in under reactive hyperemia conditions of the calf musculature. Using pharmacokinetic modeling the hyperemic fractional microvascular blood plasma volume (V(p, unit: % of the anterior tibial, gastrocnemius and soleus muscles was calculated. RESULTS: V(p was significantly lower for all muscle groups in PAD patients (4.3±1.6%, 5.0±3.3% and 6.1±3.6% for anterior tibial, gastrocnemius and soleus muscles, respectively compared to healthy control subjects (9.1±2.0%, 8.9±1.9% and 9.3±2.1%. Differences in V(p between muscle groups were not significant. The coefficient of variation of V(p varied from 10-14% and 11-16% at interscan and interreader level, respectively. CONCLUSIONS: Using DCE MRI after contrast-enhanced MR angiography with gadofosveset enables reproducible assessment of hyperemic fractional microvascular blood plasma volume of the calf musculature. V(p was lower in PAD patients than in healthy controls, which reflects a promising functional (hemodynamic biomarker for the

  1. Effect of R-CHOP chemotherapy on liver and mediastinal blood pool (18)F-FDG standardized uptake values in patients with non-Hodgkin's lymphoma.

    Science.gov (United States)

    Kaya, Bugra; Dostbil, Zeki; Ismailoglu, Murat; Tasdemir, Bekir; Sahin, Ozlem

    2015-01-01

    We aimed to investigate the impact of chemotherapy on (18)F-FDG uptake in the liver and mediastinal blood pool (MBP) among patients with non-Hodgkin's lymphoma. Twenty-three patients with NHL underwent baseline, interim, and postchemotherapy (18)F-FDG PET/CT. SUVmax and SUVmean values of the liver and MBP at imaging time were compared statistically. We did not find any significant differences between the liver and mediastinum SUVmean and SUVmax values (P>.05). Our study demonstrates that the (18)F-FDG uptake in the liver and MBP are not significantly affected by R-CHOP chemotherapy in patients with NHL. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Defective mitochondrial respiration, altered dNTP pools and reduced AP endonuclease 1 activity in peripheral blood mononuclear cells of Alzheimer's disease patients

    DEFF Research Database (Denmark)

    Maynard, Scott; Hejl, Anne-Mette; Dinh, Tran Thuan Son

    2015-01-01

    AIMS: Accurate biomarkers for early diagnosis of Alzheimer's disease (AD) are badly needed. Recent reports suggest that dysfunctional mitochondria and DNA damage are associated with AD development. In this report, we measured various cellular parameters, related to mitochondrial bioenergetics...... and DNA damage, in peripheral blood mononuclear cells (PBMCs) of AD and control participants, for biomarker discovery. METHODS: PBMCs were isolated from 53 patients with AD of mild to moderate degree and 30 age-matched healthy controls. Tests were performed on the PBMCs from as many of these participants...... on adjustments for gender and/or age. CONCLUSIONS: This study reveals impaired mitochondrial respiration, altered dNTP pools and reduced DNA repair activity in PBMCs of AD patients, thus suggesting that these biochemical activities may be useful as biomarkers for AD....

  3. The Agreement Between Blood Pool - Delayed Bone Scintigraphy and Tc-99m Human Immunoglobulin G (HIG Scintigraphy in the Determination of the Presence and Severity of Inflammatory Arthritis

    Directory of Open Access Journals (Sweden)

    Gulizar Kacar

    2011-08-01

    Full Text Available Objective: In this study, it was aimed to investigate the agreement between early phase of bone scintigraphy – human immunoglobulin scintigraphy (EPBS-HIG and late phase bone scintigraphy – HIG (LPBS-HIG in the determination of the presence and also the severity of inflammatory arthritis. Material and Methods: Twenty-eight patients (23 female, 5 male; between 19 to 80 years of age with inflammatory arthritis were included in the study. Tc-99m HIG and blood pool/late phase bone scintigraphies were performed in all patients. In scintigraphic examinations, the joints were scored with the degree of accumulation of the radiopharmaceutical by the semiquantitative analysis (0=Background activity, 1=Faint uptake, 2=Moderate uptake, 3=Marked uptake which is called as visually active joint score as severity index of the disease. To estimate the agreement between EPBS – HIG and LPBS - HIG in the determination of the presence and severity of inflammatory arthritis, 2x2 kappa coefficients were calculated. Results: Our results showed good agreement between EPBS - HIG for the presence of inflammation (kappa: 0.72 but not for the severity of the disease (kappa: 0.29, poor agreement between LPBS - HIG for both the presence (kappa: 0.51 and severity (kappa: 0.01 of inflammatory arthritis. Conclusion: The blood pool scintigraphy could be used in the investigation of the presence of inflammatory arthritis because the good agreement with HIG and the lower cost but not for the severity of the disease. (MIRT 2011;20:45-51

  4. Critical appraisal and pooled analysis of telmisartan alone or in combination with hydrochlorothiazide for achieving blood pressure goals

    Directory of Open Access Journals (Sweden)

    Satoshi Morimoto

    2010-06-01

    Full Text Available Satoshi Morimoto, Nobuyuki Takahashi, Tatsuyori Morita, Kazunori Someya, Nagaoki Toyoda, Toshiji IwasakaSecond Department of Internal Medicine, Kansai Medical University 2-3-1, Shinmachi, Hirakata, Osaka 573-1191, JapanAbstract: Rigid control of blood pressure (BP is essential to prevent cardiovascular disease. However, only about 40% of hypertensive patients undergoing pharmacological intervention with a single agent achieve their BP goals in contemporary clinical practice. Combined therapy using currently available agents is effective in maximizing treatment outcome, although it raises medical costs and decreases the drug compliance rate. To overcome such negative consequences, a combination tablet containing an angiotensin II receptor blocker (ARB with a small dose of hydrochlorothiazide (HCTZ is now available on the international market, including Japan. This article briefly describes the unique properties of telmisartan, a highly selective ARB for the angiotensin II type 1 receptor, including its long-acting characteristics and recent prospective multicenter randomized clinical trials, followed by a description of a newly-introduced combination tablet in Japan, which contains telmisartan and HCTZ. This article also reviews its safety and efficacy based on currently available evidence. Finally, evidence comparing telmisartan/HCTZ with other combination therapies is presented.Keywords: angiotensin II receptor blocker, ARB, blood pressure, hypertension, diuretics, PPAR-γ

  5. Dual-energy CT with tin filter technology for the discrimination of renal lesion proxies containing blood, protein, and contrast-agent. An experimental phantom study

    International Nuclear Information System (INIS)

    Karlo, Christoph; Lauber, Arno; Goetti, Robert Paul; Baumueller, Stephan; Stolzmann, Paul; Scheffel, Hans; Desbiolles, Lotus; Marincek, Borut; Leschka, Sebastian; Schmidt, Bernhard; Alkadhi, Hatem

    2011-01-01

    To differentiate proxy renal cystic lesions containing protein, blood, iodine contrast or saline solutions using dual-energy CT (DECT) equipped with a new tin filter technology (TFT). 70 proxies (saline, protein, blood and contrast agent) were placed in unenhanced and contrast-enhanced kidney phantoms. DECT was performed at 80/140 kV with and without tin filtering. Two readers measured the CT attenuation values in all proxies twice. An 80/140 kV ratio was calculated. All intra- and interobserver agreements were excellent (r = 0.93-0.97; p 0.05). The CT attenuation of protein, blood and contrast agent solution differed significantly with tin filtering (p < 0.01-0.05). Significant differences were found between the ratios of protein and blood compared to contrast medium solution (each, p < 0.05) and between the ratios of protein and blood in both phantoms with tin filtering (each, p < 0.05). DECT allows discrimination between a proxy renal lesion containing contrast agent and lesions containing protein and blood through their different attenuation at 80 kV and 140 kV. Further discrimination between protein and blood containing proxies is possible when using a tin filter. (orig.)

  6. 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...

  7. Off-axis holographic laser speckle contrast imaging of blood vessels in tissues

    Science.gov (United States)

    Abdurashitov, Arkady; Bragina, Olga; Sindeeva, Olga; Sergey, Sindeev; Semyachkina-Glushkovskaya, Oxana V.; Tuchin, Valery V.

    2017-09-01

    Laser speckle contrast imaging (LSCI) has become one of the most common tools for functional imaging in tissues. Incomplete theoretical description and sophisticated interpretation of measurement results are completely sidelined by a low-cost and simple hardware, fastness, consistent results, and repeatability. In addition to the relatively low measuring volume with around 700 μm of the probing depth for the visible spectral range of illumination, there is no depth selectivity in conventional LSCI configuration; furthermore, in a case of high NA objective, the actual penetration depth of light in tissues is greater than depth of field (DOF) of an imaging system. Thus, the information about these out-of-focus regions persists in the recorded frames but cannot be retrieved due to intensity-based registration method. We propose a simple modification of LSCI system based on the off-axis holography to introduce after-registration refocusing ability to overcome both depth-selectivity and DOF problems as well as to get the potential possibility of producing a cross-section view of the specimen.

  8. Intrahepatic portal vein blood volume estimated by non-contrast magnetic resonance imaging for the assessment of portal hypertension.

    Science.gov (United States)

    Aguirre-Reyes, Daniel F; Sotelo, Julio A; Arab, Juan P; Arrese, Marco; Tejos, Rodrigo; Irarrazaval, Pablo; Tejos, Cristian; Uribe, Sergio A; Andia, Marcelo E

    2015-10-01

    To investigate the feasibility of estimating the portal vein blood volume that flows into the intrahepatic volume (IHPVBV) in each cardiac cycle using non-contrast MR venography technique as a surrogate marker of portal hypertension (PH). Ten patients with chronic liver disease and clinical symptoms of PH (40% males, median age: 54.0, range: 44-73 years old) and ten healthy volunteers (80% males, median age: 54.0, range: 44-66 years old) were included in this study. A non-contrast Triple-Inversion-Recovery Arterial-Spin-Labeling (TIR-ASL) technique was used to quantify the IHPVBV in one and two cardiac cycles. Liver (LV) and spleen volumes (SV) were measured by manual segmentation from anatomical MR images as morphological markers of PH. All images were acquired in a 1.5T Philips Achieva MR scanner. PH patients had larger SV (P=0.02) and lower liver-to-spleen ratio (P=0.02) compared with healthy volunteers. The median IHPVBV in healthy volunteers was 13.5cm(3) and 26.5cm(3) for one and two cardiac cycles respectively, whereas in PH patients a median volume of 3.1cm(3) and 9.0cm(3) was observed. When correcting by LV, the IHPVBV was significantly higher in healthy volunteers than PH patients for one and two cardiac cycles. The combination of morphological information (liver-to-spleen ratio) and functional information (IHPVBV/LV) can accurately identify the PH patients with a sensitivity of 90% and specificity of 100%. Results show that the portal vein blood volume that flows into the intrahepatic volume in one and two cardiac cycles is significantly lower in PH patients than in healthy volunteers and can be quantified with non-contrast MRI techniques. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Three-dimensional black-blood multi-contrast carotid imaging using compressed sensing: a repeatability study.

    Science.gov (United States)

    Yuan, Jianmin; Usman, Ammara; Reid, Scott A; King, Kevin F; Patterson, Andrew J; Gillard, Jonathan H; Graves, Martin J

    2018-02-01

    The purpose of this work is to evaluate the repeatability of a compressed sensing (CS) accelerated multi-contrast carotid protocol at 3 T. Twelve volunteers and eight patients with carotid disease were scanned on a 3 T MRI scanner using a CS accelerated 3-D black-blood multi-contrast protocol which comprises T 1 w, T 2 w and PDw without CS, and with a CS factor of 1.5 and 2.0. The volunteers were scanned twice, the lumen/wall area and wall thickness were measured for each scan. Eight patients were scanned once, the inter/intra-observer reproducibility of the measurements was calculated. In the repeated volunteer scans, the interclass correlation coefficient (ICC) for the wall area measurement using a CS factor of 1.5 in PDw, T 1 w and T 2 w were 0.95, 0.81, and 0.97, respectively. The ICC for lumen area measurement using a CS factor of 1.5 in PDw, T 1 w and T 2 w were 0.96, 0.92, and 0.96, respectively. In patients, the ICC for inter/intra-observer measurements of lumen/wall area, and wall thickness were all above 0.81 in all sequences. The results show a CS accelerated 3-D black-blood multi-contrast protocol is a robust and reproducible method for carotid imaging. Future protocol design could use CS to reduce the scanning time.

  10. Advantages of frequency-domain modeling in dynamic-susceptibility contrast magnetic resonance cerebral blood flow quantification.

    Science.gov (United States)

    Chen, Jean J; Smith, Michael R; Frayne, Richard

    2005-03-01

    In dynamic-susceptibility contrast magnetic resonance perfusion imaging, the cerebral blood flow (CBF) is estimated from the tissue residue function obtained through deconvolution of the contrast concentration functions. However, the reliability of CBF estimates obtained by deconvolution is sensitive to various distortions including high-frequency noise amplification. The frequency-domain Fourier transform-based and the time-domain singular-value decomposition-based (SVD) algorithms both have biases introduced into their CBF estimates when noise stability criteria are applied or when contrast recirculation is present. The recovery of the desired signal components from amid these distortions by modeling the residue function in the frequency domain is demonstrated. The basic advantages and applicability of the frequency-domain modeling concept are explored through a simple frequency-domain Lorentzian model (FDLM); with results compared to standard SVD-based approaches. The performance of the FDLM method is model dependent, well representing residue functions in the exponential family while less accurately representing other functions. (c) 2005 Wiley-Liss, Inc.

  11. Contrasting effects of prenatal life stress on blood pressure and body mass index in young adults.

    Science.gov (United States)

    Bhat, Sunil K; Beilin, Lawrence J; Robinson, Monique; Burrows, Sally; Mori, Trevor A

    2015-04-01

    Various environmental stressors in pregnancy have been reported to affect high blood pressure (BP) in adult offspring. However, few studies have examined the effect of prenatal maternal psychological stress on offspring BP and BMI in early adulthood. In 957 Raine cohort participants, regression analyses were used to examine the association between the count of maternal life stress events experienced during pregnancy and offspring BP and BMI at age 20. Prenatal life stress associated positively with offspring BMI but inversely with SBP. After adjustment for confounders each additional prenatal life stress event reduced offspring SBP by 0.66  mmHg (P = 0.013) in those with an average BMI and lowered the odds of systolic (pre)hypertension by 17% (odds ratio = 0.83; P = 0.008). The inverse relationship between prenatal life stress and adult SBP was stronger in offspring with higher BMI. On the contrary, each unit increase in prenatal life stress score predicted a BMI increase of 0.37  kg/m (P = 0.022). Longitudinal analysis showed similar effects of prenatal life stress for offspring BMI from age 8 and SBP from age 14. This study has shown that maternal stress in pregnancy significantly associated with BMI from early childhood, but contrary to our hypothesis predicted lower resting SBP and lower odds of systolic (pre)hypertension in young adult offspring. The effect of prenatal life stress on BP was accentuated by a higher BMI. Fetal programming events as a result of prenatal stress may underpin some of these relationships.

  12. Vernal Pools

    Data.gov (United States)

    California Department of Resources — This is a polygon layer representing existing vernal pool complexes in California's Central Valley, as identified and mapped by Dr. Robert F. Holland. The purpose of...

  13. In vitro and in vivo comparison of a tailored magnetic particle imaging blood pool tracer with Resovist

    Science.gov (United States)

    Kaul, Michael Gerhard; Mummert, Tobias; Jung, Caroline; Salamon, Johannes; Khandhar, Amit P.; Ferguson, R. Matthew; Kemp, Scott J.; Ittrich, Harald; Krishnan, Kannan M.; Adam, Gerhard; Knopp, Tobias

    2017-05-01

    Optimizing tracers for individual imaging techniques is an active field of research. The purpose of this study was to perform in vitro and in vivo magnetic particle imaging (MPI) measurements using a new monodisperse and size-optimized tracer, LS-008, and to compare it with the performance of Resovist, the standard MPI tracer. Magnetic particle spectroscopy (MPS) and in vitro MPI measurements were performed in concerns of concentration and amount of tracer in a phantom. In vivo studies were carried out in healthy FVB mice. The first group (n  =  3) received 60 µl LS-008 (87 mM) and the second (n  =  3) diluted Resovist of the same concentration and volume. Tracer injections were performed with a syringe pump during a dynamic MPI scan. For anatomic referencing MRI was applied beforehand of the MPI measurements. Summing up MPS examinations and in vitro MPI experiments, LS-008 showed better sensitivity and spatial resolution than Resovist. In vivo both tracers can visualize the propagation of the bolus through the inferior vena cava. MPI with LS-008 did show less temporal fluctuation artifacts and the pulsation of blood due to respiratory and cardiac cycle was detectable. With LS-008 the aorta was distinguishable from the caval vein while with Resovist this failed. A liver vessel and a vessel structure leading cranially could only be observed with LS-008 and not with Resovist. Beside these structural advantages both tracers showed very different blood half-life. For LS-008 we found 88 min. Resovist did show a fast liver accumulation and a half-life of 13 min. Only with LS-008 the perfusion fraction in liver and kidney was measureable. MPI for angiography can be significantly improved by applying more effective tracers. LS-008 shows a clear improvement concerning the delineation while resolving a larger number of vessels in comparison to Resovist. Therefore, in aspects of quality and quantity LS-008 is clearly favorable for angiographic and

  14. Computational fluid dynamics simulations of blood flow regularized by 3D phase contrast MRI.

    Science.gov (United States)

    Rispoli, Vinicius C; Nielsen, Jon F; Nayak, Krishna S; Carvalho, Joao L A

    2015-11-26

    Phase contrast magnetic resonance imaging (PC-MRI) is used clinically for quantitative assessment of cardiovascular flow and function, as it is capable of providing directly-measured 3D velocity maps. Alternatively, vascular flow can be estimated from model-based computation fluid dynamics (CFD) calculations. CFD provides arbitrarily high resolution, but its accuracy hinges on model assumptions, while velocity fields measured with PC-MRI generally do not satisfy the equations of fluid dynamics, provide limited resolution, and suffer from partial volume effects. The purpose of this study is to develop a proof-of-concept numerical procedure for constructing a simulated flow field that is influenced by both direct PC-MRI measurements and a fluid physics model, thereby taking advantage of both the accuracy of PC-MRI and the high spatial resolution of CFD. The use of the proposed approach in regularizing 3D flow fields is evaluated. The proposed algorithm incorporates both a Newtonian fluid physics model and a linear PC-MRI signal model. The model equations are solved numerically using a modified CFD algorithm. The numerical solution corresponds to the optimal solution of a generalized Tikhonov regularization, which provides a flow field that satisfies the flow physics equations, while being close enough to the measured PC-MRI velocity profile. The feasibility of the proposed approach is demonstrated on data from the carotid bifurcation of one healthy volunteer, and also from a pulsatile carotid flow phantom. The proposed solver produces flow fields that are in better agreement with direct PC-MRI measurements than CFD alone, and converges faster, while closely satisfying the fluid dynamics equations. For the implementation that provided the best results, the signal-to-error ratio (with respect to the PC-MRI measurements) in the phantom experiment was 6.56 dB higher than that of conventional CFD; in the in vivo experiment, it was 2.15 dB higher. The proposed approach

  15. Quantification of resting myocardial blood flow velocity in normal humans using real-time contrast echocardiography. A feasibility study

    Science.gov (United States)

    Malm, Siri; Frigstad, Sigmund; Helland, Frode; Oye, Kjetil; Slordahl, Stig; Skjarpe, Terje

    2005-01-01

    Background Real-time myocardial contrast echocardiography (MCE) is a novel method for assessing myocardial perfusion. The aim of this study was to evaluate the feasibility of a very low-power real-time MCE for quantification of regional resting myocardial blood flow (MBF) velocity in normal human myocardium. Methods Twenty study subjects with normal left ventricular (LV) wall motion and normal coronary arteries, underwent low-power real-time MCE based on color-coded pulse inversion Doppler. Standard apical LV views were acquired during constant IV. infusion of SonoVue®. Following transient microbubble destruction, the contrast replenishment rate (β), reflecting MBF velocity, was derived by plotting signal intensity vs. time and fitting data to the exponential function; y (t) =A (1-e-β(t-t0)) + C. Results Quantification was feasible in 82%, 49% and 63% of four-chamber, two-chamber and apical long-axis view segments, respectively. The LAD (left anterior descending artery) and RCA (right coronary artery) territories could potentially be evaluated in most, but contrast detection in the LCx (left circumflex artery) bed was poor. Depending on localisation and which frames to be analysed, mean values of were 0.21–0.69 s-1, with higher values in medial than lateral, and in basal compared to apical regions of scan plane (p = 0.03 and p < 0.01). Higher β-values were obtained from end-diastole than end-systole (p < 0.001), values from all-frames analysis lying between. Conclusion Low-power real-time MCE did have the potential to give contrast enhancement for quantification of resting regional MBF velocity. However, the technique is difficult and subjected to several limitations. Significant variability in β suggests that this parameter is best suited for with-in patient changes, comparing values of stress studies to baseline. PMID:15958173

  16. Quantification of resting myocardial blood flow velocity in normal humans using real-time contrast echocardiography. A feasibility study

    Directory of Open Access Journals (Sweden)

    Slordahl Stig

    2005-06-01

    Full Text Available Abstract Background Real-time myocardial contrast echocardiography (MCE is a novel method for assessing myocardial perfusion. The aim of this study was to evaluate the feasibility of a very low-power real-time MCE for quantification of regional resting myocardial blood flow (MBF velocity in normal human myocardium. Methods Twenty study subjects with normal left ventricular (LV wall motion and normal coronary arteries, underwent low-power real-time MCE based on color-coded pulse inversion Doppler. Standard apical LV views were acquired during constant IV. infusion of SonoVue®. Following transient microbubble destruction, the contrast replenishment rate (β, reflecting MBF velocity, was derived by plotting signal intensity vs. time and fitting data to the exponential function; y (t =A (1-e-β(t-t0 + C. Results Quantification was feasible in 82%, 49% and 63% of four-chamber, two-chamber and apical long-axis view segments, respectively. The LAD (left anterior descending artery and RCA (right coronary artery territories could potentially be evaluated in most, but contrast detection in the LCx (left circumflex artery bed was poor. Depending on localisation and which frames to be analysed, mean values of were 0.21–0.69 s-1, with higher values in medial than lateral, and in basal compared to apical regions of scan plane (p = 0.03 and p Conclusion Low-power real-time MCE did have the potential to give contrast enhancement for quantification of resting regional MBF velocity. However, the technique is difficult and subjected to several limitations. Significant variability in β suggests that this parameter is best suited for with-in patient changes, comparing values of stress studies to baseline.

  17. Measurement of brain perfusion, blood volume, and blood-brain barrier permeability, using dynamic contrast-enhanced T(1)-weighted MRI at 3 tesla

    DEFF Research Database (Denmark)

    Larsson, Henrik B W; Courivaud, Frédéric; Rostrup, Egill

    2009-01-01

    /min); blood volume (6 +/- 2/4 +/- 1/7 +/- 6 mL/100 g) and permeability (0.9 +/- 0.4/0.8 +/- 0.3/3 +/- 5 mL/100 g/min) were estimated by using Patlak's method and a two-compartment model. A corroboration of these results was achieved by using model simulation. In addition, it was possible to generate maps...... imaging of a bolus of a paramagnetic contrast agent passing through the brain. The methods are applied in patients with brain tumors and in healthy subjects. Perfusion was estimated by model-free deconvolution using Tikhonov's method (gray matter/white matter/tumor: 72 +/- 16/30 +/- 8/56 +/- 45 mL/100 g...

  18. 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, ...

  19. Semi-automatic segmentation of gated blood pool emission tomographic images by watersheds: application to the determination of right and left ejection fractions

    International Nuclear Information System (INIS)

    Mariano-Goulart, D.; Collet, H.; Kotzki, P.-O.; Zanca, M.; Rossi, M.

    1998-01-01

    Tomographic multi-gated blood pool scintigraphy (TMUGA) is a widely available method which permits simultaneous assessment of right and left ventricular ejection fractions. However, the widespread clinical use of this technique is impeded by the lack of segmentation methods dedicated to an automatic analysis of ventricular activities. In this study we evaluated how a watershed algorithm succeeds in providing semi-automatic segmentation of ventricular activities in order to measure right and left ejection fractions by TMUGA. The left ejection fractions of 30 patients were evaluated both with TMUGA and with planar multi-gated blood pool scintigraphy (PMUGA). Likewise, the right ejection fractions of 25 patients were evaluated with first-pass scintigraphy (FP) and with TMUGA. The watershed algorithm was applied to the reconstructed slices in order to group together the voxels whose activity came from one specific cardiac cavity. First, the results of the watershed algorithm were compared with manual drawing around left and right ventricles. Left ejection fractions evaluated by TMUGA with the watershed procedure were not significantly different (p=0.30) from manual outlines whereas a small but significant difference was found for right ejection fractions (p=0.004). Then right and left ejection fractions evaluated by TMUGA (with the semi-automatic segmentation procedure) were compared with the results obtained by FP or PMUGA. Left ventricular ejection fractions evaluated by TMUGA showed an excellent correlation with those evaluated by PMUGA (r=0.93; SEE=5.93%; slope=0.99; intercept = 4.17%). The measurements of these ejection fractions were significantly higher with TMUGA than with PMUGA (P<0.01). The interoperator variability for the measurement of left ejection fractions by TMUGA was 4.6%. Right ventricular ejection fractions evaluated by TMUGA showed a good correlation with those evaluated by FP (r = 0.81; SEE = 6.68%; slope = 1.00; intercept = 0.85%) and were not

  20. Laser speckle contrast imaging of blood flow from anesthetized mice: correcting drifts in measurements due to breathing movements

    Science.gov (United States)

    Nogueira, Gesse E. C.; Ribeiro, Márcio A. C.; Campos, Juliane C.; Ferreira, Julio C. B.

    2015-06-01

    Background: Laser speckle contrast imaging allows non-invasive assessment of cutaneous blood flow. Although the technique is attractive to measure a quantity related to the skin blood flow (SBF) in anesthetized animal models, movements from breathing can mask the SBF signal. As a consequence, the measurement is overestimated because a variable amount of a DC component due to the breathing movements is added to the SBF signal. Objective: To evaluate a method for estimating the background level of the SBF signal, rejecting artefacts from breathing. Methods: A baseline correction method used for accurate DNA sequencing was evaluated, based on estimating the background level of a signal in small temporal sliding-windows. The method was applied to evaluate a mouse model of hindlimb ischemia. SBF signals from hindlimbs of anesthetized C57BL/6 mice (n=13) were registered. The mean SBF (Fi and Fc from ischemic and control hindlimbs) were computed from the registers and from the corresponding estimated background levels (Fib and Fcb from ischemic and control hindlimbs). Results: The mean values of the percentages (a measure of ischemia) MI = (Fi/Fc).100 and MIb = (Fib/Fcb).100 were computed to be 30+/-4% and 23+/-3% respectively (mean +/- SE). Evidences of statistical differences between both, ischemic and control hindlimbs, were obtained (pcorrupted SBF signal by breathing artefacts is feasible, allowing more accurate measurements.

  1. Contrasted study on the opening degree of blood-brain barriier after radiation therapy with SPECT and MRI

    International Nuclear Information System (INIS)

    Zhang Qing; Sun Aihua; Hu Yun; Zhang Li; Ye Hengguang

    2004-01-01

    The blood-brain barrier(BBB) is the largest barrier responsible for preventing direct contact between chemotherapeutic drugs in blood and tumors in brain, the permeability of BBB incease at different degree after brain irradiation in clinical brain tumors radiotherapy. Methods: In our study, 26 patients with metastatic brain tumors(21 cases in pr/mary lung carcinoma, 5 cases in breast carcinoma) were accepted the full brain irradiation. The detructive effects of radiation on the BBB were determined by the 99mTc-DTPA SPECT and the concentration ratio of methotrexate(MTX) in cerebrospinal fluid(CSF) and blood, the brain MRI before and after radiotherapy were retrospective contrasted study with SPECT. Results: the degree of destructive effect on the BBB was directly proportional to radiation doses. After a dose of 20Gy radiation to brain, the permeability of BBB inceased markedly(P<0.01). But in cases the dexamethasone(DXM) was administrated to decease the brain edema during radiotherapy, the permeability inceased less than that in patients without DXM(P<0.05). Conclutions: After 20Gy irradiation, the BBB would gradually open. At this time, chemotherapy is the best choice to improving the therapeutic effect. Dexamethasone was found to cause the decease in BBB permeability but no significant remission of brain edema. So, if the combination of radiotherapy and chemotherapy in treatment of metastatic brain tumors will be plan, the dexamethasone may be not used in expecting to deceasing the side effect and that no affecting the therapeutic effect. (authors)

  2. Can visual assessment of blood flow patterns by dynamic contrast-enhanced computed tomography distinguish between malignant and benign lung tumors?

    DEFF Research Database (Denmark)

    Harders, Stefan Walbom; Madsen, Hans Henrik; Nellemann, Hanne Marie

    2017-01-01

    with suspected lung cancer and a lung tumor on their chest radiograph were included for DCE-CT. The tumors were categorized using structured qualitative analysis of tumor blood flow patterns. Histopathology was used as reference standard. RESULTS: Using structured qualitative analysis of tumor blood flow...... using structured qualitative analysis of tumor blood flow patterns is accurate as well as somewhat reproducible. However, there are significant limitations to DCE-CT.......BACKGROUND: Dynamic contrast-enhanced computed tomography (DCE-CT) is a tool, which, in theory, can quantify the blood flow and blood volume of tissues. In structured qualitative analysis, parametric color maps yield a visual impression of the blood flow and blood volume within the tissue being...

  3. Assessment of left ventricular ejection fraction by gated blood pool scintigraphy on early and late phase from the onset of acute myocardial infarction

    International Nuclear Information System (INIS)

    Nakashima, Yoshiharu; Fukuzaki, Hisashi; Minamiji, Katsumi; Kida, Toru; Okada, Toshio; Yamada, Shigenobu; Goto, Takeshi; Maeda, Kazumi; Yoshida, Yutaka.

    1984-01-01

    To evaluate the change of left ventricular function after the onset of acute myocardial infarction, gated blood pool scintigraphy was performed in 19 patients on early and late phase (6 days and 1 month on the average). There was a difference in left ventricular ejection fraction (LVEF) between patients with anterior and inferior myocardial infarction. Patients with anterior infarction indicated low value of LVEF (31+-7%) on acute phase and its value was increased on chronic phase (37+-8%), whereas patients with inferior infarction had higher value of LVEF not only on acute phase but also on chronic phase (54+-9%→57+-10%), than those with anterior infarction. Left ventricular volume was larger in anterior group than in inferior group and tended to become smaller on chronic phase. In 4 of 10 cases with anterior infarction, a significant improvement of LVEF was found from 28+-6% to 43+-5%, but in 6 cases LVEF was unchanged during the same period. In 3 cases out of improved group, it was demonstrated angiographically that the collateral vessels were developed. It was, thus, suggested that collateral vessels may play an important role in the recovery of myocardial ischemia and wall motion abnormality in the marginal zone of infarcted area. From these results, we concluded that left ventricular function changed serially in most patients from the early phase to the late phase after the onset of acute myocardial infarction. (author)

  4. Error analysis of tumor blood flow measurement using dynamic contrast-enhanced data and model-independent deconvolution analysis

    International Nuclear Information System (INIS)

    Murase, Kenya; Miyazaki, Shohei

    2007-01-01

    We performed error analysis of tumor blood flow (TBF) measurement using dynamic contrast-enhanced data and model-independent deconvolution analysis, based on computer simulations. For analysis, we generated a time-dependent concentration of the contrast agent in the volume of interest (VOI) from the arterial input function (AIF) consisting of gamma-variate functions using an adiabatic approximation to the tissue homogeneity model under various plasma flow (F p ), mean capillary transit time (T c ), permeability-surface area product (PS) and signal-to-noise ratio (SNR) values. Deconvolution analyses based on truncated singular value decomposition with a fixed threshold value (TSVD-F), with an adaptive threshold value (TSVD-A) and with the threshold value determined by generalized cross validation (TSVD-G) were used to estimate F p values from the simulated concentration-time curves in the VOI and AIF. First, we investigated the relationship between the optimal threshold value and SNR in TSVD-F, and then derived the equation describing the relationship between the threshold value and SNR for TSVD-A. Second, we investigated the dependences of the estimated F p values on T c , PS, the total duration for data acquisition and the shape of AIF. Although TSVD-F with a threshold value of 0.025, TSVD-A with the threshold value determined by the equation derived in this study and TSVD-G could estimate the F p values in a similar manner, the standard deviation of the estimates was the smallest and largest for TSVD-A and TSVD-G, respectively. PS did not largely affect the estimates, while T c did in all methods. Increasing the total duration significantly improved the variations in the estimates in all methods. TSVD-G was most sensitive to the shape of AIF, especially when the total duration was short. In conclusion, this study will be useful for understanding the reliability and limitation of model-independent deconvolution analysis when applied to TBF measurement using an

  5. Pool scrubbing

    International Nuclear Information System (INIS)

    Lopez-Jimenez, J.; Herranz, J.; Escudero, M.J.; Espigares, M.M.; Peyres, V.; Polo, J.; Kortz, Ch.; Koch, M.K.; Brockmeier, U.; Unger, H.; Dutton, L.M.C.; Smedley, Ch.; Trow, W.; Jones, A.V.; Bonanni, E.; Calvo, M.; Alonso, A.

    1996-12-01

    The Source Term Project in the Third Frame Work Programme of the European Union Was conducted under and important joined effort on pool scrubbing research. CIEMAT was the Task Manager of the project and several other organizations participated in it: JRC-Ispra, NNC Limited, RUB-NES and UPM. The project was divided into several tasks. A peer review of the models in the pool scrubbing codes SPARC90 and BUSCA-AUG92 was made, considering the different aspects in the hydrodynamic phenomenology, particle retention and fission product vapor abortions. Several dominant risk accident sequences were analyzed with MAAP, SPARC90 and BUSCA-AUG92 codes, and the predictions were compared. A churn-turbulent model was developed for the hydrodynamic behaviour of the pool. Finally, an experimental programme in the PECA facility of CIEMAT was conducted in order to study the decontamination factor under jet injection regime, and the experimental observations were compared with the SPARC and BUSCA codes. (Author)

  6. Whole-body MR angiography with body coil acquisition at 3 T in patients with peripheral arterial disease using the contrast agent gadofosveset trisodium

    DEFF Research Database (Denmark)

    Nielsen, Yousef W; Eiberg, Jonas P; Løgager, Vibeke B

    2009-01-01

    Whole-body magnetic resonance angiography (WB-MRA) at 3 T with body coil acquisition has not previously been investigated. In this study, WB-MRA was performed in this manner using the blood pool contrast agent gadofosveset trisodium....

  7. Assessment of left ventricular filling in various heart disease, especially in ischemic heart disease, by ECG-gated cardiac blood pool scintigraphy

    International Nuclear Information System (INIS)

    Nakagawa, Hiroaki

    1986-01-01

    Using ECG-gated cardiac blood pool scintigraphy (BPS), left ventricular (LV) diastolic function was evaluated in various heart disease, especially in ischemic heart disease (IHD). LV function indices (2 systolic and 9 diastolic) were obtained from LV time activity curve derived from BPS. Among various diastolic indices, peak filling rate (PFR) and 2 other indices were significantly influenced by heart rate (HR), so corrected values for HR were used for this study. Various degrees of disturbance in diastolic filling were found in many cases without systolic impairment. According to the mechanism responsible for diastolic impairment, LV time activity curve showed a characteristic pattern. In IHD, filling disturbance in early diastole was observed before the impairment of systolic contraction developed, so it was thought to be an early predictor of cardiac failure. In the scar region of myocardial infarction (MI), decrease in regional ejection fraction and asynchrony in wall motion were shown, and these resulted in marked deterioration of early diastolic filling. On the other hand in angina pectoris (AP), such systolic disorders were not shown in the ischemic region perfused by stenotic coronary artery, although the disturbance of regional filling was found. The exercise capacity in AP was more related to the impairment in diastolic function at resting state than in systolic function, and furthermore the reserve of diastolic function as well as of systolic function was shown to be an important determinant of exercise capacity in AP. As HR increased, increase of PFR and decrease in time to peak filling was found, which was thought to be a sort of compensation for the shortening diastolic time due to increase in HR during exercise. Such compensation was decreased in AP with reduced exercise capacity. (J.P.N.)

  8. Contrast-enhanced harmonic endoscopic ultrasound

    DEFF Research Database (Denmark)

    Săftoiu, A; Dietrich, C F; Vilmann, P

    2012-01-01

    Second-generation intravenous blood-pool ultrasound contrast agents are increasingly used in endoscopic ultrasound (EUS) for characterization of microvascularization, differential diagnosis of benign and malignant focal lesions, and improving staging and guidance of therapeutic procedures. Although...... initially used as Doppler signal enhancers, second-generation microbubble contrast agents are now used with specific contrast harmonic imaging techniques, which benefit from the highly nonlinear behavior of the microbubbles. Contrast-specific modes based on multi-pulse technology are used to perform...... contrast-enhanced harmonic EUS based on a very low mechanical index (0.08 - 0.12). Quantification techniques based on dynamic contrast-enhanced ultrasound have been recommended for perfusion imaging and monitoring of anti-angiogenic treatment, mainly based on time-intensity curve analysis. Most...

  9. Real-time contrast-enhanced ultrasound determination of microvascular blood volume in abdominal subcutaneous adipose tissue in man. Evidence for adipose tissue capillary recruitment

    DEFF Research Database (Denmark)

    Tobin, L; Simonsen, L; Bülow, J

    2010-01-01

    The adipose tissue metabolism is dependent on its blood perfusion. During lipid mobilization e.g. during exercise and during lipid deposition e.g. postprandial, adipose tissue blood flow is increased. This increase in blood flow may involve capillary recruitment in the tissue. We investigated...... of ultrasound contrast agent to establish the reproducibility of the technique. In nine subjects, the effect of an oral glucose load on blood flow and microvascular volume was measured in abdominal subcutaneous adipose tissue and forearm skeletal muscle. ¹³³Xe washout and venous occlusion strain......-gauge plethysmography was used to measure the adipose tissue and forearm blood flow, respectively. Ultrasound signal intensity of the first plateau phases was 27 ± dB in the abdominal subcutaneous adipose tissue and 18 ± 2 dB (P

  10. Three-dimensional black-blood contrast-enhanced MRI improves detection of intraluminal thrombi in patients with acute ischaemic stroke.

    Science.gov (United States)

    Jang, Won; Kwak, Hyo Sung; Chung, Gyung Ho; Hwang, Seung Bae

    2018-03-19

    This study evaluated the utility of three-dimensional (3D), black-blood (BB), contrast-enhanced, magnetic resonance imaging (MRI) for the detection of intraluminal thrombi in acute stroke patients. Forty-seven patients with acute stroke involving the anterior circulation underwent MRI examination within 6 h of clinical onset. Cerebral angiography was used as the reference standard. In a blinded manner, two neuroradiologists interpreted the following three data sets: (1) diffusion-weighted imaging (DWI) + 3D BB contrast-enhanced MRI; (2) DWI + susceptibility weighted imaging (SWI); (3) DWI + 3D BB contrast-enhanced MRI + SWI. Of these patients, 47 had clots in the middle cerebral artery and four had clots in the anterior cerebral artery. For both observers, the area under the curve (Az) for data sets 1 and 3, which included 3D BB contrast-enhanced MRI, was significantly greater than it was for data set 2, which did not include 3D BB contrast-enhanced MR imaging (observer 1, 0.988 vs 0.904, p = 0.001; observer 2, 0.988 vs 0.894, p = 0.000). Three-dimensional BB contrast-enhanced MRI improves detection of intraluminal thrombi compared to conventional MRI methods in patients with acute ischaemic stroke. • BB contrast-enhanced MRI helps clinicians to assess the intraluminal clot • BB contrast-enhanced MRI improves detection of intraluminal thrombi • BB contrast-enhanced MRI for clot detection has a higher sensitivity.

  11. Perioperative evaluation of blood volume flow in high-flow cerebral arteriovenous malformation using phase-contrast magnetic resonance angiography

    Directory of Open Access Journals (Sweden)

    Shigeki Yamada

    2015-06-01

    Full Text Available Phase-contrast magnetic resonance angiography (PC-MRA is useful for the quantitative measurement of blood flow volume (BFV in the internal cerebral arteries (ICAs and basilar artery (BA. A 45-year-old man was diagnosed with a non-hemorrhagic high-flow arteriovenous malformation (AVM in the right temporal lobe. PC-MRA examinations of the bilateral ICAs and BA were conducted before treatment, at five days and at one and three months after the operation. The patient underwent preceding endovascular embolization of the deep part of the nidus and feeders. There were numerous feeders from the superior MCA trunk, which directly passed through the nidus to the normal brain. Therefore, the nidus was completely removed while maintaining the flow of the main superior MCA trunk in a passing artery. The BFV of the right ICA before AVM treatment was extremely high (mean: 675.7, systolic: 896.1, diastolic: 518.5 mL/min. Five days after the nidus resection, the BFV of the right ICA was decreased by almost half of that before treatment, and it was decreased even more at one month after the operation. The BFVs of the left ICA and BA were slightly increased before the operation and returned to normal values after the operation. The diastolic total BFV was immediately decreased after the operation, but the systolic total BFV was not sufficiently decreased at five days after the operation. Therefore, the difference between these systolic and diastolic total BFVs was higher at five days after the operation than before the operation. The systolic and diastolic total BFVs were decreased to normal levels one month after the operation. PC-MRA is a convenient and useful tool for quantifying BFVs in AVMs and can help plan the treatments. More research is needed to establish a definite role for PC-MRA in the quantification of flow changes in the treatment of high-flow AVMs.

  12. Can visual assessment of blood flow patterns by dynamic contrast-enhanced computed tomography distinguish between malignant and benign lung tumors?

    Science.gov (United States)

    Harders, Stefan Walbom; Madsen, Hans Henrik; Nellemann, Hanne Marie; Rasmussen, Torben Riis; Thygesen, Jesper; Hager, Henrik; Andersen, Niels Trolle; Rasmussen, Finn

    2017-05-01

    Dynamic contrast-enhanced computed tomography (DCE-CT) is a tool, which, in theory, can quantify the blood flow and blood volume of tissues. In structured qualitative analysis, parametric color maps yield a visual impression of the blood flow and blood volume within the tissue being studied, allowing for quick identification of the areas with the highest or lowest blood flow and blood volume. To examine whether DCE-CT could be used to distinguish between malignant and benign lung tumors in patients with suspected lung cancer. Fifty-nine patients with suspected lung cancer and a lung tumor on their chest radiograph were included for DCE-CT. The tumors were categorized using structured qualitative analysis of tumor blood flow patterns. Histopathology was used as reference standard. Using structured qualitative analysis of tumor blood flow patterns, it was possible to distinguish between malignant and benign lung tumors (Fisher-Freeman-Halton exact test, P  = 0.022). The inter-reader agreement of this method of analysis was slight to moderate (kappa = 0.30; 95% confidence interval [CI] = 0.13-0.46). DCE-CT in suspected lung cancer using structured qualitative analysis of tumor blood flow patterns is accurate as well as somewhat reproducible. However, there are significant limitations to DCE-CT.

  13. Evaluation of right ventricular function using gated equilibrium blood pool radionuclide ventriculography in patients with congenital volume and pressure overload late after surgical repair

    International Nuclear Information System (INIS)

    Hirata, Nobuaki; Sakakibara, Tetsuo; Watanabe, Shinichiro; Nomura, Fumikazu; Akamatsu, Hiroki; Matsumura, Yasushi; Yamamoto, Kazuhiro; Sasaki, Jiro; Kodama, Kazuhisa

    1991-01-01

    The effects of congenital right ventricular pressure and volume overload were studied in 3 patients with pulmonary stenosis, 7 with atrial septal defect and 6 with atrial septal defect plus pulmonary stenosis late after successful surgical correction. Gated equilibrium blood pool radionuclide ventriculography was used to measure right ventricular function at rest and during exercise and to compare it with eight normal subjects. Right ventricular ejection fractions at rest and during exercise were measured to be 61±9% and 66±13%, respectively, in the group with pulmonary stenosis, 49±7% and 54±8% in the group with atrial septal defect, and 65±13% and 69±13% in the group with atrial septal defect plus pulmonary stenosis. The values in the groups with pulmonary stenosis and atrial septal defect plus pulmonary stenosis were significantly higher than the control subjects (45±5% and 51±5%, p<0.01). The peak filling rate at rest and during exercise was also significantly higher in the groups with pulmonary stenosis and atrial septal defect plus pulmonary stenosis than in controls (at rest, 2.72±0.72, 2.53±0.94 vs. 1.64±0.24 p<0.05; during exercise, 4.38±1.23, 4.13±1.18 vs. 2.25±0.62, p<0.01). When patients with right ventricular systolic pressure equal to or greater than left ventricular systolic pressure and those with right ventricular systolic pressure less than left ventricular systolic pressure were compared, the right ventricular ejection fraction and peak filling rate were greater with the higher pressure at rest (71±10% and 3.12±0.81% vs. 55±3% and 2.30±0.27, p<0.05) and during exercise (75±11% and 4.86±1.01 vs. 59±3% and 2.61±0.35, p<0.05). Postoperative right ventricular hyperfunction may be due to preoperative pressure, but not volume, overload. (author)

  14. Understanding the decline of mean systolic blood pressure in Japan: an analysis of pooled data from the National Nutrition Survey, 1986-2002.

    Science.gov (United States)

    Ikeda, Nayu; Gakidou, Emmanuela; Hasegawa, Toshihiko; Murray, Christopher J L

    2008-12-01

    To assess the relationships between the observed drop in mean systolic blood pressure (SBP) in Japan in 1986-2002 and the use of antihypertensive treatment and lifestyle factors. A nationally representative sample of 90,554 men and 101,903 women aged 20 years and over was obtained from pooled data of annual cross-sectional surveys in Japan during 1986-2002. Using two-stage least squares with an instrumental variable, we examined the association between SBP and antihypertensive medication and lifestyle factors, including body mass index (BMI), physical activity, alcohol consumption, cigarette smoking and dietary salt intake. In the surveys, regular exercise was defined as exercise for more than 30 minutes at a time more than twice a week for over 1 year. Current smoking was defined as either daily or occasional cigarette use. Current drinking was defined as an intake of more than one standard cup of Japanese sake, one large bottle of regular beer, or one double measure of whisky at a time more than three times a week. Changes in mean predicted SBP in each sex and age group between 1986 and 2002 were decomposed into the respective contributions of these explanatory variables. Age-specific means of predicted SBP declined during this period by 1.8 (95% confidence interval, CI: 1.2-2.5) to 3.0 (95% CI: 2.4-3.6) mmHg in men and 3.7 (95% CI: 3.4-4.1) to 5.1 (95% CI: 4.5-5.7) mmHg in women. These reductions were partly explained by the increased use of medications across all sex and age groups and decreased mean BMI in women in their 30s and 40s. The contributions of treatment effects increased with age. Elevated mean BMI in men and elderly women offset part of the decline of their mean SBP. Declining mean SBP in Japan between 1986 and 2002 was partly attributable to the increased use of antihypertensive medications, especially in the older population, and lowered mean BMI in young women. However, a substantial part of the decline was left unexplained and needs to be

  15. Radiosynoviorthesis in hemophilic arthropathy: pathologic blood pool imaging on pre-therapeutic bone scintigraphy is not a predictor of treatment success

    Energy Technology Data Exchange (ETDEWEB)

    Sabet, Amir [University Duisburg-Essen, Department of Nuclear Medicine, Essen (Germany); University Hospital, Department of Nuclear Medicine, Bonn (Germany); Strauss, Andreas Christian; Schmolders, Jan; Bornemann, Rahel; Pennekamp, Peter Hans [University of Bonn, Department of Orthopaedics and Trauma Surgery, Bonn (Germany); Sabet, Amin; Biersack, Hans Juergen [University Hospital, Department of Nuclear Medicine, Bonn (Germany); Oldenburg, Johannes [University of Bonn, Department of Experimental Hematology and Transfusion Medicine, Bonn (Germany); Ezziddin, Samer [University Duisburg-Essen, Department of Nuclear Medicine, Essen (Germany); Saarland University, Department of Nuclear Medicine, Homburg (Germany)

    2017-03-15

    Increased articular {sup 99m}Tc MDP uptake on blood pool imaging (BPI) of patients with rheumatologic conditions is indicative of active inflammatory changes, and has been suggested as a strong predictor of response to radiosynoviorthesis (RSO). In this study, we aimed to assess the value of pretreatment BPI positivity (i.e. scintigraphic-apparent hyperemia) for successful RSO in hemophilic arthropathy. Thirty-four male patients with painful hemophilic arthropathy underwent RSO after failure of conservative treatment. Treated joints comprised the knee in eight, elbow in five, and ankle in 21 patients. Pretreatment triple-phase bone scintigraphy showed hyperemic joints (pathologic BPI) in 17 patients, whereas 17 patients had no increased tracer uptake on BPI. Response to RSO was evaluated 6 months post-treatment by measuring changes in intensity of arthralgia according to the visual analog scale (VAS), bleeding frequency, and range of motion. The association between hyperemia (pathologic BPI) and treatment outcome was examined using nonparametric tests for independent samples. Clinically evident pain relief occurred in 26 patients (76.5 %), and the mean VAS decreased from 7.7 ± 1.1 to 4.6 ± 2.7 (p < 0.001). Joint bleeding frequency (hemarthrosis) decreased from 4.5 ± 0.6 to 2.1 ± 0.4 during the first 6 months after RSO (p < 0.001). For both parameters (pain relief and bleeding frequency), patients experienced a similar benefit from RSO regardless of pretreatment BPI: arthralgia (p = 0.312) and frequency of hemarthrosis (p = 0.396). No significant improvement was observed for range of motion, but it was significantly more restricted in hyperemic joints both before (p = 0.036) and after treatment (p = 0.022). Hemophilic arthropathy can be effectively treated with RSO regardless of pre-therapeutic BPI. Patients in whom articular hyperemia is not detectable by scintigraphy may have similar (outstanding) outcomes, and thus should not be excluded from treatment. (orig.)

  16. Worldwide trends in blood pressure from 1975 to 2015: a pooled analysis of 1479 population-based measurement studies with 19.1 million participants

    NARCIS (Netherlands)

    Zhou, Bin; Bentham, James; Di Cesare, Mariachiara; Bixby, Honor; Danaei, Goodarz; Cowan, Melanie J.; Paciorek, Christopher J.; Singh, Gitanjali; Hajifathalian, Kaveh; Bennett, James E.; Taddei, Cristina; Bilano, Ver; Carrillo-Larco, Rodrigo M.; Djalalinia, Shirin; Khatibzadeh, Shahab; Lugero, Charles; Peykari, Niloofar; Zhang, Wan Zhu; Lu, Yuan; Stevens, Gretchen A.; Riley, Leanne M.; Bovet, Pascal; Elliott, Paul; Gu, Dongfeng; Ikeda, Nayu; Jackson, Rod T.; Joffres, Michel; Kengne, Andre Pascal; Laatikainen, Tiina; Lam, Tai Hing; Laxmaiah, Avula; Liu, Jing; Miranda, J. Jaime; Mondo, Charles K.; Neuhauser, Hannelore K.; Sundstrom, Johan; Smeeth, Liam; Soric, Maroje; Woodward, Mark; Ezzati, Majid; Abarca-Gomez, Leandra; Abdeen, Ziad A.; Rahim, Hanan Abdul; Abu-Rmeileh, Niveen M.; Acosta-Cazares, Benjamin; Adams, Robert; Aekplakorn, Wichai; Afsana, Kaosar; Aguilar-Salinas, Carlos A.; Agyemang, Charles; Ahmadvand, Alireza; Ahrens, Wolfgang; Al Raddadi, Rajaa; Al Woyatan, Rihab; Ali, Mohamed M.; Alkerwi, Ala'a; Aly, Eman; Amouyel, Philippe; Amuzu, Antoinette; Andersen, Lars Bo; Anderssen, Sigmund A.; Angquist, Lars; Anjana, Ranjit Mohan; Ansong, Daniel; Aounallah-Skhiri, Hajer; Araujo, Joana; Ariansen, Inger; Aris, Tahir; Arlappa, Nimmathota; Aryal, Krishna; Arveiler, Dominique; Assah, Felix K.; Assuncao, Maria Cecilia F.; Avdicova, Maria; Azevedo, Ana; Azizi, Fereidoun; Babu, Bontha V.; Bahijri, Suhad; Balakrishna, Nagalla; Bandosz, Piotr; Banegas, Jose R.; Barbagallo, Carlo M.; Barcelo, Alberto; Barkat, Amina; Barros, Aluisio J. D.; Barros, Mauro V.; Bata, Iqbal; Batieha, Anwar M.; Baur, Louise A.; Beaglehole, Robert; Ben Romdhane, Habiba; Benet, Mikhail; Benson, Lowell S.; Bernabe-Ortiz, Antonio; Bernotiene, Gailute; Bettiol, Heloisa; Bhagyalaxmi, Aroor; Bharadwaj, Sumit; Bhargava, Santosh K.; Bi, Yufang; Bikbov, Mukharram; Bjerregaard, Peter; Bjertness, Espen; Bjokelund, Cecilia; Blokstra, Anneke; Bo, Simona; Bobak, Martin; Boeing, Heiner; Boggia, Jose G.; Boissonnet, Carlos P.; Bongard, Vanina; Braeckman, Lutgart; Brajkovich, Imperia; Branca, Francesco; Breckenkamp, Juergen; Brenner, Hermann; Brewster, Lizzy M.; Bruno, Graziella; Bueno-de-Mesquita, H. B. (as); Bugge, Anna; Burns, Con; Bursztyn, Michael; de Leon, Antonio Cabrera; Cameron, Christine; Can, Gunay; Candido, Ana Paula C.; Capuano, Vincenzo; Cardoso, Viviane C.; Carlsson, Axel C.; Carvalho, Maria J.; Casanueva, Felipe F.; Casas, Juan-Pablo; Caserta, Carmelo A.; Chamukuttan, Snehalatha; Chan, Angelique W.; Chan, Queenie; Chaturvedi, Himanshu K.; Chaturvedi, Nishi; Chen, Chien-Jen; Chen, Fangfang; Chen, Huashuai; Chen, Shuohua; Chen, Zhengming; Cheng, Ching-Yu; Dekkaki, Imane Cherkaoui; Chetrit, Angela; Chiolero, Arnaud; Chiou, Shu-Ti; Chirita-Emandi, Adela; Cho, Belong; Cho, Yumi; Chudek, Jerzy; Cifkova, Renata; Claessens, Frank; Clays, Els; Concin, Hans; Cooper, Cyrus; Cooper, Rachel; Coppinger, Tara C.; Costanzo, Simona; Cottel, Dominique; Cowell, Chris; Craig, Cora L.; Crujeiras, Ana B.; Cruz, Juan J.; D'Arrigo, Graziella; d'Orsi, Eleonora; Dallongeville, Jean; Damasceno, Albertino; Dankner, Rachel; Dantoft, Thomas M.; Dauchet, Luc; de Backer, Guy; de Gaetano, Giovanni; de Henauw, Stefaan; de Smedt, Delphine; Deepa, Mohan; Dehghan, Abbas; Delisle, Helene; Deschamps, Valerie; Dhana, Klodian; Di Castelnuovo, Augusto F.; Dias-da-Costa, Juvenal Soares; Diaz, Alejandro; Dickerson, Ty T.; Do, Ha T. P.; Dobson, Annette J.; Donfrancesco, Chiara; Donoso, Silvana P.; Doering, Angela; Doua, Kouamelan; Drygas, Wojciech; Dulskiene, Virginija; Dzakula, Aleksandar; Dzerve, Vilnis; Dziankowska-Zaborszczyk, Elzbieta; Eggertsen, Robert; Ekelund, Ulf; El Ati, Jalila; Ellert, Ute; Elosua, Roberto; Erasmus, Rajiv T.; Erem, Cihangir; Eriksen, Louise; Escobedo-de la Pena, Jorge; Evans, Alun; Faeh, David; Fall, Caroline H.; Farzadfar, Farshad; Felix-Redondo, Francisco J.; Ferguson, Trevor S.; Fernandez-Berges, Daniel; Ferrante, Daniel; Ferrari, Marika; Ferreccio, Catterina; Ferrieres, Jean; Finn, Joseph D.; Fischer, Krista; Foeger, Bernhard; Foo, Leng Huat; Forslund, Ann-Sofie; Forsner, Maria; Fortmann, Stephen P.; Fouad, Heba M.; Francis, Damian K.; Franco, Maria do Carmo; Franco, Oscar H.; Frontera, Guillermo; Fuchs, Flavio D.; Fuchs, Sandra C.; Fujita, Yuki; Furusawa, Takuro; Gaciong, Zbigniew; Gareta, Dickman; Garnett, Sarah P.; Gaspoz, Jean-Michel; Gasull, Magda; Gates, Louise; Gavrila, Diana; Geleijnse, Johanna M.; Ghasemian, Anoosheh; Ghimire, Anup; Giampaoli, Simona; Gianfagna, Francesco; Giovannelli, Jonathan; Goldsmith, Rebecca A.; Goncalves, Helen; Gonzalez Gross, Marcela; Gonzalez Rivas, Juan P.; Gottrand, Frederic; Graff-Iversen, Sidsel; Grafnetter, Dusan; Grajda, Aneta; Gregor, Ronald D.; Grodzicki, Tomasz; Grontved, Anders; Gruden, Grabriella; Grujic, Vera; Guan, Ong Peng; Gudnason, Vilmundur; Guerrero, Ramiro; Guessous, Idris; Guimaraes, Andre L.; Gulliford, Martin C.; Gunnlaugsdottir, Johanna; Gunter, Marc; Gupta, Prakash C.; Gureje, Oye; Gurzkowska, Beata; Gutierrez, Laura; Gutzwiller, Felix; Hadaegh, Farzad; Halkjaer, Jytte; Hambleton, Ian R.; Hardy, Rebecca; Harikumar, Rachakulla; Hata, Jun; Hayes, Alison J.; He, Jiang; Hendriks, Marleen Elisabeth; Henriques, Ana; Hernandez Cadena, Leticia; Herqutanto, N. N.; Herrala, Sauli; Heshmat, Ramin; Hihtaniemi, Ilpo Tapani; Ho, Sai Yin; Ho, Suzanne C.; Hobbs, Michael; Hofman, Albert; Dinc, Gonul Horasan; Hormiga, Claudia M.; Horta, Bernardo L.; Houti, Leila; Howitt, Christina; Htay, Thein Thein; Htet, Aung Soe; Hu, Yonghua; Maria Huerta, Jose; Husseini, Abdullatif S.; Huybrechts, Inge; Hwalla, Nahla; Iacoviello, Licia; Iannone, Anna G.; Ibrahim, M. Mohsen; Ikram, M. Arfan; Irazola, Vilma E.; Islam, Muhammad; Ivkovic, Vanja; Iwasaki, Masanori; Jacobs, Jeremy M.; Jafar, Tazeen; Jamrozik, Konrad; Janszky, Imre; Jasienska, Grazyna; Jelakovic, Bojan; Jiang, Chao Qiang; Johansson, Mattias; Jonas, Jost B.; Jorgensen, Torben; Joshi, Pradeep; Juolevi, Anne; Jurak, Gregor; Juresa, Vesna; Kaaks, Rudolf; Kafatos, Anthony; Kalter-Leibovici, Ofra; Kamaruddin, Nor Azmi; Kasaeian, Amir; Katz, Joanne; Kauhanen, Jussi; Kaur, Prabhdeep; Kavousi, Maryam; Kazakbaeva, Gyulli; Keil, Ulrich; Boker, Lital Keinan; Keinanen-Kiukaanniemi, Sirkka; Kelishadi, Roya; Kemper, Han C. G.; Kersting, Mathilde; Key, Timothy; Khader, Yousef Saleh; Khalili, Davood; Khang, Young-Ho; Khaw, Kay-Tee; Kiechl, Stefan; Killewo, Japhet; Kim, Jeongseon; Klumbiene, Jurate; Kolle, Elin; Kolsteren, Patrick; Korrovits, Paul; Koskinen, Seppo; Kouda, Katsuyasu; Koziel, Slawomir; Kristensen, Peter Lund; Krokstad, Steinar; Kromhout, Daan; Kruger, Herculina S.; Kubinova, Ruzena; Kuciene, Renata; Kuh, Diana; Kujala, Urho M.; Kula, Krzysztof; Kulaga, Zbigniew; Kumar, R. Krishna; Kurjata, Pawel; Kusuma, Yadlapalli S.; Kuulasmaa, Kari; Kyobutungi, Catherine; Lachat, Carl; Landrove, Orlando; Lanska, Vera; Lappas, Georg; Larijani, Bagher; Laugsand, Lars E.; Le, Nguyen Bao Khanh; Le, Tuyen D.; Leclercq, Catherine; Lee, Jeannette; Lee, Jeonghee; Lehtimaki, Terho; Lekhraj, Rampal; Leon-Munoz, Luz M.; Levitt, Naomi S.; Li, Yanping; Lilly, Christa L.; Lim, Wei-Yen; Fernanda Lima-Costa, M.; Lin, Hsien-Ho; Lin, Xu; Linneberg, Allan; Lissner, Lauren; Litwin, Mieczyslaw; Lorbeer, Roberto; Lotufo, Paulo A.; Eugenio Lozano, Jose; Luksiene, Dalia; Lundqvist, Annamari; Lunet, Nuno; Lytsy, Per; Ma, Guansheng; Ma, Jun; Machado-Coelho, George L. L.; Machi, Suka; Maggi, Stefania; Magliano, Dianna J.; Majer, Marjeta; Makdisse, Marcia; Malekzadeh, Reza; Malhotra, Rahul; Rao, Kodavanti Mallikharjuna; Malyutina, Sofia; Manios, Yannis; Mann, Jim I.; Manzato, Enzo; Margozzini, Paula; Marques-Vidal, Pedro; Marrugat, Jaume; Martorell, Reynaldo; Mathiesen, Ellisiv B.; Matijasevich, Alicia; Matsha, Tandi E.; Mbanya, Jean Claude N.; Posso, Anselmo J. Mc Donald; McFarlane, Shelly R.; McGarvey, Stephen T.; McLachlan, Stela; McLean, Rachael M.; McNulty, Breige A.; Khir, Amir Sharifuddin Md; Mediene-Benchekor, Sounnia; Medzioniene, Jurate; Meirhaeghe, Aline; Meisinger, Christa; Menezes, Ana Maria B.; Menon, Geetha R.; Meshram, Indrapal I.; Metspalu, Andres; Mi, Jie; Mikkel, Kairit; Miller, Jody C.; Francisco Miquel, Juan; Jaime Miranda, J.; Misigoj-Durakovic, Marjeta; Mohamed, Mostafa K.; Mohammad, Kazem; Mohammadifard, Noushin; Mohan, Viswanathan; Yusoff, Muhammad Fadhli Mohd; Moller, Niels C.; Molnar, Denes; Momenan, Amirabbas; Monyeki, Kotsedi Daniel K.; Moreira, Leila B.; Morejon, Alain; Moreno, Luis A.; Morgan, Karen; Moschonis, George; Mossakowska, Malgorzata; Mostafa, Aya; Mota, Jorge; Motlagh, Mohammad Esmaeel; Motta, Jorge; Muiesan, Maria L.; Mueller-Nurasyid, Martina; Murphy, Neil; Mursu, Jaakko; Musil, Vera; Nagel, Gabriele; Naidu, Balkish M.; Nakamura, Harunobu; Namsna, Jana; Nang, Ei Ei K.; Nangia, Vinay B.; Narake, Sameer; Maria Navarrete-Munoz, Eva; Ndiaye, Ndeye Coumba; Neal, William A.; Nenko, Ilona; Nervi, Flavio; Nguyen, Nguyen D.; Nguyen, Quang Ngoc; Nieto-Martinez, Ramfis E.; Niiranen, Teemu J.; Ning, Guang; Ninomiya, Toshiharu; Nishtar, Sania; Noale, Marianna; Noboa, Oscar A.; Noorbala, Ahmad Ali; Norat, Teresa; Noto, Davide; Al Nsour, Mohannad; O'Reilly, Dermot; Oh, Kyungwon; Olinto, Maria Teresa A.; Oliveira, Isabel O.; Omar, Mohd Azahadi; Onat, Altan; Ordunez, Pedro; Osmond, Clive; Ostojic, Sergej M.; Otero, Johanna A.; Overvad, Kim; Owusu-Dabo, Ellis; Paccaud, Fred Michel; Padez, Cristina; Pahomova, Elena; Pajak, Andrzej; Palli, Domenico; Palmieri, Luigi; Panda-Jonas, Songhomitra; Panza, Francesco; Papandreou, Dimitrios; Parnell, Winsome R.; Parsaeian, Mahboubeh; Pecin, Ivan; Pednekar, Mangesh S.; Peer, Nasheeta; Peeters, Petra H.; Peixoto, Sergio Viana; Pelletier, Catherine; Peltonen, Markku; Pereira, Alexandre C.; Marina Perez, Rosa; Peters, Annette; Petkeviciene, Janina; Pham, Son Thai; Pigeot, Iris; Pikhart, Hynek; Pilav, Aida; Pilotto, Lorenza; Pitakaka, Freda; Plans-Rubio, Pedro; Polakowska, Maria; Polasek, Ozren; Porta, Miquel; Portegies, Marileen L. P.; Pourshams, Akram; Pradeepa, Rajendra; Prashant, Mathur; Price, Jacqueline F.; Puiu, Maria; Punab, Margus; Qasrawi, Radwan F.; Qorbani, Mostafa; Radic, Ivana; Radisauskas, Ricardas; Rahman, Mahfuzar; Raitakari, Olli; Raj, Manu; Rao, Sudha Ramachandra; Ramos, Elisabete; Rampal, Sanjay; Rangel Reina, Daniel A.; Rasmussen, Finn; Redon, Josep; Reganit, Paul Ferdinand M.; Ribeiro, Robespierre; Riboli, Elio; Rigo, Fernando; de Wit, Tobias F. Rinke; Ritti-Dias, Raphael M.; Robinson, Sian M.; Robitaille, Cynthia; Rodriguez-Artalejo, Fernando; Rodriguez-Villamizar, Laura A.; Rojas-Martinez, Rosalba; Rosengren, Annika; Rubinstein, Adolfo; Rui, Ornelas; Sandra Ruiz-Betancourt, Blanca; Russo Horimoto, Andrea R. V.; Rutkowski, Marcin; Sabanayagam, Charumathi; Sachdev, Harshpal S.; Saidi, Olfa; Sakarya, Sibel; Salanave, Benoit; Salazar Martinez, Eduardo; Salmeron, Diego; Salomaa, Veikko; Salonen, Jukka T.; Salvetti, Massimo; Sanchez-Abanto, Jose; Sans, Susana; Santos, Diana; Santos, Ina S.; dos Santos, Renata Nunes; Santos, Rute; Saramies, Jouko L.; Sardinha, Luis B.; Margolis, Giselle Sarganas; Sarrafzadegan, Nizal; Saum, Kai-Uwe; Savva, Savvas C.; Scazufca, Marcia; Schargrodsky, Herman; Schneider, Ione J.; Schultsz, Constance; Schutte, Aletta E.; Sen, Abhijit; Senbanjo, Idowu O.; Sepanlou, Sadaf G.; Sharma, Sanjib K.; Shaw, Jonathan E.; Shibuya, Kenji; Shin, Dong Wook; Shin, Youchan; Siantar, Rosalynn; Sibai, Abla M.; Santos Silva, Diego Augusto; Simon, Mary; Simons, Judith; Simons, Leon A.; Sjotrom, Michael; Skovbjerg, Sine; Slowikowska-Hilczer, Jolanta; Slusarczyk, Przemyslaw; Smith, Margaret C.; Snijder, Marieke B.; So, Hung-Kwan; Sobngwi, Eugene; Soderberg, Stefan; Solfrizzi, Vincenzo; Sonestedt, Emily; Song, Yi; Sorensen, Thorkild I. A.; Jerome, Charles Sossa; Soumare, Aicha; Staessen, Jan A.; Starc, Gregor; Stathopoulou, Maria G.; Stavreski, Bill; Steene-Johannessen, Jostein; Stehle, Peter; Stein, Aryeh D.; Stergiou, George S.; Stessman, Jochanan; Stieber, Jutta; Stoeckl, Doris; Stocks, Tanja; Stokwiszewski, Jakub; Stronks, Karien; Strufaldi, Maria Wany; Sun, Chien-An; Sung, Yn-Tz; Suriyawongpaisal, Paibul; Sy, Rody G.; Tai, E. Shyong; Tammesoo, Mari-Liis; Tamosiunas, Abdonas; Tang, Line; Tang, Xun; Tanser, Frank; Tao, Yong; Tarawneh, Mohammed Rasoul; Tarqui-Mamani, Carolina B.; Taylor, Anne; Theobald, Holger; Thijs, Lutgarde; Thuesen, Betina H.; Tjonneland, Anne; Tolonen, Hanna K.; Topbas, Murat; Topor-Madry, Roman; Jose Tormo, Maria; Torrent, Maties; Traissac, Pierre; Trichopoulos, Dimitrios; Trichopoulou, Antonia; Trinh, Oanh T. H.; Trivedi, Atul; Tshepo, Lechaba; Tulloch-Reid, Marshall K.; Tuomainen, Tomi-Pekka; Turley, Maria L.; Tynelius, Per; Tzourio, Christophe; Ueda, Peter; Ugel, Eunice; Ulmer, Hanno; Uusitalo, Hannu M. T.; Valdivia, Gonzalo; Valvi, Damaskini; van der Schouw, Yvonne T.; van Herck, Koen; van Rossem, Lenie; van Valkengoed, Irene G. M.; Vanderschueren, Dirk; Vanuzzo, Diego; Vatten, Lars; Vega, Tomas; Velasquez-Melendez, Gustavo; Veronesi, Giovanni; Verschuren, W. M. Monique; Verstraeten, Roosmarijn; Victora, Cesar G.; Viet, Lucie; Viikari-Juntura, Eira; Vineis, Paolo; Vioque, Jesus; Virtanen, Jyrki K.; Visvikis-Siest, Sophie; Viswanathan, Bharathi; Vollenweider, Peter; Vrdoljak, Ana; Vrijheid, Martine; Wade, Alisha N.; Wagner, Aline; Walton, Janette; Mohamud, Wan Nazaimoon Wan; Wang, Ming-Dong; Wang, Qian; Wang, Ya Xing; Wannamethee, S. Goya; Wareham, Nicholas; Wederkopp, Niels; Weerasekera, Deepa; Whincup, Peter H.; Widhalm, Kurt; Widyahening, Indah S.; Wiecek, Andrzej; Wijga, Alet H.; Wilks, Rainford J.; Willeit, Peter; Williams, Emmanuel A.; Wilsgaard, Tom; Wojtyniak, Bogdan; Wong, Tien Yin; Wong-McClure, Roy A.; Woo, Jean; Wu, Aleksander Giwercman; Wu, Frederick C.; Wu, Shou Ling; Xu, Haiquan; Yan, Weili; Yang, Xiaoguang; Ye, Xingwang; Yiallouros, Panayiotis K.; Yoshihara, Akihiro; Younger-Coleman, Novie O.; Yusoff, Ahmad F.; Zambon, Sabina; Zdrojewski, Tomasz; Zeng, Yi; Zhao, Dong; Zhao, Wenhua; Zheng, Yingffeng; Zhu, Dan; Zimmermann, Esther; Zuniga Cisneros, Julio

    2017-01-01

    Background Raised blood pressure is an important risk factor for cardiovascular diseases and chronic kidney disease. We estimated worldwide trends in mean systolic and mean diastolic blood pressure, and the prevalence of, and number of people with, raised blood pressure, defined as systolic blood

  17. Worldwide trends in blood pressure from 1975 to 2015 : a pooled analysis of 1479 population-based measurement studies with 19·1 million participants

    NARCIS (Netherlands)

    Zhou, B.; Bentham, James; Di Cesare, Mariachiara; Bixby, Honor; Danaei, Goodarz; Cowan, Melanie J.; Paciorek, Christopher J.; Singh, Gitanjali; Hajifathalian, Kaveh; Bennett, James E.; Taddei, Cristina; Bilano, Ver; Carrillo-Larco, Rodrigo M.; Djalalinia, Shirin; Khatibzadeh, Shahab; Lugero, Charles; Peykari, Niloofar; Zhang, Wan Zhu; Lu, Yuan; Stevens, Gretchen A.; Riley, Leanne M.; Bovet, Pascal; Elliott, Paul; Gu, Dongfeng; Ikeda, Nayu; Jackson, Rod T.; Joffres, Michel; Kengne, Andre Pascal; Laatikainen, Tiina; Lam, Tai Hing; Laxmaiah, Avula; Liu, Jing; Miranda, J. Jaime; Mondo, Charles K.; Neuhauser, Hannelore K.; Sundström, Johan; Smeeth, Liam; Sorić, Maroje; Woodward, Mark; Ezzati, Majid; Abarca-Gómez, Leandra; Abdeen, Ziad A.; Rahim, Hanan Abdul; Abu-Rmeileh, Niveen M.; Acosta-Cazares, Benjamin; Adams, Robert; Aekplakorn, Wichai; Afsana, Kaosar; Aguilar-Salinas, Carlos A.; Agyemang, Charles; Ahmadvand, Alireza; Ahrens, Wolfgang; Al Raddadi, Rajaa; Al Woyatan, Rihab; Ali, Mohamed M.; Alkerwi, Ala'a; Aly, Eman; Amouyel, Philippe; Amuzu, Antoinette; Andersen, Lars Bo; Anderssen, Sigmund A.; Ängquist, Lars; Anjana, Ranjit Mohan; Ansong, Daniel; Aounallah-Skhiri, Hajer; Araújo, Joana; Ariansen, Inger; Aris, Tahir; Arlappa, Nimmathota; Aryal, Krishna; Arveiler, Dominique; Assah, Felix K.; Assunção, Maria Cecília F.; Avdicová, Mária; Azevedo, Ana; Azizi, Fereidoun; Babu, Bontha V.; Bahijri, Suhad; Balakrishna, Nagalla; Bandosz, Piotr; Banegas, José R.; Barbagallo, Carlo M.; Barceló, Alberto; Barkat, Amina; Barros, Aluisio J.D.; Barros, Mauro V.; Bata, Iqbal; Batieha, Anwar M.; Baur, Louise A.; Beaglehole, Robert; Romdhane, Habiba Ben; Benet, Mikhail; Benson, Lowell S.; Bernabe-Ortiz, Antonio; Bernotiene, Gailute; Bettiol, Heloisa; Bhagyalaxmi, Aroor; Bharadwaj, Sumit; Bhargava, Santosh K.; Bi, Yufang; Bikbov, Mukharram; Bjerregaard, Peter; Bjertness, Espen; Björkelund, Cecilia; Blokstra, Anneke; Bo, Simona; Bobak, Martin; Boeing, Heiner; Boggia, Jose G.; Boissonnet, Carlos P.; Bongard, Vanina; Braeckman, Lutgart; Brajkovich, Imperia; Branca, Francesco; Breckenkamp, Juergen; Brenner, Hermann; Brewster, Lizzy M.; Bruno, Graziella; Bueno-de-Mesquita, H B As; Bugge, Anna; Burns, Con; Bursztyn, Michael; de León, Antonio Cabrera; Cacciottolo, Joseph; Cameron, Christine; Can, Günay; Cândido, Ana Paula C.; Capuano, Vincenzo; Cardoso, Viviane C.; Carlsson, Axel C.; Carvalho, Maria J.; Casanueva, Felipe F.; Casas, Juan-Pablo; Caserta, Carmelo A.; Chamukuttan, Snehalatha; Chan, Angelique W.; Chan, Queenie; Chaturvedi, Himanshu K.; Chaturvedi, Nishi; Chen, Chien-Jen; Chen, Fangfang; Chen, Huashuai; Chen, Shuohua; Chen, Zhengming; Cheng, Yu Ching; Dekkaki, Imane Cherkaoui; Chetrit, Angela; Chiolero, Arnaud; Chiou, Shu Ti; Chirita-Emandi, Adela; Cho, Belong; Cho, Yumi; Chudek, Jerzy; Cifkova, Renata; Claessens, Frank; Clays, Els; Concin, Hans; Cooper, Cyrus; Cooper, Rachel; Coppinger, Tara C.; Costanzo, Simona; Cottel, Dominique; Cowell, Chris; Craig, Cora L.; Crujeiras, Ana B.; Cruz, Juan J.; D'Arrigo, Graziella; d'Orsi, Eleonora; Dallongeville, Jean; Damasceno, Albertino; Danaei, Goodarz; Dankner, Rachel; Dantoft, Thomas M.; Dauchet, Luc; De Backer, Guy; De Bacquer, Dirk; de Gaetano, Giovanni; De Henauw, Stefaan; De Smedt, Delphine; Deepa, Mohan; Dehghan, Abbas; Delisle, Hélène; Deschamps, Valérie; Dhana, Klodian; Di Castelnuovo, Augusto F.; Dias-da-Costa, Juvenal Soares; Diaz, Alejandro; Dickerson, Ty T.; Do, Ha T.P.; Dobson, Annette J.; Donfrancesco, Chiara; Donoso, Silvana P.; Döring, Angela; Doua, Kouamelan; Drygas, Wojciech; Dulskiene, Virginija; Džakula, Aleksandar; Dzerve, Vilnis; Dziankowska-Zaborszczyk, Elzbieta; Eggertsen, Robert; Ekelund, Ulf; El Ati, Jalila; Ellert, Ute; Elliott, Paul; Elosua, Roberto; Erasmus, Rajiv T.; Erem, Cihangir; Eriksen, Louise; Escobedo-de la Peña, Jorge; Evans, Alun; Faeh, David; Fall, Caroline H.; Farzadfar, Farshad; Felix-Redondo, Francisco J.; Ferguson, Trevor S.; Fernández-Bergés, Daniel; Ferrante, Daniel; Ferrari, Marika; Ferreccio, Catterina; Ferrieres, Jean; Finn, Joseph D.; Fischer, Krista; Föger, Bernhard; Foo, Leng Huat; Forslund, Ann Sofie; Forsner, Maria; Fortmann, Stephen P.; Fouad, Heba M.; Francis, Damian K.; do Carmo Franco, Maria; Franco, Oscar H.; Frontera, Guillermo; Fuchs, Flavio D.; Fuchs, Sandra C.; Fujita, Yuki; Furusawa, Takuro; Gaciong, Zbigniew; Gareta, Dickman; Garnett, Sarah P.; Gaspoz, Jean-Michel; Gasull, Magda; Gates, Louise; Gavrila, Diana; Geleijnse, Johanna M.; Ghasemian, Anoosheh; Ghimire, Anup; Giampaoli, Simona; Gianfagna, Francesco; Giovannelli, Jonathan; Goldsmith, Rebecca A.; Gonçalves, Helen; Gross, Marcela Gonzalez; González Rivas, Juan P.; Gottrand, Frederic; Graff-Iversen, Sidsel; Grafnetter, Dušan; Grajda, Aneta; Gregor, Ronald D.; Grodzicki, Tomasz; Grøntved, Anders; Gruden, Grabriella; Grujic, Vera; Gu, Dongfeng; Guan, Ong Peng; Gudnason, Vilmundur; Guerrero, Ramiro; Guessous, Idris; Guimaraes, Andre L.; Gulliford, Martin C.; Gunnlaugsdottir, Johanna; Gunter, Marc J.; Gupta, Prakash C.; Gureje, Oye; Gurzkowska, Beata; Gutierrez, Laura; Gutzwiller, Felix; Hadaegh, Farzad; Halkjær, Jytte; Hambleton, Ian R.; Hardy, Rebecca; Harikumar, Rachakulla; Hata, Jun; Hayes, Alison J.; He, Jiang; Hendriks, Marleen Elisabeth; Henriques, Ana; Cadena, Leticia Hernandez; Herrala, Sauli; Heshmat, Ramin; Hihtaniemi, Ilpo Tapani; Ho, Sai Yin; Ho, Suzanne C.; Hobbs, Michael; Hofman, Albert; Dinc, Gonul Horasan; Hormiga, Claudia M.; Horta, Bernardo Lessa; Houti, Leila; Howitt, Christina; Htay, Thein Thein; Htet, Aung Soe; Hu, Yonghua; Huerta, José María; Husseini, Abdullatif S.; Huybrechts, Inge; Hwalla, Nahla; Iacoviello, Licia; Iannone, Anna G.; Ibrahim, M. Mohsen; Ikram, M. Arfan; Irazola, Vilma E.; Islam, Muhammad; Ivkovic, Vanja; Iwasaki, Masanori; Jackson, Rod T.; Jacobs, Jeremy M.; Jafar, Tazeen; Jamrozik, Konrad; Janszky, Imre; Jasienska, Grazyna; Jelakovic, Bojan; Jiang, Chao Qiang; Joffres, Michel; Johansson, Mattias; Jonas, Jost B; Jørgensen, Torben; Joshi, Pradeep; Juolevi, Anne; Jurak, Gregor; Jureša, Vesna; Kaaks, Rudolf; Kafatos, Anthony; Kalter-Leibovici, Ofra; Kamaruddin, Nor Azmi; Kasaeian, Amir; Katz, Joanne; Kauhanen, Jussi; Kaur, Prabhdeep; Kavousi, Maryam; Kazakbaeva, Gyulli; Keil, Ulrich; Boker, Lital Keinan; Keinänen-Kiukaanniemi, Sirkka; Kelishadi, Roya; Kemper, Han C.G.; Kengne, Andre Pascal; Kersting, Mathilde; Key, Timothy J.; Khader, Yousef Saleh; Khalili, Davood; Khang, Young Ho; Khaw, Kay Tee; Kiechl, Stefan; Killewo, Japhet; Kim, Jeongseon; Klumbiene, Jurate; Kolle, Elin; Kolsteren, Patrick; Korrovits, Paul; Koskinen, Seppo; Kouda, Katsuyasu; Koziel, Slawomir; Kristensen, Peter Lund; Krokstad, Steinar; Kromhout, Daan; Kruger, Herculina S.; Kubinova, Ruzena; Kuciene, Renata; Kuh, Diana; Kujala, Urho M.; Kula, Krzysztof; Kulaga, Zbigniew; Krishna Kumar, R.; Kurjata, Pawel; Kusuma, Yadlapalli S.; Kuulasmaa, Kari; Kyobutungi, Catherine; Laatikainen, Tiina; Lachat, Carl; Lam, Tai Hing; Landrove, Orlando; Lanska, Vera; Lappas, Georg; Larijani, Bagher; Laugsand, Lars E.; Laxmaiah, Avula; Le Nguyen Bao, Khanh; Le, Tuyen D.; Leclercq, Catherine; Lee, Jeannette; Lee, Jeonghee; Lehtimäki, Terho; Lekhraj, Rampal; León-Muñoz, Luz M.; Levitt, Naomi S.; Li, Yanping; Lilly, Christa L.; Lim, Wei-Yen; Lima-Costa, M. Fernanda; Lin, Hsien Ho; Lin, Xu; Linneberg, Allan; Lissner, Lauren; Litwin, Mieczyslaw; Lorbeer, Roberto; Lotufo, Paulo A.; Lozano, José Eugenio; Luksiene, Dalia; Lundqvist, Annamari; Lunet, Nuno; Lytsy, Per; Ma, Guansheng; Ma, Jun; Machado-Coelho, George L.L.; Machi, Suka; Maggi, Stefania; Magliano, Dianna J.; Majer, Marjeta; Makdisse, Marcia; Malekzadeh, Reza; Malhotra, Rahul; Rao, Kodavanti Mallikharjuna; Malyutina, Sofia; Manios, Yannis; Mann, Jim I.; Manzato, Enzo; Margozzini, Paula; Marques-Vidal, Pedro; Marrugat, Jaume; Martorell, Reynaldo; Mathiesen, Ellisiv B.; Matijasevich, Alicia; Matsha, Tandi E.; Mbanya, Jean Claude N.; McDonald Posso, Anselmo J.; McFarlane, Shelly R.; McGarvey, Stephen T.; McLachlan, Stela; McLean, Rachael M.; McNulty, Breige A.; MdKhir, Amir Sharifuddin; Mediene-Benchekor, Sounnia; Medzioniene, Jurate; Meirhaeghe, Aline; Meisinger, Christa; Menezes, Ana Maria B.; Menon, Geetha R.; Meshram, Indrapal I.; Metspalu, Andres; Mi, Jie; Mikkel, Kairit; Miller, Jody C.; Miquel, Juan-Francisco; Mišigoj-Durakovic, Marjeta; Mohamed, Mostafa K.; Mohammad, Kazem; Mohammadifard, Noushin; Mohan, Viswanathan; Mohd Yusoff, Muhammad Fadhli; Møller, Niels C.; Molnár, Dénes; Momenan, Amirabbas; Mondo, Charles K.; Monyeki, Kotsedi Daniel K.; Moreira, Leila B.; Morejon, Alain; Moreno, Luis A.; Morgan, Karen; Moschonis, George; Mossakowska, Malgorzata; Mota, Jorge; Mostafa, Aya; Motlagh, Mohammad Esmaeel; Motta, Jorge; Muiesan, Maria L.; Müller-Nurasyid, Martina; Murphy, Neil; Mursu, Jaakko; Musil, Vera; Nagel, Gabriele; Naidu, Balkish M.; Nakamura, Harunobu; Námešná, Jana; Nang, Ei Ei K.; Nangia, Vinay B.; Narake, Sameer; Navarrete-Muñoz, Eva Maria; Ndiaye, Ndeye Coumba; Neal, William A.; Nenko, Ilona; Nervi, Flavio; Nguyen, Nguyen D.; Nguyen, Quang Ngoc; Nieto-Martínez, Ramfis E.; Niiranen, Teemu J.; Ning, Guang; Ninomiya, Toshiharu; Nishtar, Sania; Noale, Marianna; Noboa, Oscar A.; Noorbala, Ahmad Ali; Norat, Teresa; Noto, Davide; Al Nsour, Mohannad; O'Reilly, Dermot; Oh, Kyungwon; Olinto, Maria Teresa A.; Oliveira, Isabel O.; Omar, Mohd Azahadi; Onat, Altan; Ordunez, Pedro; Osmond, Clive; Ostojic, Sergej M.; Otero, Johanna A.; Overvad, Kim; Owusu-Dabo, Ellis; Paccaud, Fred Michel; Padez, Cristina; Pahomova, Elena; Pajak, Andrzej; Palli, Domenico; Palmieri, Luigi; Panda-Jonas, Songhomitra; Panza, Francesco; Papandreou, Dimitrios; Parnell, Winsome R.; Parsaeian, Mahboubeh; Pecin, Ivan; Pednekar, Mangesh S.; Peer, Nasheeta; Peeters, Petra H.; Peixoto, Sergio Viana; Pelletier, Catherine; Peltonen, Markku; Pereira, Alexandre C.; Pérez, Rosa Marina; Peters, Annette; Petkeviciene, Janina; Pham, Son Thai; Pigeot, Iris; Pikhart, Hynek; Pilav, Aida; Pilotto, Lorenza; Pitakaka, Freda; Plans-Rubió, Pedro; Polakowska, Maria; Polašek, Ozren; Porta, Miquel; Portegies, Marileen L.P.; Pourshams, Akram; Pradeepa, Rajendra; Prashant, Mathur; Price, Jacqueline F.; Puiu, Maria; Punab, Margus; Qasrawi, Radwan F.; Qorbani, Mostafa; Radic, Ivana; Radisauskas, Ricardas; Rahman, Mahfuzar; Raitakari, Olli T.; Raj, Manu; Rao, Sudha Ramachandra; Ramachandran, Ambady; Ramos, Elisabete; Rampal, Sanjay; Rangel Reina, Daniel A.; Rasmussen, Finn; Redon, Josep; Reganit, Paul Ferdinand M.; Ribeiro, Robespierre; Riboli, Elio; Rigo, Fernando; Rinke de Wit, Tobias F.; Ritti-Dias, Raphael M.; Robinson, Sian M.; Robitaille, Cynthia; Rodríguez-Artalejo, Fernando; del Cristo Rodriguez-Perez, María; Rodríguez-Villamizar, Laura A.; Rojas-Martinez, Rosalba; Rosengren, Annika; Rubinstein, Adolfo; Rui, Ornelas; Ruiz-Betancourt, Blanca Sandra; Russo Horimoto, Andrea R.V.; Rutkowski, Marcin; Sabanayagam, Charumathi; Sachdev, Harshpal S.; Saidi, Olfa; Sakarya, Sibel; Salanave, Benoit; Martinez, Eduardo Salazar; Salmerón, Diego; Salomaa, Veikko; Salonen, Jukka T.; Salvetti, Massimo; Sánchez-Abanto, Jose; Sans, Susana; Santos, Diana; Santos, Ina S.; dos Santos, Renata Nunes; Santos, Rute; Saramies, Jouko L.; Sardinha, Luis B.; Margolis, Giselle Sarganas; Sarrafzadegan, Nizal; Saum, Kai Uwe; Savva, Savvas C.; Scazufca, Marcia; Schargrodsky, Herman; Schneider, Ione J.; Schultsz, Constance; Schutte, Aletta E.; Schutte, Aletta E.; Sen, Abhijit; Senbanjo, Idowu O.; Sepanlou, Sadaf G.; Sharma, Sanjib K.; Shaw, Jonathan E.; Shibuya, Kenji; Shin, Dong Wook; Shin, Youchan; Siantar, Rosalynn; Sibai, Abla M.; Santos Silva, Diego Augusto; Simon, Mary; Simons, Judith; Simons, Leon A; Sjöström, Michael; Skovbjerg, Sine; Slowikowska-Hilczer, Jolanta; Slusarczyk, Przemyslaw; Smith, Margaret C.; Snijder, Marieke B.; So, Hung Kwan; Sobngwi, Eugène; Söderberg, Stefan; Solfrizzi, Vincenzo; Sonestedt, Emily; Song, Yi; Sørensen, Thorkild I A; Soric, Maroje; Jérome, Charles Sossa; Soumare, Aicha; Staessen, Jan A.; Starc, Gregor; Stathopoulou, Maria G.; Stavreski, Bill; Steene-Johannessen, Jostein; Stehle, Peter; Stein, Aryeh D.; Stergiou, George S.; Stessman, Jochanan; Stieber, Jutta; Stöckl, Doris; Stocks, Tanja; Stokwiszewski, Jakub; Stronks, Karien; Strufaldi, Maria Wany; Sun, Chien An; Sung, Yn Tz; Suriyawongpaisal, Paibul; Sy, Rody G.; Tai, E. Shyong; Tammesoo, Mari Liis; Tamosiunas, Abdonas; Tang, Line; Tang, Xun; Tao, Yong; Tanser, Frank; Tarawneh, Mohammed Rasoul; Tarqui-Mamani, Carolina B.; Taylor, Anne; Theobald, Holger; Thijs, Lutgarde; Thuesen, Betina Heinsbek; Tjonneland, Anne; Tolonen, Hanna K.; Tolstrup, Janne S.; Topbas, Murat; Topór-Madry, Roman; Tormo, María José; Torrent, Maties; Traissac, Pierre; Trichopoulos, Dimitrios; Trichopoulou, Antonia; Trinh, Oanh T.H.; Trivedi, Atul; Tshepo, Lechaba; Tulloch-Reid, Marshall K.; Tuomainen, Tomi-Pekka; Tuomilehto, Jaakko; Turley, Maria L.; Tynelius, Per; Tzourio, Christophe; Ueda, Peter; Ugel, Eunice; Ulmer, Hanno; Uusitalo, Hannu M.T.; Valdivia, Gonzalo; Valvi, Damaskini; van der Schouw, Yvonne T.; Van Herck, Koen; van Rossem, Lenie; Van Valkengoed, Irene G M; Vanderschueren, Dirk; Vanuzzo, Diego; Vatten, Lars; Vega, Tomas; Velasquez-Melendez, Gustavo; Veronesi, Giovanni; Verschuren, W. M.Monique; Verstraeten, Roosmarijn; Victora, Cesar G.; Viet, Lucie; Viikari-Juntura, Eira; Vineis, Paolo; Vioque, Jesus; Virtanen, Jyrki K.; Visvikis-Siest, Sophie; Viswanathan, Bharathi; Vollenweider, Peter; Voutilainen, Sari; Vrdoljak, Ana; Vrijheid, Martine; Wade, Alisha N.; Wagner, Aline; Walton, Janette; Wan Mohamud, Wan Nazaimoon; Wang, Ming Dong; Wang, Qian; Wang, Ya Xing; Wannamethee, S. Goya; Wareham, Nicholas J.; Wederkopp, Niels; Weerasekera, Deepa; Whincup, Peter H.; Widhalm, Kurt; Widyahening, Indah S.; Wijga, Alet H; Wiecek, Andrzej; Wilks, Rainford J.; Willeit, Johann; Willeit, Peter; Williams, Emmanuel A.; Wilsgaard, Tom; Wojtyniak, Bogdan; Wong, Tien-Yin; Wong-McClure, Roy A.; Woo, Jean; Woodward, Mark; Woodward, Mark; Wu, Aleksander Giwercman; Wu, Frederick C.; Wu, Shou Ling; Xu, Haiquan; Yan, Weili; Yang, Xiaoguang; Ye, Xingwang; Yiallouros, Panayiotis K.; Yoshihara, Akihiro; Younger-Coleman, Novie O.; Yusoff, Ahmad F.; Yusoff, Muhammad Fadhli M.; Zambon, Sabina; Zdrojewski, Tomasz; Zeng, Yi-Xin; Zeng, Yi-Xin; Zhao, Dong; Zhao, Wenhua; Zheng, Yingffeng; Zimmermann, Esther; Cisneros, Julio Zuñiga; Zhu, Dan

    2017-01-01

    Background Raised blood pressure is an important risk factor for cardiovascular diseases and chronic kidney disease. We estimated worldwide trends in mean systolic and mean diastolic blood pressure, and the prevalence of, and number of people with, raised blood pressure, defined as systolic blood

  18. Worldwide trends in blood pressure from 1975 to 2015 : a pooled analysis of 1479 population-based measurement studies with 19.1 million participants

    NARCIS (Netherlands)

    Zhou, Bin; Bentham, James; Di Cesare, Mariachiara; Bixby, Honor; Danaei, Goodarz; Cowan, Melanie J.; Paciorek, Christopher J.; Singh, Gitanjali M; Hajifathalian, Kaveh; Bennett, James E.; Taddei, Cristina; Bilano, Ver; Carrillo-Larco, Rodrigo M.; Djalalinia, Shirin; Khatibzadeh, Shahab; Lugero, Charles; Peykari, Niloofar; Zhang, Wan Zhu; Lu, Yuan; Stevens, Gretchen A.; Riley, Leanne M.; Bovet, Pascal; Elliott, Paul; Gu, Dongfeng; Ikeda, Nayu; Jackson, Rod T.; Joffres, Michel; Kengne, Andre-Pascal; Laatikainen, Tiina; Lam, Tai Hing; Laxmaiah, Avula; Liu, Jing; Miranda, J. Jaime; Mondo, Charles K.; Neuhauser, Hannelore K.; Sundstrom, Johan; Smeeth, Liam; Soric, Maroje; Woodward, Mark; Ezzati, Majid; Abarca-Gomez, Leandra; Abdeen, Ziad A.; Rahim, Hanan Abdul; Abu-Rmeileh, Niveen Me; Acosta-Cazares, Benjamin; Adams, Robert; Aekplakorn, Wichai; Afsana, Kaosar; Aguilar-Salinas, Carlos A; Agyemang, Charles; Ahmadvand, Alireza; Ahrens, Wolfgang; Al-Raddadi, Rajaa; Al Woyatan, Rihab; Karamat Ali, Mohamed Hanief; Alkerwi, Ala'a; Aly, Eman; Amouyel, Philippe; Amuzu, Antoinette; Andersen, Lars Bo; Anderssen, Sigmund A.; Angquist, Lars; Anjana, Ranjit Mohan; Ansong, Daniel; Aounallah-Skhiri, Hajer; Araujo, Joana; Ariansen, Inger; Aris, Tahir; Arlappa, Nimmathota; Aryal, Krishna; Arveiler, Dominique; Assah, Felix K.; Assuncao, Maria Cecilia F.; Avdicova, Maria; Azevedo, Ana; Azizi, Fereidoun; Babu, Bontha V.; Bahijri, Suhad; Balakrishna, Nagalla; Bandosz, Piotr; Banegas, Jose R.; Barbagallo, Carlo M.; Barcelo, Alberto; Barkat, Amina; Barros, Aluisio J. D.; Barros, Mauro V.; Bata, Iqbal; Batieha, Anwar M.; Baur, Louise A.; Beaglehole, Robert; Ben Romdhane, Habiba; Benet, Mikhail; Benson, Lowell S.; Bernabe-Ortiz, Antonio; Bernotiene, Gailute; Bettiol, Heloisa; Bhagyalaxmi, Aroor; Bharadwaj, Sumit; Bhargava, Santosh K.; Bi, Yufang; Bikbov, Mukharram; Bjerregaard, Peter; Bjertness, Espen; Bjokelund, Cecilia; Blokstra, Anneke; Bo, Simona; Bobak, Martin; Boeing, Heiner; Boggia, Jose G.; Boissonnet, Carlos P.; Bongard, Vanina; Bovet, Pascal; Braeckman, Lutgart; Brajkovich, Imperia; Branca, Francesco; Breckenkamp, Juergen; Brenner, Hermann; Brewster, Lizzy M.; Bruno, Graziella; Bueno-de-Mesquita, H. B(as).; Bugge, Anna; Burns, Con; Bursztyn, Michael; de Leon, Antonio Cabrera; Cameron, Christine; Can, Gunay; Candido, Ana Paula C.; Capuano, Vincenzo; Cardoso, Viviane C.; Carlsson, Axel C.; Carvalho, Maria J.; Casanueva, Felipe F.; Casanueva, Felipe F.; Casas, Juan Pablo; Caserta, Carmelo A.; Chamukuttan, Snehalatha; Chan, Angelique W.; Chan, Queenie; Chaturvedi, Himanshu K.; Chaturvedi, Nishi; Chen, Chien-Jen; Chen, Fangfang; Chen, Huashuai; Chen, Shuohua; Chen, Zhengming; Cheng, Yu-Ching; Dekkaki, Imane Cherkaoui; Chetrit, Angela; Chiolero, Arnaud; Chiou, Shu-Ti; Chirita-Emandi, Adela; Cho, Belong; Cho, Yumi; Chudek, Jerzy; Cifkova, Renata; Claessens, Frank; Clays, Els; Concin, Hans; Cooper, Cyrus; Cooper, Rachel; Coppinger, Tara C.; Costanzo, Simona; Cottel, Dominique; Cowell, Chris T.; Craig, Cora L.; Crujeiras, Ana B.; Cruz Moreno, Juan; D'Arrigo, Graziella; d'Orsi, Eleonora; Dallongeville, Jean; Damasceno, Albertino; Danaei, Goodarz; Dankner, Rachel; Dantoft, Thomas M.; Dauchet, Luc; De Backer, Guy; de Gaetano, Giovanni; De Henauw, Stefaan; De Smedt, Delphine; Deepa, Mohan; Dehghan, Abbas; Delisle, Helene; Deschamps, Valerie; Dhana, Klodian; Di Castelnuovo, Augusto F.; Dias-da-Costa, Juvenal Soares; Diaz, Alejandro; Dickerson, Ty T.; Djalalinia, Shirin; Do, Ha T. P.; Dobson, Annette J.; Donfrancesco, Chiara; Donoso, Silvana P.; Doering, Angela; Doua, Kouamelan; Drygas, Wojciech; Dulskiene, Virginija; Dzakula, Aleksandar; Dzerve, Vilnis; Dziankowska-Zaborszczyk, Elzbieta; Eggertsen, Robert; Ekelund, Ulf; El Ati, Jalila; Ellert, Ute; Elliott, Paul; Elosua, Roberto; Erasmus, Rajiv T.; Erem, Cihangir; Eriksen, Louise; Escobedo-de la Pena, Jorge; Evans, Alun; Faeh, David; Fall, Caroline H.; Farzadfar, Farshad; Felix-Redondo, Francisco J.; Ferguson, Trevor S.; Fernandez-Berges, Daniel; Ferrante, Daniel; Ferrari, Marika; Ferreccio, Catterina; Ferrieres, Jean; Finn, Joseph D.; Fischer, Krista; Foeger, Bernhard; Foo, Leng Huat; Forslund, Ann-Sofie; Forsner, Maria; Fortmann, Stephen P.; Fouad, Heba M.; Francis, Damian K.; Franco, Maria do Carmo; Franco, Oscar H.; Frontera, Guillermo; Fuchs, Flavio D.; Fuchs, Sandra C.; Fujita, Yuki; Furusawa, Takuro; Gaciong, Zbigniew; Gareta, Dickman; Garnett, Sarah P.; Gaspoz, Jean-Michel; Gasull, Magda; Gates, Louise; Gavrila, Diana; Geleijnse, Johanna M.; Ghasemian, Anoosheh; Ghimire, Anup; Giampaoli, Simona; Gianfagna, Francesco; Giovannelli, Jonathan; Goldsmith, Rebecca A.; Goncalves, Helen; Gonzalez Gross, Marcela; Gonzalez Rivas, Juan P.; Gottrand, Frederic; Graff-Iversen, Sidsel; Grafnetter, Dusan; Grajda, Aneta; Gregor, Ronald D.; Grodzicki, Tomasz; Grontved, Anders; Gruden, Grabriella; Grujic, Vera; Gu, Dongfeng; Guan, Ong Peng; Gudnason, Vilmundur; Guerrero, Ramiro; Guessous, Idris; Guimaraes, Andre L.; Gulliford, Martin C.; Gunnlaugsdottir, Johanna; Gunter, Marc; Gupta, Prakash C.; Gureje, Oye; Gurzkowska, Beata; Gutierrez, Laura; Gutzwiller, Felix; Hadaegh, Farzad; Halkjaer, Jytte; Hambleton, Ian R.; Hardy, Rebecca; Harikumar, Rachakulla; Hata, Jun; Hayes, Alison J.; He, Jiang; Hendriks, Marleen Elisabeth; Henriques, Ana; Hernandez Cadena, Leticia; Herqutanto,; Herrala, Sauli; Heshmat, Ramin; Hihtaniemi, Ilpo Tapani; Ho, Sai Yin; Ho, Suzanne C.; Hobbs, Michael; Hofman, Albert; Dinc, Gonul Horasan; Hormiga, Claudia M.; Horta, Bernardo Lessa; Houti, Leila; Howitt, Christina; Htay, Thein Thein; Htet, Aung Soe; Hu, Yonghua; Maria Huerta, Jose; Husseini, Abdullatif S.; Huybrechts, Inge; Hwalla, Nahla; Iacoviello, Licia; Iannone, Anna G.; Ibrahim, M. Mohsen; Ikram, M. Arfan; Irazola, Vilma E.; Islam, Muhammad; Ivkovic, Vanja; Iwasaki, Masanori; Jackson, Rod T.; Jacobs, Jeremy M.; Jafar, Tazeen H.; Jamrozik, Konrad; Janszky, Imre; Jasienska, Grazyna; Jelakovic, Bojan; Jiang, Chao Qiang; Johansson, Mattias; Jonas, Jost B; Jorgensen, Torben; Joshi, Pradeep; Juolevi, Anne; Jurak, Gregor; Juresa, Vesna; Kaaks, Rudolf; Kafatos, Anthony; Kalter-Leibovici, Ofra; Kamaruddin, Nor Azmi; Kasaeian, Amir; Katz, Joanne; Kauhanen, Jussi; Kaur, Prabhdeep; Kavousi, Maryam; Kazakbaeva, Gyulli; Keil, Ulrich; Boker, Lital Keinan; Keinanen-Kiukaanniemi, Sirkka; Kelishadi, Roya; Kemper, Han C. G.; Kengne, Andre-Pascal; Kersting, Mathilde; Key, Timothy; Khader, Yousef Saleh; Khalili, Davood; Khang, Young-Ho; Khaw, Kay Tee; Kiechl, Stefan; Killewo, Japhet; Kim, Jeongseon; Klumbiene, Jurate; Kolle, Elin; Kolsteren, Patrick; Korrovits, Paul; Koskinen, Seppo; Kouda, Katsuyasu; Koziel, Slawomir; Kristensen, Peter Lund; Krokstad, Steinar; Kromhout, Daan; Kruger, Herculina S.; Kubinova, Ruzena; Kuciene, Renata; Kuh, Diana; Kujala, Urho M.; Kula, Krzysztof; Kulaga, Zbigniew; Kumar, R. Krishna; Kurjata, Pawel; Kusuma, Yadlapalli S.; Kuulasmaa, Kari; Kyobutungi, Catherine; Laatikainen, Tiina; Lachat, Carl; Landrove, Orlando; Lanska, Vera; Lappas, Georg; Larijani, Bagher; Laugsand, Lars E.; Laxmaiah, Avula; Khanh Le Nguyen Bao,; Le, Tuyen D.; Leclercq, Catherine; Lee, Jeannette Jen-Mai; Lee, Jeonghee; Lehtimaki, Terho; Lekhraj, Rampal; Leon-Munoz, Luz M.; Levitt, Naomi S.; Li, Yanping; Lilly, Christa L.; Lim, Wei-Yen; Fernanda Lima-Costa, M.; Lin, Hsien-Ho; Lin, Xu; Linneberg, Allan; Lissner, Lauren; Litwin, Mieczyslaw; Liu, Jing; Lorbeer, Roberto; Lotufo, Paulo A.; Eugenio Lozano, Jose; Luksiene, Dalia; Lundqvist, Annamari; Lunet, Nuno; Lytsy, Per; Ma, Guansheng; Ma, Jun; Machado-Coelho, George L. L.; Machi, Suka; Maggi, Stefania; Magliano, Dianna J.; Majer, Marjeta; Makdisse, Marcia; Malekzadeh, Reza; Malhotra, Rahul; Rao, Kodavanti Mallikharjuna; Malyutina, Sofia; Manios, Yannis; Mann, Jim I.; Manzato, Enzo; Margozzini, Paula; Marques-Vidal, Pedro; Marrugat, Jaume; Martorell, Reynaldo; Mathiesen, Ellisiv B.; Matijasevich, Alicia; Matsha, Tandi E.; Mbanya, Jean Claude N.; Posso, Anselmo J. Mc Donald; McFarlane, Shelly R.; McFarlane, Shelly R.; McGarvey, Stephen Theodore; McLachlan, Stela; McLean, Rachael M.; McNulty, Breige A.; Khir, Amir Sharifuddin Md; Mediene-Benchekor, Sounnia; Medzioniene, Jurate; Meirhaeghe, Aline; Meisinger, Christa; Menezes, Ana Maria B.; Menon, Geetha R.; Meshram, Indrapal I.; Metspalu, Andres; Mi, Jie; Mikkel, Kairit; Miller, Jody C.; Francisco Miquel, Juan; Jaime Miranda, J.; Misigoj-Durakovic, Marjeta; Mohamed, Mostafa K.; Mohammad, Kazem; Mohammadifard, Noushin; Mohan, Viswanathan; Yusoff, Muhammad Fadhli Mohd; Moller, Niels C.; Molnar, Denes; Momenan, Amirabbas; Mondo, Charles K.; Monyeki, Kotsedi Daniel K.; Moreira, Leila B.; Morejon, Alain; Moreno, Luis A.; Morgan, Karen; Moschonis, George; Mossakowska, Malgorzata; Mostafa, Aya; Mota, Jorge; Motlagh, Mohammad Esmaeel; Motta, Jorge; Muiesan, Maria L.; Mueller-Nurasyid, Martina; Murphy, Neil; Mursu, Jaakko; Musil, Vera; Nagel, Gabriele; Naidu, Balkish M.; Nakamura, Harunobu; Namsna, Jana; Nang, Ei Ei K.; Nangia, Vinay B.; Narake, Sameer; Maria Navarrete-Munoz, Eva; Ndiaye, Ndeye Coumba; Neal, William A.; Nenko, Ilona; Nervi, Flavio; Neuhauser, Hannelore K.; Nguyen, Nguyen D.; Quang Ngoc Nguyen,; Nieto-Martinez, Ramfis E.; Niiranen, Teemu J.; Ning, Guang; Ninomiya, Toshiharu; Nishtar, Sania; Noale, Marianna; Noboa, Oscar A.; Noorbala, Ahmad Ali; Norat, Teresa; Noto, Davide; Al Nsour, Mohannad; O'Reilly, Dermot; Oh, Kyungwon; Olinto, Maria Teresa A.; Oliveira, Isabel O.; Omar, Mohd Azahadi; Onat, Altan; Ordunez, Pedro; Osmond, Clive; Ostojic, Sergej M.; Otero, Johanna A.; Overvad, Kim; Owusu-Dabo, Ellis; Paccaud, Fred Michel; Padez, Cristina; Pahomova, Elena; Pajak, Andrzej; Palli, Domenico; Palmieri, Luigi; Panda-Jonas, Songhomitra; Panza, Francesco; Papandreou, Dimitrios; Parnell, Winsome R.; Parsaeian, Mahboubeh; Pecin, Ivan; Pednekar, Mangesh S.; Peer, Nasheeta; Peeters, Petra H.; Peixoto, Sergio Viana; Pelletier, Catherine; Peltonen, Markku; Pereira, Alexandre C.; Marina Perez, Rosa; Peters, Annette; Petkeviciene, Janina; Peykari, Niloofar; Son Thai Pham,; Pigeot, Iris; Pikhart, Hynek; Pilav, Aida; Pilotto, Lorenza; Pitakaka, Freda; Plans-Rubio, Pedro; Polakowska, Maria; Polasek, Ozren; Porta, Miquel; Portegies, Marileen L. P.; Pourshams, Akram; Pradeepa, Rajendra; Prashant, Mathur; Price, Jacqueline F.; Puiu, Maria; Punab, Margus; Qasrawi, Radwan F.; Qorbani, Mostafa; Radic, Ivana; Radisauskas, Ricardas; Rahman, Mahfuzar; Raitakari, Olli; Raj, Manu; Rao, Sudha Ramachandra; Ramos, Elisabete; Rampal, Sanjay; Rangel Reina, Daniel A.; Rasmussen, Finn; Redon, Josep; Reganit, Paul Ferdinand M.; Ribeiro, Robespierre; Riboli, Elio; Rigo, Fernando; de Wit, Tobias F. Rinke; Ritti-Dias, Raphael M.; Robinson, Sian M.; Robitaille, Cynthia; Rodriguez-Artalejo, Fernando; Rodriguez-Villamizar, Laura A.; Rojas-Martinez, Rosalba; Rosengren, Annika; Rubinstein, Adolfo; Rui, Ornelas; Sandra Ruiz-Betancourt, Blanca; Russo Horimoto, Andrea R. V.; Rutkowski, Marcin; Sabanayagam, Charumathi; Sachdev, Harshpal S.; Saidi, Olfa; Sakarya, Sibel; Salanave, Benoit; Salazar Martinez, Eduardo; Salmeron, Diego; Salomaa, Veikko; Salonen, Jukka T.; Salvetti, Massimo; Sanchez-Abanto, Jose; Sans, Susana; Santos, Diana; Santos, Ina S.; dos Santos, Renata Nunes; Santos, Rute; Saramies, Jouko L.; Sardinha, Luis B.; Margolis, Giselle Sarganas; Sarrafzadegan, Nizal; Saum, Kai-Uwe; Savva, Savvas C.; Scazufca, Marcia; Schargrodsky, Herman; Schneider, Ione J. C.; Schultsz, Constance; Schutte, Aletta E.; Sen, Abhijit; Senbanjo, Idowu O.; Sepanlou, Sadaf G.; Sharma, Sanjib K.; Shaw, Jonathan E.; Shibuya, Kenji; Shin, Dong Wook; Shin, Youchan; Siantar, Rosalynn; Sibai, Abla M.; Santos Silva, Diego Augusto; Simon, Mary; Simons, Judith; Simons, Leon A.; Sjotrom, Michael; Skovbjerg, Sine; Slowikowska-Hilczer, Jolanta; Slusarczyk, Przemyslaw; Smeeth, Liam; Smith, Margaret C. M.; Snijder, Marieke B.; So, Hung-Kwan; Sobngwi, Eugene; Soderberg, Stefan; Solfrizzi, Vincenzo; Sonestedt, Emily; Song, Yi; Sorensen, Thorkild I. A.; Soric, Maroje; Jerome, Charles Sossa; Soumare, Aicha; Staessen, Jan A.; Starc, Gregor; Stathopoulou, Maria G.; Stavreski, Bill; Steene-Johannessen, Jostein; Stehle, Peter; Stein, Aryeh D.; Stergiou, George S.; Stessman, Jochanan; Stieber, Jutta; Stoeckl, Doris; Stocks, Tanja; Stokwiszewski, Jakub; Stronks, Karien; Strufaldi, Maria Wany; Sun, Chien-An; Sundstrom, Johan; Sung, Yn-Tz; Suriyawongpaisal, Paibul; Sy, Rody G.; Tai, E-Shyong; Tammesoo, Mari-Liis; Tamosiunas, Abdonas; Tang, Line; Tang, Xun; Tanser, Frank; Tao, Yong; Tarawneh, Mohammed Rasoul; Tarqui-Mamani, Carolina B.; Taylor, Anne W.; Theobald, Holger; Thijs, Lutgarde; Thuesen, Betina H.; Tjonneland, Anne; Tolonen, Hanna K.; Topbas, Murat; Topor-Madry, Roman; Jose Tormo, Maria; Torrent, Maties; Traissac, Pierre; Trichopoulos, Dimitrios; Trichopoulou, Antonia; Trinh, Oanh T. H.; Trivedi, Atul; Tshepo, Lechaba; Tulloch-Reid, Marshall K.; Tuomainen, Tomi-Pekka; Turley, Maria L.; Tynelius, Per; Tzourio, Christophe; Ueda, Peter; Ugel, Eunice; Ulmer, Hanno; Uusitalo, Hannu M. T.; Valdivia, Gonzalo; Valvi, Damaskini; van der Schouw, Yvonne T.; Van Herck, Koen; van Rossem, Lenie; van Valkengoed, Irene G. M.; Vanderschueren, Dirk; Vanuzzo, Diego; Vatten, Lars; Vega, Tomas; Velasquez-Melendez, Gustavo; Veronesi, Giovanni; Verschuren, W. Monique; Verstraeten, Roosmarijn; Victora, Cesar G.; Viet, Lucie; Viikari-Juntura, Eira; Vineis, Paolo; Vioque, Jesus; Virtanen, Jyrki K.; Visvikis-Siest, Sophie; Viswanathan, Bharathi; Vollenweider, Peter; Vrdoljak, Ana; Vrijheid, Martine; Wade, Alisha N.; Wagner, Aline; Walton, Janette; Mohamud, Wan Nazaimoon Wan; Wang, Ming-Dong; Wang, Qian; Wang, Ya Xing; Wannamethee, S. Goya; Wareham, Nicholas; Wederkopp, Niels; Weerasekera, Deepa; Whincup, Peter H.; Widhalm, Kurt; Widyahening, Indah S.; Wiecek, Andrzej; Wijga, Alet H.; Wilks, Rainford J.; Willeit, Peter; Williams, Emmanuel A.; Wilsgaard, Tom; Wojtyniak, Bogdan J.; Wong, Tien-Yin; Wong-McClure, Roy A.; Woo, Jean; Woodward, Mark; Wu, Aleksander Giwercman; Wu, Frederick C.; Wu, Shou Ling; Xu, Haiquan; Yan, Weili; Yang, Xiaoguang; Ye, Xingwang; Yiallouros, Panayiotis K.; Yoshihara, Akihiro; Younger-Coleman, Novie O.; Yusoff, Ahmad F.; Zambon, Sabina; Zdrojewski, Tomasz; Zeng, Yi; Zhao, Dong; Zhao, Wenhua; Zheng, Yingffeng; Zhu, Dan; Zimmermann, Esther; Zuniga Cisneros, Julio

    2017-01-01

    Background Raised blood pressure is an important risk factor for cardiovascular diseases and chronic kidney disease. We estimated worldwide trends in mean systolic and mean diastolic blood pressure, and the prevalence of, and number of people with, raised blood pressure, defined as systolic blood

  19. Cerebral blood volume calculated by dynamic susceptibility contrast-enhanced perfusion MR imaging: preliminary correlation study with glioblastoma genetic profiles.

    Directory of Open Access Journals (Sweden)

    Inseon Ryoo

    Full Text Available To evaluate the usefulness of dynamic susceptibility contrast (DSC enhanced perfusion MR imaging in predicting major genetic alterations in glioblastomas.Twenty-five patients (M:F = 13∶12, mean age: 52.1±15.2 years with pathologically proven glioblastoma who underwent DSC MR imaging before surgery were included. On DSC MR imaging, the normalized relative tumor blood volume (nTBV of the enhancing solid portion of each tumor was calculated by using dedicated software (Nordic TumorEX, NordicNeuroLab, Bergen, Norway that enabled semi-automatic segmentation for each tumor. Five major glioblastoma genetic alterations (epidermal growth factor receptor (EGFR, phosphatase and tensin homologue (PTEN, Ki-67, O6-methylguanine-DNA methyltransferase (MGMT and p53 were confirmed by immunohistochemistry and analyzed for correlation with the nTBV of each tumor. Statistical analysis was performed using the unpaired Student t test, ROC (receiver operating characteristic curve analysis and Pearson correlation analysis.The nTBVs of the MGMT methylation-negative group (mean 9.5±7.5 were significantly higher than those of the MGMT methylation-positive group (mean 5.4±1.8 (p = .046. In the analysis of EGFR expression-positive group, the nTBVs of the subgroup with loss of PTEN gene expression (mean: 10.3±8.1 were also significantly higher than those of the subgroup without loss of PTEN gene expression (mean: 5.6±2.3 (p = .046. Ki-67 labeling index indicated significant positive correlation with the nTBV of the tumor (p = .01.We found that glioblastomas with aggressive genetic alterations tended to have a high nTBV in the present study. Thus, we believe that DSC-enhanced perfusion MR imaging could be helpful in predicting genetic alterations that are crucial in predicting the prognosis of and selecting tailored treatment for glioblastoma patients.

  20. Cine phase-contrast MR to assess portal blood flow in a 10-year-old girl with abdominal aortic coarctation: a case report

    International Nuclear Information System (INIS)

    Clark, T.W.I.; Culham, J.A.G.

    1998-01-01

    We report the case of a 10-year-old girl with repaired abdominal aortic coarctation in whom chronic mesenteric ischemia was clinically suspected. Cine phase-contrast magnetic resonance (MR) was used to determine the difference between fasting and postprandial portal blood flow. Fasting flow rates in the portal vein were normal. After a meal, blood flow in the portal vein increased 226 % over the fasting state, showing normal augmentation. To the best of our knowledge, this is the first application of this technique to a pediatric setting. (orig.)

  1. 4-D flow magnetic resonance imaging: blood flow quantification compared to 2-D phase-contrast magnetic resonance imaging and Doppler echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Gabbour, Maya [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging 9, Chicago, IL (United States); Schnell, Susanne [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Jarvis, Kelly [Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Evanston, IL (United States); Robinson, Joshua D. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Pediatrics, Division of Pediatric Cardiology, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Pediatrics, Chicago, IL (United States); Markl, Michael [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Evanston, IL (United States); Rigsby, Cynthia K. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging 9, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States)

    2015-06-15

    Doppler echocardiography (echo) is the reference standard for blood flow velocity analysis, and two-dimensional (2-D) phase-contrast magnetic resonance imaging (MRI) is considered the reference standard for quantitative blood flow assessment. However, both clinical standard-of-care techniques are limited by 2-D acquisitions and single-direction velocity encoding and may make them inadequate to assess the complex three-dimensional hemodynamics seen in congenital heart disease. Four-dimensional flow MRI (4-D flow) enables qualitative and quantitative analysis of complex blood flow in the heart and great arteries. The objectives of this study are to compare 4-D flow with 2-D phase-contrast MRI for quantification of aortic and pulmonary flow and to evaluate the advantage of 4-D flow-based volumetric flow analysis compared to 2-D phase-contrast MRI and echo for peak velocity assessment in children and young adults. Two-dimensional phase-contrast MRI of the aortic root, main pulmonary artery (MPA), and right and left pulmonary arteries (RPA, LPA) and 4-D flow with volumetric coverage of the aorta and pulmonary arteries were performed in 50 patients (mean age: 13.1 ± 6.4 years). Four-dimensional flow analyses included calculation of net flow and regurgitant fraction with 4-D flow analysis planes similarly positioned to 2-D planes. In addition, 4-D flow volumetric assessment of aortic root/ascending aorta and MPA peak velocities was performed and compared to 2-D phase-contrast MRI and echo. Excellent correlation and agreement were found between 2-D phase-contrast MRI and 4-D flow for net flow (r = 0.97, P < 0.001) and excellent correlation with good agreement was found for regurgitant fraction (r = 0.88, P < 0.001) in all vessels. Two-dimensional phase-contrast MRI significantly underestimated aortic (P = 0.032) and MPA (P < 0.001) peak velocities compared to echo, while volumetric 4-D flow analysis resulted in higher (aortic: P = 0.001) or similar (MPA: P = 0.98) peak

  2. Prognostic Significance of Hyponatremia in Acute Intracerebral Hemorrhage: Pooled Analysis of the Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial Studies

    NARCIS (Netherlands)

    Carcel, C.; Sato, S.; Zheng, D.; Heeley, E.; Arima, H.; Yang, J.; Wu, G.; Chen, G.; Zhang, S.; Delcourt, C; Lavados, P.; Robinson, T.; Lindley, R.I.; Wang, X.; Chalmers, J.; Anderson, C.S.; Klijn, C.J.M.; et al.,

    2016-01-01

    OBJECTIVES: To determine the association of hyponatremia at presentation with clinical and imaging outcomes in patients with acute intracerebral hemorrhage. DESIGN: Retrospective pooled analysis of prospectively collected data from 3,243 participants of the pilot and main phases of the Intensive

  3. Correction with blood T1 is essential when measuring post-contrast myocardial T1 value in patients with acute myocardial infarction.

    Science.gov (United States)

    Choi, Eui-Young; Hwang, Sung Ho; Yoon, Young Won; Park, Chul Hwan; Paek, Mun Young; Greiser, Andreas; Chung, Hyemoon; Yoon, Ji-Hyun; Kim, Jong-Youn; Min, Pil-Ki; Lee, Byoung Kwon; Hong, Bum-Kee; Rim, Se-Joong; Kwon, Hyuck Moon; Kim, Tae Hoon

    2013-01-19

    Post-contrast T1 mapping by modified Look-Locker inversion recovery (MOLLI) sequence has been introduced as a promising means to assess an expansion of the extra-cellular space. However, T1 value in the myocardium can be affected by scanning time after bolus contrast injection. In this study, we investigated the changes of the T1 values according to multiple slicing over scanning time at 15 minutes after contrast injection and usefulness of blood T1 correction. Eighteen reperfused acute myocardial infarction (AMI) patients, 13 cardiomyopathy patients and 8 healthy volunteers underwent cardiovascular magnetic resonance with 15 minute-post contrast MOLLI to generate T1 maps. In 10 cardiomyopathy cases, pre- and post-contrast MOLLI techniques were performed to generate extracellular volume fraction (Ve). Six slices of T1 maps according to the left ventricular (LV) short axis, from apex to base, were consecutively obtained. Each T1 value was measured in the whole myocardium, infarcted myocardium, non-infarcted myocardium and LV blood cavity. The mean T1 value of infarcted myocardium was significantly lower than that of non-infarcted myocardium (425.4 ± 68.1 ms vs. 540.5 ± 88.0 ms, respectively, p infarcted myocardium increased significantly from apex to base (from 523.1 ± 99.5 ms to 561.1 ± 81.1 ms, p = 0.001), and were accompanied by a similar increase in blood T1 value in LV cavity (from 442.1 ± 120.7 ms to 456.8 ± 97.5 ms, p myocardial T1 values, however, were adjusted by the blood T1 values, they were consistent throughout the slices from apex to base (from 1.17 ± 0.18 to 1.25 ± 0.13, p > 0.05). The Ve did not show significant differences from apical to basal slices. Post-contrast myocardial T1 corrected by blood T1 or Ve, provide more stable measurement of degree of fibrosis in non-infarcted myocardium in short- axis multiple slicing.

  4. Real-time contrast-enhanced ultrasound determination of microvascular blood volume in abdominal subcutaneous adipose tissue in man. Evidence for adipose tissue capillary recruitment

    DEFF Research Database (Denmark)

    Tobin, L; Simonsen, L; Bülow, J

    2010-01-01

    The adipose tissue metabolism is dependent on its blood perfusion. During lipid mobilization e.g. during exercise and during lipid deposition e.g. postprandial, adipose tissue blood flow is increased. This increase in blood flow may involve capillary recruitment in the tissue. We investigated...... the basic and postprandial microvascular volume in adipose tissue using real-time contrast-enhanced ultrasound (CEU) imaging in healthy normal weight subjects. In nine subjects, CEU was performed in abdominal subcutaneous adipose tissue and in the underlying skeletal muscle after a bolus injection...... constant. It is concluded that the microvascular volume and changes in volume in abdominal subcutaneous adipose tissue can be assessed using CEU with good reproducibility. Postprandial capillary recruitment takes place in abdominal subcutaneous adipose tissue....

  5. Luminance contrast of a visual stimulus modulates the BOLD response more than the cerebral blood flow response in the human brain.

    Science.gov (United States)

    Liang, Christine L; Ances, Beau M; Perthen, Joanna E; Moradi, Farshad; Liau, Joy; Buracas, Giedrius T; Hopkins, Susan R; Buxton, Richard B

    2013-01-01

    The blood oxygenation level dependent (BOLD) response measured with functional magnetic resonance imaging (fMRI) depends on the evoked changes in cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO(2)) in response to changes in neural activity. This response is strongly modulated by the CBF/CMRO(2) coupling relationship with activation, defined as n, the ratio of the fractional changes. The reliability of the BOLD signal as a quantitative reflection of underlying physiological changes depends on the stability of n in response to different stimuli. The effect of visual stimulus contrast on this coupling ratio was tested in 9 healthy human subjects, measuring CBF and BOLD responses to a flickering checkerboard at four visual contrast levels. The theory of the BOLD effect makes a robust prediction-independent of details of the model-that if the CBF/CMRO(2) coupling ratio n remains constant, then the response ratio between the lowest and highest contrast levels should be higher for the BOLD response than the CBF response because of the ceiling effect on the BOLD response. Instead, this response ratio was significantly lower for the BOLD response (BOLD response: 0.23 ± 0.13, mean ± SD; CBF response: 0.42 ± 0.18; p=0.0054). This data is consistent with a reduced dynamic range (strongest/weakest response ratio) of the CMRO(2) response (~1.7-fold) compared to that of the CBF response (~2.4-fold) as luminance contrast increases, corresponding to an increase of n from 1.7 at the lowest contrast level to 2.3 at the highest contrast level. The implication of these results for fMRI studies is that the magnitude of the BOLD response does not accurately reflect the magnitude of underlying physiological processes. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Perfusion MRI (dynamic susceptibility contrast imaging) with different measurement approaches for the evaluation of blood flow and blood volume in human gliomas

    DEFF Research Database (Denmark)

    Thomsen, H; Steffensen, E; Larsson, Elna-Marie

    2012-01-01

    technique arterial spin labelling (ASL) presently provides measurement only of cerebral blood flow (CBF), which has not been widely used in human brain tumor studies. Purpose: To assess if measurement of blood flow is comparable with measurement of blood volume in human biopsy-proven gliomas obtained by DSC......, and glioblastomas. Results: rCBF and rCBV measurements obtained with the maximum perfusion method were correlated when normalized to white matter (r ¼ 0.60) and to the cerebellum (r ¼ 0.49). Histogram analyses of rCBF and rCBV showed that mean and median values as well as skewness and peak position were correlated......-MRI using two different regions for normalization and two different measurement approaches. Material and Methods: Retrospective study of 61 patients with different types of gliomas examined with DSC perfusion MRI. Regions of interest (ROIs) were placed in tumor portions with maximum perfusion on rCBF and r...

  7. Hawaii ESI: POOLS (Anchialine Pool Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for anchialine pools in Hawaii. Anchialine pools are small, relatively shallow coastal ponds that occur...

  8. String-like lumen in below-the-knee chronic total occlusions on contrast-enhanced magnetic resonance angiography predicts intraluminal recanalization and better blood flow restoration

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yue-Qi; Lu, Hai-Tao; Wei, Li-Ming; Cheng, Ying-Sheng; Wang, Jian-Bo; Zhao, Jun-Gong [Shanghai Jiao Tong University Affiliated Sixth People' s Hospital, Department of Diagnostic and Interventional Radiology, Shanghai (China); Liu, Fang [Shanghai Jiao Tong University Affiliated Sixth People' s Hospital, Department of Endocrinology, Shanghai (China)

    2017-07-15

    To determine whether string-like lumina (SLs) on contrast-enhanced magnetic resonance angiography (CE-MRA) predict better outcomes in diabetic patients with below-the-knee (BTK) chronic total occlusions (CTOs). This study involved 317 long-segment (>5 cm) BTK CTOs of 245 patients that were examined using CE-MRA and treated using endovascular angioplasty. An SL with a CTO was slowly filled with blood on conventional CE-MRA. Univariate and multivariate analyses were performed to identify predictors of procedural success, recanalisation method and immediate blood flow restoration. The target-lesion patency and limb-salvage rates were assessed. SL-positive CTOs (n = 60) achieved a higher technique success rate, preferred intraluminal angioplasty and better blood flow restoration than SL-negative CTOs (n = 257, P < 0.05). Multivariate analyses revealed that lesion length was the independent predictor of procedural success (P = 0.028). SL was a predictor of intraluminal angioplasty (P < 0.001) and good blood-flow restoration (P = 0.004). Kaplan-Meier analyses at 12 months revealed a higher target lesion patency rate (P = 0.04) and limb-salvage rate (P = 0.35) in SL-positive CTOs. In patients with BTK CTOs, SL predicted intraluminal angioplasty and good blood-flow restoration for BTK CTOs. (orig.)

  9. The Steroid Effect on the Blood-Ocular Barrier Change Induced by Triolein Emulsion as seen on Contrast-Enhanced MR Images

    International Nuclear Information System (INIS)

    Lee, Jong Yuk; Eun, Choong Ki; Kim, Yong Woo; Kim, Hak Jin; Jung, Yeon Joo; Jae, Seung Youn; Cho, Byung Mann; Choi, Seon Hee

    2008-01-01

    The purpose of this study is to evaluate the effect of dexamethasone on the damaged blood-ocular barrier caused by triolein emulsion, using contrast-enhanced MR imaging. An emulsion of 0.1-mL triolein in 20 mL of saline was infused into the carotid arteries of 32 cats, 12 cats were placed in the treatment group and 18 cats were placed in the Control group. Thirty minutes after the infusion of triolein emulsion, a set of orbital pre- and post-contrast T1-weighted MR images (T1WIs) were obtained. Infusion of 10 mg/kg dexamethasone into the ipsilateral carotid artery of each of the cats in the treatment group cats and 20 mL saline in each of the cats in the control group was given. A second set of pre- and post-contrast orbital T1WIs were obtained three hours following triolein emulsion infusion. Qualitative analysis was performed for the the anterior chamber (AC), the posterior chamber (PC), and in the vitreous humor of the ipsilateral and contralateral eyes. The signal intensity ratios of the ipsilateral eye over the contralateral eye were quantitatively evaluated in the three ocular chambers on the first and second set of T1WIs, and were then statistically compared. Qualitatively, the AC, the PC or the vitreous did not show immediate contrast enhancement on the first and the second set of post-contrast T1WIs. However, the AC and the PC showed delayed contrast enhancement for both groups of cats on the second pre-contrast T1WIs. No enhancement or minimally delayed enhancement was seen for the vitreous humor. Quantitatively, the signal intensity ratios in the PC of the treatment group of cats were statistically lower than the ratios of the control group of cats for the second set of T1WIs (p = 0.037). The AC and vitreous showed no statistically significant difference between the feline treatment group and control group (p > 0.05). Contrast-enhanced MR images revealed increased vascular permeability in the PC of the eye after infusion of triolein emulsion

  10. The Effect of Contrast Temperature Water Therapy on Blood Lactic Acid clearance of male students of Mazandaran University of Science and Technology after exhausting activity

    Directory of Open Access Journals (Sweden)

    Mohammadbagher Forghani

    2015-09-01

    Full Text Available The purpose of this research was the considering of the effect of Contrast Temperature Water Therapy on Blood Lactic Acid clearance of male students of Mazandaran University of Science and Technology after exhausting activity. In this semi-experimental study, 30 male students were randomly chosen and classified between two groups with 15 members, in a design with control group and experimental group, before and two hours after CTWT (experimental group the Bruce test on treadmill was done. The measurement of blood Lactic Acid was done by Lactometer, before and after Bruce tests, and also immediately after CTWT. And then in both groups the results of each test was compared with another test. After that the results between two groups were compared. To analyze the data, the Kolmogorov-Smirnov test, pair T test, and match T test were used in meaning level α≤0/05 for statistical analyze. To summarize, the following findings have been obtained: 1.CTWT reduced the concentration of blood Lactic Acid after exhausting performance significantly; 2. Two hours after recovery, the effect of CTWT on Lactic Acid concentration did not differ from the passive recovery method effect significantly; 3. CTWT did not also have any significant effect on the Lactic Acid accumulation in next exhausting performance; 4. CTWT did not have any significant effect on fluctuations of blood Lactic Acid in next exhausting performance. It is believed that CTWT facilitates recovery by blood circulation, vaso-pumping, hydrostatic pressure due to immersion, relieving of metabolic waste, and central nervous system stimulation. Keywords: Contrast Temperature Water Therapy, exhausting performance, Lactic Acid clearance

  11. Contrast enhancement of intracranial lesions at 1.5 T: comparison among 2D spin echo, black-blood (BB) Cube, and BB Cube-FLAIR sequences

    Energy Technology Data Exchange (ETDEWEB)

    Im, SungWoon; Ashikaga, Ryuichiro; Yagyu, Yukinobu; Hyodo, Tomoko; Imaoka, Izumi; Kumano, Seishi; Ishii, Kazunari; Murakami, Takamichi [Kinki University Faculty of Medicine, Department of Radiology, Osaka-Sayama, Osaka (Japan); Wakayama, Tetsuya; Miyoshi, Mitsuharu [GE Healthcare Japan, MR Applications and Workflow, Asia Pacific, Hino, Tokyo (Japan)

    2015-11-15

    The purpose of this study was to investigate the usefulness of T1W black-blood Cube (BB Cube) and T1W BB Cube fluid-attenuated inversion recovery (BB Cube-FLAIR) sequences for contrast-enhanced brain imaging, by evaluating flow-related artefacts, detectability, and contrast ratio (CR) of intracranial lesions among these sequences and T1W-SE. Phantom studies were performed to determine the optimal parameters of BB Cube and BB Cube-FLAIR. A clinical study in 23 patients with intracranial lesions was performed to evaluate the usefulness of these two sequences for the diagnosis of intracranial lesions compared with the conventional 2D T1W-SE sequence. The phantom study revealed that the optimal parameters for contrast-enhanced T1W imaging were TR/TE = 500 ms/minimum in BB Cube and TR/TE/TI = 600 ms/minimum/300 ms in BB Cube-FLAIR imaging. In the clinical study, the degree of flow-related artefacts was significantly lower in BB Cube and BB Cube-FLAIR than in T1W-SE. Regarding tumour detection, BB Cube showed the best detectability; however, there were no significant differences in CR among the sequences. At 1.5 T, contrast-enhanced BB Cube was a better imaging sequence for detecting brain lesions than T1W-SE or BB Cube-FLAIR. (orig.)

  12. Phase-contrast MR assessment of pulmonary venous blood flow in children with surgically repaired pulmonary veins

    International Nuclear Information System (INIS)

    Valsangiacomo, Emanuela R.; Yoo, Shi-Joon; Barrea, Catherine; Smallhorn, Jeffrey F.; Macgowan, Christopher K.; Coles, John G.

    2003-01-01

    Pulmonary venous (PV) obstruction may complicate surgical repair of PV abnormalities. By combining phase-contrast cine (PC) imaging and contrast-enhanced angiography, magnetic resonance (MR) imaging can provide physiological information complementing anatomical diagnosis. To compare the PV flow pattern observed after surgical repair of PV abnormalities with normal PV flow pattern and to investigate the changes occurring in the presence of PV stenosis by using PC MR in children. By using PC MR, PV flow was evaluated in 14 patients (3 months-14 years) who underwent surgical repair for PV abnormalities. Eleven children (8-18 years) were studied as normal controls. Peak flow velocities and patterns were compared among three groups: normal veins (n=23), surgically repaired veins without (n=44) and with stenosis (n=10). Normal and unobstructed pulmonary veins after surgery showed a biphasic or triphasic flow pattern with one or two systolic peaks and a diastolic peak. Unobstructed surgically repaired veins showed decreased peak systolic velocity (P =0.001) and an increased peak diastolic velocity (P=0.005) when compared to normal values. Obstructed veins showed decreased systolic and diastolic velocities when measured upstream from the stenosis. PC MR shows different flow patterns among normal, surgically repaired pulmonary veins with and without stenosis. (orig.)

  13. Dynamic Susceptibility Contrast Perfusion Magnetic Resonance Imaging Demonstrates Reduced Periventricular Cerebral Blood Flow in Dogs with Ventriculomegaly

    Directory of Open Access Journals (Sweden)

    Martin J. Schmidt

    2017-08-01

    Full Text Available The nature of ventriculomegaly in dogs is still a matter of debate. Signs of increased intraventricular pressure and atrophy of the cerebral white matter have been found in dogs with ventriculomegaly, which would imply increased intraventricular pressure and, therefore, a pathological condition, i.e., to some extent. Reduced periventricular blood flow was found in people with high elevated intraventricular pressure. The aim of this study was to compare periventricular brain perfusion in dogs with and without ventriculomegaly using perfusion weighted-magnetic-resonance-imaging to clarify as to whether ventriculomegaly might be associated with an increase in intraventricular pressure. Perfusion was measured in 32 Cavalier King Charles spaniels (CKCS with ventriculomegaly, 10 CKCSs were examined as a control group. Cerebral blood flow (CBF was measured using free-hand regions of interest (ROI in five brain regions: periventricular white matter, caudate nucleus, parietal cortex, hippocampus, and thalamus. CBF was significantly lower in the periventricular white matter of the dogs with ventriculomegaly (p = 0.0029 but not in the other ROIs. Reduction of periventricular CBF might imply increase of intraventricular pressure in ventriculomegaly.

  14. The assessment of the breath hold and the free breath methods about the blood flow evaluation by using phase contrast MRI

    International Nuclear Information System (INIS)

    Kim, Seong Ho

    2016-01-01

    Measurement of cardiac blood flow using the magnetic resonance imaging has been limited due to breathing and involuntary movements of the heart. The present study attempted to improve the accuracy of cardiac blood flow testing through phase contrast magnetic resonance imaging by presenting the adequate breathing method and imaging variables by comparing the measurement values of cardiac blood flow. Each was evaluated by comparing the breath hold retrospective 1NEX and non breath hold retrospective 1-3NEX in the ascending aorta and descending aorta. As a result, the average blood flow amount/ velocity of the breath hold retrosepctive 1NEX method in the ascending aorta were 96.17±19.12 ml/sec, 17.04±4.12 cm/sec respectively, which demonstrates a statistically significant difference(p<0.05) with the non-breath hold retrospective method 1NEX of 72.31±13.27 ml and 12.32±3.85. On the other hand, the average 2NEX blood flow and mean flow velocity is 101.90±24.09, 16.84±4.32, 3NEX 103.06±25.49, 16.88±4.19 did not show statistically significant differences(p>0.05).The average blood flow amount/ velocity of the breath hold retrospective 1NEX method in the descending aorta were 76.68±19.72 ml/s, and 22.23±4.8, which did not demonstrate a significant difference in comparison to non-breath hold retrospective method 1-3 NEX. Therefore, the non breath hold retrospective method does not significantly differ in terms of cardiac blood flow in comparison with the breath hold retrospective method in accordance with the increase of NEX, so pediatric patients or patients who are not able to breathe well must have the diagnostic value of their cardiac blood flow tests improved

  15. The assessment of the breath hold and the free breath methods about the blood flow evaluation by using phase contrast MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seong Ho [Dept. of Radiology, Konkuk Medical center, Seoul (Korea, Republic of)

    2016-06-15

    Measurement of cardiac blood flow using the magnetic resonance imaging has been limited due to breathing and involuntary movements of the heart. The present study attempted to improve the accuracy of cardiac blood flow testing through phase contrast magnetic resonance imaging by presenting the adequate breathing method and imaging variables by comparing the measurement values of cardiac blood flow. Each was evaluated by comparing the breath hold retrospective 1NEX and non breath hold retrospective 1-3NEX in the ascending aorta and descending aorta. As a result, the average blood flow amount/ velocity of the breath hold retrosepctive 1NEX method in the ascending aorta were 96.17±19.12 ml/sec, 17.04±4.12 cm/sec respectively, which demonstrates a statistically significant difference(p<0.05) with the non-breath hold retrospective method 1NEX of 72.31±13.27 ml and 12.32±3.85. On the other hand, the average 2NEX blood flow and mean flow velocity is 101.90±24.09, 16.84±4.32, 3NEX 103.06±25.49, 16.88±4.19 did not show statistically significant differences(p>0.05).The average blood flow amount/ velocity of the breath hold retrospective 1NEX method in the descending aorta were 76.68±19.72 ml/s, and 22.23±4.8, which did not demonstrate a significant difference in comparison to non-breath hold retrospective method 1-3 NEX. Therefore, the non breath hold retrospective method does not significantly differ in terms of cardiac blood flow in comparison with the breath hold retrospective method in accordance with the increase of NEX, so pediatric patients or patients who are not able to breathe well must have the diagnostic value of their cardiac blood flow tests improved.

  16. Autoregressive moving average (ARMA) model applied to quantification of cerebral blood flow using dynamic susceptibility contrast-enhanced magnetic resonance imaging

    International Nuclear Information System (INIS)

    Murase, Kenya; Yamazaki, Youichi; Shinohara, Masaaki

    2003-01-01

    The purpose of this study was to investigate the feasibility of the autoregressive moving average (ARMA) model for quantification of cerebral blood flow (CBF) with dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSC-MRI) in comparison with deconvolution analysis based on singular value decomposition (DA-SVD). Using computer simulations, we generated a time-dependent concentration of the contrast agent in the volume of interest (VOI) from the arterial input function (AIF) modeled as a gamma-variate function under various CBFs, cerebral blood volumes and signal-to-noise ratios (SNRs) for three different types of residue function (exponential, triangular, and box-shaped). We also considered the effects of delay and dispersion in AIF. The ARMA model and DA-SVD were used to estimate CBF values from the simulated concentration-time curves in the VOI and AIFs, and the estimated values were compared with the assumed values. We found that the CBF value estimated by the ARMA model was more sensitive to the SNR and the delay in AIF than that obtained by DA-SVD. Although the ARMA model considerably overestimated CBF at low SNRs, it estimated the CBF more accurately than did DA-SVD at high SNRs for the exponential or triangular residue function. We believe this study will contribute to an understanding of the usefulness and limitations of the ARMA model when applied to quantification of CBF with DSC-MRI. (author)

  17. Alteration of Blood Flow in a Venular Network by Infusion of Dextran 500: Evaluation with a Laser Speckle Contrast Imaging System.

    Science.gov (United States)

    Namgung, Bumseok; Ng, Yan Cheng; Nam, Jeonghun; Leo, Hwa Liang; Kim, Sangho

    2015-01-01

    This study examined the effect of dextran-induced RBC aggregation on the venular flow in microvasculature. We utilized the laser speckle contrast imaging (LSCI) as a wide-field imaging technique to visualize the flow distribution in venules influenced by abnormally elevated levels of RBC aggregation at a network-scale level, which was unprecedented in previous studies. RBC aggregation in rats was induced by infusing Dextran 500. To elucidate the impact of RBC aggregation on microvascular perfusion, blood flow in the venular network of a rat cremaster muscle was analyzed with a stepwise reduction of the arterial pressure (100 → 30 mmHg). The LSCI analysis revealed a substantial decrease in the functional vascular density after the infusion of dextran. The relative decrease in flow velocity after dextran infusion was notably pronounced at low arterial pressures. Whole blood viscosity measurements implied that the reduction in venular flow with dextran infusion could be due to the elevation of medium viscosity in high shear conditions (> 45 s-1). In contrast, further augmentation to the flow reduction at low arterial pressures could be attributed to the formation of RBC aggregates (networks.

  18. Visualization of the intracavitary blood flow in systemic ventricles of Fontan patients by contrast echocardiography using particle image velocimetry

    Directory of Open Access Journals (Sweden)

    Lampropoulos Konstantinos

    2012-02-01

    Full Text Available Abstract Background Flow patterns in univentricular hearts may have clinical value. Therefore, it is our objective to asses and characterize vortex flow patterns with Fontan circulation in comparison with healthy controls. Methods Twenty-three patients (8 Fontan and 15 normal patients underwent echocardiography with intravenous contrast agent (Sonovue® administration. Dedicated software was used to perform particle image velocimetry (PIV and to visualize intracavitary flow in the systemic ventricles of the patients. Vortex parameters including vortex depth, length, width, and sphericity index were measured. Vortex pulsatility parameters including relative strength, vortex relative strength, and vortex pulsation correlation were also measured. Results The data from this study show that it is feasible to perform particle velocimetry in Fontan patients. Vortex length (VL was significantly lower (0.51 ± 0.09 vs 0.65 ± 0.12, P = 0.010 and vortex width (VW (0.32 ± 0.06 vs 0.27 ± 0.04, p = 0.014, vortex pulsation correlation (VPC (0.26 ± 0.25 vs -0.22 ± 0.87, p = 0.05 were significantly higher in Fontan patients. Sphericity index (SI (1.66 ± 0.48 vs 2.42 ± 0.62, p = 0.005, relative strength (RS (0.77 ± 0.33 vs 1.90 ± 0.47, p = 0.0001, vortex relative strength (VRS (0.18 ± 0.13 vs 0.43 ± 0.14, p = 0.0001 were significantly lower in the Fontan patients group. Conclusions PIV using contrast echocardiography is feasible in Fontan patients. Fontan patients had aberrant flow patterns as compared to normal hearts in terms of position, shape and sphericity of the main vortices. The vortex from the Fontan group was consistently shorter, wider and rounder than in controls. Whether vortex characteristics are related with clinical outcome is subject to further investigation.

  19. Feasibility of measuring renal blood flow by phase-contrast magnetic resonance imaging in patients with autosomal dominant polycystic kidney disease

    Energy Technology Data Exchange (ETDEWEB)

    Spithoven, E.M.; Meijer, E.; Boertien, W.E.; Gaillard, C.A.J.M.; Jong, P.E. de; Gansevoort, R.T. [University of Groningen, Department of Nephrology, Community and Occupational Medicine, University Medical Center Groningen, PO Box 30.001, RB Groningen (Netherlands); Borns, C.; Kappert, P.; Greuter, M.J.W.; Jagt, E. van der [University of Groningen, Department of Radiology, Community and Occupational Medicine, University Medical Center Groningen, Groningen (Netherlands); Vart, P. [University of Groningen, Department of Health Sciences, Community and Occupational Medicine, University Medical Center Groningen, Groningen (Netherlands)

    2016-03-15

    Renal blood flow (RBF) has been shown to predict disease progression in autosomal dominant polycystic kidney disease (ADPKD). We investigated the feasibility and accuracy of phase-contrast RBF by MRI (RBF{sub MRI}) in ADPKD patients with a wide range of estimated glomerular filtration rate (eGFR) values. First, we validated RBF{sub MRI} measurement using phantoms simulating renal artery hemodynamics. Thereafter, we investigated in a test-set of 21 patients intra- and inter-observer coefficient of variation of RBF{sub MRI}. After validation, we measured RBF{sub MRI} in a cohort of 91 patients and compared the variability explained by characteristics indicative for disease severity for RBF{sub MRI} and RBF measured by continuous hippuran infusion. The correlation in flow measurement using phantoms by phase-contrast MRI was high and fluid collection was high (CCC=0.969). Technical problems that precluded RBF{sub MRI} measurement occurred predominantly in patients with a lower eGFR (34% vs. 16%). In subjects with higher eGFRs, variability in RBF explained by disease characteristics was similar for RBF{sub MRI} compared to RBF{sub Hip,} whereas in subjects with lower eGFRs, this was significantly less for RBF{sub MRI}. Our study shows that RBF can be measured accurately in ADPKD patients by phase-contrast, but this technique may be less feasible in subjects with a lower eGFR. (orig.)

  20. Delineation and segmentation of cerebral tumors by mapping blood-brain barrier disruption with dynamic contrast-enhanced CT and tracer kinetics modeling-a feasibility study

    International Nuclear Information System (INIS)

    Bisdas, S.; Vogl, T.J.; Yang, X.; Koh, T.S.; Lim, C.C.T.

    2008-01-01

    Dynamic contrast-enhanced (DCE) imaging is a promising approach for in vivo assessment of tissue microcirculation. Twenty patients with clinical and routine computed tomography (CT) evidence of intracerebral neoplasm were examined with DCE-CT imaging. Using a distributed-parameter model for tracer kinetics modeling of DCE-CT data, voxel-level maps of cerebral blood flow (F), intravascular blood volume (v i ) and intravascular mean transit time (t 1 ) were generated. Permeability-surface area product (PS), extravascular extracellular blood volume (v e ) and extraction ratio (E) maps were also calculated to reveal pathologic locations of tracer extravasation, which are indicative of disruptions in the blood-brain barrier (BBB). All maps were visually assessed for quality of tumor delineation and measurement of tumor extent by two radiologists. Kappa (κ) coefficients and their 95% confidence intervals (CI) were calculated to determine the interobserver agreement for each DCE-CT map. There was a substantial agreement for the tumor delineation quality in the F, v e and t 1 maps. The agreement for the quality of the tumor delineation was excellent for the v i , PS and E maps. Concerning the measurement of tumor extent, excellent and nearly excellent agreement was achieved only for E and PS maps, respectively. According to these results, we performed a segmentation of the cerebral tumors on the base of the E maps. The interobserver agreement for the tumor extent quantification based on manual segmentation of tumor in the E maps vs. the computer-assisted segmentation was excellent (κ = 0.96, CI: 0.93-0.99). The interobserver agreement for the tumor extent quantification based on computer segmentation in the mean images and the E maps was substantial (κ = 0.52, CI: 0.42-0.59). This study illustrates the diagnostic usefulness of parametric maps associated with BBB disruption on a physiology-based approach and highlights the feasibility for automatic segmentation of

  1. Swimming pool granuloma

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/001357.htm Swimming pool granuloma To use the sharing features on this page, please enable JavaScript. A swimming pool granuloma is a long-term (chronic) skin ...

  2. Blood

    Science.gov (United States)

    ... production of red blood cells, including: Iron deficiency anemia. Iron deficiency anemia is the most common type of anemia and ... inflammatory bowel disease are especially likely to have iron deficiency anemia. Anemia due to chronic disease. People with chronic ...

  3. [An Examination of Variable Image Positions in the Aortic Valve Blood Flow Using Phase Contrast MRI: Effect of Breath-holding Methods in Healthy Volunteers].

    Science.gov (United States)

    Nakagawa, Kenichi; Morimoto, Noriyoshi; Fukushima, Sachi

    2015-12-01

    Phase contrast MRI (PC-MRI) is a useful tool for evaluating valvular pathology. In addition, PC-MRI can provide a noninvasive assessment of blood flow in an arbitrary cross section. However, the blood flow measurement with breath-hold or free breath PC-MRI may be different from each other because of intrathoracic pressure changing and variable image position. The aim of this study was to find both the optimal breath-hold technique and the image position. Quantitative flow images were acquired in four planes (ascending aorta: Ao, sino-tubular junction: STJ, valsalva sinus: valsalva, left ventricular outflow tract: LVOT), in healthy subjects (n=10). The study protocol was divided into two parts: (1) stroke volume (SV) measured in each slice positions by using inspiration, expiration, and navigation method during normal breathing and (2) SV measured at each breath-hold techniques in the Ao, STJ, valsalva, and LVOT. As a result, (1) SV of the respective measurement positions were not significant by using inspiration, expiration, and navigation method and (2) LVOT SV was significantly lower than Ao, STJ, and valsalva.

  4. Fourier analysis of multi-gated cardiac blood-pool data in patients with congenital heart diseases, (2). Assessment of diseases with complex cardiac anomalies, especially tetralogy of Fallot

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Kan; Maeda, Hisato; Yamaguchi, Nobuo; Nakamura, Kazuyoshi; Matsumura, Kaname; Nakagawa, Tsuyoshi; Sakurai, Minoru; Aoki, Kenzo

    1985-04-01

    The clinical usefulness of Fourier analysis of multi-gated cardiac blood-pool data was evaluated in 18 subjects with normal cardiac functions and 14 patients with complex cardiac anomalies (ten with tetralogy of Fallot, two with tricuspid atresia (TA), one with double-outlet right ventricle (DORV), and one with Ebstein's anomaly (EA)). Using global ventricular time-activity curves, the phase and amplitude at fundamental frequency were calculated, and emptying patterns of the left and right ventricles (LV, RV) were evaluated by phase difference (D(phase)=RV phase minus LV phase) and amplitude ratio of RV to LV (R(amp)). In patients with TOF, mean values of D (phase) and R(amp) were 25.3 +- 10.5 degrees and 13.5 +- 0.49 respectively and significantly larger than those of normal subjects. D (phase) became larger in inverse proportion to the ratio of pulmonary-to-systemic blood flow and there was an inverse linear correlation between these two variables. On visual interpretation of functional images, the dynamic property of hypoplastic ventricles could be easily estimated in patients with TA or DORV. In a case with EA, the atrialized RV was shown clearly as a hypokinetic, atrial phase area. This method is valuable for pathophysiologic investigation of diseases with complex cardiac anomalies. (author).

  5. A method to identify early ventricular dysfunction using resting gated blood pool scans (GBPS) in patients with coronary artery disease (CAD)

    International Nuclear Information System (INIS)

    Schwarzberg, R.J.; Seldin, D.W.; Johnson, L.L.; Alderson, P.O.

    1984-01-01

    To determine the sensitivity of regional 1st and 2nd time derivative (1DV, 2DV) images to assess ventricular function (VF) in CAD, the resting GBPS of 8 normal patients (pts) and 20 pts with CAD who had coronary angiography and contrast ventriculography (CV) were analyzed. The 1DV and 2DV of the systolic time-activity curve were determined for each left ventricular pixel in the GBPS. These values were displayed as functional images that were reviewed by three readers to determine the presence of regional abnormalities. No regional abnormalities were seen in the conventional GBPS or 1DV or 2DV images of the 8 normal pts. Regional GBPS and DV image abnormalities were seen in all 10 pts with CAD and abnormal wall motion by CV. The DV image abnormalities were in the distribution of 18/22 coronary arteries (CA) with ≥50% stenoses; 2 of these regions showed normal wall motion by CV and conventional GBPS. DV images were abnormal in 2/8 CAs without significant stenoses. In addition, regional DV image abnormalities were present in 9 of 10 pts with CAD who had normal wall motion and global ejection fraction by both CV and resting GBPS. These 10 pts showed regional abnormalities in the distribution of 13/15 CAs with significant stenoses and 2/15 CAs without such stenoses. The results suggest that time derivative functional images derived from resting GBPS provide a more sensitive means for detecting regional left ventricular dysfunction than several other current methods, especially in pts with mild CAD

  6. A study evaluating of the dependence of the clinical usefulness on the use of a half-time acquisition factor in a multiple-gated blood-pool (MUGA) scan using Tc-99 m

    Science.gov (United States)

    Lee, Dong-Hun; Jung, Woo-Young; Kim, Ho-Sung; Dong, Kyung-Rae; Park, Yong-Soon; Chung, Woon-Kwan; Cho, Jae-Hwan; Yeo, Hwa-Yeon

    2012-12-01

    This study evaluated the clinical usefulness of reducing the scan time based on a comparative analysis of the left ventricular cardiac ejection fraction of a full-time image in a gated cardiac blood-pool scan by using the half-time image obtained by applying an image processing technique and using the results from a blind test conducted by radiologists. Fifty patients who underwent a multiple-gated blood-pool (MUGA) scan at the Nuclear Medicine Department of ASAN Medical Center from June 20 to August 14, 2011 were enrolled in this study. Images of the left anterior oblique (LAO) view were obtained continuously in full time (6,000 kcts) and half time (3,000 kcts) in the same posture. The obtained images were used to calculate the left ventricular cardiac ejection fraction 10 times in the full-time image, the half-time image obtained without applying an image processing technique, and the half-time image obtained by applying an image processing technique. To evaluate the cardiac ejection fraction under the same conditions, we set the regions of interest (ROIs) of the left ventricle and the background radioactivity to be the automated ROIs on the same X and Y axes. According to the results of quantitative analyses of the cardiac ejection fraction, the mean ± standard deviation value for the full-time image, the half-time image obtained without applying an image processing technique, and the half-time images obtained by applying an image processing technique were 69.1 ± 7.6%, 68.2 ± 8.4%, and 68.7 ± 8.0%, respectively. The cardiac ejection fraction did not show any significant difference (p > 0.05). For a qualitative analysis, a blinding test was conducted with two radiologists. According to the test results, when the examination was conducted for cardiac wall motion of the left ventricle, no difference was found between the full-time and half-time images obtained by applying an image processing technique.

  7. Point-of-care diagnostic tests for childhood urinary-tract infection: phase-contrast microscopy for bacteria, stick testing, and counting white blood cells.

    Science.gov (United States)

    Coulthard, Malcolm G; Nelson, Andrew; Smith, Terry; Perry, John D

    2010-09-01

    To evaluate point-of-care testing for childhood urinary-tract infections (UTI). Point-of-care testing of prospectively collected sequential paired urines was compared with quantitative culture after serial dilution in 203 children, of whom 36 had UTIs. Proportionate reduction in uncertainty (PRU) plots were used to compare between methods and with published values. Phase-contrast microscopy for bacteria, as with culturing a single urine and using a threshold of 10(5) bacteria/ml, was 100% sensitive, making it powerful to rule UTIs out. The specificity was slightly lower than urine culture (0.860 vs 0.925) except in girls >9 years where vaginal Lactobacillus contamination reduced it to 0.61, but this increased to 0.81 when 'urethral stream' urines were collected. Nitrite positivity is highly specific at 0.985, making it powerful at ruling UTIs in, but its low sensitivity (0.61) makes it unsafe to rule UTIs out. A PRU plot of 16 previous studies confirmed this. Though the presence of urinary white blood cells (WBC) correlates with UTI, whether tested by point-of-care of laboratory microscopy or by stick testing, the coefficient of determination is too low to make them clinically useful, alone or combined with nitrite analysis. Seventeen other studies confirmed this. Phase-contrast microscopy can rule out UTIs as reliably as urine culture but is immediate, which may be clinically important. To interpret positive results reliably, girls >9 years must collect a 'urethral stream' urine. While nitrite positivity is useful to rule UTIs in, negative results are unreliable. Urinary WBC testing has little value.

  8. Contrasting effects of age on the plasma/whole blood lead ratio in men and women with a history of lead exposure

    International Nuclear Information System (INIS)

    Barbosa, Fernando; Ramires, Irene; Rodrigues, Maria Heloisa C.; Saint' Pierre, Tatiana D.; Curtius, Adilson J.; Buzalaf, Marilia R.; Gerlach, Raquel F.; Tanus-Santos, Jose E.

    2006-01-01

    We examined the effect of age and sex on the relationship between the concentrations of Pb in blood (Pb-B) and in plasma (Pb-P) in an adult population with a history of lead exposure. Pb-P was determined by inductively coupled plasma mass spectrometry (ICP-MS) and Pb-B by graphite furnace atomic absorption spectrometry (GF AAS). We studied 154 adults (56 men and 98 women) from 18 to 60-year old. Pb-B levels varied from 10.0 to 428.0 μg/L, with a mean of 76 μg/L. Blood lead levels varied from 10.0 to 428.0 μg/L in men (mean, 98.3 μg/L) and from 10.0 to 263.0 μg/L (mean, 62.8 μg/L) in women. Corresponding Pb-Ps were 0.02-2.9 μg/L (mean, 0.66 μg/L) and 0.02-1.5 μg/L (mean, 0.42 μg/L) in men and women, respectively. The relationship between Pb-B and Pb-P was found to be curvilinear (r=0.757, P 1492 (y=Pb-P, and x=Pb-B). The %Pb-P/Pb-B ratio ranged from 0.03% to 1.85%. A positive association was found between %Pb-P/Pb-B ratio and Pb-B levels. When data were separated by sex, this association was also relevant for men (y=0.0184x 0.702 ) and women (y=0.0534x 0.5209 ) (y=%Pb-P/Pb-B and x=Pb-B). Moreover, we found an interesting positive correlation between Log (Pb-P/Pb-B) and age for women (r=0.31, P<0.0001) and a negative correlation for men (r=-0.164, P=0.07). Taken together, these results suggest contrasting effects of age on the plasma/whole blood lead ratio in men and women with a history of lead exposure. Moreover, sex might play an important role in the metabolism of lead, implying further consideration on the kinetic models constructed of lead toxicity

  9. Hybrid of opposite-contrast MRA of the brain by combining time-of-flight and black-blood sequences: initial experience in major trunk stenoocclusive diseases.

    Science.gov (United States)

    Tsuchiya, Kazuhiro; Kobayashi, Kuninori; Nitatori, Toshiaki; Kimura, Tokunori; Ikedo, Masato; Takemoto, Shuhei

    2010-01-01

    To assess the feasibility of a new MR angiography (MRA) technique named hybrid of opposite-contrast MRA (HOP MRA) that combined the time-of-flight (TOF) MRA with a flow-sensitive black-blood (FSBB) sequence in the diagnosis of major trunk stenoocclusive diseases. On a 1.5 Tesla imager using a dual-echo three-dimensional (3D)-gradient-echo sequence, we obtained the first echo for TOF MRA followed by the second echo for FSBB. We then subtracted the FSBB data set from that of TOF MRA followed by maximum intensity projection. In four normal volunteers and 19 patients with chronic stenoocclusive disease of the major trunk, we performed HOP MRA along with 3D-TOF MRA and compared the findings. In the volunteer group, the HOP MRA technique improved the demonstration of distal arterial branches. In 12 of the 19 patients, the HOP MRA better visualized branches distal to the lesion as well as distal branches of normal trunks than 3D-TOF MRA, while both techniques provided equivalent depiction of branches distal to the lesion but better depiction of normal distal branches in three patients. The HOP-MRA technique is promising in major trunk stenoocclusive diseases as it better demonstrates distal branches probably representing collaterals than 3D-TOF MRA. (c) 2009 Wiley-Liss, Inc.

  10. Comparison of Global Cerebral Blood Flow Measured by Phase-Contrast Mapping MRI with O-15-H2O Positron Emission Tomography

    DEFF Research Database (Denmark)

    Vestergaard, Mark Bitsch; Lindberg, Ulrich; Aachmann-Andersen, Niels Jacob

    2017-01-01

    Purpose To compare mean global cerebral blood flow (CBF) measured by phase-contrast mapping magnetic resonance imaging (PCM MRI) and by 15O-H2O positron emission tomography (PET) in healthy subjects. PCM MRI is increasingly being used to measure mean global CBF, but has not been validated in vivo...... against an accepted reference technique. Materials and Methods Same-day measurements of CBF by 15O-H2O PET and subsequently by PCM MRI were performed on 22 healthy young male volunteers. Global CBF by PET was determined by applying a one-tissue compartment model with measurement of the arterial input...... function. Flow was measured in the internal carotid and vertebral arteries by a noncardiac triggered PCM MRI sequence at 3T. The measured flow was normalized to total brain weight determined from a volume-segmented 3D T1-weighted anatomical MR-scan. Results Mean CBF was 34.9 ± 3.4 mL/100 g/min measured...

  11. Evaluation of Laser Speckle Contrast Imaging for the Assessment of Oral Mucosal Blood Flow following Periodontal Plastic Surgery: An Exploratory Study.

    Science.gov (United States)

    Molnár, Eszter; Molnár, Bálint; Lohinai, Zsolt; Tóth, Zsuzsanna; Benyó, Zoltán; Hricisák, Laszló; Windisch, Péter; Vág, János

    2017-01-01

    The laser speckle contrast imaging (LSCI) is proved to be a reliable tool in flap monitoring in general surgery; however, it has not been evaluated in oral surgery yet. We applied the LSCI to compare the effect of a xenogeneic collagen matrix (Geistlich Mucograft®) to connective tissue grafts (CTG) on the microcirculation of the modified coronally advanced tunnel technique (MCAT) for gingival recession coverage. Gingival microcirculation and wound fluid were measured before and after surgery for six months at twenty-seven treated teeth. In males, the flap microcirculation was restored within 3 days for both grafts followed by a hyperemic response. During the first 8 days the blood flow was higher at xenogeneic graft comparing to the CTG. In females, the ischemic period lasted for 7-12 days depending on the graft and no hyperemic response was observed. Females had more intense and prolonged wound fluid production. The LSCI method is suitable to capture the microcirculatory effect of the surgical intervention in human oral mucosa. The application of xenogeneic collagen matrices as a CTG substitute does not seem to restrain the recovery of graft bed circulation. Gender may have an effect on postoperative circulation and inflammation.

  12. Evaluation of Laser Speckle Contrast Imaging for the Assessment of Oral Mucosal Blood Flow following Periodontal Plastic Surgery: An Exploratory Study

    Directory of Open Access Journals (Sweden)

    Eszter Molnár

    2017-01-01

    Full Text Available The laser speckle contrast imaging (LSCI is proved to be a reliable tool in flap monitoring in general surgery; however, it has not been evaluated in oral surgery yet. We applied the LSCI to compare the effect of a xenogeneic collagen matrix (Geistlich Mucograft® to connective tissue grafts (CTG on the microcirculation of the modified coronally advanced tunnel technique (MCAT for gingival recession coverage. Gingival microcirculation and wound fluid were measured before and after surgery for six months at twenty-seven treated teeth. In males, the flap microcirculation was restored within 3 days for both grafts followed by a hyperemic response. During the first 8 days the blood flow was higher at xenogeneic graft comparing to the CTG. In females, the ischemic period lasted for 7–12 days depending on the graft and no hyperemic response was observed. Females had more intense and prolonged wound fluid production. The LSCI method is suitable to capture the microcirculatory effect of the surgical intervention in human oral mucosa. The application of xenogeneic collagen matrices as a CTG substitute does not seem to restrain the recovery of graft bed circulation. Gender may have an effect on postoperative circulation and inflammation.

  13. Neuroimaging: do we really need new contrast agents for MRI?

    International Nuclear Information System (INIS)

    Roberts, T.P.L.; Chuang, N.; Roberts, H.C.

    2000-01-01

    The use of exogenous contrast media in magnetic resonance imaging of the brain has brought dramatic improvement in the sensitivity of detection and delineation of pathological structures, such as primary and metastatic brain tumors, inflammation and ischemia. Disruption of the blood brain barrier leads to accumulation of the intravenously injected contrast material in the extravascular space, leading to signal enhancement. Magnetic resonance angiography benefits from T 1 -shortening effects of contrast agent, improving small vessel depiction and providing vascular visualization even in situations of slow flow. High speed dynamic MRI after bolus injection of contrast media allows tracer kinetic modeling of cerebral perfusion. Progressive enhancement over serial post-contrast imaging allows modeling of vascular permeability and thus quantitative estimation of the severity of blood brain barrier disruption. With such an array of capabilities and ever improving technical abilities, it seems that the role of contrast agents in MR neuroimaging is established and the development of new agents may be superfluous. However, new agents are being developed with prolonged intravascular residence times, and with in-vivo binding of ever-increasing specificity. Intravascular, or blood pool, agents are likely to benefit magnetic resonance angiography of the carotid and cerebral vessels; future agents may allow the visualization of therapeutic drug delivery, the monitoring of, for example, gene expression, and the imaging evaluation of treatment efficacy. So while there is a substantial body of work that can be performed with currently available contrast agents, especially in conjunction with optimized image acquisition strategies, post processing, and mathematical analysis, there are still unrealized opportunities for novel contrast agent introduction, particularly those exploiting biological specificity. This article reviews the current use of contrast media in magnetic resonance

  14. Collaborative Car Pooling System

    OpenAIRE

    João Ferreira; Paulo Trigo; Porfírio Filipe

    2009-01-01

    This paper describes the architecture for a collaborative Car Pooling System based on a credits mechanism to motivate the cooperation among users. Users can spend the accumulated credits on parking facilities. For this, we propose a business model to support the collaboration between a car pooling system and parking facilities. The Portuguese Lisbon-s Metropolitan area is used as application scenario.

  15. Blood pressure and fasting lipid changes after 24 weeks’ treatment with vildagliptin: a pooled analysis in >2,000 previously drug-naïve patients with type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Evans M

    2016-08-01

    Full Text Available Marc Evans,1 Anja Schweizer,2 James E Foley3 1Diabetes Resource Centre, Llandough Hospital, Cardiff, UK; 2Medical Affairs Cardio Metabolic, Novartis Pharma AG, Basel, Switzerland; 3Medical Affairs Cardio-Metabolic, Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA Introduction: We have previously shown modest weight loss with vildagliptin treatment. Since body weight balance is associated with changes in blood pressure (BP and fasting lipids, we have assessed these parameters following vildagliptin treatment. Methods: Data were pooled from all double-blind, randomized, controlled, vildagliptin monotherapy trials on previously drug-naïve patients with type 2 diabetes mellitus who received vildagliptin 50 mg once daily (qd or twice daily (bid; n=2,108 and wherein BP and fasting lipid data were obtained. Results: Data from patients receiving vildagliptin 50 mg qd or bid showed reductions from baseline to week 24 in systolic BP (from 132.5±0.32 to 129.8±0.34 mmHg; P<0.0001, diastolic BP (from 81.2±0.18 to 79.6±0.19 mmHg; P<0.0001, fasting triglycerides (from 2.00±0.02 to 1.80±0.02 mmol/L; P<0.0001, very low density lipoprotein cholesterol (from 0.90±0.01 to 0.83±0.01 mmol/L; P<0.0001, and low density lipoprotein cholesterol (from 3.17±0.02 to 3.04±0.02 mmol/L; P<0.0001, whereas high density lipoprotein cholesterol increased (from 1.19±0.01 to 1.22±0.01 mmol/L; P<0.001. Weight decreased by 0.48±0.08 kg (P<0.001. Conclusion: This large pooled analysis demonstrated that vildagliptin shows a significant reduction in BP and a favorable fasting lipid profile that are associated with modest weight loss. Keywords: TG, HDL, LDL, body weight DPP-4 inhibitor, GLP-1 

  16. PDA: Pooled DNA analyzer

    Directory of Open Access Journals (Sweden)

    Lin Chin-Yu

    2006-04-01

    Full Text Available Abstract Background Association mapping using abundant single nucleotide polymorphisms is a powerful tool for identifying disease susceptibility genes for complex traits and exploring possible genetic diversity. Genotyping large numbers of SNPs individually is performed routinely but is cost prohibitive for large-scale genetic studies. DNA pooling is a reliable and cost-saving alternative genotyping method. However, no software has been developed for complete pooled-DNA analyses, including data standardization, allele frequency estimation, and single/multipoint DNA pooling association tests. This motivated the development of the software, 'PDA' (Pooled DNA Analyzer, to analyze pooled DNA data. Results We develop the software, PDA, for the analysis of pooled-DNA data. PDA is originally implemented with the MATLAB® language, but it can also be executed on a Windows system without installing the MATLAB®. PDA provides estimates of the coefficient of preferential amplification and allele frequency. PDA considers an extended single-point association test, which can compare allele frequencies between two DNA pools constructed under different experimental conditions. Moreover, PDA also provides novel chromosome-wide multipoint association tests based on p-value combinations and a sliding-window concept. This new multipoint testing procedure overcomes a computational bottleneck of conventional haplotype-oriented multipoint methods in DNA pooling analyses and can handle data sets having a large pool size and/or large numbers of polymorphic markers. All of the PDA functions are illustrated in the four bona fide examples. Conclusion PDA is simple to operate and does not require that users have a strong statistical background. The software is available at http://www.ibms.sinica.edu.tw/%7Ecsjfann/first%20flow/pda.htm.

  17. Diagnostic examination performance by using microvascular leakage, cerebral blood volume, and blood flow derived from 3-T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in the differentiation of glioblastoma multiforme and brain metastasis

    International Nuclear Information System (INIS)

    Server, Andres; Nakstad, Per H.; Orheim, Tone E.D.; Graff, Bjoern A.; Josefsen, Roger; Kumar, Theresa

    2011-01-01

    Conventional magnetic resonance (MR) imaging has limited capacity to differentiate between glioblastoma multiforme (GBM) and metastasis. The purposes of this study were: (1) to compare microvascular leakage (MVL), cerebral blood volume (CBV), and blood flow (CBF) in the distinction of metastasis from GBM using dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging (DSC-MRI), and (2) to estimate the diagnostic accuracy of perfusion and permeability MR imaging. A prospective study of 61 patients (40 GBMs and 21 metastases) was performed at 3 T using DSC-MRI. Normalized rCBV and rCBF from tumoral (rCBVt, rCBFt), peri-enhancing region (rCBVe, rCBFe), and by dividing the value in the tumor by the value in the peri-enhancing region (rCBVt/e, rCBFt/e), as well as MVL were calculated. Hemodynamic and histopathologic variables were analyzed statistically and Spearman/Pearson correlations. Receiver operating characteristic curve analysis was performed for each of the variables. The rCBVe, rCBFe, and MVL were significantly greater in GBMs compared with those of metastases. The optimal cutoff value for differentiating GBM from metastasis was 0.80 which implies a sensitivity of 95%, a specificity of 92%, a positive predictive value of 86%, and a negative predictive value of 97% for rCBVe ratio. We found a modest correlation between rCBVt and rCBFt ratios. MVL measurements in GBMs are significantly higher than those in metastases. Statistically, both rCBVe, rCBVt/e and rCBFe, rCBFt/e were useful in differentiating between GBMs and metastases, supporting the hypothesis that perfusion MR imaging can detect infiltration of tumor cells in the peri-enhancing region. (orig.)

  18. Resting myocardial blood flow quantification using contrast-enhanced magnetic resonance imaging in the presence of stenosis: A computational fluid dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, Karsten, E-mail: sommerk@uni-mainz.de, E-mail: Schreiber-L@ukw.de [Section of Medical Physics, Department of Radiology, Johannes Gutenberg University Medical Center, Mainz 55131, Germany and Max Planck Graduate Center with the Johannes Gutenberg University Mainz, Mainz 55128 (Germany); Bernat, Dominik; Schmidt, Regine; Breit, Hanns-Christian [Section of Medical Physics, Department of Radiology, Johannes Gutenberg University Medical Center, Mainz 55131 (Germany); Schreiber, Laura M., E-mail: sommerk@uni-mainz.de, E-mail: Schreiber-L@ukw.de [Comprehensive Heart Failure Center, Department of Cardiovascular Imaging, Würzburg University Hospital, Würzburg 97078 (Germany)

    2015-07-15

    Purpose: The extent to which atherosclerotic plaques affect contrast agent (CA) transport in the coronary arteries and, hence, quantification of myocardial blood flow (MBF) using magnetic resonance imaging (MRI) is unclear. The purpose of this work was to evaluate the influence of plaque induced stenosis both on CA transport and on the accuracy of MBF quantification. Methods: Computational fluid dynamics simulations in a high-detailed realistic vascular model were employed to investigate CA bolus transport in the coronary arteries. The impact of atherosclerosis was analyzed by inserting various medium- to high-grade stenoses in the vascular model. The influence of stenosis morphology was examined by varying the stenosis shapes but keeping the area reduction constant. Errors due to CA bolus transport were analyzed using the tracer-kinetic model MMID4. Results: Dispersion of the CA bolus was found in all models and for all outlets, but with a varying magnitude. The impact of stenosis was complex: while high-grade stenoses amplified dispersion, mild stenoses reduced the effect. Morphology was found to have a marked influence on dispersion for a small number of outlets in the post-stenotic region. Despite this marked influence on the concentration–time curves, MBF errors were less affected by stenosis. In total, MBF was underestimated by −7.9% to −44.9%. Conclusions: The presented results reveal that local hemodynamics in the coronary vasculature appears to have a direct impact on CA bolus dispersion. Inclusion of atherosclerotic plaques resulted in a complex alteration of this effect, with both degree of area reduction and stenosis morphology affecting the amount of dispersion. This strong influence of vascular transport effects impairs the accuracy of MRI-based MBF quantification techniques and, potentially, other bolus-based perfusion measurement techniques like computed tomography perfusion imaging.

  19. High-resolution phase-contrast MRI of aortic and pulmonary blood flow during rest and physical exercise using a MRI compatible bicycle ergometer

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Tim Frederik, E-mail: tim.weber@med.uni-heidelberg.de [Department of Diagnostic and Interventional Radiology, University Medical Center Heidelberg, INF 110, 69120 Heidelberg (Germany); Department of Radiology, German Cancer Research Center, INF 280, 69120 Heidelberg (Germany); Tengg-Kobligk, Hendrik von, E-mail: hendrik.tengg-kobligk@med.uni-heidelberg.de [Department of Diagnostic and Interventional Radiology, University Medical Center Heidelberg, INF 110, 69120 Heidelberg (Germany); Department of Radiology, German Cancer Research Center, INF 280, 69120 Heidelberg (Germany); Kopp-Schneider, Annette, E-mail: kopp@dkfz-heidelberg.de [Department of Biostatistics, German Cancer Research Center, INF 280, 69120 Heidelberg (Germany); Ley-Zaporozhan, Julia, E-mail: julia.ley-zaporozhan@med.uni-heidelberg.de [Department of Pediatric Radiology, University Medical Center Heidelberg, INF 430, 69120 Heidelberg (Germany); Kauczor, Hans-Ulrich, E-mail: hans-ulrich.kauczor@med.uni-heidelberg.de [Department of Diagnostic and Interventional Radiology, University Medical Center Heidelberg, INF 110, 69120 Heidelberg (Germany); Ley, Sebastian, E-mail: sebastian.ley@med.uni.heidelberg.de [Department of Radiology, German Cancer Research Center, INF 280, 69120 Heidelberg (Germany); Department of Pediatric Radiology, University Medical Center Heidelberg, INF 430, 69120 Heidelberg (Germany)

    2011-10-15

    Purpose: To establish high-resolution phase-contrast magnetic resonance imaging (PC-MRI) using a MRI compatible bicycle ergometer to quantify aortic and pulmonary blood flow during resting conditions and exercise. Materials and methods: In 20 healthy volunteers (mean age, 26.8 {+-} 5.0 years) high-resolution PC-MRI (mean temporal resolution, 7.4 {+-} 3.2 ms) was performed in the ascending aorta (AA) and main pulmonary artery (PA) during physical rest and three exercise stages: stage 1, no-load operation; stage 2, heart rate increase 40% compared to rest; stage 3, heart rate increase 80% compared to rest. Flow quantification in AA and PA included flow volume (FV), average velocity (AV), peak velocity (PV) and time to PV (TP). Results: In stage 1 only TP demonstrated a significant change. With progression to stage 2, all parameters altered significantly. Flow measurements during stage 3 evidenced further alterations only of AV and TP regarding both AA and PA. The deviation of the heart rate from the desired target value was significantly higher for stage 3 compared to stage 2, and 15% of the subjects did not reach the desired target heart rate of stage 3 at all. Conclusion: Flow quantification by high-resolution PC-MRI during exercise using a MRI compatible bicycle ergometer is feasible. Medium exercise stages are necessary and sufficient to demonstrate flow alterations in healthy volunteers. PC-MRI ergometry may give insights into aberrant hemodynamic conditions in patients with cardiovascular and pulmonary disease.

  20. Preoperative Grading of Glioma Using Dynamic Susceptibility Contrast MRI: Relative Cerebral Blood Volume Analysis of Intra-tumoural and Peri-tumoural Tissue.

    Science.gov (United States)

    Soliman, Radwa K; Gamal, Sara A; Essa, Abdel-Hakeem A; Othman, Mostafa H

    2018-04-01

    To assess the usefulness of intra-tumor and peri-tumoral relative cerebral blood volume (rCBV) in preoperative glioma grading. 21 patients with histopathologically confirmed glioma were included. Imaging was achieved on a 1.5T MRI scanner. Dynamic susceptibility contrast (DSC) MRI was performed using T2* weighted gradient echo-planner imaging (EPI). Multiple regions of interest (ROIs) have been drawn in the hotspots regions, the highest ROI has been selected to represent the rCBV of each intra-tumoral and peri-tumoral regions. Based on histopathology, tumors were subdivided into low grade and high grade. Receiver operating characteristic analysis (ROC) of rCBV, of both intra-tumoral and peri-tumoral regions, was performed to find cut-off values between high and low-grade tumors. The resulting sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated. Based on the histopathology, high-grade glioma (HGG) represented 76.2% whereas low-grade glioma (LGG) represented 23.8%. Both intra-tumoral and peri-tumoral rCBV of HGG were significantly higher than those of LGG. A cut-off value >2.9 for intra-tumoral rCBV provided sensitivity, specificity, and accuracy of 80%, 100%, and 85.7% respectively to differentiate between HGG and LGG. Additionally, the cut-off value >0.7 for peri-tumoral rCBV provided sensitivity, specificity, and accuracy of 100%, 66.6%, and 90.5% respectively to differentiate between HGG and LGG. rCBV of each of intra-tumoral and peri-tumoral rCBV are significantly reliable for the preoperative distinction between HGG and LGG. Combined intra-tumoral and peri-tumoral rCBV provides overall better diagnostic accuracy and helps to decrease the invasive intervention for non-surgical candidates. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. T1 relaxivities of gadolinium-based magnetic resonance contrast agents in human whole blood at 1.5, 3, and 7 T.

    Science.gov (United States)

    Shen, Yaqi; Goerner, Frank L; Snyder, Christopher; Morelli, John N; Hao, Dapeng; Hu, Daoyu; Li, Xiaoming; Runge, Val M

    2015-05-01

    Calculation of accurate T1 relaxivity (r1) values for gadolinium-based magnetic resonance contrast agents (GBCAs) is a complex process. As such, often referenced r1 values for the GBCAs at 1.5 T, 3 T, and 7 T are based on measurements obtained in media that are not clinically relevant, derived from only a small number of concentrations, or available for only a limited number of GBCAs. This study derives the r1 values of the 8 commercially available GBCAs in human whole blood at 1.5 T, 3 T, and 7 T. Eight GBCAs were serially diluted in human whole blood, at 7 concentrations from 0.0625 to 4 mM. A custom-built phantom held the dilutions in air-tight cylindrical tubes maintained at 37 ± 0.5°C by a heat-circulating system. Images were acquired using inversion recovery sequences with inversion times from 30 milliseconds to 10 seconds at 1.5 T and 3 T as well as 60 milliseconds to 5 seconds at 7 T. A custom MATLAB program was used to automate signal intensity measurements from the images acquired of the phantom. SigmaPlot was used to calculate T1 relaxation times and, finally, r1. Measured r1 values in units of s⁻¹·mM⁻¹ at 1.5 T (3 T/7 T) were 3.9 ± 0.2 (3.4 ± 0.4/2.8 ± 0.4) for Gd-DOTA, 4.6 ± 0.2 (4.5 ± 0.3/4.2 ± 0.3) for Gd-DO3A-butrol, 4.3 ± 0.4 (3.8 ± 0.2/3.1 ± 0.4) for Gd-DTPA, 6.2 ± 0.5 (5.4 ± 0.3/4.7 ± 0.1) for Gd-BOPTA, 4.5 ± 0.1 (3.9 ± 0.2/3.7 ± 0.2) for Gd-DTPA-BMA, 4.4 ± 0.2 (4.2 ± 0.2/4.3 ± 0.2) for Gd-DTPA-BMEA, 7.2 ± 0.2 (5.5 ± 0.3/4.9 ± 0.1) for Gd-EOB-DTPA, and 4.4 ± 0.6 (3.5 ± 0.6/3.4 ± 0.1) for Gd-HP-DO3A. The agents can be stratified by relaxivity, with a significant additional dependency on field strength. This report quantifies, for the first time, T1 relaxivity for all 8 gadolinium chelates in common clinical use worldwide, at current relevant field strengths, in human whole blood at physiological temperature (37°C). The measured r1 values differ to a small degree from previously published values, where such

  2. Nanoparticle Contrast Agents for Computed Tomography: A Focus on Micelles

    Science.gov (United States)

    Cormode, David P.; Naha, Pratap C.; Fayad, Zahi A.

    2014-01-01

    Computed tomography (CT) is an X-ray based whole body imaging technique that is widely used in medicine. Clinically approved contrast agents for CT are iodinated small molecules or barium suspensions. Over the past seven years there has been a great increase in the development of nanoparticles as CT contrast agents. Nanoparticles have several advantages over small molecule CT contrast agents, such as long blood-pool residence times, and the potential for cell tracking and targeted imaging applications. Furthermore, there is a need for novel CT contrast agents, due to the growing population of renally impaired patients and patients hypersensitive to iodinated contrast. Micelles and lipoproteins, a micelle-related class of nanoparticle, have notably been adapted as CT contrast agents. In this review we discuss the principles of CT image formation and the generation of CT contrast. We discuss the progress in developing non-targeted, targeted and cell tracking nanoparticle CT contrast agents. We feature agents based on micelles and used in conjunction with spectral CT. The large contrast agent doses needed will necessitate careful toxicology studies prior to clinical translation. However, the field has seen tremendous advances in the past decade and we expect many more advances to come in the next decade. PMID:24470293

  3. Dendrimer-based Macromolecular MRI Contrast Agents: Characteristics and Application

    Directory of Open Access Journals (Sweden)

    Hisataka Kobayashi

    2003-01-01

    Full Text Available Numerous macromolecular MRI contrast agents prepared employing relatively simple chemistry may be readily available that can provide sufficient enhancement for multiple applications. These agents operate using a ~100-fold lower concentration of gadolinium ions in comparison to the necessary concentration of iodine employed in CT imaging. Herein, we describe some of the general potential directions of macromolecular MRI contrast agents using our recently reported families of dendrimer-based agents as examples. Changes in molecular size altered the route of excretion. Smaller-sized contrast agents less than 60 kDa molecular weight were excreted through the kidney resulting in these agents being potentially suitable as functional renal contrast agents. Hydrophilic and larger-sized contrast agents were found better suited for use as blood pool contrast agents. Hydrophobic variants formed with polypropylenimine diaminobutane dendrimer cores created liver contrast agents. Larger hydrophilic agents are useful for lymphatic imaging. Finally, contrast agents conjugated with either monoclonal antibodies or with avidin are able to function as tumor-specific contrast agents, which also might be employed as therapeutic drugs for either gadolinium neutron capture therapy or in conjunction with radioimmunotherapy.

  4. Vitamin D Pooling Project

    Science.gov (United States)

    The Vitamin D Pooling Project of Rarer Cancers brought together investigators from 10 cohorts to conduct a large prospective epidemiologic study of the association between vitamin D status and seven rarer cancers.

  5. Swimming Pool Safety

    Science.gov (United States)

    ... Spread the Word Shop AAP Find a Pediatrician Safety & Prevention Immunizations All Around At Home At Play ... Español Text Size Email Print Share Swimming Pool Safety Page Content ​What is the best way to ...

  6. Assessment of Blood-Brain Barrier Permeability by Dynamic Contrast-Enhanced MRI in Transient Middle Cerebral Artery Occlusion Model after Localized Brain Cooling in Rats

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Soo [Department of Radiology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang 14068 (Korea, Republic of); Lee, Seung-Koo [Department of Radiology, Yonsei University College of Medicine, Seoul 03722 (Korea, Republic of); Kwon, Mi Jung [Department of Pathology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang 14068 (Korea, Republic of); Lee, Phil Hye [Department of Neurology, Yonsei University College of Medicine, Seoul 03722 (Korea, Republic of); Ju, Young-Su [Department of Industrial Medicine, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang 14068 (Korea, Republic of); Yoon, Dae Young [Department of Radiology, Hallym University Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul 05355 (Korea, Republic of); Kim, Hye Jeong [Department of Radiology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul 07441 (Korea, Republic of); Lee, Kwan Seop [Department of Radiology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang 14068 (Korea, Republic of)

    2016-11-01

    The purpose of this study was to evaluate the effects of localized brain cooling on blood-brain barrier (BBB) permeability following transient middle cerebral artery occlusion (tMCAO) in rats, by using dynamic contrast-enhanced (DCE)-MRI. Thirty rats were divided into 3 groups of 10 rats each: control group, localized cold-saline (20℃) infusion group, and localized warm-saline (37℃) infusion group. The left middle cerebral artery (MCA) was occluded for 1 hour in anesthetized rats, followed by 3 hours of reperfusion. In the localized saline infusion group, 6 mL of cold or warm saline was infused through the hollow filament for 10 minutes after MCA occlusion. DCE-MRI investigations were performed after 3 hours and 24 hours of reperfusion. Pharmacokinetic parameters of the extended Tofts-Kety model were calculated for each DCE-MRI. In addition, rotarod testing was performed before tMCAO, and on days 1-9 after tMCAO. Myeloperoxidase (MPO) immunohisto-chemistry was performed to identify infiltrating neutrophils associated with the inflammatory response in the rat brain. Permeability parameters showed no statistical significance between cold and warm saline infusion groups after 3-hour reperfusion 0.09 ± 0.01 min{sup -1} vs. 0.07 ± 0.02 min{sup -1}, p = 0.661 for K{sup trans}; 0.30 ± 0.05 min{sup -1} vs. 0.37 ± 0.11 min{sup -1}, p = 0.394 for kep, respectively. Behavioral testing revealed no significant difference among the three groups. However, the percentage of MPO-positive cells in the cold-saline group was significantly lower than those in the control and warm-saline groups (p < 0.05). Localized brain cooling (20℃) does not confer a benefit to inhibit the increase in BBB permeability that follows transient cerebral ischemia and reperfusion in an animal model, as compared with localized warm-saline (37℃) infusion group.

  7. Assessment of blood-brain barrier permeability by dynamic contrast-enhanced MRI in transient middle cerebral artery occlusion model after localized brain cooling in rats

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Soo; Lee, Kwan Seop; Kwon, Mi Jung; Ju, Young Su [Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang (Korea, Republic of); Lee, Seung Koo; Lee, Phil Hye [Yonsei University College of Medicine, Seoul (Korea, Republic of); Yoon, Dae Young [Dept. of Radiology, Hallym University Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul (Korea, Republic of); Kim, Hye Jeong [Dept. of Radiology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul (Korea, Republic of)

    2016-09-15

    The purpose of this study was to evaluate the effects of localized brain cooling on blood-brain barrier (BBB) permeability following transient middle cerebral artery occlusion (tMCAO) in rats, by using dynamic contrast-enhanced (DCE)-MRI. Thirty rats were divided into 3 groups of 10 rats each: control group, localized cold-saline (20 .deg. ) infusion group, and localized warm-saline (37 .deg. ) infusion group. The left middle cerebral artery (MCA) was occluded for 1 hour in anesthetized rats, followed by 3 hours of reperfusion. In the localized saline infusion group, 6 mL of cold or warm saline was infused through the hollow filament for 10 minutes after MCA occlusion. DCE-MRI investigations were performed after 3 hours and 24 hours of reperfusion. Pharmacokinetic parameters of the extended Tofts-Kety model were calculated for each DCE-MRI. In addition, rotarod testing was performed before tMCAO, and on days 1-9 after tMCAO. Myeloperoxidase (MPO) immunohisto-chemistry was performed to identify infiltrating neutrophils associated with the inflammatory response in the rat brain. Permeability parameters showed no statistical significance between cold and warm saline infusion groups after 3-hour reperfusion 0.09 ± 0.01 min{sup -1} vs. 0.07 ± 0.02 min{sup -1},p = 0.661 for K{sup trans}; 0.30 ± 0.05 min{sup -1} vs. 0.37 ± 0.11 min{sup -1},p = 0.394 for kep, respectively. Behavioral testing revealed no significant difference among the three groups. However, the percentage of MPO-positive cells in the cold-saline group was significantly lower than those in the control and warm-saline groups (p < 0.05). Localized brain cooling (20 .deg. ) does not confer a benefit to inhibit the increase in BBB permeability that follows transient cerebral ischemia and reperfusion in an animal model, as compared with localized warm-saline (37 .deg. ) infusion group.

  8. Assessment of Blood-Brain Barrier Permeability by Dynamic Contrast-Enhanced MRI in Transient Middle Cerebral Artery Occlusion Model after Localized Brain Cooling in Rats

    International Nuclear Information System (INIS)

    Kim, Eun Soo; Lee, Seung-Koo; Kwon, Mi Jung; Lee, Phil Hye; Ju, Young-Su; Yoon, Dae Young; Kim, Hye Jeong; Lee, Kwan Seop

    2016-01-01

    The purpose of this study was to evaluate the effects of localized brain cooling on blood-brain barrier (BBB) permeability following transient middle cerebral artery occlusion (tMCAO) in rats, by using dynamic contrast-enhanced (DCE)-MRI. Thirty rats were divided into 3 groups of 10 rats each: control group, localized cold-saline (20℃) infusion group, and localized warm-saline (37℃) infusion group. The left middle cerebral artery (MCA) was occluded for 1 hour in anesthetized rats, followed by 3 hours of reperfusion. In the localized saline infusion group, 6 mL of cold or warm saline was infused through the hollow filament for 10 minutes after MCA occlusion. DCE-MRI investigations were performed after 3 hours and 24 hours of reperfusion. Pharmacokinetic parameters of the extended Tofts-Kety model were calculated for each DCE-MRI. In addition, rotarod testing was performed before tMCAO, and on days 1-9 after tMCAO. Myeloperoxidase (MPO) immunohisto-chemistry was performed to identify infiltrating neutrophils associated with the inflammatory response in the rat brain. Permeability parameters showed no statistical significance between cold and warm saline infusion groups after 3-hour reperfusion 0.09 ± 0.01 min -1 vs. 0.07 ± 0.02 min -1 , p = 0.661 for K trans ; 0.30 ± 0.05 min -1 vs. 0.37 ± 0.11 min -1 , p = 0.394 for kep, respectively. Behavioral testing revealed no significant difference among the three groups. However, the percentage of MPO-positive cells in the cold-saline group was significantly lower than those in the control and warm-saline groups (p < 0.05). Localized brain cooling (20℃) does not confer a benefit to inhibit the increase in BBB permeability that follows transient cerebral ischemia and reperfusion in an animal model, as compared with localized warm-saline (37℃) infusion group

  9. The effect of blood inflow and B(1)-field inhomogeneity on measurement of the arterial input function in axial 3D spoiled gradient echo dynamic contrast-enhanced MRI.

    Science.gov (United States)

    Roberts, Caleb; Little, Ross; Watson, Yvonne; Zhao, Sha; Buckley, David L; Parker, Geoff J M

    2011-01-01

    A major potential confound in axial 3D dynamic contrast-enhanced magnetic resonance imaging studies is the blood inflow effect; therefore, the choice of slice location for arterial input function measurement within the imaging volume must be considered carefully. The objective of this study was to use computer simulations, flow phantom, and in vivo studies to describe and understand the effect of blood inflow on the measurement of the arterial input function. All experiments were done at 1.5 T using a typical 3D dynamic contrast-enhanced magnetic resonance imaging sequence, and arterial input functions were extracted for each slice in the imaging volume. We simulated a set of arterial input functions based on the same imaging parameters and accounted for blood inflow and radiofrequency field inhomogeneities. Measured arterial input functions along the vessel length from both in vivo and the flow phantom agreed with simulated arterial input functions and show large overestimations in the arterial input function in the first 30 mm of the vessel, whereas arterial input functions measured more centrally achieve accurate contrast agent concentrations. Use of inflow-affected arterial input functions in tracer kinetic modeling shows potential errors of up to 80% in tissue microvascular parameters. These errors emphasize the importance of careful placement of the arterial input function definition location to avoid the effects of blood inflow. © 2010 Wiley-Liss, Inc.

  10. Tissue-specific MR contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Weinmann, Hanns-Joachim E-mail: hannsjoachim.weinmann@schering.de; Ebert, Wolfgang; Misselwitz, Bernd; Schmitt-Willich, Heribert

    2003-04-01

    The purpose of this review is to outline recent trends in contrast agent development for magnetic resonance imaging. Up to now, small molecular weight gadolinium chelates are the workhorse in contrast enhanced MRI. These first generation MR contrast agents distribute into the intravascular and interstitial space, thus allowing the evaluation of physiological parameters, such as the status or existence of the blood-brain-barrier or the renal function. Shortly after the first clinical use of paramagnetic metallochelates in 1983, compounds were suggested for liver imaging and enhancing a cardiac infarct. Meanwhile, liver specific contrast agents based on gadolinium, manganese or iron become reality. Dedicated blood pool agents will be available within the next years. These gadolinium or iron agents will be beneficial for longer lasting MRA procedures, such as cardiac imaging. Contrast enhanced lymphography after interstitial or intravenous injection will be another major step forward in diagnostic imaging. Metastatic involvement will be seen either after the injection of ultrasmall superparamagnetic iron oxides or dedicated gadolinium chelates. The accumulation of both compound classes is triggered by an uptake into macrophages. It is likely that similar agents will augment MRI of atheriosclerotic plaques, a systemic inflammatory disease of the arterial wall. Thrombus-specific agents based on small gadolinium labeled peptides are on the horizon. It is very obvious that the future of cardiovascular MRI will benefit from the development of new paramagnetic and superparamagnetic substances. The expectations for new tumor-, pathology- or receptor-specific agents are high. However, is not likely that such a compound will be available for daily routine MRI within the next decade.

  11. Valsalva maneuver procedures in the diagnosis of right-to-left shunt by contrast-enhanced transcranial doppler using agitated saline solution with blood as a contrast agent Manobra de Valsalva no diagnóstico de embolia paradoxal pelo doppler transcraniano contrastado com o uso de solução salina agitada associada a sangue como meio de contraste

    Directory of Open Access Journals (Sweden)

    Marcos Christiano Lange

    2010-06-01

    Full Text Available OBJECTIVE: To compare two different timings for the performance of the Valsalva maneuver (VM using an infusion of agitated saline solution with blood as contrast agent (CA to right-to-left shunt (RLS screening. METHOD: 42 patients were submitted to a standardized contrast-enhanced transcranial doppler (cTCD to screen for right-to-left shunt (RLS. cTCD technique was done with two different moments of the VM: [1] the CA injection during the VM (CAduringVM test; [2] the CA injection before the VM (CApreVM test. RESULTS: Positive MCA tests were observed in 47 (56% CAduringVM tests and in 50 (59.5% CApreVM tests, p=0.64. There was an almost perfect agreement for the positive tests between the CAduringVM and CApreVM test, r s=0.829 (95% CI 0.61-1.00, pOBJETIVO: Comparar dois momentos diferentes da manobra de Valsalva (MV com o uso de solução salina com sangue como meio de contraste (MC para investigação de embolia paradoxal (EP. MÉTODO: 42 pacientes foram submetidos a protocolo padronizado de DTCc com a MV em dois momentos diferentes: [1] injeção do MC durante a MV (teste ACduranteMV; [2] injeção de MC antes da MV (teste ACpreMV. RESULTADOS: Exames positivos foram observados em 47 (56% ACMs testes ACduranteMV e 50 (59.5% testes ACpreMV, p=0.64. Houve uma correlação quase perfeita entre ambos os testes, r s=0.829 (95% CI 0.61-1.00, p<0.001. CONCLUSÃO: O presente estudo demonstra que não existe diferença significativa na positividade de EP pelo DTCc quando são comparados dois momentos diferentes da MV.

  12. Utility of the pooling approach as applied to whole genome association scans with high-density Affymetrix microarrays

    Directory of Open Access Journals (Sweden)

    Gray Joanna

    2010-11-01

    Full Text Available Abstract Background We report an attempt to extend the previously successful approach of combining SNP (single nucleotide polymorphism microarrays and DNA pooling (SNP-MaP employing high-density microarrays. Whereas earlier studies employed a range of Affymetrix SNP microarrays comprising from 10 K to 500 K SNPs, this most recent investigation used the 6.0 chip which displays 906,600 SNP probes and 946,000 probes for the interrogation of CNVs (copy number variations. The genotyping assay using the Affymetrix SNP 6.0 array is highly demanding on sample quality due to the small feature size, low redundancy, and lack of mismatch probes. Findings In the first study published so far using this microarray on pooled DNA, we found that pooled cheek swab DNA could not accurately predict real allele frequencies of the samples that comprised the pools. In contrast, the allele frequency estimates using blood DNA pools were reasonable, although inferior compared to those obtained with previously employed Affymetrix microarrays. However, it might be possible to improve performance by developing improved analysis methods. Conclusions Despite the decreasing costs of genome-wide individual genotyping, the pooling approach may have applications in very large-scale case-control association studies. In such cases, our study suggests that high-quality DNA preparations and lower density platforms should be preferred.

  13. Zooplankton at deep Red Sea brine pools

    KAUST Repository

    Kaartvedt, Stein

    2016-03-02

    The deep-sea anoxic brines of the Red Sea comprise unique, complex and extreme habitats. These environments are too harsh for metazoans, while the brine–seawater interface harbors dense microbial populations. We investigated the adjacent pelagic fauna at two brine pools using net tows, video records from a remotely operated vehicle and submerged echosounders. Waters just above the brine pool of Atlantis II Deep (2000 m depth) appeared depleted of macrofauna. In contrast, the fauna appeared to be enriched at the Kebrit Deep brine–seawater interface (1466 m).

  14. Pool water cleaning facility

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Kazuhiro; Kinoshita, Shoichiro [Hitachi Ltd., Tokyo (Japan); Asano, Takashi

    1998-05-29

    Only one system comprising a suppression poor water cleaning system (SPCU) and a filtration desalting tower (F/D) is connected for a plurality of nuclear power plants. Pipelines/valves for connecting the one system of the SPCU pump, the F/D and the plurality of nuclear power plants are disposed, and the system is used in common with the plurality of nuclear power plants. Pipelines/valves for connecting a pipeline for passing SP water to the commonly used SPCU pump and a skimmer surge tank are disposed, and fuel pool water is cooled and cleaned by the commonly used SPCU pump and the commonly used F/D. The number of SPCU pumps and the F/D facilities can be reduced, and a fuel pool water cooling operation mode and a fuel pool water cleaning operation mode which were conducted by an FPC pump so far are conducted by the SPCU pump. (N.H.)

  15. Intra-patient variability of FDG standardized uptake values in mediastinal blood pool, liver, and myocardium during R-CHOP chemotherapy in patients with diffuse large B- cell lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soo Jeong; Yi, Hyun Kyung; Lim, Chae Hong; Cho, Young Seok; Choi, Joon Young; Choe, Yeam Seong; Lee, Kyung Han; Moon, Seung Hwan [Dept. of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2016-12-15

    {sup 18}F-fluorodeoxyglucose (FDG) PET/CT is useful for staging and evaluating treatment response in patients with diffuse large B-cell lymphoma (DLBCL). A five-point scale model using the mediastinal blood pool (MBP) and liver as references is a recommended method for interpreting treatment response. We evaluated the variability in standardized uptake values (SUVs) of the MBP, liver, and myocardium during chemotherapy in patients with DLBCL. We analyzed 60 patients with DLBCL who received rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) treatment and underwent baseline, interim, and final FDG PET/CT scans. The FDG uptakes of lymphoma lesions, MBP, liver, and myocardium were assessed, and changes in the MBP and liver SUV and possible associated factors were evaluated. The SUV of the liver did not change significantly during the chemotherapy. However, the SUV{sub mean} of MBP showed a significant change though the difference was small (p = 0.019). SUV{sub mean} of MBP and liver at baseline and interim scans was significantly lower in patients with advanced Ann Arbor stage on diagnosis. The SUV{sub mean} of the MBP and liver was negatively correlated with the volumetric index of lymphoma lesions in baseline scans (r = -0.547, p < 0.001; r = -0.502, p < 0.001). Positive myocardial FDG uptake was more frequently observed in interim and final scans than in the baseline scan, but there was no significant association between the MBP and liver uptake and myocardial uptake. The SUV of the liver was not significantly changed during R-CHOP chemotherapy in patients with DLBCL, whereas the MBP SUV of the interim scan decreased slightly. However, the SUV of the reference organs may be affected by tumor burden, and this should be considered when assessing follow-up scans. Although myocardial FDG uptake was more frequently observed after R-CHOP chemotherapy, it did not affect the SUV of the MBP and liver.

  16. Intra-patient variability of FDG standardized uptake values in mediastinal blood pool, liver, and myocardium during R-CHOP chemotherapy in patients with diffuse large B- cell lymphoma

    International Nuclear Information System (INIS)

    Kim, Soo Jeong; Yi, Hyun Kyung; Lim, Chae Hong; Cho, Young Seok; Choi, Joon Young; Choe, Yeam Seong; Lee, Kyung Han; Moon, Seung Hwan

    2016-01-01

    18 F-fluorodeoxyglucose (FDG) PET/CT is useful for staging and evaluating treatment response in patients with diffuse large B-cell lymphoma (DLBCL). A five-point scale model using the mediastinal blood pool (MBP) and liver as references is a recommended method for interpreting treatment response. We evaluated the variability in standardized uptake values (SUVs) of the MBP, liver, and myocardium during chemotherapy in patients with DLBCL. We analyzed 60 patients with DLBCL who received rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) treatment and underwent baseline, interim, and final FDG PET/CT scans. The FDG uptakes of lymphoma lesions, MBP, liver, and myocardium were assessed, and changes in the MBP and liver SUV and possible associated factors were evaluated. The SUV of the liver did not change significantly during the chemotherapy. However, the SUV mean of MBP showed a significant change though the difference was small (p = 0.019). SUV mean of MBP and liver at baseline and interim scans was significantly lower in patients with advanced Ann Arbor stage on diagnosis. The SUV mean of the MBP and liver was negatively correlated with the volumetric index of lymphoma lesions in baseline scans (r = -0.547, p < 0.001; r = -0.502, p < 0.001). Positive myocardial FDG uptake was more frequently observed in interim and final scans than in the baseline scan, but there was no significant association between the MBP and liver uptake and myocardial uptake. The SUV of the liver was not significantly changed during R-CHOP chemotherapy in patients with DLBCL, whereas the MBP SUV of the interim scan decreased slightly. However, the SUV of the reference organs may be affected by tumor burden, and this should be considered when assessing follow-up scans. Although myocardial FDG uptake was more frequently observed after R-CHOP chemotherapy, it did not affect the SUV of the MBP and liver

  17. Evaluation of pharmacokinetic models for perfusion imaging with dynamic contrast-enhanced magnetic resonance imaging in porcine skeletal muscle using low-molecular-weight contrast agents.

    Science.gov (United States)

    Hindel, Stefan; Papanastasiou, Giorgos; Wust, Peter; Maaß, Marc; Söhner, Anika; Lüdemann, Lutz

    2018-06-01

    Pharmacokinetic models for perfusion quantification with a low-molecular-weight contrast agent (LMCA) in skeletal muscle using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) were evaluated. Tissue perfusion was measured in seven regions of interest (ROIs) placed in the total hind leg supplied by the femoral artery in seven female pigs. DCE-MRI was performed using a 3D gradient echo sequence with k-space sharing. The sequence was acquired twice, first after LMCA and then after blood pool contrast agent injection. Blood flow was augmented by continuous infusion of the vasodilator adenosine into the femoral artery, resulting in up to four times increased blood flow. The results obtained with several LMCA models were compared with those of a two-compartment blood pool model (2CBPM) consisting of a capillary and an arteriolar compartment. Measurements performed with a Doppler flow probe placed at the femoral artery served as ground truth. The two-compartment exchange model extended by an arteriolar compartment (E2CXM) showed the highest fit quality of all LMCA models and the most significant correlation with the Doppler measurements, r = 0.78 (P Reson Med 79:3154-3162, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  18. Liquid sodium pool fires

    International Nuclear Information System (INIS)

    Casselman, C.

    1979-01-01

    Experimental sodium pool combustion results have led to a definition of the combustion kinetics, and have revealed the hazards of sodium-concrete contact reactions and the possible ignition of organic matter (paint) by hydration of sodium peroxide aerosols. Analysis of these test results shows that the controlling mechanism is sodium evaporation diffusion. (author)

  19. Luminance contrast of a visual stimulus modulates the BOLD response more than the cerebral blood flow response in the human brain

    OpenAIRE

    Liang, Christine L.; Ances, Beau M.; Perthen, Joanna E.; Moradi, Farshad; Liau, Joy; Buracas, Giedrius T.; Hopkins, Susan R.; Buxton, Richard B.

    2012-01-01

    The blood oxygenation level dependent (BOLD) response measured with functional magnetic resonance imaging (fMRI) depends on the evoked changes in cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) in response to changes in neural activity. This response is strongly modulated by the CBF/CMRO2 coupling relationship with activation, defined as n, the ratio of the fractional changes. The reliability of the BOLD signal as a quantitative reflection of underlying physiological c...

  20. 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.)

  1. 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.)

  2. 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.)

  3. Pool gateway seal

    International Nuclear Information System (INIS)

    Starr, J.A.; Steinert, L.A.

    1983-01-01

    A device for sealing a gateway between interconnectable pools in a nuclear facility comprising a frame supporting a liquid impermeable sheet positioned in a u-shaped gateway between the pools. An inflatable tube carried in a channel in the periphery of the frame and adjoining the gateway provides a seal therebetween when inflated. A restraining arrangement on the bottom edge of the frame is releasably engagable with an adjacent portion of the gateway to restrict the movement of the frame in the u-shaped gateway upon inflation of the tube, thereby enhancing the seal. The impermeable sheet is formed of an elastomer and thus is conformable to a liquid permeable supportive wall upon application of liquid pressure to the side of the sheet opposite the wall

  4. Fuel assembly storage pool

    International Nuclear Information System (INIS)

    Hiranuma, Hiroshi.

    1976-01-01

    Object: To remove limitation of the number of storage of fuel assemblies to increase the number of storage thereof so as to relatively reduce the water depth required for shielding radioactive rays. Structure: Fuel assembly storage rack containers for receiving a plurality of spent fuel assembly racks are stacked in multi-layer fashion within a storage pool filled with water for shielding radioactive rays and removing heat. (Furukawa, Y.)

  5. CERN Electronics Pool presentations

    CERN Multimedia

    2011-01-01

    The CERN Electronics Pool has organised a series of presentations in collaboration with oscilloscope manufacturers. The last one will take place according to the schedule below.   Time will be available at the end of the presentation to discuss your personal needs. The Agilent presentation had to be postponed and will be organised later. -     Lecroy: Thursday, 24 November 2011, in 530-R-030, 14:00 to 16:30.

  6. Remote non-invasive stereoscopic imaging of blood vessels: first in-vivo results of a new multispectral contrast enhancement technology

    NARCIS (Netherlands)

    Wieringa, F.P.; Mastik, F.; Cate, F.J. ten; Neumann, H.A.M.; Steen, A.F.W. van der

    2006-01-01

    We describe a contactless optical technique selectively enhancing superficial blood vessels below variously pigmented intact human skin by combining images in different spectral bands. Two CMOS-cameras, with apochromatic lenses and dual-band LED-arrays, simultaneously streamed Left (L) and Right (R)

  7. Laser speckle contrast imaging in biomedical optics.

    Science.gov (United States)

    Boas, David A; Dunn, Andrew K

    2010-01-01

    First introduced in the 1980s, laser speckle contrast imaging is a powerful tool for full-field imaging of blood flow. Recently laser speckle contrast imaging has gained increased attention, in part due to its rapid adoption for blood flow studies in the brain. We review the underlying physics of speckle contrast imaging and discuss recent developments to improve the quantitative accuracy of blood flow measures. We also review applications of laser speckle contrast imaging in neuroscience, dermatology and ophthalmology.

  8. Contrast enhancement of intracranial lesions at 1.5 T: comparison among 2D spin echo, black-blood (BB) Cube, and BB Cube-FLAIR sequences.

    Science.gov (United States)

    Im, SungWoon; Ashikaga, Ryuichiro; Yagyu, Yukinobu; Wakayama, Tetsuya; Miyoshi, Mitsuharu; Hyodo, Tomoko; Imaoka, Izumi; Kumano, Seishi; Ishii, Kazunari; Murakami, Takamichi

    2015-11-01

    The purpose of this study was to investigate the usefulness of T1W black-blood Cube (BB Cube) and T1W BB Cube fluid-attenuated inversion recovery (BB Cube-FLAIR) sequences for contrast-enhanced brain imaging, by evaluating flow-related artefacts, detectability, and contrast ratio (CR) of intracranial lesions among these sequences and T1W-SE. Phantom studies were performed to determine the optimal parameters of BB Cube and BB Cube-FLAIR. A clinical study in 23 patients with intracranial lesions was performed to evaluate the usefulness of these two sequences for the diagnosis of intracranial lesions compared with the conventional 2D T1W-SE sequence. The phantom study revealed that the optimal parameters for contrast-enhanced T1W imaging were TR/TE = 500 ms/minimum in BB Cube and TR/TE/TI = 600 ms/minimum/300 ms in BB Cube-FLAIR imaging. In the clinical study, the degree of flow-related artefacts was significantly lower in BB Cube and BB Cube-FLAIR than in T1W-SE. Regarding tumour detection, BB Cube showed the best detectability; however, there were no significant differences in CR among the sequences. At 1.5 T, contrast-enhanced BB Cube was a better imaging sequence for detecting brain lesions than T1W-SE or BB Cube-FLAIR. • Cube is a single-slab 3D FSE imaging sequence. • We applied a black-blood (BB) imaging technique to T1W Cube. • At 1.5 T, contrast-enhanced T1W BB Cube was valuable for detecting brain lesions.

  9. Swimming Pools and Molluscum Contagiosum

    Science.gov (United States)

    ... Travelers’ Health: Smallpox & Other Orthopoxvirus-Associated Infections Poxvirus Swimming Pools Recommend on Facebook Tweet Share Compartir The ... often ask if molluscum virus can spread in swimming pools. There is also concern that it can ...

  10. Characterization of colloidal manganese hydroxylapatite: A potential magnetic resonance contrast agent

    Science.gov (United States)

    Dorshow, Richard B.; Kofi Adzamli, I.; Nosco, Dennis L.; Joslin, Frederick L.

    1996-03-01

    Particulate contrast agents for blood pool imaging need to be constructed with the appropriate particle size distribution (PSD), and need to be resistant to opsonization. Hence, the PSD of an aqueous colloidal suspension of polyethylene glycol (PEG)-stabilized manganese hydroxylapatite (potentially useful as a magnetic resonance contrast agent for blood pool imaging) has been investigated as a function of PEG concentration and molecular weight. At low PEG concentrations, dynamic light scattering (DLS) and sedimentation field flow fractionation measurements yield a broad PSD, with the largest particle diameters near 100nm. Flow field flow fractionation (FlFFF) measurements, however, yield a distinct population near 10nm, which is not readily detectable by the other two techniques. As the PEG concentration is increased, the PSD shifts toward the lower size population. At the highest PEG concentration employed, only particles of diameter 10nm remain, verified by both FlFFF and DLS. Thus, the search for an optimum PSD for blood pool imaging is facilitated by choice of PEG molecular weight and concentration, and by employing complementary use of light scattering and field flow fractionation techniques.

  11. Large molten pool heat transfer

    International Nuclear Information System (INIS)

    1994-01-01

    This workshop on large molten pool heat transfer is composed of 5 sessions which titles are: feasibility of in-vessel core debris cooling; experiments on molten pool heat transfer; calculational efforts on molten pool convection; heat transfer to the surrounding water, experimental techniques; future experiments and ex-vessel studies (RASPLAV, TOLBIAC, BALI, SULTAN, CORVIS, VULCANO, CORINE programs)

  12. Evaluation of hemodynamic changes by use of phase-contrast MRI for patients with interstitial pneumonia, with special focus on blood flow reduction after breath-holding and bronchopulmonary shunt flow.

    Science.gov (United States)

    Tsuchiya, Nanae; Ayukawa, Yuichiro; Murayama, Sadayuki

    2013-03-01

    The purpose of this study was to determine the effects of interstitial pneumonia on pulmonary, systemic, and bronchopulmonary shunt flow. Phase-contrast flow measurements in the ascending aorta and pulmonary trunk were performed during free breathing and inspiratory breath-holding by use of a 1.5 T MR scanner. The study population comprised 11 patients with interstitial pneumonia and 15 healthy volunteers. Absolute blood flow, bronchopulmonary shunt flow, and difference in flow between normal breathing and breath-holding were compared between the groups. Both pulmonary and systemic blood flow during both breathing patterns in patients were significantly reduced compared with the volunteers (p breath-holding. The bronchopulmonary shunt was not increased in interstitial pneumonia patients, probably because of stiffness of the bronchial arteries.

  13. COLPEX - Cold Pool Experiment

    Science.gov (United States)

    Wells, H.; Price, J.; Horlacher, V.; Sheridan, P. F.; Vosper, S. B.; Brown, A. R.; Mobbs, S. D.; Ross, A. N.

    2009-04-01

    Planning has started towards designing a new field campaign aimed at studying the behaviour of the boundary layer over complex terrain. Of specific interest is the formation of cold-pools in valleys during stable night-time conditions. The field campaign will run continuously until the end of the winter in 2009/10. The experiment will make use of a wide variety of ground-based sensors including turbulence towers, automatic weather stations, Doppler lidar, radiation sensors and soil temperature probes. We also hope to deploy an instrumented car and a tethered balloon facility for limited periods. Data from the field campaign will be used for a number of purposes. Firstly, to increase our understanding of how the valley cold pools form and why, for instance, some valleys offer a more favourable environment for their formation than others. Secondly, to investigate the formation and dissipation of fog in complex terrain. Thirdly, the data set will also be used to help validate and develop the Met Office Unified Model at high resolution. An area for the experiment has been identified in the Shropshire/Powis area of the UK where a network of valleys and low hills exist with a typical valley width of ~1.5km and hill top to valley floor heights of 75-200m. 0m.

  14. Mapping of cerebral metabolic rate of oxygen using dynamic susceptibility contrast and blood oxygen level dependent MR imaging in acute ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Gersing, Alexandra S.; Schwaiger, Benedikt J. [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); University of California, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Ankenbrank, Monika; Toth, Vivien; Bauer, Jan S.; Zimmer, Claus [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); Janssen, Insa [Technical University Munich, Department of Neurosurgery, Munich (Germany); Kooijman, Hendrik [Philips Healthcare, Hamburg (Germany); Wunderlich, Silke [Technical University Munich, Department of Neurology, Munich (Germany); Preibisch, Christine [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); Technical University Munich, Department of Neurology, Munich (Germany)

    2015-12-15

    MR-derived cerebral metabolic rate of oxygen utilization (CMRO{sub 2}) has been suggested to be analogous to PET-derived CMRO{sub 2} and therefore may be used for detection of viable tissue at risk for infarction. The purpose of this study was to evaluate MR-derived CMRO{sub 2} mapping in acute ischemic stroke in relation to established diffusion- and perfusion-weighted imaging. In 23 patients (mean age 63 ± 18.7 years, 11 women) with imaging findings for acute ischemic stroke, relative oxygen extraction fraction was calculated from quantitative transverse relaxation times (T2, T2*) and relative cerebral blood volume using a quantitative blood oxygenation level dependent (BOLD) approach in order to detect a local increase of deoxyhemoglobin. Relative CMRO{sub 2} (rCMRO{sub 2}) maps were calculated by multiplying relative oxygen extraction fraction (rOEF) by cerebral blood flow, derived from PWI. After co-registration, rCMRO{sub 2} maps were evaluated in comparison with apparent diffusion coefficient (ADC) and time-to-peak (TTP) maps. Mean rCMRO{sub 2} values in areas with diffusion-restriction or TTP/ADC mismatch were compared with rCMRO{sub 2} values in the contralateral tissue. In tissue with diffusion restriction, mean rCMRO{sub 2} values were significantly decreased compared to perfusion-impaired (17.9 [95 % confidence interval 10.3, 25.0] vs. 58.1 [95 % confidence interval 50.1, 70.3]; P < 0.001) and tissue in the contralateral hemisphere (68.2 [95 % confidence interval 61.4, 75.0]; P < 0.001). rCMRO{sub 2} in perfusion-impaired tissue showed no significant change compared to tissue in the contralateral hemisphere (58.1 [95 % confidence interval 50.1, 70.3] vs. 66.7 [95 % confidence interval 53.4, 73.4]; P = 0.34). MR-derived CMRO{sub 2} was decreased within diffusion-restricted tissue and stable within perfusion-impaired tissue, suggesting that this technique may be adequate to reveal different pathophysiological stages in acute stroke. (orig.)

  15. Cerebrospinal fluid pulsation amplitude and its quantitative relationship to cerebral blood flow pulsations: a phase-contrast MR flow imaging study

    International Nuclear Information System (INIS)

    Bhadelia, R.A.; Bogdan, A.R.; Kaplan, R.F.; Wolpert, S.M.

    1997-01-01

    Our purpose in this investigation was to explain the heterogeneity in the cerebrospinal fluid (CSF) flow pulsation amplitudes. To this end, we determined the contributions of the cerebral arterial and jugular venous flow pulsations to the amplitude of the CSF pulsation. We examined 21 healthy subjects by cine phase-contrast MRI at the C2-3 disc level to demonstrate the CSF and vascular flows as waveforms. Multiple regression analysis was performed to calculate the contributions of (a) the arterial and venous waveform amplitudes and (b) the delay between the maximum systolic slopes of the arterial and venous waveforms (AV delay), in order to predict the amplitude of the CSF waveform. The contribution of the arterial waveform amplitude was positive (r = 0.61; p 0.003) to the CSF waveform amplitude and that of the venous waveform amplitude was negative (r = -0.50; p = 0.006). Both in combination accounted for 56 % of the variance in predicting the CSF waveform amplitude (p < 0.0006). The contribution of AV delay was not significant. The results show that the variance in the CSF flow pulsation amplitudes can be explained by concurrent evaluation of the CSF and vascular flows. Improvement in the techniques, and controlled experiments, may allow use of CSF flow pulsation amplitudes for clinical applications in the non-invasive assessment of intracranial dynamics by MRI. (orig.). With 3 figs., 2 tabs

  16. Minimizing the blood velocity differences between phase-contrast magnetic resonance imaging and computational fluid dynamics simulation in cerebral arteries and aneurysms.

    Science.gov (United States)

    Mohd Adib, Mohd Azrul Hisham; Ii, Satoshi; Watanabe, Yoshiyuki; Wada, Shigeo

    2017-09-01

    The integration of phase-contrast magnetic resonance images (PC-MRI) and computational fluid dynamics (CFD) is a way to obtain detailed information of patient-specific hemodynamics. This study proposes a novel strategy for imposing a pressure condition on the outlet boundary (called the outlet pressure) in CFD to minimize velocity differences between the PC-MRI measurement and the CFD simulation, and to investigate the effects of outlet pressure on the numerical solution. The investigation involved ten patient-specific aneurysms reconstructed from a digital subtraction angiography image, specifically on aneurysms located at the bifurcation region. To evaluate the effects of imposing the outlet pressure, three different approaches were used, namely: a pressure-fixed (P-fixed) approach; a flow rate control (Q-control) approach; and a velocity-field-optimized (V-optimized) approach. Numerical investigations show that the highest reduction in velocity difference always occurs in the V-optimized approach, where the mean of velocity difference (normalized by inlet velocity) is 19.3%. Additionally, the highest velocity differences appear near to the wall and vessel bifurcation for 60% of the patients, resulting in differences in wall shear stress. These findings provide a new methodology for PC-MRI integrated CFD simulation and are useful for understanding the evaluation of velocity difference between the PC-MRI and CFD.

  17. Human parvovirus PARV4 in plasma pools of Chinese origin.

    Science.gov (United States)

    Ma, Y-Y; Guo, Y; Zhao, X; Wang, Z; Lv, M-M; Yan, Q-P; Zhang, J-G

    2012-10-01

    Human parvovirus 4 (PARV4) is present in blood and blood products. As the presence and levels of PARV4 in Chinese source plasma pools have never been determined, we implemented real-time quantitative PCR to investigate the presence of PARV4 in source plasma pools in China. Results showed that 26·15% (51/195) of lots tested positive for PARV4. The amounts of DNA ranged from 2·83 × 10(3) copies/ml to 2·35×10(7) copies/ml plasma. The high level of PARV4 in plasma pools may pose a potential risk to recipients. Further studies on the pathogenesis of PARV4 are urgently required. © 2012 The Author(s). Vox Sanguinis © 2012 International Society of Blood Transfusion.

  18. Restoration of myocardial blood flow following percutaneous coronary balloon dilatation and stent implantation: Assessment with qualitative and quantitative contrast-enhanced magnetic resonance imaging

    International Nuclear Information System (INIS)

    Sensky, P.R.; Samani, N.J.; Horsfield, M.A.; Cherryman, G.R.

    2002-01-01

    AIM: To examine the serial use of magnetic resonance imaging (MRI) to evaluate regional myocardial perfusion changes following percutaneous coronary angioplasty and stent implantation (PTCA). MATERIALS AND METHODS: Six patients with single vessel coronary artery disease (CAD) underwent contrast-enhanced first pass MRI immediately prior to (visit A) and within 7 days after (visit B) PTCA. Three sequential short axis slices were obtained after gadodiamide (Gd) bolus (0.025 mmol/kg -1 ) at rest and during adenosine. Each short axis was divided radially into eight regions of interest (ROIs). ROIs were anatomically assigned to a coronary artery territory (CAT). Stress and rest qualitative and quantitative (unidirectional extraction fraction constant (K i ); index of myocardial perfusion reserve (MPRI) = stressK i / restK i ) perfusion parameters were determined for ROI supplied by remote and stenosed/stented vessels for each visit. RESULTS: In stented ROIs the number of ROIs demonstrating normal perfusion, as opposed to reversible perfusion deficits, increased. Qualitative perfusion assessment in remote CATs was unchanged. MPRI in stenotic CATs was lower than in remote CATs at visit A (P < 0.001). Following PTCA, MPRI increased in stented CATs (P < 0.001) but was unchanged in remote CATs. CONCLUSION: Restoration of myocardial perfusion following PTCA can be delineated with qualitative and quantitative perfusion MRI. Although at present the investigation is technically complex and not perfectly sensitive or specific, MRI has the potential to be a valuable tool for patient follow-up and evaluation of revascularization strategy efficacy. Sensky, P.R. et al. (2002)

  19. Efficacy Analysis of a Script-based Guide for EVAR Execution: is it Possible to Reduce Patient Exposure to Contrast, Operative Time and Blood Loss even when Advanced Technologies are not Available?

    Directory of Open Access Journals (Sweden)

    Giovani José Dal Poggetto Molinari

    2015-12-01

    Full Text Available ABSTRACT INTRODUCTION: Despite the patient and medical staff exposure to radiation in endovascular aneurysm repair, the benefits of this abdominal aortic aneurysm type of surgical management are justfied by minor recovery time and hospitalization, as well as an option for patients not elected to conventional open repair. In this minimally invasive surgical aproach, time of procedure and radiation doses can be substantial - and the increasing frequency of these procedures and it's complexity have impelled vascular surgeons to face additional and successive risk to occupational radiation exposure. Meticulous study of the computed tomography angiography during the endovascular aneurysm repair preparation allows reduction of unnecessary radiation exposure, as also reduces consecutive image acquisition and contrast use (that may be related to renal overload in susceptible patients. Some studies have proposed strategies to optimize endovascular intervention to reduce contrast use and X-ray exposure. Although they might prove to be effective, they rely on use of additional specific and advanced equipment, available only in major centers. As an alternative to this expensive and restrict technology, it is presented a simpler technique through image manipulation on software OsiriX, aiming to reduce both exposures. OBJECTIVE: To analyze the efficacy of the adoption of a study protocol and a script-based guide in preparation for endovascular aneurysm repair through verifying it's impact over the surgical procedure - as referred to intravascular contrast infuse, effects over renal function, blood loss and operatory time. METHODS: A longitudinal prospective study from March 2014 through March 2015, where 30 performed endovascular aneurysm repair were compared to a historic control group. The planning for endovascular aneurysm repair through the patient's tomographic image manipulation in the prospective group was performed with OsiriX MD software. A script

  20. Model of large pool fires

    International Nuclear Information System (INIS)

    Fay, J.A.

    2006-01-01

    A two zone entrainment model of pool fires is proposed to depict the fluid flow and flame properties of the fire. Consisting of combustion and plume zones, it provides a consistent scheme for developing non-dimensional scaling parameters for correlating and extrapolating pool fire visible flame length, flame tilt, surface emissive power, and fuel evaporation rate. The model is extended to include grey gas thermal radiation from soot particles in the flame zone, accounting for emission and absorption in both optically thin and thick regions. A model of convective heat transfer from the combustion zone to the liquid fuel pool, and from a water substrate to cryogenic fuel pools spreading on water, provides evaporation rates for both adiabatic and non-adiabatic fires. The model is tested against field measurements of large scale pool fires, principally of LNG, and is generally in agreement with experimental values of all variables

  1. Evaluation of blood signal in cardiac MR imaging using ''black-blood'' technique

    International Nuclear Information System (INIS)

    Nakanishi, Tadashi; Yamada, Takayuki; Tamura, Akihisa; Miyasaka, Kenji; Kohata, Minako; Ono, Chiaki; Kajima, Toshio; Ito, Katsuhide

    1999-01-01

    Degradation of image quality encountered in cardiac imaging has been attributed to flowing blood signal in the ventricular cavity. To solve this problem, a sequence in which a pair of selective and non-selective inversion pulse in used for a preparation pulse, has been proposed. However, even with this sequence we frequently observed the signal in the blood pool caused by blood itself rather than blood flow. In this article, we investigated the characteristics of those signals. Five healthy normal volunteers and 13 patients with ischemic heart disease were scanned with a 1.5-tesla MR imager. Breath-hold ECG gated fast spin echo with the pair of inversion pulses was performed to obtain cardiac images with T 2 contrast. Typical blood signal appeared as inhomogeneous high intense band adjacent to inner surface of left ventricular apex. At ventricular base, no such signal was encountered even at akinetic myocardium in patients with old myocardial infarction. This signal was observed in all volunteers and 39% of patients. Decrease of TR resulting from tachycardia tended to reduce the blood signal in the left ventricular cavity. Thicker slice section and selective inversion pulse tended to increase the blood signal. Recognition of the signal is essential to differentiate true myocardial infarcts from blood signal, although bright blood imaging like gradient echo or thinner section can partly be helpful. (author)

  2. Effects of MRI Protocol Parameters, Preload Injection Dose, Fractionation Strategies, and Leakage Correction Algorithms on the Fidelity of Dynamic-Susceptibility Contrast MRI Estimates of Relative Cerebral Blood Volume in Gliomas.

    Science.gov (United States)

    Leu, K; Boxerman, J L; Ellingson, B M

    2017-03-01

    DSC perfusion MR imaging assumes that the contrast agent remains intravascular; thus, disruptions in the blood-brain barrier common in brain tumors can lead to errors in the estimation of relative CBV. Acquisition strategies, including the choice of flip angle, TE, TR, and preload dose and incubation time, along with post hoc leakage-correction algorithms, have been proposed as means for combating these leakage effects. In the current study, we used DSC-MR imaging simulations to examine the influence of these various acquisition parameters and leakage-correction strategies on the faithful estimation of CBV. DSC-MR imaging simulations were performed in 250 tumors with perfusion characteristics randomly generated from the distributions of real tumor population data, and comparison of leakage-corrected CBV was performed with a theoretic curve with no permeability. Optimal strategies were determined by protocol with the lowest mean error. The following acquisition strategies (flip angle/TE/TR and contrast dose allocation for preload and bolus) produced high CBV fidelity, as measured by the percentage difference from a hypothetic tumor with no leakage: 1) 35°/35 ms/1.5 seconds with no preload and full dose for DSC-MR imaging, 2) 35°/25 ms/1.5 seconds with ¼ dose preload and ¾ dose bolus, 3) 60°/35 ms/2.0 seconds with ½ dose preload and ½ dose bolus, and 4) 60°/35 ms/1.0 second with 1 dose preload and 1 dose bolus. Results suggest that a variety of strategies can yield similarly high fidelity in CBV estimation, namely those that balance T1- and T2*-relaxation effects due to contrast agent extravasation. © 2017 by American Journal of Neuroradiology.

  3. Comparison of contrast-enhanced modified T1-weighted 3D TSE black-blood and 3D MP-RAGE sequences for the detection of cerebral metastases and brain tumours

    Energy Technology Data Exchange (ETDEWEB)

    Kammer, N.N.; Coppenrath, E.; Treitl, K.M.; Saam, T. [Ludwig-Maximilians-University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); Kooijman, H. [Philips Healthcare, Hamburg (Germany); Dietrich, O. [Ludwig-Maximilians-University Hospital Munich, Josef Lissner Laboratory for Biomedical Imaging, Institute for Clinical Radiology, Munich (Germany)

    2016-06-15

    To compare a modified T1-weighted 3D TSE black-blood sequence with sub-millimetre resolution (T1-mVISTA) with a magnetization-prepared rapid gradient echo (MP-RAGE) sequence for the diagnosis of cerebral malignomas. Forty-six patients with known or suspected intracranial tumours and 15 control patients were included in this retrospective study. All patients underwent T1-mVISTA (0.75-mm isotropic resolution, 4:43 min) and MP-RAGE (0.8-mm isotropic resolution, 4:46 minutes) at 3-Tesla in random order after application of contrast agent. Two experienced radiologists determined the number of lesions. Maximum diameter, diagnostic confidence (DC), visual assessment of contrast enhancement (VCE) and CNR{sub lesion/parenchyma} were assessed for each lesion. Significantly more lesions were detected with T1-mVISTA compared to the MP-RAGE (61 vs. 36; p < 0.05). Further, DC and VCE was rated significantly higher in the T1-mVISTA (p < 0.05 and p < 0.001). Mean CNR{sub lesion/parenchyma} was twofold higher for T1-mVISTA (24.2 ± 17.5 vs. 12.7 ± 11.5, p < 0.001). The 25 lesions detected only in T1-mVISTA were significantly smaller than those detected in both sequences (4.3 ± 3.7 mm vs. 11.3 ± 10.7 mm; p < 0.01). T1-mVISTA increases the contrast of lesions significantly compared to MP-RAGE and might therefore improve detection rates of small lesions in early stages of disease. (orig.)

  4. Spent fuel storage pool and reactor well pool

    International Nuclear Information System (INIS)

    Fuchisawa, Hiroshi.

    1996-01-01

    An overflow device is disposed to a water draining channel communicating a spent fuel storage pool, a well pool and a cask cleaning pit, and a cleaning treatment system is connected to the cask cleaning pit. In addition, a tank chamber having an overflow device communicating with the well pool is disposed to the inside of the spent fuel storage pool, and a cleaning system is connected to the tank chamber. Namely, water overflow from the spent fuel storage pool and the well pool flows down to the cask cleaning pit directly, the water level can be kept to a predetermined value without disposing a skimmer serge tank, and the overflow water is transported to and cleaned in the cleaning treatment system. In addition, the overflow water flow to the tank chamber directly is transferred to and cleaned in the cleaning treatment system. The cost for the reactor building can be reduced, and interference with the building and adjustment for the steps upon installation of the skimmer serge tank are no more necessary to shorten the terms for the building construction. (N.H.)

  5. ENERGY STAR Certified Pool Pumps

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.1 ENERGY STAR Program Requirements for Pool Pumps that are effective as of February 15,...

  6. Sustainability of common pool resources

    OpenAIRE

    Timilsina, Raja Rajendra; Kotani, Koji; Kamijo, Yoshio

    2017-01-01

    Sustainability has become a key issue in managing natural resources together with growing concerns for capitalism, environmental and resource problems. We hypothesize that the ongoing modernization of competitive societies, which we refer to as "capitalism," affects human nature for utilizing common pool resources, thus compromising sustainability. To test this hypothesis, we design and implement a set of dynamic common pool resource games and experiments in the following two types of Nepales...

  7. Grundfoss: Chlorination of Swimming Pools

    DEFF Research Database (Denmark)

    Hjorth, Poul G.; Hogan, John; Andreassen, Viggo

    1998-01-01

    Grundfos asked for a model, describing the problem of mixing chemicals, being dosed into water systems, to be developed. The application of the model should be dedicated to dosing aqueous solution of chlorine into swimming pools.......Grundfos asked for a model, describing the problem of mixing chemicals, being dosed into water systems, to be developed. The application of the model should be dedicated to dosing aqueous solution of chlorine into swimming pools....

  8. Reserve growth in oil pools of Alberta: Model and forecast

    Science.gov (United States)

    Verma, M.; Cook, T.

    2010-01-01

    Reserve growth is recognized as a major component of additions to reserves in most oil provinces around the world, particularly in mature provinces. It takes place as a result of the discovery of new pools/reservoirs and extensions of known pools within existing fields, improved knowledge of reservoirs over time leading to a change in estimates of original oil-in-place, and improvement in recovery factor through the application of new technology, such as enhanced oil recovery methods, horizontal/multilateral drilling, and 4D seismic. A reserve growth study was conducted on oil pools in Alberta, Canada, with the following objectives: 1) evaluate historical oil reserve data in order to assess the potential for future reserve growth; 2) develop reserve growth models/ functions to help forecast hydrocarbon volumes; 3) study reserve growth sensitivity to various parameters (for example, pool size, porosity, and oil gravity); and 4) compare reserve growth in oil pools and fields in Alberta with those from other large petroleum provinces around the world. The reported known recoverable oil exclusive of Athabasca oil sands in Alberta increased from 4.5 billion barrels of oil (BBO) in 1960 to 17 BBO in 2005. Some of the pools that were included in the existing database were excluded from the present study for lack of adequate data. Therefore, the known recoverable oil increased from 4.2 to 13.9 BBO over the period from 1960 through 2005, with new discoveries contributing 3.7 BBO and reserve growth adding 6 BBO. This reserve growth took place mostly in pools with more than 125,000 barrels of known recoverable oil. Pools with light oil accounted for most of the total known oil volume, therefore reflecting the overall pool growth. Smaller pools, in contrast, shrank in their total recoverable volumes over the years. Pools with heavy oil (gravity less than 20o API) make up only a small share (3.8 percent) of the total recoverable oil; they showed a 23-fold growth compared to

  9. Pool impacts of Leidenfrost drop

    Science.gov (United States)

    Darbois Texier, Baptiste; Maquet, Laurent; Dorbolo, Stephane; Dehandschoewercker, Eline; Pan, Zhao; Truscott, Tadd

    2015-11-01

    This work concerns the impact of a droplet made of a volatile liquid (typically HFE) on a pool of an other liquid (typically silicone oil) which temperature is above the boiling point of the drop. Depending on the properties of the two liquids and the impacting conditions, four different regimes are observed. For low impacting speeds, the droplet bounces on the surface of the bath and finally levitates above it in a Leidenfrost state. Such a regime occurs as soon as the pool temperature exceeds the boiling point of the drop. This observation means that there is no threshold in temperature for a Leidenfrost effect on a liquid surface contrary to the case of a solid substrate. For intermediate impacting velocities, the pinch-off of the surface of the pool entraps the drop in the liquid bulk. The entrapped drop is separated from the pool by a layer of its own vapour in a similar way of antibulles. For increasing impacting speeds, the vapour layer between the drop and the pool does not hold during the pinch-off event. The contact of the drop with the hot liquid provokes a sudden and intense evaporation. At very large impacting speeds, the drop rapidely contacts the pool, spreads and finally induces a hemi-spherical cavity. In the end, these four different regimes are summarized in a Froud-Weber diagram which boundaries are discussed.

  10. 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)

  11. Seismic analysis of large pools

    International Nuclear Information System (INIS)

    Dong, R.G.; Tokarz, F.J.

    1976-01-01

    Large pools for storing spent, nuclear fuel elements are being proposed to augment present storage capacity. To preserve the ability to isolate portions of these pools, a modularization requirement appears desirable. The purpose of this project was to investigate the effects of modularization on earthquake resistance and to assess the adequacy of current design methods for seismic loads. After determining probable representative pool geometries, three rectangular pool configurations, all 240 x 16 ft and 40 ft deep, were examined. One was unmodularized; two were modularized into 80 x 40 ft cells in one case and 80 x 80 ft cells in the other. Both embedded and above-ground installations for a hard site and embedded installations for an intermediate hard site were studied. It was found that modularization was unfavorable in terms of reducing the total structural load attributable to dynamic effects, principally because one or more cells could be left unfilled. The walls of unfilled cells would be subjected to significantly higher loads than the walls of a filled, unmodularized pool. Generally, embedded installations were preferable to above-ground installations, and the hard site was superior to the intermediate hard site. It was determined that Housner's theory was adequate for calculating hydrodynamic effects on spent fuel storage pools. Current design methods for seismic loads were found to be satisfactory when results from these methods were compared with those from LUSH analyses. As a design method for dynamic soil pressure, we found the Mononobe-Okabe theory, coupled with correction factors as suggested by Seed, to be acceptable. The factors we recommend for spent fuel storage pools are tabulated

  12. Seismic analysis of large pools

    Energy Technology Data Exchange (ETDEWEB)

    Dong, R.G.; Tokarz, F.J.

    1976-11-17

    Large pools for storing spent, nuclear fuel elements are being proposed to augment present storage capacity. To preserve the ability to isolate portions of these pools, a modularization requirement appears desirable. The purpose of this project was to investigate the effects of modularization on earthquake resistance and to assess the adequacy of current design methods for seismic loads. After determining probable representative pool geometries, three rectangular pool configurations, all 240 x 16 ft and 40 ft deep, were examined. One was unmodularized; two were modularized into 80 x 40 ft cells in one case and 80 x 80 ft cells in the other. Both embedded and above-ground installations for a hard site and embedded installations for an intermediate hard site were studied. It was found that modularization was unfavorable in terms of reducing the total structural load attributable to dynamic effects, principally because one or more cells could be left unfilled. The walls of unfilled cells would be subjected to significantly higher loads than the walls of a filled, unmodularized pool. Generally, embedded installations were preferable to above-ground installations, and the hard site was superior to the intermediate hard site. It was determined that Housner's theory was adequate for calculating hydrodynamic effects on spent fuel storage pools. Current design methods for seismic loads were found to be satisfactory when results from these methods were compared with those from LUSH analyses. As a design method for dynamic soil pressure, we found the Mononobe-Okabe theory, coupled with correction factors as suggested by Seed, to be acceptable. The factors we recommend for spent fuel storage pools are tabulated.

  13. Polymer Assembly Encapsulation of Lanthanide Nanoparticles as Contrast Agents for In Vivo Micro-CT.

    Science.gov (United States)

    Cruje, Charmainne; Dunmore-Buyze, Joy; MacDonald, Jarret P; Holdsworth, David W; Drangova, Maria; Gillies, Elizabeth R

    2018-03-12

    Despite recent technological advancements in microcomputed tomography (micro-CT) and contrast agent development, preclinical contrast agents are still predominantly iodine-based. Higher contrast can be achieved when using elements with higher atomic numbers, such as lanthanides; lanthanides also have X-ray attenuation properties that are ideal for spectral CT. However, the formulation of lanthanide-based contrast agents at the high concentrations required for vascular imaging presents a significant challenge. In this work, we developed an erbium-based contrast agent that meets micro-CT imaging requirements, which include colloidal stability upon redispersion at high concentrations, evasion of rapid renal clearance, and circulation times of tens of minutes in small animals. Through systematic studies with poly(ethylene glycol) (PEG)-poly(propylene glycol), PEG-polycaprolactone, and PEG-poly(l-lactide) (PLA) block copolymers, the amphiphilic block copolymer PEG 114 -PLA 53 was identified to be ideal for encapsulating oleate-coated lanthanide-based nanoparticles for in vivo intravenous administration. We were able to synthesize a contrast agent containing 100 mg/mL of erbium that could be redispersed into colloidally stable particles in saline after lyophilization. Contrast enhancement of over 250 HU was achieved in the blood pool for up to an hour, thereby meeting the requirements of live animal micro-CT.

  14. Correlation between quantitative and semiquantitative parameters in DCE-MRI with a blood pool agent in rectal cancer: can semiquantitative parameters be used as a surrogate for quantitative parameters?

    Science.gov (United States)

    Dijkhoff, Rebecca A P; Maas, Monique; Martens, Milou H; Papanikolaou, Nikolaos; Lambregts, Doenja M J; Beets, Geerard L; Beets-Tan, Regina G H

    2017-05-01

    The aim of this study was to assess correlation between quantitative and semiquantitative parameters in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in rectal cancer patients, both in a primary staging and restaging setting. Nineteen patients were included with DCE-MRI before and/or after neoadjuvant therapy. DCE-MRI was performed with gadofosveset trisodium (Ablavar ® , Lantheus Medical Imaging, North Billerica, Massachusetts, USA). Regions of interest were placed in the tumor and quantitative parameters were extracted with Olea Sphere 2.2 software permeability module using the extended Tofts model. Semiquantitative parameters were calculated on a pixel-by-pixel basis. Spearman rank correlation tests were used for assessment of correlation between parameters. A p value ≤0.05 was considered statistically significant. Strong positive correlations were found between mean peak enhancement and mean K trans : 0.79 (all patients, prectal cancer. Peak enhancement correlates strongly with K trans and wash-in showed strong correlation with V p and K ep . These parameters have been reported to predict tumor aggressiveness and response in rectal cancer. Therefore, semiquantitative analyses might be a surrogate for quantitative analyses.

  15. Cord Blood

    Directory of Open Access Journals (Sweden)

    Saeed Abroun

    2014-05-01

    Full Text Available   Stem cells are naïve or master cells. This means they can transform into special 200 cell types as needed by body, and each of these cells has just one function. Stem cells are found in many parts of the human body, although some sources have richer concentrations than others. Some excellent sources of stem cells, such as bone marrow, peripheral blood, cord blood, other tissue stem cells and human embryos, which last one are controversial and their use can be illegal in some countries. Cord blood is a sample of blood taken from a newborn baby's umbilical cord. It is a rich source of stem cells, umbilical cord blood and tissue are collected from material that normally has no use following a child’s birth. Umbilical cord blood and tissue cells are rich sources of stem cells, which have been used in the treatment of over 80 diseases including leukemia, lymphoma and anemia as bone marrow stem cell potency.  The most common disease category has been leukemia. The next largest group is inherited diseases. Patients with lymphoma, myelodysplasia and severe aplastic anemia have also been successfully transplanted with cord blood. Cord blood is obtained by syringing out the placenta through the umbilical cord at the time of childbirth, after the cord has been detached from the newborn. Collecting stem cells from umbilical blood and tissue is ethical, pain-free, safe and simple. When they are needed to treat your child later in life, there will be no rejection or incompatibility issues, as the procedure will be using their own cells. In contrast, stem cells from donors do have these potential problems. By consider about cord blood potency, cord blood banks (familial or public were established. In IRAN, four cord blood banks has activity, Shariati BMT center cord blood bank, Royan familial cord blood banks, Royan public cord blood banks and Iranian Blood Transfusion Organ cord blood banks. Despite 50,000 sample which storage in these banks, but the

  16. Patent pools: Intellectual property rights and competition.

    NARCIS (Netherlands)

    Rodriguez, V.F.

    2010-01-01

    Patent pools do not correct all problems associated with patent thickets. In this respect, patent pools might not stop the outsider problem from striking pools. Moreover, patent pools can be expensive to negotiate, can exclude patent holders with smaller numbers of patents or enable a group of major

  17. Utility of a prototype liposomal contrast agent for x-ray imaging of breast cancer: a proof of concept using micro-CT in small animals

    Science.gov (United States)

    Badea, C. T.; Samei, E.; Ghaghada, K.; Saunders, R.; Yuan, H.; Qi, Y.; Hedlund, L. W.; Mukundan, S.

    2008-03-01

    Imaging tumor angiogenesis in small animals is extremely challenging due to the size of the tumor vessels. Consequently, both dedicated small animal imaging systems and specialized intravascular contrast agents are required. The goal of this study was to investigate the use of a liposomal contrast agent for high-resolution micro-CT imaging of breast tumors in small animals. A liposomal blood pool agent encapsulating iodine with a concentration of 65.5 mg/ml was used with a Duke Center for In Vivo Microscopy (CIVM) prototype micro-computed tomography (micro-CT) system to image the R3230AC mammary carcinoma implanted in rats. The animals were injected with equivalent volume doses (0.02 ml/kg) of contrast agent. Micro-CT with the liposomal blood pool contrast agent ensured a signal difference between the blood and the muscle higher than 450 HU allowing the visualization of the tumors 3D vascular architecture in exquisite detail at 100-micron resolution. The micro-CT data correlated well with the histological examination of tumor tissue. We also studied the ability to detect vascular enhancement with limited angle based reconstruction, i.e. tomosynthesis. Tumor volumes and their regional vascular percentage were estimated. This imaging approach could be used to better understand tumor angiogenesis and be the basis for evaluating anti-angiogenic therapies.

  18. EP BICYCLE POOL - VIGNETTES 2002

    CERN Multimedia

    EP-SMI Help Desk

    2002-01-01

    The vignettes (insurance certificates) for 2002 become obligatory from 1 June. If you have a bicycle from the EP Pool, please bring it to the EP-SMI Help Desk (Building 124) on any working day up to 31 May between 8h.30 - 12h.00 or 13h.30 - 17h.30. EP-SMI Help Desk

  19. Efficient pooling designs for library screening

    OpenAIRE

    Bruno, William J.; Knill, Emanuel; Balding, David J.; Bruce, D. C.; Doggett, N. A.; Sawhill, W. W.; Stallings, R. L.; Whittaker, Craig C.; Torney, David C.

    1994-01-01

    We describe efficient methods for screening clone libraries, based on pooling schemes which we call ``random $k$-sets designs''. In these designs, the pools in which any clone occurs are equally likely to be any possible selection of $k$ from the $v$ pools. The values of $k$ and $v$ can be chosen to optimize desirable properties. Random $k$-sets designs have substantial advantages over alternative pooling schemes: they are efficient, flexible, easy to specify, require fewer pools, and have er...

  20. [Infections transmitted in swimming pools].

    Science.gov (United States)

    von Suzani, C; Hazeghi, P

    1976-01-01

    Public swimmingpools can be the source of infections due to micro-organism such as mycobacterium balnei, adeno and enteroviruses, the virus of plantar warts and molluscum contagiosum, the TRIC-Agent of swimmingpool-conjonctivitis and pathogenic fungi. The transmission of trichomonas vaginalis is considered unlikely-Water of pools, supposed to present satisfactory qualities by standard controls, was found to contain pathogenic staphylococci and pseudomonas aeruginosa. Effective preventive measures include the continuous recording of the redox-potential of the water, limiting the number of visitors to pool design specifications, better desinfection of sanitary installations, regular maintenance of technical equipment including frequent backwashing of filters and exclusion of visitors with communicable disease.

  1. Sustainability of common pool resources.

    Science.gov (United States)

    Timilsina, Raja Rajendra; Kotani, Koji; Kamijo, Yoshio

    2017-01-01

    Sustainability has become a key issue in managing natural resources together with growing concerns for capitalism, environmental and resource problems. We hypothesize that the ongoing modernization of competitive societies, which we refer to as "capitalism," affects human nature for utilizing common pool resources, thus compromising sustainability. To test this hypothesis, we design and implement a set of dynamic common pool resource games and experiments in the following two types of Nepalese areas: (i) rural (non-capitalistic) and (ii) urban (capitalistic) areas. We find that a proportion of prosocial individuals in urban areas is lower than that in rural areas, and urban residents deplete resources more quickly than rural residents. The composition of proself and prosocial individuals in a group and the degree of capitalism are crucial in that an increase in prosocial members in a group and the rural dummy positively affect resource sustainability by 65% and 63%, respectively. Overall, this paper shows that when societies move toward more capitalistic environments, the sustainability of common pool resources tends to decrease with the changes in individual preferences, social norms, customs and views to others through human interactions. This result implies that individuals may be losing their coordination abilities for social dilemmas of resource sustainability in capitalistic societies.

  2. 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

  3. Pool power control in remelting systems

    Science.gov (United States)

    Williamson, Rodney L [Albuquerque, NM; Melgaard, David K [Albuquerque, NM; Beaman, Joseph J [Austin, TX

    2011-12-13

    An apparatus for and method of controlling a remelting furnace comprising adjusting current supplied to an electrode based upon a predetermined pool power reference value and adjusting the electrode drive speed based upon the predetermined pool power reference value.

  4. The warm pool in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Vinayachandran, P.N.; Shetye, S.R.

    The structure of the warm pool (region with temperature greater than 28 degrees C) in the equatorial Indian Ocean is examined and compared with its counterpart in the Pacific Ocean using the climatology of Levitus. Though the Pacific warm pool...

  5. CDC Study Finds Fecal Contamination in Pools

    Science.gov (United States)

    ... Communication (404) 639-3286 CDC study finds fecal contamination in pools A study of public pools done ... The E. coli is a marker for fecal contamination. Finding a high percentage of E. coli-positive ...

  6. Contrast harmonic TEE: A feasibility study

    NARCIS (Netherlands)

    Bouakaz, Ayache; Krenning, Boudewijn; Biagini, Elena; Galema, Tjebbe; ten Cate, Folkert; de Jong, N.

    2004-01-01

    Ultrasound (US) contrast agents serve as tracers for the noninvasive quantification of blood flow, and many of them are now approved for left ventricular opacification and for enhanced endocardial border delineation. The availability of more stable contrast bubbles has stimulated many new classes of

  7. Measurement of blood flow in the superior sagittal sinus in healthy volunteers, and in patients with normal pressure hydrocephalus and idiopathic intracranial hypertension with phase-contrast cine MR imaging

    DEFF Research Database (Denmark)

    Gideon, P; Thomsen, C; Gjerris, F

    1996-01-01

    PURPOSE: To measure blood flow and velocity in the superior sagittal ++sinus. MATERIAL AND METHODS: MR velocity mapping was used to examine 14 healthy volunteers, 15 patients with normal pressure hydrocephalus (NPH), 3 patients with high pressure hydrocephalus (HPH), and 11 patients with idiopathic...... intracranial hypertension (IIH). RESULTS: Mean blood flow was 443 ml/min in healthy volunteers with a tendency towards reduced blood flow with increasing age. In NPH patients significantly lower superior sagittal sinus blood flow values were found, but this difference was no longer significant when patients...

  8. Contrast settling in cerebral aneurysm angiography

    International Nuclear Information System (INIS)

    Wang Zhijie; Hoffmann, Kenneth R; Guterman, Lee R; Wang Zhou; Rudin, Stephen; Meng Hui

    2005-01-01

    During angiography, blood flow is visualized with a radiopaque contrast agent, which is denser than blood. In complex vasculature, such as cerebral saccular aneurysms, the density difference may produce an appreciable gravity effect, where the contrast material separates from blood and settles along the gravity direction. Although contrast settling has been occasionally reported before, the fluid mechanics behind it have not been explored. Furthermore, the severity of contrast settling in cerebral aneurysms varies significantly from case to case. Therefore, a better understanding of the physical principles behind this phenomenon is needed to evaluate contrast settling in clinical angiography. In this study, flow in two identical groups of sidewall aneurysm models with varying parent-vessel curvature was examined by angiography. Intravascular stents were deployed into one group of the models. To detect contrast settling, we used lateral view angiography. Time-intensity curves were analysed from the angiographic data, and a computational fluid dynamic analysis was conducted. Results showed that contrast settling was strongly related to the local flow dynamics. We used the Froude number, a ratio of flow inertia to gravity force, to characterize the significance of gravity force. An aneurysm with a larger vessel curvature experienced higher flow, which resulted in a larger Froude number and, thus, less gravitational settling. Addition of a stent reduced the aneurysmal flow, thereby increasing the contrast settling. We found that contrast settling resulted in an elevated washout tail in the time-intensity curve. However, this signature is not unique to contrast settling. To determine whether contrast settling is present, a lateral view should be obtained in addition to the anteroposterior (AP) view routinely used clinically so as to rule out contrast settling and hence to enable a valid time-intensity curve analysis of blood flow in the aneurysm

  9. Contrast Gain Control Model Fits Masking Data

    Science.gov (United States)

    Watson, Andrew B.; Solomon, Joshua A.; Null, Cynthia H. (Technical Monitor)

    1994-01-01

    We studied the fit of a contrast gain control model to data of Foley (JOSA 1994), consisting of thresholds for a Gabor patch masked by gratings of various orientations, or by compounds of two orientations. Our general model includes models of Foley and Teo & Heeger (IEEE 1994). Our specific model used a bank of Gabor filters with octave bandwidths at 8 orientations. Excitatory and inhibitory nonlinearities were power functions with exponents of 2.4 and 2. Inhibitory pooling was broad in orientation, but narrow in spatial frequency and space. Minkowski pooling used an exponent of 4. All of the data for observer KMF were well fit by the model. We have developed a contrast gain control model that fits masking data. Unlike Foley's, our model accepts images as inputs. Unlike Teo & Heeger's, our model did not require multiple channels for different dynamic ranges.

  10. 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

  11. Structural integrity assessment of HANARO pool cover

    International Nuclear Information System (INIS)

    Ryu, Jeong Soo

    2001-11-01

    This report is for the seismic analysis and the structural integrity evaluation of HANARO Pool Cover in accordances with the requirement of the Technical Specification for Seismic Analysis of HANARO Pool Cover. For performing the seismic analysis and evaluating the structural integrity for HANARO Pool Cover, the finite element analysis model using ANSYS 5.7 was developed and the dynamic characteristics were analyzed. The seismic response spectrum analyses of HANARO Pool Cover under the design floor response spectrum loads of OBE and SSE were performed. The analysis results show that the stress values in HANARO Pool Cover for the seismic loads are within the ASME Code limits. It is also confirmed that the fatigue usage factor is less than 1.0. Therefore any damage on structural integrity is not expected when an HANARO Pool Cover is installed in the upper part of the reactor pool

  12. Karst pools in subsurface environments: collectors of microbial diversity or temporary residence between habitat types.

    Science.gov (United States)

    Shabarova, Tanja; Pernthaler, Jakob

    2010-04-01

    We studied bacterial diversity and community composition in three shallow pools of a Swiss karst cave system with contrasting hydrological and hydrochemical properties. The microbial assemblages in the pools were remarkably different, and only one operational taxonomic unit of 16S rRNA genes (OTU, 97% similarity) was shared between the three of them (total OTU number in all pools: 150). Unexpectedly high microbial phylotype richness was found even in the two pools without groundwater contact and with low concentrations of organic carbon and total cell numbers (types. Two bacterial clades affiliated with the obligate methylamine utilizer Methylotenera mobilis were only found in the pool that was exposed to repeated flooding events. These bacteria formed relatively stable populations of up to 6% of total cell counts over periods of several months irrespective of inundation by groundwater. This suggests that karst water may provide a means of transport for these bacteria from terrestrial to freshwater habitats.

  13. Leidenfrost drops on a heated liquid pool

    Science.gov (United States)

    Maquet, L.; Sobac, B.; Darbois-Texier, B.; Duchesne, A.; Brandenbourger, M.; Rednikov, A.; Colinet, P.; Dorbolo, S.

    2016-09-01

    We show that a volatile liquid drop placed at the surface of a nonvolatile liquid pool warmer than the boiling point of the drop can be held in a Leidenfrost state even for vanishingly small superheats. Such an observation points to the importance of the substrate roughness, negligible in the case considered here, in determining the threshold Leidenfrost temperature. A theoretical model based on the one proposed by Sobac et al. [Phys. Rev. E 90, 053011 (2014), 10.1103/PhysRevE.90.053011] is developed in order to rationalize the experimental data. The shapes of the drop and of the liquid substrate are analyzed. The model notably provides scalings for the vapor film thickness profile. For small drops, these scalings appear to be identical to the case of a Leidenfrost drop on a solid substrate. For large drops, in contrast, they are different, and no evidence of chimney formation has been observed either experimentally or theoretically in the range of drop sizes considered in this study. Concerning the evaporation dynamics, the radius is shown to decrease linearly with time whatever the drop size, which differs from the case of a Leidenfrost drop on a solid substrate. For high superheats, the characteristic lifetime of the drops versus the superheat follows a scaling law that is derived from the model, but, at low superheats, it deviates from this scaling by rather saturating.

  14. Livermore pool-type reactor

    International Nuclear Information System (INIS)

    Mann, L.G.

    1977-01-01

    The Livermore Pool-Type Reactor (LPTR) has served a dual purpose since 1958--as an instrument for fundamental research and as a tool for measurement and calibration. Our early efforts centered on neutron-diffraction, fission, and capture gamma-ray studies. During the 1960's it was used for extensive calibration work associated with radiochemical and physical measurements on nuclear-explosive tests. Since 1970 the principal applications have been for trace-element measurements and radiation-damage studies. Today's research program is dominated by radiochemical studies of the shorter-lived fission products and by research on the mechanisms of radiation damage. Trace-element measurement for the National Uranium Resource Evaluation (NURE) program is the major measurement application today

  15. Radioisotope Power System Pool Concept

    Science.gov (United States)

    Rusick, Jeffrey J.; Bolotin, Gary S.

    2015-01-01

    Advanced Radioisotope Power Systems (RPS) for NASA deep space science missions have historically used static thermoelectric-based designs because they are highly reliable, and their radioisotope heat sources can be passively cooled throughout the mission life cycle. Recently, a significant effort to develop a dynamic RPS, the Advanced Stirling Radioisotope Generator (ASRG), was conducted by NASA and the Department of Energy, because Stirling based designs offer energy conversion efficiencies four times higher than heritage thermoelectric designs; and the efficiency would proportionately reduce the amount of radioisotope fuel needed for the same power output. However, the long term reliability of a Stirling based design is a concern compared to thermoelectric designs, because for certain Stirling system architectures the radioisotope heat sources must be actively cooled via the dynamic operation of Stirling converters throughout the mission life cycle. To address this reliability concern, a new dynamic Stirling cycle RPS architecture is proposed called the RPS Pool Concept.

  16. Ultrasound imaging beyond the vasculature with new generation contrast agents.

    Science.gov (United States)

    Perera, Reshani H; Hernandez, Christopher; Zhou, Haoyan; Kota, Pavan; Burke, Alan; Exner, Agata A

    2015-01-01

    Current commercially available ultrasound contrast agents are gas-filled, lipid- or protein-stabilized microbubbles larger than 1 µm in diameter. Because the signal generated by these agents is highly dependent on their size, small yet highly echogenic particles have been historically difficult to produce. This has limited the molecular imaging applications of ultrasound to the blood pool. In the area of cancer imaging, microbubble applications have been constrained to imaging molecular signatures of tumor vasculature and drug delivery enabled by ultrasound-modulated bubble destruction. Recently, with the rise of sophisticated advancements in nanomedicine, ultrasound contrast agents, which are an order of magnitude smaller (100-500 nm) than their currently utilized counterparts, have been undergoing rapid development. These agents are poised to greatly expand the capabilities of ultrasound in the field of targeted cancer detection and therapy by taking advantage of the enhanced permeability and retention phenomenon of many tumors and can extravasate beyond the leaky tumor vasculature. Agent extravasation facilitates highly sensitive detection of cell surface or microenvironment biomarkers, which could advance early cancer detection. Likewise, when combined with appropriate therapeutic agents and ultrasound-mediated deployment on demand, directly at the tumor site, these nanoparticles have been shown to contribute to improved therapeutic outcomes. Ultrasound's safety profile, broad accessibility and relatively low cost make it an ideal modality for the changing face of healthcare today. Aided by the multifaceted nano-sized contrast agents and targeted theranostic moieties described herein, ultrasound can considerably broaden its reach in future applications focused on the diagnosis and staging of cancer. © 2015 Wiley Periodicals, Inc.

  17. From antidunes to step-pools

    Science.gov (United States)

    Recking, Alain; Leduc, Pauline

    2014-05-01

    Step-pools are bed morphologies that are typical in high-gradient streams , recognizable by a staircase-like longitudinal profile resulting from accumulation of cobbles and boulders that are transverse to the channel and alternating with pools containing finer sediments. Within the last two decades step-pools have been the subject of increased efforts to characterize their nature; however their origin is still in debate. Researchers have very soon suspected step-pools to be the residual form of antidunes produced during flooding, but this hypothesis was continuously contested. Other theories has been proposed, considering, that step-pool profile develops a maximum flow resistance, or that pools geometry is controlled by the energy of a falling jet, or that steps form by boulders accumulation in a channel-spanning manner. All these theories gave very satisfying results when compared with experimental data, but does it mean that the antidune theory should we abandoned? We performed new flume experiments on steep slopes to investigate the antidune origin for step-pools. Our experiments showed that step-pools can have several origins, depending on the flow conditions and sediment mixture used. In some circumstances antidunes were well observed but did not produce stable step-pools morphology. In many occasions, step-pools obtained in the flume were isolated step-pools, with no real apparent periodicity. Only a few flow and sediment conditions allowed us to reproduce trains of antidunes which stabilized at the flow recession to produce stable periodical step-pools. These conditions are presented and discussed.

  18. Pooling, meta-analysis, and the evaluation of drug safety

    Directory of Open Access Journals (Sweden)

    Leizorovicz Alain

    2002-03-01

    Full Text Available Abstract Background The "integrated safety report" of the drug registration files submitted to health authorities usually summarizes the rates of adverse events observed for a new drug, placebo or active control drugs by pooling the safety data across the trials. Pooling consists of adding the numbers of events observed in a given treatment group across the trials and dividing the results by the total number of patients included in this group. Because it considers treatment groups rather than studies, pooling ignores validity of the comparisons and is subject to a particular kind of bias, termed "Simpson's paradox." In contrast, meta-analysis and other stratified analyses are less susceptible to bias. Methods We use a hypothetical, but not atypical, application to demonstrate that the results of a meta-analysis can differ greatly from those obtained by pooling the same data. In our hypothetical model, a new drug is compared to 1 a placebo in 4 relatively small trials in patients at high risk for a certain adverse event and 2 an active reference drug in 2 larger trials of patients at low risk for this event. Results Using meta-analysis, the relative risk of experiencing the adverse event with the new drug was 1.78 (95% confidence interval [1.02; 3.12] compared to placebo and 2.20 [0.76; 6.32] compared to active control. By pooling the data, the results were, respectively, 1.00 [0.59; 1.70] and 5.20 [2.07; 13.08]. Conclusions Because these findings could mislead health authorities and doctors, regulatory agencies should require meta-analyses or stratified analyses of safety data in drug registration files.

  19. 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

  20. 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....

  1. 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....

  2. 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....

  3. Oxidation kinetics of corium pool

    International Nuclear Information System (INIS)

    Sulatsky, A.A.; Smirnov, S.A.; Granovsky, V.S.; Khabensky, V.B.; Krushinov, E.V.; Vitol, S.A.; Kotova, S.Yu.; Fischer, M.; Hellmann, S.; Tromm, W.; Miassoedov, A.; Bottomley, D.; Piluso, P.; Barrachin, M.

    2013-01-01

    Highlights: • The analysis of experimental data on molten corium oxidation was been carried out. • The analysis has revealed the main factors influencing the oxidation kinetics. • The analysis was used for developing a qualitative analytical model. • The numerical modeling has confirmed the results of experimental data analysis. -- Abstract: Experimental, theoretical and numerical studies of oxidation kinetics of an open surface corium pool have been reported. The experiments have been carried out within OECD MASCA program and ISTC METCOR, METCOR-P and EVAN projects. It has been shown that the melt oxidation is controlled by an oxidant supply to the melt free surface from the atmosphere, not by the reducer supply from the melt. The project experiments have not detected any input of the zirconium oxidation kinetics into the process chemistry. The completed analysis puts forward a simple analytical model, which gives an explanation of the main features of melt oxidation process. The numerical modeling results are in good agreement with experimental data and theoretical considerations

  4. Blood Types

    Science.gov (United States)

    ... Drive Home Types of Blood Donations Blood Types Blood Types Not all blood is alike. There are eight ... African descent. Learn More About Blood and Diversity Blood Types and Transfusion There are very specific ways in ...

  5. 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.

  6. Measurement of blood flow in the superior sagittal sinus in healthy volunteers, and in patients with normal pressure hydrocephalus and idiopathic intracranial hypertension with phase-contrast cine MR imaging

    DEFF Research Database (Denmark)

    Gideon, P; Thomsen, C; Gjerris, F

    1996-01-01

    PURPOSE: To measure blood flow and velocity in the superior sagittal ++sinus. MATERIAL AND METHODS: MR velocity mapping was used to examine 14 healthy volunteers, 15 patients with normal pressure hydrocephalus (NPH), 3 patients with high pressure hydrocephalus (HPH), and 11 patients with idiopath...

  7. 21 CFR 1250.89 - Swimming pools.

    Science.gov (United States)

    2010-04-01

    ... equipped so as to provide complete circulation, replacement, and filtration of the water in the pool every six hours or less. Suitable means of chlorination and, if necessary, other treatment of the water shall be provided to maintain the residual chlorine in the pool water at not less than 0.4 part per...

  8. Blood meal and blood products detection using Synchronous fluorescence spectroscopy

    OpenAIRE

    Lecrenier, Marie-Caroline; Abbas, Ouissam; Taira, Aurélien; Arnould, Quentin; Baeten, Vincent

    2016-01-01

    In Europe, ruminant processed animal proteins (PAPs) and blood products are not allowed to be used in feed for farmed animal. In contrast, blood meal and blood products of porcine origin are both authorised in aqua feed, whereas only porcine blood products are allowed to be used in feed intended for other non-ruminants. Besides official methods (light microscopy and PCR), complementary methods are developed in order to refine the by-products identification. By-products derived from blood ...

  9. Ripples in a superconducting tidal pool

    CERN Document Server

    Hudson, E

    2003-01-01

    The behaviour of electrons in a metal is often compared to that of water in a pool. An empty pool is like a material that has all of its electrons removed. As electrons are 'poured' into the metal, they first occupy the lowest energies available - the bottom of the pool - and eventually fill up to the Fermi energy, the top of the pool. At this point we no longer discuss electrons but quasiparticles. These are electrons that have modified properties due to their interactions within the material. Waves in a pool can be excited, and their properties will depend on the depth of the water. Similarly in a metal, quasiparticles behave like waves that have a material-dependent dispersion relation between their energy and their wavevector, which specifies their direction and wavelength. This simple analogy also hints at an indirect method of measuring the dispersion relation of a metal, and hence the myriad of properties that depend on it. (U.K.)

  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. 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....

  12. Pool scrubbing models for iodine components

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, K. [Battelle Ingenieurtechnik GmbH, Eschborn (Germany)

    1996-12-01

    Pool scrubbing is an important mechanism to retain radioactive fission products from being carried into the containment atmosphere or into the secondary piping system. A number of models and computer codes has been developed to predict the retention of aerosols and fission product vapours that are released from the core and injected into water pools of BWR and PWR type reactors during severe accidents. Important codes in this field are BUSCA, SPARC and SUPRA. The present paper summarizes the models for scrubbing of gaseous Iodine components in these codes, discusses the experimental validation, and gives an assessment of the state of knowledge reached and the open questions which persist. The retention of gaseous Iodine components is modelled by the various codes in a very heterogeneous manner. Differences show up in the chemical species considered, the treatment of mass transfer boundary layers on the gaseous and liquid sides, the gas-liquid interface geometry, calculation of equilibrium concentrations and numerical procedures. Especially important is the determination of the pool water pH value. This value is affected by basic aerosols deposited in the water, e.g. Cesium and Rubidium compounds. A consistent model requires a mass balance of these compounds in the pool, thus effectively coupling the pool scrubbing phenomena of aerosols and gaseous Iodine species. Since the water pool conditions are also affected by drainage flow of condensate water from different regions in the containment, and desorption of dissolved gases on the pool surface is determined by the gas concentrations above the pool, some basic limitations of specialized pool scrubbing codes are given. The paper draws conclusions about the necessity of coupling between containment thermal-hydraulics and pool scrubbing models, and proposes ways of further simulation model development in order to improve source term predictions. (author) 2 tabs., refs.

  13. Pool scrubbing models for iodine components

    International Nuclear Information System (INIS)

    Fischer, K.

    1996-01-01

    Pool scrubbing is an important mechanism to retain radioactive fission products from being carried into the containment atmosphere or into the secondary piping system. A number of models and computer codes has been developed to predict the retention of aerosols and fission product vapours that are released from the core and injected into water pools of BWR and PWR type reactors during severe accidents. Important codes in this field are BUSCA, SPARC and SUPRA. The present paper summarizes the models for scrubbing of gaseous Iodine components in these codes, discusses the experimental validation, and gives an assessment of the state of knowledge reached and the open questions which persist. The retention of gaseous Iodine components is modelled by the various codes in a very heterogeneous manner. Differences show up in the chemical species considered, the treatment of mass transfer boundary layers on the gaseous and liquid sides, the gas-liquid interface geometry, calculation of equilibrium concentrations and numerical procedures. Especially important is the determination of the pool water pH value. This value is affected by basic aerosols deposited in the water, e.g. Cesium and Rubidium compounds. A consistent model requires a mass balance of these compounds in the pool, thus effectively coupling the pool scrubbing phenomena of aerosols and gaseous Iodine species. Since the water pool conditions are also affected by drainage flow of condensate water from different regions in the containment, and desorption of dissolved gases on the pool surface is determined by the gas concentrations above the pool, some basic limitations of specialized pool scrubbing codes are given. The paper draws conclusions about the necessity of coupling between containment thermal-hydraulics and pool scrubbing models, and proposes ways of further simulation model development in order to improve source term predictions. (author) 2 tabs., refs

  14. Nanoparticles in magnetic resonance imaging: from simple to dual contrast agents

    Directory of Open Access Journals (Sweden)

    Estelrich J

    2015-03-01

    Full Text Available Joan Estelrich,1,2 María Jesús Sánchez-Martín,1 Maria Antònia Busquets1,2 1Departament de Fisicoquímica, Facultat de Farmàcia, Universitat de Barcelona, Barcelona, Catalonia, Spain; 2Institut de Nanociència I Nanotecnologia (IN2UB, Barcelona, Catalonia, SpainAbstract: Magnetic resonance imaging (MRI has become one of the most widely used and powerful tools for noninvasive clinical diagnosis owing to its high degree of soft tissue contrast, spatial resolution, and depth of penetration. MRI signal intensity is related to the relaxation times (T1, spin–lattice relaxation and T2, spin–spin relaxation of in vivo water protons. To increase contrast, various inorganic nanoparticles and complexes (the so-called contrast agents are administered prior to the scanning. Shortening T1 and T2 increases the corresponding relaxation rates, 1/T1 and 1/T2, producing hyperintense and hypointense signals respectively in shorter times. Moreover, the signal-to-noise ratio can be improved with the acquisition of a large number of measurements. The contrast agents used are generally based on either iron oxide nanoparticles or ferrites, providing negative contrast in T2-weighted images; or complexes of lanthanide metals (mostly containing gadolinium ions, providing positive contrast in T1-weighted images. Recently, lanthanide complexes have been immobilized in nanostructured materials in order to develop a new class of contrast agents with functions including blood-pool and organ (or tumor targeting. Meanwhile, to overcome the limitations of individual imaging modalities, multimodal imaging techniques have been developed. An important challenge is to design all-in-one contrast agents that can be detected by multimodal techniques. Magnetoliposomes are efficient multimodal contrast agents. They can simultaneously bear both kinds of contrast and can, furthermore, incorporate targeting ligands and chains of polyethylene glycol to enhance the accumulation of

  15. Operation and maintenance techniques of pool and pool water purification system in IMEF

    International Nuclear Information System (INIS)

    Soong, Woong Sup

    1999-03-01

    IMEF pool is used pass way between pool and hot cell in order to inlet and outlet of fuel pin in cask. All operation is performed conforming with naked eyes. Therefore floating matter is filtered so as to easy under water handling. Also radioactivity in pool water is controlled according to the nuclear law, radioactivity ration maintained less than 15mR/hr on pool side. Perfect operation and maintenance can be achieved well trained operator. Result obtained from the perfection can give more influence over restrain, spreading contamination of radioactivity materials. This report describes operation and maintenance technique of pool water purification system in IMEF. (Author). 7 refs., 13 figs

  16. [Chlorine concentrations in the air of indoor swimming pools and their effects on swimming pool workers].

    Science.gov (United States)

    Fernández-Luna, Álvaro; Burillo, Pablo; Felipe, José Luis; Gallardo, Leonor; Tamaral, Francisco Manuel

    2013-01-01

    To describe chlorine levels in the air of indoor swimming pools in Castilla-La Mancha (Spain) and relate them to other chemical parameters in the installation and to the health problems perceived by swimming pool workers. We analyzed 21 pools with chlorine as chemical treatment in Castilla-La Mancha. The iodometry method was applied to measure chlorine concentrations in the air. The concentrations of free and combined chlorine in water, pH and temperature were also evaluated. Health problems were surveyed in 230 swimming pool workers in these facilities. The mean chlorine level in the air of swimming pools was 4.3 ± 2.3mg/m(3). The pH values were within the legal limits. The temperature parameters did not comply with regulations in 17 of the 21 pools analyzed. In the pools where chlorine values in the air were above the legal regulations, a significantly higher percentage of swimming pool workers perceived eye irritation, dryness and irritation of skin, and ear problems. Chlorine values in the air of indoor swimming pools were higher than those reported in similar studies. Most of the facilities (85%) exceeded the concentration of 1.5mg/m(3) established as the limit for the risk of irritating effects. The concentration of chlorine in indoor swimming pool air has a direct effect on the self-perceived health problems of swimming pool workers. Copyright © 2012 SESPAS. Published by Elsevier Espana. All rights reserved.

  17. Spent fuel pool cleanup and stabilization

    International Nuclear Information System (INIS)

    Miller, R.L.

    1987-06-01

    Each of the plutonium production reactors at Hanford had a large water-filled spent fuel pool to provide interim storage of irradiated fuel while awaiting shipment to the separation facilities. After cessation of reactor operations the fuel was removed from the pools and the water levels were drawn down to a 5- to 10-foot depth. The pools were maintained with the water to provide shielding and radiological control. What appeared to be a straightforward project to process the water, remove the sediments from the basin, and stabilize the contamination on the floors and walls became a very complex and time consuming operation. The sediment characteristics varied from pool to pool, the ion exchange system required modification, areas of hard-pack sediments were discovered on the floors, special arrangements to handle and package high dose rate items for shipment were required, and contract problems ensued with the subcontractor. The original schedule to complete the project from preliminary engineering to final stabilization of the pools was 15 months. The actual time required was about 25 months. The original cost estimate to perform the work was $2,651,000. The actual cost of the project was $5,120,000, which included $150,000 for payment of claims to the subcontractor. This paper summarizes the experiences associated with the cleanup and radiological stabilization of the 100-B, -C, -D, and -DR spent fuel pools, and discusses a number of lessons learned items

  18. A Pool of Distant Galaxies

    Science.gov (United States)

    2008-11-01

    Anyone who has wondered what it might be like to dive into a pool of millions of distant galaxies of different shapes and colours, will enjoy the latest image released by ESO. Obtained in part with the Very Large Telescope, the image is the deepest ground-based U-band image of the Universe ever obtained. It contains more than 27 million pixels and is the result of 55 hours of observations with the VIMOS instrument. A Sea of Galaxies ESO PR Photo 39/08 A Pool of Distant Galaxies This uniquely beautiful patchwork image, with its myriad of brightly coloured galaxies, shows the Chandra Deep Field South (CDF-S), arguably the most observed and best studied region in the entire sky. The CDF-S is one of the two regions selected as part of the Great Observatories Origins Deep Survey (GOODS), an effort of the worldwide astronomical community that unites the deepest observations from ground- and space-based facilities at all wavelengths from X-ray to radio. Its primary purpose is to provide astronomers with the most sensitive census of the distant Universe to assist in their study of the formation and evolution of galaxies. The new image released by ESO combines data obtained with the VIMOS instrument in the U- and R-bands, as well as data obtained in the B-band with the Wide-Field Imager (WFI) attached to the 2.2 m MPG/ESO telescope at La Silla, in the framework of the GABODS survey. The newly released U-band image - the result of 40 hours of staring at the same region of the sky and just made ready by the GOODS team - is the deepest image ever taken from the ground in this wavelength domain. At these depths, the sky is almost completely covered by galaxies, each one, like our own galaxy, the Milky Way, home of hundreds of billions of stars. Galaxies were detected that are a billion times fainter than the unaided eye can see and over a range of colours not directly observable by the eye. This deep image has been essential to the discovery of a large number of new galaxies

  19. Blood Tests

    Science.gov (United States)

    ... your blood, as discussed in the following paragraphs. Red Blood Cells Red blood cells carry oxygen from ... leaks out, and its levels in your blood rise. For example, blood levels of troponin rise when ...

  20. The Role of Nuclear Insurance Pools

    International Nuclear Information System (INIS)

    Reitsma, S. M. S.

    2006-01-01

    Since fifty years insurers respond to the need of both governments and the electricity industry to provide financial protection to cover the perils presented by the use of nuclear energy for peaceful purposes. This paper aims at explaining what difficulties had to be solved in order to enable insurers to provide such protection, that as a solution to these difficulties Nuclear Insurance Pools were formed, how such pools operate and what security they provide. Thereby not only a number of universal principles underlying nuclear pool insurance will be explained, but also some differences in the characteristics of such insurance per group of countries. (author)

  1. Laser surveillance systems for fuel storage pools

    International Nuclear Information System (INIS)

    Boeck, H.

    1985-06-01

    A Laser Surveillance System (LASSY) as a new safeguards device has been developed under the IAEA research contract No. 3458/RB at the Atominstitut Wien using earlier results by S. Fiarman. This system is designed to act as a sheet of light covering spent fuel assemblies in spent fuel storage pools. When movement of assemblies takes place, LASSY detects and locates the position of the movement in the pool and when interrogated, presents a list of pool positions and times of movement to the safeguards inspector. A complete prototype system was developed and built. Full scale tests showed the principal working capabilities of a LASSY underwater

  2. 10 CFR 36.63 - Pool water purity.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Pool water purity. 36.63 Section 36.63 Energy NUCLEAR... § 36.63 Pool water purity. (a) Pool water purification system must be run sufficiently to maintain the conductivity of the pool water below 20 microsiemens per centimeter under normal circumstances. If pool water...

  3. 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).

  4. 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.

  5. Ontogeny of the granulocyte/macrophage progenitor cell (GM-CFC) pools in the beagle.

    Science.gov (United States)

    Nothdurft, W; Braasch, E; Calvo, W; Prümmer, O; Carbonell, F; Grilli, G; Fliedner, T M

    1984-04-01

    The pattern of development of the granulocyte/macrophage progenitor cell (GM-CFC) pools in the course of canine ontogeny was studied by means of the agar culture technique. Colony formation was stimulated by colony stimulating activity (CSA) in serum from lethally irradiated dogs in combination with erythrocyte-depleted peripheral blood leukocytes from normal adult dogs. The colonies thus obtained in cultures from the different organs were in general large (estimated maximum 50 000 cells) and consisted predominantly of mononucleated macrophages, suggesting that, in these studies, a progenitor cell with high proliferative potential (HPP-CFC) has been monitored. In the yolk sac, a transitory GM-CFC pool became established between day 23 and day 48 of gestation, reaching maximum numbers of approximately 41 X 10(3) per organ on days 36/37. At the same time the GM-CFC concentration in blood collected from the heart also reached a maximum of about 31 X 10(3)/ml, indicating its carrier function for the migration of GM-CFC. In the liver a quasi-exponential increase in the GM-CFC numbers took place between days 36/37 and days 57 to 59 when a total of about 15.2 X 10(6) was found but thereafter and up to day 4 post partum the GM-CFC numbers decreased by almost two orders of magnitude. A continuous increase in the GM-CFC numbers was found in the spleen between day 42 of gestation and day 4 post partum when a maximum of 5.1 X 10(6) to 8.7 X 10(6) was reached. In contrast to the GM-CFC numbers in the liver, the splenic GM-CFC dropped only by 50% of peak values when the dogs reached adulthood. The bone marrow always had the highest incidence of GM-CFC, the concentration per 10(6) cells being 18.7 X 10(3)/10(6) cells on days 45/46, the earliest time point at which cultures could be set up. The absolute GM-CFC numbers in the two femora increased continuously between days 45/46 and day 4 post partum in parallel with the growth of the bones. In the thymus a relatively small

  6. Southeastern superpave center pooled-fund activities.

    Science.gov (United States)

    2010-02-01

    Much has been learned about materials characteristics, testing procedures, new equipment, mix design, and pavement performance through the many studies conducted as a part of the Southeastern Superpave Center (SSC) pooled-fund program. Lessons learne...

  7. Strategies for chemically healthy public swimming pools

    DEFF Research Database (Denmark)

    Hansen, Kamilla Marie Speht

    Swimming pools are used around the world for recreational, rehabilitation and physical activity and therefore it is imperative that the water and air quality are safe for the health of the bathers. Chlorination is by far the most widely applied method to control pool water quality and to prevent...... spreading of pathogens between swimmers because of its residual disinfection effect. In addition to potential contamination of pathogenic microorganisms, swimming pool water is polluted by organic matter deposited from the bathers such as saliva, urine, sweat, hair and personal care products. Since chlorine...... is a strong oxidant it oxidizes the organic matter in the pool water and forms disinfection byproducts (DBPs). More than 100 different DBPs have been identified. Some of these have been found to be genotoxic and may pose an increased cancer risk for the bathers. The aim of this thesis was to give an overview...

  8. AE/VCE Unconfirmed Vernal Pools

    Data.gov (United States)

    Vermont Center for Geographic Information — This dataset is derived from a project by the Vermont Center for Ecostudies(VCE) and Arrowwood Environmental(AE) to map vernal pools throughout the state of Vermont....

  9. Nuclear Insurance Pools: Worldwide Practice and Development

    International Nuclear Information System (INIS)

    Reitsma, S. M. S.

    1998-01-01

    The development of nuclear installations to produce electricity led to the establishment of Nuclear Insurance Pools and the introduction of international Conventions on Third Party Liability. Nuclear Pools offer both Third Party Liability insurance, reflecting the Conventions' principles, and other insurance products. They are market-wide, providing a facility for participation by insurers who could not otherwise write the insurance for the particularly sensitive nuclear risk. All acceptances are for the net retention of each Member without recourse to individual reinsurance protection. Common account reinsurance is arranged with other Nuclear Pools all over the world. Thus, a transparency is created, which ensures the highest degree of reinsurance security and imposes a known finite limit to each participating insurer's commitment. Therefore, Pool-members are prepared to make a greater commitment to nuclear risks than would be case where they felt uncertain as regards their total exposure following a significant loss. (author)

  10. 7 CFR 1131.7 - Pool plant.

    Science.gov (United States)

    2010-01-01

    ... supply plant's shipments in computing the plant's shipping percentage. (d) A plant located within the... order in this part, or the plant has automatic pooling status under the other Federal order; and (7...

  11. 7 CFR 1126.7 - Pool plant.

    Science.gov (United States)

    2010-01-01

    ... excluded from the supply plant's shipments in computing the plant's shipping percentage. (d) A plant... part, or the plant has automatic pooling status under the other Federal order; and (7) That portion of...

  12. 7 CFR 1001.7 - Pool plant.

    Science.gov (United States)

    2010-01-01

    ... excluded from the supply plant's shipments in computing the percentages in paragraphs (c)(1) and (2) of... plant has automatic pooling status under the other Federal order. [64 FR 47954, Sept. 1, 1999, as...

  13. 7 CFR 1007.7 - Pool plant.

    Science.gov (United States)

    2010-01-01

    ...-upon use other than Class I shall be excluded from the supply plant's shipments in computing the plant... under the order in this part, or such plant has automatic pooling status under such other order. (h) Any...

  14. 7 CFR 1006.7 - Pool plant.

    Science.gov (United States)

    2010-01-01

    ...-upon use other than Class I shall be excluded from the supply plant's shipments in computing the plant... under the order in this part, or such plant has automatic pooling status under such other order. (h) Any...

  15. Ingestion of swimming pool water by recreational

    Data.gov (United States)

    U.S. Environmental Protection Agency — Swimming pool water ingestion data. This dataset is associated with the following publication: Dufour, A., L. Wymer, M. Magnuson, T. Behymer, and R. Cantu. Ingestion...

  16. Microbial quality of a marine tidal pool

    CSIR Research Space (South Africa)

    Genthe, Bettina

    1995-01-01

    Full Text Available In this study the source of microbial pollution to a tidal pool was investigated. Both adjacent seawater which could contribute to possible faecal pollution and potential direct bather pollution were studied. The microbial quality of the marine...

  17. The Nuclear Insurance Pools: Operations and Covers

    International Nuclear Information System (INIS)

    Tetley, M.

    2008-01-01

    Nuclear insurance pools have provided insurance for the nuclear industry for over fifty years and it is fair to say that the development of civil nuclear power would not have been possible without the support of the commercial insurance market. The unknown risks presented by the nascent nuclear power industry in the 1950s required a leap of faith by insurers who developed specialist pooled insurance capacity to ensure adequate capacity to back up the operators' compensation obligations. Since then, nuclear insurance pools have evolved to become comprehensive suppliers of most types of insurance for nuclear plant globally. This paper will outline the structure, development, products and current operations of nuclear insurance pools.(author)

  18. Robotic cleaning of a spent fuel pool

    International Nuclear Information System (INIS)

    Roman, H.T.; Marian, F.A.; Silverman, E.B.; Barkley, V.P.

    1987-01-01

    Spent fuel pools at nuclear power plants are not cleaned routinely, other than by purifying the water that they contain. Yet, debris can collect on the bottom of a pool and should be removed prior to fuel transfer. At Public Service Electric and Gas Company's Hope Creek Nuclear Power Plant, a submersible mobile robot - ARD Corporation's SCAVENGER - was used to clean the bottom of the spent fuel pool prior to initial fuel loading. The robotic device was operated remotely (as opposed to autonomously) with a simple forward/reverse control, and it cleaned 70-80% of the pool bottom. This paper reports that a simple cost-benefit analysis shows that the robotic device would be less expensive, on a per mission basis, than other cleaning alternatives, especially if it were used for other similar cleaning operations throughout the plant

  19. Virulent Naegleria fowleri in indoor swimming pool.

    Science.gov (United States)

    Kadlec, V; Skvárová, J; Cerva, L; Nebáznivá, D

    1980-01-01

    Naegleria fowleri was isolated from water during a hygienic inspection of a swimming pool in December 1977. This swimming pool was identified as a source of the infectious agent in the years 1962-1965, when a large outbreak of primary amoebic meningoencephalitis (PAME) occurred. First two strains of N. fowleri, pathogenic for white mice after intracerebral and intranasal inoculation, were isolated from water of outlet troughs, additional strains were then isolated from various places; particularly from a cavity in the damaged wall of the pool. The incubation temperature did not inhibit a simultaneous growth of amoebae of the genera Acanthamoeba, Flabellula, Hartmannella and Vahlkampfia in the primocultures. Epidemiological investigations did not reveal any new case of PAME in relation with the occurrence of pathogenic N. fowleri in the swimming pool.

  20. A quantitative high resolution voxel-wise assessment of myocardial blood flow from contrast-enhanced first-pass magnetic resonance perfusion imaging: microsphere validation in a magnetic resonance compatible free beating explanted pig heart model.

    Science.gov (United States)

    Schuster, Andreas; Sinclair, Matthew; Zarinabad, Niloufar; Ishida, Masaki; van den Wijngaard, Jeroen P H M; Paul, Matthias; van Horssen, Pepijn; Hussain, Shazia T; Perera, Divaka; Schaeffter, Tobias; Spaan, Jos A E; Siebes, Maria; Nagel, Eike; Chiribiri, Amedeo

    2015-10-01

    To assess the feasibility of high-resolution quantitative cardiovascular magnetic resonance (CMR) voxel-wise perfusion imaging using clinical 1.5 and 3 T sequences and to validate it using fluorescently labelled microspheres in combination with a state of the art imaging cryomicrotome in a novel, isolated blood-perfused MR-compatible free beating pig heart model without respiratory motion. MR perfusion imaging was performed in pig hearts at 1.5 (n = 4) and 3 T (n = 4). Images were acquired at physiological flow ('rest'), reduced flow ('ischaemia'), and during adenosine-induced hyperaemia ('stress') in control and coronary occlusion conditions. Fluorescently labelled microspheres and known coronary myocardial blood flow represented the reference standards for quantitative perfusion validation. For the comparison with microspheres, the LV was divided into 48 segments based on a subdivision of the 16 AHA segments into subendocardial, midmyocardial, and subepicardial subsegments. Perfusion quantification of the time-signal intensity curves was performed using a Fermi function deconvolution. High-resolution quantitative voxel-wise perfusion assessment was able to distinguish between occluded and remote myocardium (P < 0.001) and between rest, ischaemia, and stress perfusion conditions at 1.5 T (P < 0.001) and at 3 T (P < 0.001). CMR-MBF estimates correlated well with the microspheres at the AHA segmental level at 1.5 T (r = 0.94, P < 0.001) and at 3 T (r = 0.96, P < 0.001) and at the subendocardial, midmyocardial, and subepicardial level at 1.5 T (r = 0.93, r = 0.9, r = 0.88, P < 0.001, respectively) and at 3 T (r = 0.91, r = 0.95, r = 0.84, P < 0.001, respectively). CMR-derived voxel-wise quantitative blood flow assessment is feasible and very accurate compared with microspheres. This technique is suitable for both clinically used field strengths and may provide the tools to assess extent and severity of myocardial ischaemia. Published on behalf of the European Society

  1. Delayed contrast enhancement imaging of a murine model for ischemia reperfusion with carbon nanotube micro-CT.

    Directory of Open Access Journals (Sweden)

    Laurel M Burk

    Full Text Available We aim to demonstrate the application of free-breathing prospectively gated carbon nanotube (CNT micro-CT by evaluating a myocardial infarction model with a delayed contrast enhancement technique. Evaluation of murine cardiac models using micro-CT imaging has historically been limited by extreme imaging requirements. Newly-developed CNT-based x-ray sources offer precise temporal resolution, allowing elimination of physiological motion through prospective gating. Using free-breathing, cardiac-gated CNT micro-CT, a myocardial infarction model can be studied non-invasively and with high resolution. Myocardial infarction was induced in eight male C57BL/6 mice aged 8-12 weeks. The ischemia reperfusion model was achieved by surgically occluding the LAD artery for 30 minutes followed by 24 hours of reperfusion. Tail vein catheters were placed for contrast administration. Iohexol 300 mgI/mL was administered followed by images obtained in diastole. Iodinated lipid blood pool contrast agent was then administered, followed with images at systole and diastole. Respiratory and cardiac signals were monitored externally and used to gate the scans of free-breathing subjects. Seven control animals were scanned using the same imaging protocol. After imaging, the heart was harvested, cut into 1mm slices and stained with TTC. Post-processing analysis was performed using ITK-Snap and MATLAB. All animals demonstrated obvious delayed contrast enhancement in the left ventricular wall following the Iohexol injection. The blood pool contrast agent revealed significant changes in cardiac function quantified by 3-D volume ejection fractions. All subjects demonstrated areas of myocardial infarct in the LAD distribution on both TTC staining and micro-CT imaging. The CNT micro-CT system aids straightforward, free-breathing, prospectively-gated 3-D murine cardiac imaging. Delayed contrast enhancement allows identification of infarcted myocardium after a myocardial ischemic

  2. How to map your industry's profit pool.

    Science.gov (United States)

    Gadiesh, O; Gilbert, J L

    1998-01-01

    Many managers chart strategy without a full understanding of the sources and distribution of profits in their industry. Sometimes they focus their sights on revenues instead of profits, mistakenly assuming that revenue growth will eventually translate into profit growth. In other cases, they simply lack the data or the analytical tools required to isolate and measure variations in profitability. In this Manager's Tool Kit, the authors present a way to think clearly about where the money's being made in any industry. They describe a framework for analyzing how profits are distributed among the activities that form an industry's value chain. Such an analysis can provide a company's managers with a rich understanding of their industry's profit structure--what the authors call its profit pool--enabling them to identify which activities are generating disproportionately large or small shares of profits. Even more important, a profit-pool map opens a window onto the underlying structure of the industry, helping managers see the various forces that are determining the distribution of profits. As such, a profit-pool map provides a solid basis for strategic thinking. Mapping a profit pool involves four steps: defining the boundaries of the pool, estimating the pool's overall size, estimating the size of each value-chain activity in the pool, and checking and reconciling the calculations. The authors briefly describe each step and then apply the process by providing a detailed example of a hypothetical retail bank. They conclude by looking at ways of organizing the data in chart form as a first step toward plotting a profit-pool strategy.

  3. Pooling strategies for St Petersburg gamblers

    OpenAIRE

    Csörgö, Sandor; Simons, Gordon

    2006-01-01

    Peter offers to play exactly one St Petersburg game with each of [math] players, Paul [math] , [math] , Paul [math] , whose conceivable pooling strategies are described by all possible probability distributions [math] . Comparing infinite expectations, we characterize among all [math] those admissible strategies for which the pooled winnings, each distributed as [math] , yield a finite added value for each and every one of Paul [math] , [math] , Paul [math] in comparison with their individual...

  4. Welding pool measurement using thermal array sensor

    Science.gov (United States)

    Cho, Chia-Hung; Hsieh, Yi-Chen; Chen, Hsin-Yi

    2015-08-01

    Selective laser melting (SLM) is an additive manufacturing (AM) technology that uses a high-power laser beam to melt metal powder in chamber of inert gas. The process starts by slicing the 3D CAD data as a digital information source into layers to create a 2D image of each layer. Melting pool was formed by using laser irradiation on metal powders which then solidified to consolidated structure. In a selective laser melting process, the variation of melt pool affects the yield of a printed three-dimensional product. For three dimensional parts, the border conditions of the conductive heat transport have a very large influence on the melt pool dimensions. Therefore, melting pool is an important behavior that affects the final quality of the 3D object. To meet the temperature and geometry of the melting pool for monitoring in additive manufacturing technology. In this paper, we proposed the temperature sensing system which is composed of infrared photodiode, high speed camera, band-pass filter, dichroic beam splitter and focus lens. Since the infrared photodiode and high speed camera look at the process through the 2D galvanometer scanner and f-theta lens, the temperature sensing system can be used to observe the melting pool at any time, regardless of the movement of the laser spot. In order to obtain a wide temperature detecting range, 500 °C to 2500 °C, the radiation from the melting pool to be measured is filtered into a plurality of radiation portions, and since the intensity ratio distribution of the radiation portions is calculated by using black-body radiation. The experimental result shows that the system is suitable for melting pool to measure temperature.

  5. An international pooled analysis for obtaining a benchmark dose for environmental lead exposure in children

    DEFF Research Database (Denmark)

    Budtz-Jørgensen, Esben; Bellinger, David; Lanphear, Bruce

    2013-01-01

    Lead is a recognized neurotoxicant, but estimating effects at the lowest measurable levels is difficult. An international pooled analysis of data from seven cohort studies reported an inverse and supra-linear relationship between blood lead concentrations and IQ scores in children. The lack...

  6. 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, ...

  7. 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 ...

  8. 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....

  9. Aging management of nuclear fuel pool structures

    International Nuclear Information System (INIS)

    Hookham, C.J.

    1991-01-01

    The long-term operations of a nuclear power plant (NPP) are currently impacted by the utility's capabilities with respect to spent fuel storage. Available options for the safe, long-term storage of spent fuel are quite limited; as such, maximized usage of existing on-site storage capacity (NPP) is quite important. The service life of existing fuel pool structures may be determined by a number of operations or age-related events. Management of these events is often critical to the structure's integrity and durability. From an operations vantage point, aging management relates to such characteristics as storage capacity, performance of pool water treatment systems, and physical liner damage. Primary issues related to structural integrity include materials degradation and environmental enclosure factors. The development of an effective aging management program should address both operational and structural issues. The goal of this paper is to provide recommendations for pool structure aging management, with benefits to both short and long-term, or extended life, operations. Because of their critical nature, the report will focus on spent fuel pools. Many of the concepts generated in this report may also be applied to other NPP pool structures (i.e., new fuel pools, reactor internals pits and transfer canals) because of similar physical/environmental effects

  10. Numerical modelling of methanol liquid pool fires

    Science.gov (United States)

    Prasad, Kuldeep; Li, Chiping; Kailasanath, K.; Ndubizu, Chuka; Ananth, Ramagopal; Tatem, P. A.

    1999-12-01

    The focus of this paper is on numerical modelling of methanol liquid pool fires. A mathematical model is first developed to describe the evaporation and burning of a two-dimensional or axisymmetric pool containing pure liquid methanol. Then, the complete set of unsteady, compressible Navier-Stokes equations for reactive flows are solved in the gas phase to describe the convection of the fuel gases away from the pool surface, diffusion of the gases into the surrounding air and the oxidation of the fuel into product species. Heat transfer into the liquid pool and the metal container through conduction, convection and radiation are modelled by solving a modified form of the energy equation. Clausius-Clapeyron relationships are invoked to model the evaporation rate of a two-dimensional pool of pure liquid methanol. The governing equations along with appropriate boundary and interface conditions are solved using the flux-corrected transport algorithm. Numerical results exhibit a flame structure that compares well with experimental observations. Temperature profiles and burning rates were found to compare favourably with experimental data from single- and three-compartment laboratory burners. The model predicts a puffing frequency of approximately 12 Hz for a 1 cm diameter methanol pool in the absence of any air co-flow. It is also observed that increasing the air co-flow velocity helps in stabilizing the diffusion flame, by pushing the vortical structures away from the flame region.

  11. 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...

  12. Convective heat transfer correlations for molten core debris pools growing in concrete

    International Nuclear Information System (INIS)

    Felde, D.K.; Kim, H.S.; Abdel-Khalik, S.I.

    1980-01-01

    A volumetrically-heated pool with gas injection at the boundaries is used to simulate the heat transfer processes taking place in molten core debris-concrete systems. Measurements of the upward, downward, and sideward heat transfer rates at the pool boundaries have been made over wide ranges of power density, superficial gas velocity, and pool aspect ratio. Pools with either a free upper surface or an isothermal solid upper boundary to simulate an overlaying solid crust of oxides have been examined. Detailed measurements of the temperature distribution within the pool have also been made. A total of nearly 400 experiments, generalized correlations for the downward and sideward Nusselt numbers have been developed. The results indicate that the Nusselt numbers are nearly independent of the internal Rayleigh number and depend only on the nondimensional quantity (pV 3 /μg) where V is the superficial gas velocity, p is the pool density, μ is the viscosity, and g is the gravitational acceleration. The results also indicate that the downward and sideward Nusselt numbers in pools with gas release at the boundaries are comparable. This result is in contrast to the natural convection case where the sideward Nusselt numbers are significantly higher than those in the downward direction. The correlations developed in this investigation cover a wide range of the relevant nondimensional quantity (5 x 10 -10 3 /μg) -3 ). They can be used to determine the heat transfer rates at the pool boundaries, and hence, the pool growth rate into the concrete. Such information is necessary since it constitutes the last line of defence against violation of the containment. (orig.)

  13. Spatially pooled contrast responses predict neural and perceptual similarity of naturalistic image categories

    NARCIS (Netherlands)

    Groen, I.I.A.; Ghebreab, S.; Lamme, V.A.F.; Scholte, H.S.

    2012-01-01

    The visual world is complex and continuously changing. Yet, our brain transforms patterns of light falling on our retina into a coherent percept within a few hundred milliseconds. Possibly, low-level neural responses already carry substantial information to facilitate rapid characterization of the

  14. Swimming pool use and birth defect risk.

    Science.gov (United States)

    Agopian, A J; Lupo, Philip J; Canfield, Mark A; Mitchell, Laura E

    2013-09-01

    Swimming during pregnancy is recommended. However, the use of swimming pools is also associated with infection by water-borne pathogens and exposure to water disinfection byproducts, which are 2 mechanisms that are suspected to increase risk for birth defects. Thus, we evaluated the relationship between maternal swimming pool use during early pregnancy and risk for select birth defects in offspring. Data were evaluated for nonsyndromic cases with 1 of 16 types of birth defects (n = 191-1829) and controls (n = 6826) from the National Birth Defects Prevention Study delivered during 2000-2006. Logistic regression analyses were conducted separately for each birth defect type. Separate analyses were conducted to assess any pool use (yes vs no) and frequent use (5 or more occasions in 1 month) during the month before pregnancy through the third month of pregnancy. There was no significant positive association between any or frequent pool use and any of the types of birth defects, even after adjustment for several potential confounders (maternal race/ethnicity, age at delivery, education, body mass index, folic acid use, nulliparity, smoking, annual household income, surveillance center, and season of conception). Frequent pool use was significantly negatively associated with spina bifida (adjusted odds ratio, 0.68; 95% confidence interval, 0.47-0.99). Among offspring of women 20 years old or older, pool use was associated with gastroschisis (adjusted odds ratio, 1.3; 95% confidence interval, 1.0-1.8), although not significantly so. We observed little evidence suggesting teratogenic effects of swimming pool use. Because swimming is a common and suggested form of exercise during pregnancy, these results are reassuring. Copyright © 2013 Mosby, Inc. All rights reserved.

  15. 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.

  16. 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.

  17. Blood culture

    Science.gov (United States)

    Culture - blood ... A blood sample is needed . The site where blood will be drawn is first cleaned with an antiseptic such ... organism from the skin getting into (contaminating) the blood sample and causing a false-positive result (see ...

  18. 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.

  19. Condensation in a two-phase pool

    International Nuclear Information System (INIS)

    Duffey, R.B.; Hughes, E.D.

    1991-01-01

    We consider the case of vapor condensation in a liquid pool, when the heat transfer is controlled by heat losses through the walls. The analysis is based on drift flux theory for phase separation in the pool, and determines the two-phase mixture height for the pool. To our knowledge this is the first analytical treatment of this classic problem that gives an explicit result, previous work having established the result for the evaporative case. From conservation of mass and energy in a one-dimensional steady flow, together with a void relation between the liquid and vapor fluxes, we determine the increase in the mixture level from the base level of the pool. It can be seen that the thermal and hydrodynamic influences are separable. Thus, the thermal influence of the wall heat transfer appears through its effect on the condensing length L*, so that at high condensation rates the pool is all liquid, and at low rates overflows (the level swell or foaming effect). Similarly, the phase separation effect hydrodynamically determines the height via the relative velocity of the mixture to the entering flux. We examine some practical applications of this result to level swell in condensing flows, and also examine some limits in ideal cases

  20. 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...

  1. 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)

  2. One component, volume heated, boiling pool thermohydraulics

    International Nuclear Information System (INIS)

    Bede, M.; Perret, C.; Pretrel, H.; Seiler, J.M.

    1993-01-01

    Prior work on boiling pools provided heat exchange correlations valid for bubbly flow with laminar or turbulent boundary layers. New experiments performed with water (SEBULON) and UO 2 (SCARABEE BF2) in a churn-turbulent flow configuration show unexpected heat flux distributions for which the maximum heat flux may be situated well below the pool surface. The origin of this behaviour is attributed to condensation effects, very unstable boundary layer flow and surface oscillation. A calculation model is discussed which permits to approach the experimental heat flux distribution with reasonable accuracy. (authors). 7 figs., 2 appendix., 14 refs

  3. Numerical modeling of sodium fire – Part II: Pool combustion and combined spray and pool combustion

    International Nuclear Information System (INIS)

    Sathiah, Pratap; Roelofs, Ferry

    2014-01-01

    Highlights: • A CFD based method is proposed for the simulation of sodium pool combustion. • A sodium evaporation based model is proposed to model sodium pool evaporation. • The proposed method is validated against sodium pool experiments of Newman and Payne. • The results obtained using the proposed method are in good agreement with the experiments. - Abstract: The risk of sodium-air reaction has received considerable attention after the sodium-fire accident in Monju reactor. The fires resulting from the sodium-air reaction can be detrimental to the safety of a sodium fast reactor. Therefore, predicting the consequences of a sodium fire is important from a safety point of view. A computational method based on CFD is proposed here to simulate sodium pool fire and understand its characteristics. The method solves the Favre-averaged Navier-Stokes equation and uses a non-premixed mixture fraction based combustion model. The mass transfer of sodium vapor from the pool surface to the flame is obtained using a sodium evaporation model. The proposed method is then validated against well-known sodium pool experiments of Newman and Payne. The flame temperature and location predicted by the model are in good agreement with experiments. Furthermore, the trends of the mean burning rate with initial pool temperature and oxygen concentration are captured well. Additionally, parametric studies have been performed to understand the effects of pool diameter and initial air temperature on the mean burning rate. Furthermore, the sodium spray and sodium pool combustion models are combined to simulate simultaneous spray and pool combustion. Simulations were performed to demonstrate that the combined code could be applied to simulate this. Once sufficiently validated, the present code can be used for safety evaluation of a sodium fast reactor

  4. Numerical modeling of sodium fire – Part II: Pool combustion and combined spray and pool combustion

    Energy Technology Data Exchange (ETDEWEB)

    Sathiah, Pratap, E-mail: pratap.sathiah78@gmail.com [Shell Global Solutions Ltd., Brabazon House, Concord Business Park, Threapwood Road, Manchester M220RR (United Kingdom); Roelofs, Ferry, E-mail: roelofs@nrg.eu [Nuclear Research and Consultancy Group (NRG), Westerduinweg 3, 1755ZG Petten (Netherlands)

    2014-10-15

    Highlights: • A CFD based method is proposed for the simulation of sodium pool combustion. • A sodium evaporation based model is proposed to model sodium pool evaporation. • The proposed method is validated against sodium pool experiments of Newman and Payne. • The results obtained using the proposed method are in good agreement with the experiments. - Abstract: The risk of sodium-air reaction has received considerable attention after the sodium-fire accident in Monju reactor. The fires resulting from the sodium-air reaction can be detrimental to the safety of a sodium fast reactor. Therefore, predicting the consequences of a sodium fire is important from a safety point of view. A computational method based on CFD is proposed here to simulate sodium pool fire and understand its characteristics. The method solves the Favre-averaged Navier-Stokes equation and uses a non-premixed mixture fraction based combustion model. The mass transfer of sodium vapor from the pool surface to the flame is obtained using a sodium evaporation model. The proposed method is then validated against well-known sodium pool experiments of Newman and Payne. The flame temperature and location predicted by the model are in good agreement with experiments. Furthermore, the trends of the mean burning rate with initial pool temperature and oxygen concentration are captured well. Additionally, parametric studies have been performed to understand the effects of pool diameter and initial air temperature on the mean burning rate. Furthermore, the sodium spray and sodium pool combustion models are combined to simulate simultaneous spray and pool combustion. Simulations were performed to demonstrate that the combined code could be applied to simulate this. Once sufficiently validated, the present code can be used for safety evaluation of a sodium fast reactor.

  5. Unitization of a common oil pool: Theory and evidence

    International Nuclear Information System (INIS)

    Deilami, I.

    1991-01-01

    When heterogeneous firms gain access to the same oil pool, they drill and drain the pool based on their own preferences. The anticipated result is over-capitalization and rent dissipation: the tragedy of the commons. Given the notion of rationality based upon self interest, the rational behavior of these firms might instead be to unitize, acting in a manner efficient to the group. Failure to do so can be attributed to prohibitive bargaining costs required to coordinate many firms; this is supported by studies of the oil industry in the 1930s. In contrast, if the oil industry in the 1950s to 1980s is studied, very different conclusions are reached. Today, joint operations on oil and gas are found in all phases of petroleum-production process. Why did there occur such a drastic change in the degree of success in unitization? In the early 1930s to the late 1940s, both the drilling cost of oil extraction and the price of oil were low, so the gains from unitization were not large enough to be profitable. However, by the late 1950s the real price of oil and the cost of drilling had doubled from what they were in the early 1930s. This made the loss from rent dissipation significant and forced the firms to reevaluate their noncooperative behavior

  6. 47 CFR 90.35 - Industrial/Business Pool.

    Science.gov (United States)

    2010-10-01

    ... MOBILE RADIO SERVICES Industrial/Business Radio Pool § 90.35 Industrial/Business Pool. (a) Eligibility... Industrial/Business Pool to provide commercial mobile radio service as defined in part 20 of this chapter or... 47 Telecommunication 5 2010-10-01 2010-10-01 false Industrial/Business Pool. 90.35 Section 90.35...

  7. Rank-based pooling for deep convolutional neural networks.

    Science.gov (United States)

    Shi, Zenglin; Ye, Yangdong; Wu, Yunpeng

    2016-11-01

    Pooling is a key mechanism in deep convolutional neural networks (CNNs) which helps to achieve translation invariance. Numerous studies, both empirically and theoretically, show that pooling consistently boosts the performance of the CNNs. The conventional pooling methods are operated on activation values. In this work, we alternatively propose rank-based pooling. It is derived from the observations that ranking list is invariant under changes of activation values in a pooling region, and thus rank-based pooling operation may achieve more robust performance. In addition, the reasonable usage of rank can avoid the scale problems encountered by value-based methods. The novel pooling mechanism can be regarded as an instance of weighted pooling where a weighted sum of activations is used to generate the pooling output. This pooling mechanism can also be realized as rank-based average pooling (RAP), rank-based weighted pooling (RWP) and rank-based stochastic pooling (RSP) according to different weighting strategies. As another major contribution, we present a novel criterion to analyze the discriminant ability of various pooling methods, which is heavily under-researched in machine learning and computer vision community. Experimental results on several image benchmarks show that rank-based pooling outperforms the existing pooling methods in classification performance. We further demonstrate better performance on CIFAR datasets by integrating RSP into Network-in-Network. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. A strategy for optimizing item-pool management

    NARCIS (Netherlands)

    Ariel, A.; van der Linden, Willem J.; Veldkamp, Bernard P.

    2006-01-01

    Item-pool management requires a balancing act between the input of new items into the pool and the output of tests assembled from it. A strategy for optimizing item-pool management is presented that is based on the idea of a periodic update of an optimal blueprint for the item pool to tune item

  9. 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...

  10. 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.)

  11. Gadolinium-based contrast agents in pediatric magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gale, Eric M.; Caravan, Peter [Massachusetts General Hospital, Harvard Medical School, Department of Radiology, The Martinos Center for Biomedical Imaging, Boston, MA (United States); Rao, Anil G. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); McDonald, Robert J. [College of Medicine, Mayo Clinic, Department of Radiology, Rochester, MN (United States); Winfeld, Matthew [University of Pennsylvania Perelman School of Medicine, Philadelphia, PA (United States); Fleck, Robert J. [Cincinnati Children' s Hospital Medical Center, Department of Pediatric Radiology, Cincinnati, OH (United States); Gee, Michael S. [MassGeneral Hospital for Children, Harvard Medical School, Division of Pediatric Imaging, Department of Radiology, Boston, MA (United States)

    2017-05-15

    Gadolinium-based contrast agents can increase the accuracy and expediency of an MRI examination. However the benefits of a contrast-enhanced scan must be carefully weighed against the well-documented risks associated with administration of exogenous contrast media. The purpose of this review is to discuss commercially available gadolinium-based contrast agents (GBCAs) in the context of pediatric radiology. We discuss the chemistry, regulatory status, safety and clinical applications, with particular emphasis on imaging of the blood vessels, heart, hepatobiliary tree and central nervous system. We also discuss non-GBCA MRI contrast agents that are less frequently used or not commercially available. (orig.)

  12. Gadolinium-based contrast agents in pediatric magnetic resonance imaging

    International Nuclear Information System (INIS)

    Gale, Eric M.; Caravan, Peter; Rao, Anil G.; McDonald, Robert J.; Winfeld, Matthew; Fleck, Robert J.; Gee, Michael S.

    2017-01-01

    Gadolinium-based contrast agents can increase the accuracy and expediency of an MRI examination. However the benefits of a contrast-enhanced scan must be carefully weighed against the well-documented risks associated with administration of exogenous contrast media. The purpose of this review is to discuss commercially available gadolinium-based contrast agents (GBCAs) in the context of pediatric radiology. We discuss the chemistry, regulatory status, safety and clinical applications, with particular emphasis on imaging of the blood vessels, heart, hepatobiliary tree and central nervous system. We also discuss non-GBCA MRI contrast agents that are less frequently used or not commercially available. (orig.)

  13. Spectrum pooling in MnWave Networks

    DEFF Research Database (Denmark)

    Boccardi, Federico; Shokri-Ghadikolaei, Hossein; Fodor, Gabor

    2016-01-01

    Motivated by the specific characteristics of mmWave technologies, we discuss the possibility of an authorization regime that allows spectrum sharing between multiple operators, also referred to as spectrum pooling. In particular, considering user rate as the performance measure, we assess the ben...

  14. DNA pooling strategies for categorical (ordinal) traits

    Science.gov (United States)

    Despite reduced genotyping costs in recent years, obtaining genotypes for all individuals in a population may still not be feasible when sample size is large. DNA pooling provides a useful alternative to determining genotype effects. Clustering algorithms allow for grouping of individuals (observati...

  15. Pooling Objects for Recognizing Scenes without Examples

    NARCIS (Netherlands)

    Kordumova, S.; Mensink, T.; Snoek, C.G.M.

    2016-01-01

    In this paper we aim to recognize scenes in images without using any scene images as training data. Different from attribute based approaches, we do not carefully select the training classes to match the unseen scene classes. Instead, we propose a pooling over ten thousand of off-the-shelf object

  16. Pooling ASR data for closely related languages

    CSIR Research Space (South Africa)

    Van Heerden, C

    2010-05-01

    Full Text Available We describe several experiments that were conducted to assess the viability of data pooling as a means to improve speech-recognition performance for under-resourced languages. Two groups of closely related languages from the Southern Bantu language...

  17. "Teisele poole" Agambeniga ja Agambenita / Ragne Nukk

    Index Scriptorium Estoniae

    Nukk, Ragne, 1984-

    2012-01-01

    Tallinna Fotokuu rahvusvahelise fotonäituse "Teisele poole" ideeliste lähtekohtade tõlgendamisest. Autor kõrvutab Adam Budaki kuraatornäituse aluseks olnud Giorgio Agambeni esseed „Viimne kohtupäev“ näitusel eksponeeritud piltidega

  18. Enhanced heat transfer in confined pool boiling

    NARCIS (Netherlands)

    Rops, C.M.; Lindken, R.; Velthuis, J.F.M.; Westerweel, J.

    2009-01-01

    We report the results of an experimental investigation of the heat transfer during nucleate boiling on a spatially confined boiling surface. The heat flux as a function of the boiling surface temperature was measured in pool boiling pots with diameters ranging from 15 mm down to 4.5 mm. It was found

  19. Measurements of fluid flow in weld pools

    NARCIS (Netherlands)

    Zhao, C.

    2011-01-01

    Understanding the fluid flow in weld pools contributes significantly toward controlling the heat distribution in the base material and the mass distribution of molten base and additive materials. Currently, most investigations focus primarily on numerical models, due to the experimental difficulties

  20. Pricing Electricity in Pools With Wind Producers

    DEFF Research Database (Denmark)

    Morales González, Juan Miguel; Conejo, A. J.; Kai Liu

    2012-01-01

    This paper considers an electricity pool that includes a significant number of wind producers and is cleared through a network-constrained auction, one day in advance and on an hourly basis. The hourly auction is formulated as a two-stage stochastic programming problem, where the first stage...

  1. Storage device for fuel elements in pool

    International Nuclear Information System (INIS)

    Kerjean, J.

    1985-01-01

    The fuel elements are stored in compartments set at the bottom of the pools and separated by water spaces; the walls of the cells are coated on the external side with a cadmium liner acting as a neutronic protection associated with the water space [fr

  2. 28 CFR 540.64 - Press pools.

    Science.gov (United States)

    2010-07-01

    ... magazines and newspapers; and (4) All media in the local community where the institution is located. If no... PERSONS IN THE COMMUNITY Contact With News Media § 540.64 Press pools. (a) The Warden may establish a... shall notify all news media representatives who have requested interviews or visits that have not been...

  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. Benthic assemblages of rock pools in northern Portugal: seasonal and between-pool variability

    Directory of Open Access Journals (Sweden)

    Iacopo Bertocci

    2012-11-01

    Full Text Available We investigated the seasonal (winter vs summer and within season and spatial (between-pool variability of benthic assemblages of rock pools at mid-intertidal level along the shore of Viana do Castelo (North Portugal. Physical traits of rock pools, including size, depth and position along the shore, were also compared between pools. While pools did not differ for any of the examined physical traits, results indicated a clear seasonal difference in the structure of assemblages, including a total of 49 macroalgal and 13 animal taxa. This finding was driven by six taxa that are more abundant in winter (the reef-forming polychaete Sabellaria alveolata, the articulated coralline algae Corallina spp., the brown alga Bifurcaria bifurcata, the encrusting coralline alga Lithophyllum incrustans, the red alga Chondracanthus acicularis and the grazing snails Gibbula spp. and four algal taxa that are more abundant in summer (the invasive brown Sargassum muticum, the green Ulva spp., the kelp Laminaria ochroleuca and the filamentous red Ceramium spp.. These data provide a new contribution to the knowledge of rock pool systems and have potential implications for monitoring programmes aimed at assessing ecological modifications related to natural and anthropogenic disturbances and for identifying processes responsible for the variability of rock pool assemblages.

  5. Blood typing

    Science.gov (United States)

    Blood typing is a method to tell what type of blood you have. Blood typing is done so you can safely donate your blood or receive a blood transfusion. It is also done to see if you have a substance called Rh factor on the surface of your red ...

  6. Blood Types

    Science.gov (United States)

    ... KidsHealth / For Teens / Blood Types What's in this article? Four Blood Groups... Plus Rh Factor... ...Make Eight Blood Types Why Blood Type Matters Print en español Tipos de sangre About 5 million Americans need blood transfusions every ...

  7. 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

  8. Airway dysfunction and inflammation in pool- and non-pool-based elite athletes.

    Science.gov (United States)

    Martin, Neil; Lindley, Martin R; Hargadon, Beverley; Monteiro, Will R; Pavord, Ian D

    2012-08-01

    This study sought to determine and compare the levels of airway dysfunction and inflammation in a large cohort of symptomatic international athletes from pool- and non-pool-based sporting backgrounds. In total, 118 athletes were recruited. All subjects had symptoms of exercise asthma and were steroid naïve. They completed baseline spirometry, a symptom score, exhaled nitric oxide, a eucapnic voluntary hyperventilation (EVH) test, and a postchallenge induced sputum and urine test. Pool-based athletes had better lung function (FEV1 = 110% vs 102% predicted, mean difference = 8.200 ± 2.339, P = 0.0006 and FVC = 5.64 vs 4.75 L, mean difference = 0.8855 ± 0.1951, P < 0.0001) and more marked airways hyper-reactivity (AHR) (percent drop in FEV1 after EVH = 18.14 vs 11.47, mean difference = 6.67, 95% confidence interval = 2.89-10.53, P = 0.0009). More pool-based athletes had a positive EVH test (72% pool vs 39% nonpool), but there was no difference between groups with respect to eosinophilic inflammation (sputum eosinophil percentage: pool = 2.07, nonpool = 2.28, P = 0.77; exhaled nitric oxide: pool = 32.54, nonpool = 35.77, P = 0.60). Athletes with a positive EVH test had less neutrophilic inflammation (P = 0.01) and more epithelial cells (P = 0.03) in their sputum. Pool-based endurance athletes have greater evidence of AHR than non-pool-based athletes but no evidence of greater eosinophilic airway inflammation. Athletes who test positive on EVH are more likely to be eosinophilic and have higher levels of epithelial cells in their sputum.

  9. Suncatcher and cool pool. Project report

    Energy Technology Data Exchange (ETDEWEB)

    Hammond, J.

    1981-03-01

    The Suncatcher is a simple, conical solar concentrating device that captures light entering clerestory windows and directs it onto thermal storage elements at the back of a south facing living space. The cone shape and inclination are designed to capture low angle winter sunlight and to reflect away higher angle summer sunlight. It is found that winter radiation through a Suncatcher window is 40 to 50% higher than through an ordinary window, and that the average solar fraction is 59%. Water-filled steal culvert pipes used for thermal storage are found to undergo less stratification, and thus to be more effective, when located where sunlight strikes the bottom rather than the top. Five Suncatcher buildings are described. Designs are considered for 32/sup 0/, 40/sup 0/ and 48/sup 0/ north latitude, and as the latitude increases, the inclination angle of the cone should be lowered. The Cool Pool is an evaporating, shaded roof pond which thermosiphons cool water into water-filled columns within a building. Preliminary experiments indicate that the best shade design has unimpeded north sky view, good ventilation, complete summer shading, a low architectural profile, and low cost attic vent lowers work. Another series of experiments established the satisfactory performance of the Cool Pool on a test building using four water-filled cylinders, two cylinders, and two cylinders connected to the Cool Pool through a heat exchanger. Although an unshaded pool cools better at night than a shaded one, daytime heat gain far offsets this advantage. A vinyl waterbag heat exchanger was developed for use with the Cool Pool. (LEW)

  10. Autotrophic microbe metagenomes and metabolic pathways differentiate adjacent red sea brine pools

    KAUST Repository

    Wang, Yong

    2013-04-29

    In the Red Sea, two neighboring deep-sea brine pools, Atlantis II and Discovery, have been studied extensively, and the results have shown that the temperature and concentrations of metal and methane in Atlantis II have increased over the past decades. Therefore, we investigated changes in the microbial community and metabolic pathways. Here, we compared the metagenomes of the two pools to each other and to those of deep-sea water samples. Archaea were generally absent in the Atlantis II metagenome; Bacteria in the metagenome were typically heterotrophic and depended on aromatic compounds and other extracellular organic carbon compounds as indicated by enrichment of the related metabolic pathways. In contrast, autotrophic Archaea capable of CO2 fixation and methane oxidation were identified in Discovery but not in Atlantis II. Our results suggest that hydrothermal conditions and metal precipitation in the Atlantis II pool have resulted in elimination of the autotrophic community and methanogens.

  11. 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

  12. Generalizing Pooling Functions in CNNs: Mixed, Gated, and Tree.

    Science.gov (United States)

    Lee, Chen-Yu; Gallagher, Patrick; Tu, Zhuowen

    2018-04-01

    In this paper, we seek to improve deep neural networks by generalizing the pooling operations that play a central role in the current architectures. We pursue a careful exploration of approaches to allow pooling to learn and to adapt to complex and variable patterns. The two primary directions lie in: (1) learning a pooling function via (two strategies of) combining of max and average pooling, and (2) learning a pooling function in the form of a tree-structured fusion of pooling filters that are themselves learned. In our experiments every generalized pooling operation we explore improves performance when used in place of average or max pooling. We experimentally demonstrate that the proposed pooling operations provide a boost in invariance properties relative to conventional pooling and set the state of the art on several widely adopted benchmark datasets. These benefits come with only a light increase in computational overhead during training (ranging from additional 5 to 15 percent in time complexity) and a very modest increase in the number of model parameters (e.g., additional 1, 9, and 27 parameters for mixed, gated, and 2-level tree pooling operators, respectively). To gain more insights about our proposed pooling methods, we also visualize the learned pooling masks and the embeddings of the internal feature responses for different pooling operations. Our proposed pooling operations are easy to implement and can be applied within various deep neural network architectures.

  13. Parvovirus B19 viraemia in Dutch blood donors

    NARCIS (Netherlands)

    Zaaijer, H. L.; Koppelman, M. H. G. M.; Farrington, C. P.

    2004-01-01

    Blood, donated by asymptomatic donors, may contain and transmit parvovirus B19. To investigate the dynamics of parvovirus viraemia in asymptomatic blood donors, we studied the amounts of parvovirus DNA in pools of donor plasma, the prevalence of parvovirus antibodies among blood donors in relation

  14. 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.)

  15. 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.)

  16. 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...

  17. Iodinated contrast media alter immune responses in pro-inflammatory states.

    LENUS (Irish Health Repository)

    O'Donnell, David H

    2010-07-01

    Hypertonic saline causes a transient elevation of blood osmolality and has been shown to alter cellular inflammatory responses in pro-inflammatory states. Intravascular administration of iodine contrast media also causes a transient elevation of blood osmolarity.

  18. Types of Blood Donations

    Science.gov (United States)

    ... ill patients. Blood Donation 101 Blood Donation FAQs Types of Blood Donations The Foundation for America's Blood Centers Donate Blood Blood Donation 101 Blood Donation FAQs Types of Blood Donations About Blood What is Blood? ...

  19. Estimating HIV prevalence from surveys with low individual consent rates: annealing individual and pooled samples.

    Science.gov (United States)

    Hund, Lauren; Pagano, Marcello

    2013-02-27

    : Many HIV prevalence surveys are plagued by the problem that a sizeable number of surveyed individuals do not consent to contribute blood samples for testing. One can ignore this problem, as is often done, but the resultant bias can be of sufficient magnitude to invalidate the results of the survey, especially if the number of non-responders is high and the reason for refusing to participate is related to the individual's HIV status. One reason for refusing to participate may be for reasons of privacy. For those individuals, we suggest offering the option of being tested in a pool. This form of testing is less certain than individual testing, but, if it convinces more people to submit to testing, it should reduce the potential for bias and give a cleaner answer to the question of prevalence. This paper explores the logistics of implementing a combined individual and pooled testing approach and evaluates the analytical advantages to such a combined testing strategy. We quantify improvements in a prevalence estimator based on this combined testing strategy, relative to an individual testing only approach and a pooled testing only approach. Minimizing non-response is key for reducing bias, and, if pooled testing assuages privacy concerns, offering a pooled testing strategy has the potential to substantially improve HIV prevalence estimates.

  20. Pool Boiling CHF in Inclined Narrow Annuli

    International Nuclear Information System (INIS)

    Kang, Myeong Gie

    2010-01-01

    Pool boiling heat transfer has been studied extensively since it is frequently encountered in various heat transfer equipment. Recently, it has been widely investigated in nuclear power plants for application to the advanced light water reactors designs. Through the review on the published results it can be concluded that knowledge on the combined effects of the surface orientation and a confined space on pool boiling heat transfer is of great practical importance and also of great academic interest. Fujita et al. investigated pool boiling heat transfer, from boiling inception to the critical heat flux (CHF, q' CHF ), in a confined narrow space between heated and unheated parallel rectangular plates. They identified that both the confined space and the surface orientation changed heat transfer much. Kim and Suh changed the surface orientation angles of a downward heating rectangular channel having a narrow gap from the downward-facing position (180 .deg.) to the vertical position (90 .deg.). They observed that the CHF generally decreased as the inclination angle (θ ) increased. Yao and Chang studied pool boiling heat transfer in a confined heat transfer for vertical narrow annuli with closed bottoms. They observed that when the gap size ( s ) of the annulus was decreased the effect of space confinement to boiling heat transfer increased. The CHF was occurred at much lower value for the confined space comparing to the unconfined pool boiling. Pool boiling heat transfer in narrow horizontal annular crevices was studied by Hung and Yao. They concluded that the CHF decreased with decreasing gap size of the annuli and described the importance of the thin film evaporation to explain the lower CHF of narrow crevices. The effect of the inclination angle on the CHF on countercurrent boiling in an inclined uniformly heated tube with closed bottoms was also studied by Liu et al. They concluded that the CHF reduced with the inclination angle decrease. A study was carried out

  1. Sodium pool fire model for CONACS code

    International Nuclear Information System (INIS)

    Yung, S.C.

    1982-01-01

    The modeling of sodium pool fires constitutes an important ingredient in conducting LMFBR accident analysis. Such modeling capability has recently come under scrutiny at Westinghouse Hanford Company (WHC) within the context of developing CONACS, the Containment Analysis Code System. One of the efforts in the CONACS program is to model various combustion processes anticipated to occur during postulated accident paths. This effort includes the selection or modification of an existing model and development of a new model if it clearly contributes to the program purpose. As part of this effort, a new sodium pool fire model has been developed that is directed at removing some of the deficiencies in the existing models, such as SOFIRE-II and FEUNA

  2. Suppression pool in nuclear power plant

    International Nuclear Information System (INIS)

    Hayakumo, Sunao.

    1981-01-01

    Purpose: To improve the efficiency of vapour condensation for the sake of steam-load depression at the time of blowdown, and to prevent the quake of supression pool water at the time of earthquake. Constitution: Double branching plates having a function of a branching vapor stream in two directions when blowing down the vapor and operating the vent safety valve are provided on the central line of the vent tube disposed radially from the center of a reactor housing in a dry well. Further, a vent safety valve exhaust device is provided between the branching plates. When the vapor discharged from the space in the dry well is discharged through the vent tube and the vent safety valve exhaust device into a suppression pool, the stream line is roughly split by the branching plates, and the flows from the adjacent branching plates and the exhaust device collide with one another, thereby improving the condensing action. (Sekiya, K.)

  3. Economic efficiency of pool coordinated electricity markets

    International Nuclear Information System (INIS)

    Al-Agtash, S.; Renjeng Su

    2004-01-01

    This paper presents economic efficiency evaluation of pool coordinated electricity markets. The evaluation accounts for the overall cost of power generation, network losses and costs, and various operational constraints. We assume a non-collusive oligopolistic competition. An iterative supply function model is used to characterize the competitive behavior of suppliers. A social welfare function is defined for PoolCo market that operates over multiple hours time span. This leads to a mixed-integer non-linear programming problem. An Augmented Lagrangian approach is used to solve iteratively for global optimal operation schedules (i.e. power generation, load, and price for each bus node) while considering constraints of different sorts. An IEEE 24-bus, eight-supplier, 17-customer test system is used for illustration. The results show deflection of electricity prices from the marginal costs of power generation. The results of 2-year (730 round) market simulations show a range of deadweight efficiency loss between 0.5. (author)

  4. Review and assessment of pool scrubbing models

    Energy Technology Data Exchange (ETDEWEB)

    Herranz, L.E.; Escudero, M.J.; Peyres, V.; Polo, J.; Lopez, J.

    1996-07-01

    Decontamination of fission products bearing bubbles as they pass through aqueous pools becomes a crucial phenomenon for source term evaluation of hypothetical risk dominant sequences of Light Water Reactors. In the present report a peer review and assessment of models encapsulated in SPARC and BUSCA codes is presented. Several aspects of pool scrubbing have been addressed: particle removal, fission product vapour retention and bubble hydrodynamics. Particular emphasis has been given to the close link between retention and hydrodynamics, from both modelling and experimental point of view. In addition, RHR and SGTR sequences were simulated with SPARC90 and BUSCA-AUG92 codes, and their results were compared with those obtained with MAAP 3.0B. As a result of this work, model capabilities and shortcomings have been assessed and some areas susceptible of further research have been identified. (Author) 73 refs.

  5. Exome Pool-Seq in neurodevelopmental disorders.

    Science.gov (United States)

    Popp, Bernt; Ekici, Arif B; Thiel, Christian T; Hoyer, Juliane; Wiesener, Antje; Kraus, Cornelia; Reis, André; Zweier, Christiane

    2017-12-01

    High throughput sequencing has greatly advanced disease gene identification, especially in heterogeneous entities. Despite falling costs this is still an expensive and laborious technique, particularly when studying large cohorts. To address this problem we applied Exome Pool-Seq as an economic and fast screening technology in neurodevelopmental disorders (NDDs). Sequencing of 96 individuals can be performed in eight pools of 12 samples on less than one Illumina sequencer lane. In a pilot study with 96 cases we identified 27 variants, likely or possibly affecting function. Twenty five of these were identified in 923 established NDD genes (based on SysID database, status November 2016) (ACTB, AHDC1, ANKRD11, ATP6V1B2, ATRX, CASK, CHD8, GNAS, IFIH1, KCNQ2, KMT2A, KRAS, MAOA, MED12, MED13L, RIT1, SETD5, SIN3A, TCF4, TRAPPC11, TUBA1A, WAC, ZBTB18, ZMYND11), two in 543 (SysID) candidate genes (ZNF292, BPTF), and additionally a de novo loss-of-function variant in LRRC7, not previously implicated in NDDs. Most of them were confirmed to be de novo, but we also identified X-linked or autosomal-dominantly or autosomal-recessively inherited variants. With a detection rate of 28%, Exome Pool-Seq achieves comparable results to individual exome analyses but reduces costs by >85%. Compared with other large scale approaches using Molecular Inversion Probes (MIP) or gene panels, it allows flexible re-analysis of data. Exome Pool-Seq is thus well suited for large-scale, cost-efficient and flexible screening in characterized but heterogeneous entities like NDDs.

  6. Feature Quantization and Pooling for Videos

    Science.gov (United States)

    2014-05-01

    same codebook center in a query volleyball video. On the right we show the (incorrect) match using Nearest Neighbor - a biking video. (b) In the...proposed representation, Motion Words, features pooled over supervoxels match similar regions and enable interpretability. Figure 3.3: A volleyball query...regions with very different motion and appearance (the players, the volleyball net, the ceiling and walls) and it is not clear why the biking video is

  7. 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

  8. Heated indoor swimming pools, infants, and the pathogenesis of adolescent idiopathic scoliosis: a neurogenic hypothesis

    Directory of Open Access Journals (Sweden)

    McMaster Marianne E

    2011-10-01

    Full Text Available Abstract Background In a case-control study a statistically significant association was recorded between the introduction of infants to heated indoor swimming pools and the development of adolescent idiopathic scoliosis (AIS. In this paper, a neurogenic hypothesis is formulated to explain how toxins produced by chlorine in such pools may act deleteriously on the infant's immature central nervous system, comprising brain and spinal cord, to produce the deformity of AIS. Presentation of the hypothesis Through vulnerability of the developing central nervous system to circulating toxins, and because of delayed epigenetic effects, the trunk deformity of AIS does not become evident until adolescence. In mature healthy swimmers using such pools, the circulating neurotoxins detected are chloroform, bromodichloromethane, dibromochloromethane, and bromoform. Cyanogen chloride and dichloroacetonitrile have also been detected. Testing the hypothesis In infants, the putative portals of entry to the blood could be dermal, oral, or respiratory; and entry of such circulating small molecules to the brain are via the blood-brain barrier, blood-cerebrospinal fluid barrier, and circumventricular organs. Barrier mechanisms of the developing brain differ from those of adult brain and have been linked to brain development. During the first 6 months of life cerebrospinal fluid contains higher concentrations of specific proteins relative to plasma, attributed to mechanisms continued from fetal brain development rather than immaturity. Implications of the hypothesis The hypothesis can be tested. If confirmed, there is potential to prevent some children from developing AIS.

  9. Heated indoor swimming pools, infants, and the pathogenesis of adolescent idiopathic scoliosis: a neurogenic hypothesis.

    Science.gov (United States)

    McMaster, Marianne E

    2011-10-05

    In a case-control study a statistically significant association was recorded between the introduction of infants to heated indoor swimming pools and the development of adolescent idiopathic scoliosis (AIS). In this paper, a neurogenic hypothesis is formulated to explain how toxins produced by chlorine in such pools may act deleteriously on the infant's immature central nervous system, comprising brain and spinal cord, to produce the deformity of AIS. Through vulnerability of the developing central nervous system to circulating toxins, and because of delayed epigenetic effects, the trunk deformity of AIS does not become evident until adolescence. In mature healthy swimmers using such pools, the circulating neurotoxins detected are chloroform, bromodichloromethane, dibromochloromethane, and bromoform. Cyanogen chloride and dichloroacetonitrile have also been detected. In infants, the putative portals of entry to the blood could be dermal, oral, or respiratory; and entry of such circulating small molecules to the brain are via the blood-brain barrier, blood-cerebrospinal fluid barrier, and circumventricular organs. Barrier mechanisms of the developing brain differ from those of adult brain and have been linked to brain development. During the first 6 months of life cerebrospinal fluid contains higher concentrations of specific proteins relative to plasma, attributed to mechanisms continued from fetal brain development rather than immaturity. The hypothesis can be tested. If confirmed, there is potential to prevent some children from developing AIS.

  10. Thermal analyses of solar swimming pool heating in Pakistan

    International Nuclear Information System (INIS)

    Ahmad, I.

    2011-01-01

    Hotels and swimming clubs in Pakistan pay huge gas bills for heating Swimming pools in winter. Winter days in most parts of Pakistan remain sunny and unglazed low cost solar collectors may be used to extend the swimming season. Installing the pool in a wind-protected area, which receives unobstructed solar radiation, may further reduce the size of the solar collectors required to heat the swimming pools. The pools should be covered with plastic sheet to eliminate evaporative heat losses and to prevent dust and tree leaves falling in the pool. The results of the thermal analysis show that in some parts of the country, a solar exposed pool can maintain comfortable temperature simply by using a plastic sheet on the pool surface. On the other hand, there are cities where solar collector array equal to twice the surface area of the pool is required to keep desired temperature in winter. (author)

  11. Hydrology of vernal pools at three sites, southern Sacramento Valley

    Science.gov (United States)

    2005-04-01

    The subsurface hydrology of vernal pools at three vernal pool complexes was investigated during three wet seasons in 2002- : 2004. The complexes were at Gridley Ranch, Valensin Ranch, and the Mather Field in northern California. The selected : comple...

  12. [Tiit Hennoste loengusarjast 'Hüpped modernismi poole'] / Hasso Krull

    Index Scriptorium Estoniae

    Krull, Hasso, 1964-

    1997-01-01

    Tiit Hennoste loengusarjast 'Hüpped modernismi poole : Eesti 20. sajandi kirjandusest Euroopa modernismi taustal' (1993, nr. 10 - 1997, nr. 10/11).Vastukaja: Hüpped modernismi poole: kajad ja vastukajad // Vikerkaar (1998) nr. 6, lk. 99-111

  13. Performance Study and Dynamic Optimization Design for Thread Pool Systems

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Dongping [Iowa State Univ., Ames, IA (United States)

    2004-12-19

    Thread pools have been widely used by many multithreaded applications. However, the determination of the pool size according to the application behavior still remains problematic. To automate this process, in this thesis we have developed a set of performance metrics for quantitatively analyzing thread pool performance. For our experiments, we built a thread pool system which provides a general framework for thread pool research. Based on this simulation environment, we studied the performance impact brought by the thread pool on different multithreaded applications. Additionally, the correlations between internal characterizations of thread pools and their throughput were also examined. We then proposed and evaluated a heuristic algorithm to dynamically determine the optimal thread pool size. The simulation results show that this approach is effective in improving overall application performance.

  14. Opportunities and challenges when pooling milk samples using ELISA

    DEFF Research Database (Denmark)

    Græsbøll, Kaare; Andresen, Lars Ole; Hisham Beshara Halasa, Tariq

    2017-01-01

    -positive samples by pooling. To illustrate this, the sensitivity of antibody ELISA on pooled samples of bovine milk for Salmonella Dublin, Mycobacterium avium spp. paratuberculosis, and bovine virus diarrhea was tested. For these milk assays, the analytical sensitivity decreased rapidly with increasing pool sizes...

  15. Isolation of Fungi in Swimming pools in Enugu, Nigeria | Mbata ...

    African Journals Online (AJOL)

    Background: It has been established that swimming pools contribute to the spread of fungal infections in susceptible hosts. Objectives: To isolate and identify fungi associated with swimming pools. Methods: A total of 147 samples from water and related areas of each swimming pool were tested for the presence of fungi.

  16. The Ineffectiveness of Manual Treatment of Swimming Pools | Nnaji ...

    African Journals Online (AJOL)

    The University of Nigeria, Nsukka swimming pool was monitored for a period spanning about three months. The pool was constructed in 1961 and has been in operation since then except that many facilities including the treatment system are no longer functional forcing management to resort to treatment of the pool water ...

  17. A skeleton for distributed work pools in Eden

    DEFF Research Database (Denmark)

    Dieterle, Mischa; Berthold, Jost; Loogen, Rita

    2010-01-01

    We present a flexible skeleton for implementing distributed work pools in our parallel functional language Eden. The skeleton manages a pool of tasks (work pool) in a distributed manner using a demand-driven work stealing approach for load balancing. All coordination is done locally within...

  18. Mitigating the impact of swimming pools on domestic water demand

    African Journals Online (AJOL)

    demand. The study shows the need to reduce the impact of swimming pools. This could include: pool covers to reduce evaporation, the recycling of backwash water, the use of rainwater to top up swimming pools, water use surcharges and, finally, appropriate regulation and enforcement to prevent the use of municipal water ...

  19. 17 CFR 4.22 - Reporting to pool participants.

    Science.gov (United States)

    2010-04-01

    ... National Futures Association pursuant to this paragraph (c); or (B) The date of the formation of the pool...); or (2) The date of the formation of the pool; and (B) The close of the pool's fiscal year or the date... capital contribution are “special allocations.” Special allocations of partnership equity or other...

  20. L-Carnitine and its Protective Role in Contrast-Induced Renal Injury in Rats

    Directory of Open Access Journals (Sweden)

    Mosaddeg Jabbari

    2012-06-01

    Full Text Available Background & Objectives: Contrast media-induced nephrotoxicity is one of the most common causes of acute renal failure and promotes both increased morbidity and greater healthcare costs. several mechanisms by which contrast media induces renal injury. These include renal vasoconstriction and direct effect of the contrast agents and reactive oxygen metabolites production. L-carnitine facilitates the transfer of long-chain fatty acids into the mitochondria. By this mechanism carnitine maintains low pools of fatty acid (acyl-coenzyme a compounds, which are potentially toxic. However some of the actions of L-carnitine may be opposite to the toxic effects of contrast media. This study examined wheter administration of L-carnitine ameliorates contrast media-induced renal injury in rats.   Methods : Fifty Sprauge-Dawley rats, weighting 140-230 gr were assigned to one of five treatment groups: group A(control rats were given normal saline injections daily for 4 consecutive days, group B rats were given contrast media(diatrizoate meglumine 1cc/kg/d, group C rats were given meglumine 1cc/kg/d and carnitine 200mg/kg/d, group D rats were given meglumine 1cc/kg and carnitine 80mg/kg/d, and group E rats were given carnitine 200mg/kg/d. Four days after injections, the rat were killed and their kidneys and blood samples were prepared for pathological and biochemistry examination. Histological scoring of renal cortical pathology was performed.   Results: In rats that were given meglumine and no carnitine, renal function tend to be lower than in control group (p=0.001. Among rats injected with meglumine, those given 200mg/kg/d of L-carnitine had higher creatinine clearances at day 4 than the rats not given carnitine (p=00.04. Renal cortical histopathology changes were milder with meglumine and L-carnitine, particularly at 200mg/kg/d.   Conclusions: In rats receiving meglumine, daily L- carnitine injections, particularly at 200 mg/kg ameliorates the severity of

  1. Does volumetric absorptive microsampling eliminate the hematocrit bias for caffeine and paraxanthine in dried blood samples? A comparative study.

    Science.gov (United States)

    De Kesel, Pieter M M; Lambert, Willy E; Stove, Christophe P

    2015-06-30

    Volumetric absorptive microsampling (VAMS) is a novel sampling technique that allows the straightforward collection of an accurate volume of blood (approximately 10μL) from a drop or pool of blood by dipping an absorbent polymeric tip into it. The resulting blood microsample is dried and analyzed as a whole. The aim of this study was to evaluate the potential of VAMS to overcome the hematocrit bias, an important issue in the analysis of dried blood microsamples. An LC-MS/MS method for analysis of the model compounds caffeine and paraxanthine in VAMS samples was fully validated and fulfilled all pre-established criteria. In conjunction with previously validated procedures for dried blood spots (DBS) and blood, this allowed us to set up a meticulous comparative study in which both compounds were determined in over 80 corresponding VAMS, DBS and liquid whole blood samples. These originated from authentic human patient samples, covering a wide hematocrit range (0.21-0.50). By calculating the differences with reference whole blood concentrations, we found that analyte concentrations in VAMS samples were not affected by a bias that changed over the evaluated hematocrit range, in contrast to DBS results. However, VAMS concentrations tend to overestimate whole blood concentrations, as a consistent positive bias was observed. A different behavior of VAMS samples prepared from incurred and spiked blood, combined with a somewhat reduced recovery of caffeine and paraxanthine from VAMS tips at high hematocrit values, an effect that was not observed for DBS using a very similar extraction procedure, was found to be at the basis of the observed VAMS-whole blood deviations. Based on this study, being the first in which the validity and robustness of VAMS is evaluated by analyzing incurred human samples, it can be concluded that VAMS effectively assists in eliminating the effect of hematocrit. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  2. Pool boiling visualization on open microchannel surfaces

    Directory of Open Access Journals (Sweden)

    Kaniowski Robert

    2017-01-01

    Full Text Available The paper presents visualization investigations into pool boiling heat transfer for open minichannel surfaces. The experiments were carried out wih saturated water at atmospheric pressure. Parallel microchannels fabricated by machining were about 0.3 mm wide and 0.2 to 0.4 mm deep. High-speed videos were used as an aid to understanding the heat transfer mechanism. The visualization study aimed at identifying nucleation sites of the departing bubbles and determining their diameters and frequency at various superheats.

  3. Laser Speckle Contrast Imaging: theory, instrumentation and applications.

    Science.gov (United States)

    Senarathna, Janaka; Rege, Abhishek; Li, Nan; Thakor, Nitish V

    2013-01-01

    Laser Speckle Contrast Imaging (LSCI) is a wide field of view, non scanning optical technique for observing blood flow. Speckles are produced when coherent light scattered back from biological tissue is diffracted through the limiting aperture of focusing optics. Mobile scatterers cause the speckle pattern to blur; a model can be constructed by inversely relating the degree of blur, termed speckle contrast to the scatterer speed. In tissue, red blood cells are the main source of moving scatterers. Therefore, blood flow acts as a virtual contrast agent, outlining blood vessels. The spatial resolution (~10 μm) and temporal resolution (10 ms to 10 s) of LSCI can be tailored to the application. Restricted by the penetration depth of light, LSCI can only visualize superficial blood flow. Additionally, due to its non scanning nature, LSCI is unable to provide depth resolved images. The simple setup and non-dependence on exogenous contrast agents have made LSCI a popular tool for studying vascular structure and blood flow dynamics. We discuss the theory and practice of LSCI and critically analyze its merit in major areas of application such as retinal imaging, imaging of skin perfusion as well as imaging of neurophysiology.

  4. The use of pooled viral load testing to identify antiretroviral treatment failure

    Science.gov (United States)

    Smith, Davey M.; May, Susanne J.; Pérez-Santiago, Josué; Strain, Matthew C.; Ignacio, Caroline C.; Haubrich, Richard H.; Richman, Douglas D.; Benson, Constance A.; Little, Susan J.

    2010-01-01

    Background To develop less costly methods to virologically monitor patients receiving antiretroviral therapy, we evaluated methods that use pooled blood samples and quantitative information available from viral load assays to monitor a cohort of patients on first-line antiretroviral therapy for virologic failure. Methods We evaluated 150 blood samples collected after 6 months of therapy from participants enrolled in a San Diego primary infection program between January 1998 and January 2007. Samples were screened for virologic failure with individual viral load testing, 10 × 10 matrix pools and minipools of five samples. For the pooled platforms (matrix and minipools), we used a search and retest algorithm based on the quantitative viral load data to resolve samples that remained ambiguous for virologic failure. Viral load thresholds were more than 500 and more than 1500 copies/ml for the matrix and more than 250 and more than 500 copies/ml for the minipool. Efficiency, accuracy and result turnaround times were evaluated. Results Twenty-three percent of cohort samples were detectable at more than 50 HIV RNA copies/ml. At an algorithm threshold of more than 500 HIV RNA copies/ml, both minipool and matrix methods used less than half the number of viral load assays to screen the cohort, compared with testing samples individually. Both pooling platforms had negative predictive values of 100% for viral loads of more than 500 HIV RNA copies/ml and at least 94% for viral loads of more than 250 HIV RNA copies/ml. Conclusion In this cohort, both pooling methods improved the efficiency of virologic monitoring over individual testing with a minimal decrease in accuracy. These methods may allow for the induction and sustainability of the virologic monitoring of patients receiving antiretroviral therapy in resource-limited settings. PMID:19730348

  5. 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

  6. [Hygienic profile of the water in Milan swimming pools: a three-year comparative study].

    Science.gov (United States)

    Tesauro, M; Bianchi, A; Consonni, M; Bollani, M; Cesaria, M; Trolli, F Radice; Galli, M G

    2010-01-01

    The aim of this work was to determine whether swimming pool water quality in Milan from 2006 to 2008 was within the standards established by national and local Italian laws (Circolare Min. Sanità 128/71 and DGR 2552/2006). In 2006, 580 samples of water from public swimming pools were analyzed to determine the presence of heterotrophic counts at 37 degrees and total coliforms; pH, free chlorine and chloride of each sample were also measured. In the following years, water from both public and private swimming pools were examined to measure heterotrophic count at 22 degrees and 36 degrees, Escherichia coli, enterococci, Pseudomonas aeruginosa, Staphylococcus aureus, pH, free chlorine, and nitrates. The total number of analyses carried out in 2007 and 2008 was 2074 and 1532, respectively. In 2006, the extent of noncompliance of all swimming pools that was observed for both physical/chemical and microbiological parameters was 72.3%, which then decreased to 53.2% and 36.2% in 2007 and 2008, respectively. In particular with regard to the microbiological analysis, an increase of noncompliance based on at least one parameter was determined (7.1% in 2006 vs. 21.5% in 2007 and 22% in 2008). In contrast, a decrease of the extent of noncompliance based on at least one physical/chemical parameter was observed (from 68.1% in 2006 to 40.4% and 22.3% in 2007 and 2008, respectively). Interestingly, public swimming pools exceeded the legal limits of microbiological concentration more often than the private ones, whereas both types of swimming pools showed a decrease in noncompliance with regard to the physical/chemical parameters.

  7. Deoxyribonucleoside triphosphate pools and thymidine chemosensitization in human T-cell leukemia.

    Science.gov (United States)

    Cohen, J D; Robins, H I; Katz, T B; Miller, E M; Kuzminsky, S R; Javid, M J

    1993-02-01

    Thymidine kills cells by depleting dCTP stores. The present experiments tested whether deoxycytidine, by replenishing dCTP pools, could prevent thymidine cytotoxicity and thymidine's enhancement of carboplatin killing in two human T-cell acute leukemia cell lines. MOLT3 and JM cells were exposed to combinations of thymidine, deoxycytidine, and carboplatin and then assessed for survival, the magnitude of thymidine-carboplatin chemosensitization, and changes in deoxyribonucleoside triphosphate pools. For both cell lines, deoxycytidine (up to 144.5 micrograms/ml x 24 h) completely restored dCTP pools but only partially protected against thymidine cytotoxicity (100-1000 micrograms/ml x 24 h) and thymidine-carboplatin sensitization (up to 60 micrograms carboplatin/ml during the last hour of thymidine). This contrasts with complete protection in prior studies using other cell types. Thymidine alone markedly increased dTTP and dGTP pools and decreased dCTP; dATP pools underwent a sharp decline which has not been observed before in any cell line. In subsequent studies 0.0336-137.3 micrograms deoxyadenosine/ml partially prevented cytotoxicity and carboplatin sensitization by 300 micrograms thymidine/ml. Together, deoxycytidine and deoxyadenosine completely prevented thymidine-carboplatin sensitization even though dATP and dCTP pools were not entirely returned to normal. These findings are discussed in regard to the unusual sensitivity of T-cell malignancies to thymidine toxicity, mechanisms of cytotoxicity and chemosensitization by thymidine, and the possibility of thymidine selectively sensitizing T-cell malignancies to killing by alkylating agents.

  8. 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.

  9. Measurement of pulmonary transit time in healthy cats by use of ultrasound contrast media "Sonovue®": feasibility, reproducibility, and values in 42 cats.

    Science.gov (United States)

    Streitberger, Andrea; Hocke, Verena; Modler, Peter

    2013-09-01

    To evaluate the feasibility of measuring pulmonary transit time (PTT) in healthy cats by transthoracic echocardiography using the ultrasound contrast agent Sonovue(®). To determine normalized PTT (nPTT) values in 42 healthy cats and to estimate the interobserver variability and the within-day repeatability of nPTT measurements. Forty-two privately owned healthy cats of different breeds, gender and age presented for cardiac examination. A bolus injection of contrast agent (Sonovue(®)) was administered intravenously. The right parasternal short axis echocardiographic view was used to record the contrast agent's transit time from the pulmonary artery to the left atrium. Pulmonary transit time and nPTT were determined independently by three examiners with different levels of experience. Normalized PTT was 4.12 ± 1.0 (mean ± SD) in our population. The median interobserver variability across our population was 6.8%, the median within-day variability for the three observers were 13.1%, 12.7% and 13%. No effect of the observer's experience on nPTT measurement was identified. Age, sex and body weight did not significantly influence nPTT. This study demonstrates that nPTT measurement is feasible in cats using ultrasound and the blood pool contrast media Sonovue(®). Measurements of nPTT can be performed in a clinical setting. Normalized PTT values in healthy cats are comparable with those reported in healthy dogs. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Blood transfusions

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000431.htm Blood transfusions To use the sharing features on this page, ... There are many reasons you may need a blood transfusion: After knee or hip replacement surgery, or other ...

  11. Blood Donation

    Science.gov (United States)

    ... A, B, AB or O — and your Rh factor. The Rh factor refers to the presence or absence of a ... information is important because your blood type and Rh factor must be compatible with the blood type and ...

  12. What's Blood?

    Science.gov (United States)

    ... toes. Let's find out more about each ingredient. Red Blood Cells Red blood cells (also called erythrocytes, ... after you are better, B cells can become memory cells that remember how to make the special ...

  13. Donating Blood

    Science.gov (United States)

    ... KidsHealth / For Teens / Donating Blood What's in this article? Who Can Donate Blood? Before Donating Are There Any Risks? Print en español Donar sangre According to the American Red Cross, there's a ...

  14. Vomiting Blood

    Science.gov (United States)

    ... if vomiting blood causes dizziness after standing, rapid, shallow breathing or other signs of shock. Call 911 ... severe blood loss or shock, such as: Rapid, shallow breathing Dizziness or lightheadedness after standing up Blurred ...

  15. Chinese nuclear insurance and Chinese nuclear insurance pool

    International Nuclear Information System (INIS)

    Gong Zhiqi

    2000-01-01

    Chinese Nuclear Insurance Started with Daya Bay Nuclear Power Station, PICC issued the insurance policy. Nuclear insurance cooperation between Chinese and international pool's organizations was set up in 1989. In 1996, the Chinese Nuclear Insurance Pool was prepared. The Chinese Nuclear Insurance Pool was approved by The Chinese Insurance Regulatory Committee in May of 1999. The principal aim is to centralize maximum the insurance capacity for nuclear insurance from local individual insurers and to strengthen the reinsurance relations with international insurance pools so as to provide the high quality insurance service for Chinese nuclear industry. The Member Company of Chinese Nuclear Pool and its roles are introduced in this article

  16. Generalized Pooling for Robust Object Tracking.

    Science.gov (United States)

    Ma, Bo; Hu, Hongwei; Shen, Jianbing; Liu, Yangbiao; Shao, Ling

    2016-07-07

    Feature pooling in a majority of sparse coding based tracking algorithms computes final feature vectors only by loworder statistics or extreme responses of sparse codes. The highorder statistics and correlations between responses to different dictionary items are neglected. We present a more generalized feature pooling method for visual tracking by utilizing the probabilistic function to model the statistical distribution of sparse codes. Since immediate matching between two distributions usually requires high computational costs, we introduce the Fisher vector to derive a more compact and discriminative representation for sparse codes of the visual target. We encode target patches by local coordinate coding, utilize Gaussian Mixture Model (GMM) to compute Fisher vectors, and finally train semi-supervised linear kernel classifiers for visual tracking. In order to handle the drifting problem during the tracking process, these classifiers are updated online with current tracking results. The experimental results on two challenging tracking benchmarks demonstrate that the proposed approach achieves better performance than the state-of-the-art tracking algorithms.

  17. Hardening Stratum, the Bitcoin Pool Mining Protocol

    Directory of Open Access Journals (Sweden)

    Recabarren Ruben

    2017-07-01

    Full Text Available Stratum, the de-facto mining communication protocol used by blockchain based cryptocurrency systems, enables miners to reliably and efficiently fetch jobs from mining pool servers. In this paper we exploit Stratum’s lack of encryption to develop passive and active attacks on Bitcoin’s mining protocol, with important implications on the privacy, security and even safety of mining equipment owners. We introduce StraTap and ISP Log attacks, that infer miner earnings if given access to miner communications, or even their logs. We develop BiteCoin, an active attack that hijacks shares submitted by miners, and their associated payouts. We build BiteCoin on WireGhost, a tool we developed to hijack and surreptitiously maintain Stratum connections. Our attacks reveal that securing Stratum through pervasive encryption is not only undesirable (due to large overheads, but also ineffective: an adversary can predict miner earnings even when given access to only packet timestamps. Instead, we devise Bedrock, a minimalistic Stratum extension that protects the privacy and security of mining participants. We introduce and leverage the mining cookie concept, a secret that each miner shares with the pool and includes in its puzzle computations, and that prevents attackers from reconstructing or hijacking the puzzles.

  18. Visual attention and flexible normalization pools

    Science.gov (United States)

    Schwartz, Odelia; Coen-Cagli, Ruben

    2013-01-01

    Attention to a spatial location or feature in a visual scene can modulate the responses of cortical neurons and affect perceptual biases in illusions. We add attention to a cortical model of spatial context based on a well-founded account of natural scene statistics. The cortical model amounts to a generalized form of divisive normalization, in which the surround is in the normalization pool of the center target only if they are considered statistically dependent. Here we propose that attention influences this computation by accentuating the neural unit activations at the attended location, and that the amount of attentional influence of the surround on the center thus depends on whether center and surround are deemed in the same normalization pool. The resulting form of model extends a recent divisive normalization model of attention (Reynolds & Heeger, 2009). We simulate cortical surround orientation experiments with attention and show that the flexible model is suitable for capturing additional data and makes nontrivial testable predictions. PMID:23345413

  19. Plant diversity associated with pools in natural and restored peatlands

    Directory of Open Access Journals (Sweden)

    N. Fontaine

    2007-06-01

    Full Text Available This study describes plant assemblages associated with the edges of peatland pools. We conducted inventories in six natural peatlands in the province of Québec (Canada in order to measure the contribution of pools to species diversity in climatic regions where peatlands are used for peat extraction. We also carried out vegetation surveys in a peatland that has been restored after peat extraction/harvesting to determine whether pool vegetation establishes along the edges of created pools when dry surface restoration techniques only are used. Pools enhanced plant species richness in natural peatlands. Around created pools, species associated with natural pools were still absent, and non-bog species were present, six years after restoration. On this basis, we emphasise the importance of preserving natural peatlands with pools. In order to restore fully the plant diversity associated with peatlands at harvested sites, it may be necessary to modify pool excavation techniques so that created pools resemble more closely those in natural peatlands. Active introduction of the plant species or communities associated with natural pools may also be needed; candidate species for North America include Andromeda glaucophylla, Cladopodiella fluitans, Carex limosa, Eriophorum virginicum, Rhynchospora alba and Sphagnum cuspidatum.

  20. Weld pool oscillation during gas tungsten arc welding

    Science.gov (United States)

    Xiao, You Hong

    The oscillation behavior of Gas Tungsten Arc (GTA) weld pools in mild steels Fe 360 and in austenitic stainless steel AISI 304 is considered. Special attention is given to the possibility of using the weld pool oscillation behavior as a sensor of weld pool geometry during welding, which is one of the objectives in adaptive control of the welding process. The topics discussed include the theoretical background of the oscillation phenomenon, the direct observation of weld pool oscillation, the experimental determination of the relation between the weld pool geometry and the oscillation frequency both under stationary arc conditions and under traveling arc conditions and the possibility of sensing the weld pool geometry, especially the weld pool penetration, by monitoring the oscillation frequency.

  1. 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.

  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 Positive Control for Detection of Functional CD4 T Cells in PBMC: The CPI Pool.

    Science.gov (United States)

    Schiller, Annemarie; Zhang, Ting; Li, Ruliang; Duechting, Andrea; Sundararaman, Srividya; Przybyla, Anna; Kuerten, Stefanie; Lehmann, Paul V

    2017-12-07

    Testing of peripheral blood mononuclear cells (PBMC) for immune monitoring purposes requires verification of their functionality. This is of particular concern when the PBMC have been shipped or stored for prolonged periods of time. While the CEF (Cytomegalo-, Epstein-Barr and Flu-virus) peptide pool has become the gold standard for testing CD8 cell functionality, a positive control for CD4 cells is so far lacking. The latter ideally consists of proteins so as to control for the functionality of the antigen processing and presentation compartments, as well. Aiming to generate a positive control for CD4 cells, we first selected 12 protein antigens from infectious/environmental organisms that are ubiquitous: Varicella, Influenza, Parainfluenza, Mumps, Cytomegalovirus, Streptococcus , Mycoplasma , Lactobacillus , Neisseria , Candida , Rubella, and Measles. Of these antigens, three were found to elicited interferon (IFN)-γ-producing CD4 cells in the majority of human test subjects: inactivated cytomegalo-, parainfluenza-, and influenza virions (CPI). While individually none of these three antigens triggered a recall response in all donors, the pool of the three (the 'CPI pool'), did. One hundred percent of 245 human donors tested were found to be CPI positive, including Caucasians, Asians, and African-Americans. Therefore, the CPI pool appears to be suitable to serve as universal positive control for verifying the functionality of CD4 and of antigen presenting cells.

  4. To pool or not to pool? Impact of the use of individual and pooled fecal samples for in vitro fermentation studies

    NARCIS (Netherlands)

    Aguirre, M.; Ramiro-Garcia, J.; Koenen, M.E.; Venema, K.

    2014-01-01

    This study investigated the stability and the activity of the microbiota from a single and a pool of donors in the TNO in vitro model of the colon (TIM-2 system). Our findings demonstrate the suitability of the preparation of a pool of fecal sample to be used for fermentation experiments.

  5. Quantitative low mechanical index contrast-enhanced endoscopic ultrasound for the differential diagnosis of chronic pseudotumoral pancreatitis and pancreatic cancer

    Directory of Open Access Journals (Sweden)

    Gheonea Dan Ionuţ

    2013-01-01

    Full Text Available Abstract Background Second-generation intravenous blood-pool ultrasound contrast agents are increasingly used in endoscopic ultrasound (EUS for characterization of microvascularization, differential diagnosis of benign and malignant focal lesions, as well as improved staging and guidance of therapeutic procedures. Methods The aim of our study was to prospectively compare the vascularisation patterns in chronic pseudotumoral pancreatitis and pancreatic cancer using quantitative low mechanical index (MI contrast-enhanced EUS. We included 51 patients with chronic pseudotumoral pancreatitis (n = 19 and pancreatic cancer (n = 32. Perfusion imaging started with a bolus injection of Sonovue (2.4 ml, followed by analysis in the early arterial (wash-in and late venous (wash-out phase. Perfusion analysis was performed by post-processing of the raw data (time intensity curve [TIC] analysis. TIC analysis was performed inside the tumor and the pancreatic parenchyma, with depiction of the dynamic vascular pattern generated by specific software. Statistical analysis was performed on raw data extracted from the TIC analysis. Final diagnosis was based on a combination of EUS-FNA, surgery and follow-up of minimum 6 months in negative cases. Results The sensitivity and specificity of low MI contrast enhanced EUS using TIC were sensitivity and specificity of low MI contrast enhanced EUS using TIC analysis were 93.75% (95% CI = 77.77 - 98.91% and 89.47% (95% CI = 65.46 - 98.15%, respectively. Pseudotumoral chronic pancreatitis showed in the majority of cases a hypervascular appearance in the early arterial phase of contrast-enhancement, with a dynamic enhancement pattern similar with the rest of the parenchyma. Statistical analysis of the resulting series of individual intensities revealed no statistically relevant differences (p = .78. Pancreatic adenocarcinoma was usually a hypovascular lesion, showing low contrast-enhancement during the

  6. The new pooled cohort equations risk calculator

    DEFF Research Database (Denmark)

    Preiss, David; Kristensen, Søren L

    2015-01-01

    total cardiovascular risk score. During development of joint guidelines released in 2013 by the American College of Cardiology (ACC) and American Heart Association (AHA), the decision was taken to develop a new risk score. This resulted in the ACC/AHA Pooled Cohort Equations Risk Calculator. This risk...... strengths are its inclusion of stroke as an end point and race as a characteristic, which allows better risk prediction especially in African-American individuals, plus provision of lifetime ASCVD risk estimates for adults aged 20-59 years. Notable omissions from the risk factors include chronic kidney...... the intended 7.5% 10-year ASCVD risk threshold for treatment in the joint ACC/AHA cholesterol guidelines. In this review we discuss the development of the new risk calculator, its strengths and weaknesses, and potential implications for its routine use....

  7. Determining a pool - type reactor fuel policy

    International Nuclear Information System (INIS)

    1964-01-01

    Refuelling the 10 to 15 MW pool type reactor considered here will occur frequently (some 10 elements every 3 to 4 weeks). It is therefore necessary to determine the most economic fuel policy. This study proposes to define a strategy that will make it possible to decide on the number and characteristics of the shipment containers, as well as on the means of storage, so as to reduce the risks as much as possible should the basic parameters of the study vary. Among these parameters, the respective influence of which is investigated, chemical reprocessing costs play a vital part. Two examples of optimum fuel management are given according to whether the reprocessing charges applied are those of the old or of the 1961 U.S. AEC base charges for reprocessing highly enriched irradiated fuel. (authors) [fr

  8. Soil carbon pools in different pasture systems

    Directory of Open Access Journals (Sweden)

    Francisco M. Cardozo, Jr.

    2016-03-01

    Full Text Available The aim of this study was to assess the carbon pools of a tropical soil where the native forest was replaced with different pasture systems. We studied five pasture production systems, including four monoculture systems with forage grasses such as Andropogon, Brachiaria, Panicum, and Cynodon, and an agroforestry system as well as a native vegetation plot. Greater availability of fulvic acid was detected in the agroforestry system as compared with that in the other systems. Higher lability of C was detected in the Andropogon system during the dry and rainy seasons and during the dry season in Cynodon. During the dry season, all pastures systems showed deficits in the net removal of atmospheric CO2. The structure and practices of the agroforestry system enables more carbon to be sequestered in the soil as compared with the monoculture pasture, suggesting that it is an important practice to mitigate climatic change and to improve soil quality.

  9. Corrosion surveillance in spent fuel storage pools

    International Nuclear Information System (INIS)

    Howell, J.P.

    1996-01-01

    In mid-1991, corrosion of aluminum-clad spent nuclear fuel was observed in the light-water filled basins at the Savannah River site. A corrosion surveillance program was initiated in the P, K, L-Reactor basins and in the Receiving Basin for Offsite Fuels (RBOF). This program verified the aggressive nature of the pitting corrosion and provided recommendations for changes in basin operations to permit extended longer term interim storage. The changes were implemented during 1994--1996 and have resulted in significantly improved basin water quality with conductivity in the 1--3 microS/cm range. Under these improved conditions, no new pitting has been observed over the last three years. This paper describes the corrosion surveillance program at SRS and what has been learned about the corrosion of aluminum-clad in spent fuel storage pools

  10. Technical Facilities Management, Loan Pool, and Calibration

    Science.gov (United States)

    Smith, Jacob

    2011-01-01

    My work at JPL for the SURF program began on June 11, 2012 with the Technical Facilities Management group (TFM). As well as TFM, I worked with Loan Pool and Metrology to help them out with various tasks. Unlike a lot of other interns, I did not have a specific project rather many different tasks to be completed over the course of the 10 weeks.The first task to be completed was to sort through old certification reports in 6 different boxes to locate reports that needed to be archived into a digital database. There were no reports within these boxes that needed to be archived but rather were to be shredded. The reports went back to the early 1980's and up to the early 2000's. I was looking for reports dated from 2002 to 2012

  11. Drop Impact on to Moving Liquid Pools

    Science.gov (United States)

    Muñoz-Sánchez, Beatriz Natividad; Castrejón-Pita, José Rafael; Castrejón-Pita, Alfonso Arturo; Hutchings, Ian M.

    2014-11-01

    The deposition of droplets on to moving liquid substrates is an omnipresent situation both in nature and industry. A diverse spectrum of phenomena emerges from this simple process. In this work we present a parametric experimental study that discerns the dynamics of the impact in terms of the physical properties of the fluid and the relative velocity between the impacting drop and the moving liquid pool. The behaviour ranges from smooth coalescence (characterized by little mixing) to violent splashing (generation of multiple satellite droplets and interfacial vorticity). In addition, transitional regimes such as bouncing and surfing are also found. We classify the system dynamics and show a parametric diagram for the conditions of each regime. This work was supported by the EPSRC (Grant EP/H018913/1), the Royal Society, Becas Santander Universidades and the International Relationships Office of the University of Extremadura.

  12. One knowledge base or many knowledge pools?

    DEFF Research Database (Denmark)

    Lundvall, Bengt-Åke

    It is increasingly realized that knowledge is the most important resource and that learning is the most important process in the economy. Sometimes this is expressed by coining the current era as characterised by a ‘knowledge based economy'. But this concept might be misleading by indicating...... that there is one common knowledge base on which economic activities can be built. In this paper we argue that it is more appropriate to see the economy as connecting to different ‘pools of knowledge'. The argument is built upon a conceptual framework where we make distinctions between private/public, local....../global, individual/collective and tacit/codified knowledge. The purpose is both ‘academic' and practical. Our analysis demonstrates the limits of a narrowly economic perspective on knowledge and we show that these distinctions have important implications both for innovation policy and for management of innovation....

  13. The flexible gene pool of Propionibacterium acnes

    DEFF Research Database (Denmark)

    Brüggemann, Holger; Lomholt, Hans B; Kilian, Mogens

    2012-01-01

    Propionibacterium acnes is a Gram-positive bacterium that is intimately associated with humans. The nature and consequences of this symbiosis are poorly understood; it might comprise both mutualistic and parasitic properties. Recent advances in distinguishing phylotypes of P. acnes have revealed...... that certain type I lineages are predominantly associated with acne vulgaris. Genome analyses revealed a highly conserved core genome and the existence of island-like genomic regions and possible mobile genetic elements as part of the flexible gene pool. The analysis of clustered regularly interspaced short...... palindromic repeats (CRISPR), found exclusively in type II P. acnes, recently revealed the presence of CRISPR spacers that derived from mobile genetic elements. These elements are present in a subset of P. acnes type I lineages. Their significance for type-specific host-interacting properties...

  14. DNA Probe Pooling for Rapid Delineation of Chromosomal Breakpoints

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Chun-Mei; Kwan, Johnson; Baumgartner, Adolf; Weier, Jingly F.; Wang, Mei; Escudero, Tomas; Munne' , Santiago; Zitzelsberger, Horst F.; Weier, Hei