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18FDG uptake in brown fat: potential for false positives.

https://arctichealth.org/en/permalink/ahliterature77628
Source
Radiol Technol. 2007 May-Jun;78(5):361-6
Publication Type
Article
Author
Evans Kevin D
Tulloss Timothy A
Hall Nathan
Author Affiliation
Radiologic Sciences and Therapy, Division of the School of Allied Medical Professions and the Department of Radiology at the Ohio State University, Columbus, OH, USA.
Source
Radiol Technol. 2007 May-Jun;78(5):361-6
Language
English
Publication Type
Article
Keywords
Adipose Tissue, Brown - metabolism - radionuclide imaging
Artifacts
False Positive Reactions
Fluorodeoxyglucose F18 - diagnostic use - pharmacokinetics
Humans
Neoplasms - metabolism - radionuclide imaging
Radiopharmaceuticals - diagnostic use - pharmacokinetics
Abstract
CONTEXT: (18)FDG is used widely to enhance PET and PET-CT images. However, this radiotracer tends to be taken up by brown fat, which can lead to false-positive diagnoses. Purpose To determine which patients, areas of the body and circumstances are more likely to be associated with false-positive diagnoses due to (18)FDG uptake in brown fat. METHOD: A review of the literature was conducted on factors that contribute to false-positive diagnoses caused by (18)FDG uptake in brown fat. RESULTS: Brown fat commonly is found in women and children and can be located in the supraclavicular, mediastinal, paravertebral and perirenal areas of the body. Research has shown that these areas can be sources of a false-positive diagnosis because of (18)FDG uptake. Studies also have indicated that cold climate affects the uptake of (18)FDG, contributing to false-positive results on PET-CT examinations. CONCLUSIONS: This literature review should stimulate continued research into and awareness of the potential for false-positive PET findings in women and children during the winter months and in cold climates. This information is especially applicable to young female patients undergoing PET or PET-CT.
PubMed ID
17519372 View in PubMed
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Aberrant circulating levels of purinergic signaling markers are associated with several key aspects of peripheral atherosclerosis and thrombosis.

https://arctichealth.org/en/permalink/ahliterature263533
Source
Circ Res. 2015 Mar 27;116(7):1206-15
Publication Type
Article
Date
Mar-27-2015
Author
Juho Jalkanen
Gennady G Yegutkin
Maija Hollmén
Kristiina Aalto
Tuomas Kiviniemi
Veikko Salomaa
Sirpa Jalkanen
Harri Hakovirta
Source
Circ Res. 2015 Mar 27;116(7):1206-15
Date
Mar-27-2015
Language
English
Publication Type
Article
Keywords
5'-Nucleotidase - blood
Adenosine Diphosphate - blood
Adenosine Triphosphate - blood
Adult
Age Factors
Aged
Aged, 80 and over
Alkaline Phosphatase - blood
Angiotensin-Converting Enzyme Inhibitors - therapeutic use
Anoxia - blood
Antigens, CD - blood
Apyrase - blood
Artifacts
Atherosclerosis - blood - epidemiology
Biological Markers
Chronic Disease
Comorbidity
Disease Progression
Drug Utilization
Female
Finland - epidemiology
GPI-Linked Proteins - blood
Humans
Hydroxymethylglutaryl-CoA Reductase Inhibitors - therapeutic use
Hypertension - blood - drug therapy - epidemiology
Male
Middle Aged
Models, Cardiovascular
Peripheral Arterial Disease - blood - epidemiology
Purinergic P2Y Receptor Antagonists - therapeutic use
Risk factors
Second Messenger Systems
Smoking - adverse effects - blood - epidemiology
Thrombophilia - blood - epidemiology - etiology
Abstract
Purinergic signaling plays an important role in inflammation and vascular integrity, but little is known about purinergic mechanisms during the pathogenesis of atherosclerosis in humans.
The objective of this study is to study markers of purinergic signaling in a cohort of patients with peripheral artery disease.
Plasma ATP and ADP levels and serum nucleoside triphosphate diphosphohydrolase-1 (NTPDase1/CD39) and ecto-5'-nucleotidase/CD73 activities were measured in 226 patients with stable peripheral artery disease admitted for nonurgent invasive imaging and treatment. The major findings were that ATP, ADP, and CD73 values were higher in atherosclerotic patients than in controls without clinically evident peripheral artery disease (P
PubMed ID
25645301 View in PubMed
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Adaptive registration of varying contrast-weighted images for improved tissue characterization (ARCTIC): application to T1 mapping.

https://arctichealth.org/en/permalink/ahliterature268568
Source
Magn Reson Med. 2015 Apr;73(4):1469-82
Publication Type
Article
Date
Apr-2015
Author
Sébastien Roujol
Murilo Foppa
Sebastian Weingärtner
Warren J Manning
Reza Nezafat
Source
Magn Reson Med. 2015 Apr;73(4):1469-82
Date
Apr-2015
Language
English
Publication Type
Article
Keywords
Algorithms
Artifacts
Female
Humans
Image Enhancement - methods
Image Interpretation, Computer-Assisted - methods
Magnetic Resonance Imaging, Cine - methods
Male
Middle Aged
Motion
Myocardium - pathology
Pattern Recognition, Automated - methods
Reproducibility of Results
Sensitivity and specificity
Subtraction Technique
Abstract
To propose and evaluate a novel nonrigid image registration approach for improved myocardial T1 mapping.
Myocardial motion is estimated as global affine motion refined by a novel local nonrigid motion estimation algorithm. A variational framework is proposed, which simultaneously estimates motion field and intensity variations, and uses an additional regularization term to constrain the deformation field using automatic feature tracking. The method was evaluated in 29 patients by measuring the DICE similarity coefficient and the myocardial boundary error in short axis and four chamber data. Each image series was visually assessed as "no motion" or "with motion." Overall T1 map quality and motion artifacts were assessed in the 85 T1 maps acquired in short axis view using a 4-point scale (1-nondiagnostic/severe motion artifact, 4-excellent/no motion artifact).
Increased DICE similarity coefficient (0.78 ± 0.14 to 0.87 ± 0.03, P
Notes
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PubMed ID
24798588 View in PubMed
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Adding attenuation corrected images in myocardial perfusion imaging reduces the need for a rest study.

https://arctichealth.org/en/permalink/ahliterature115070
Source
BMC Med Imaging. 2013;13:14
Publication Type
Article
Date
2013
Author
Elin Trägårdh
Sven Valind
Lars Edenbrandt
Author Affiliation
Clinical Physiology and Nuclear Medicine Unit, Skåne University Hospital, Lund University, Entrance 44, 205 05 Malmö, Sweden. elin.tragardh@med.lu.se
Source
BMC Med Imaging. 2013;13:14
Date
2013
Language
English
Publication Type
Article
Keywords
Adult
Aged
Artifacts
Coronary Artery Disease - epidemiology - radionuclide imaging
Exercise Test - methods - statistics & numerical data
Female
Humans
Image Enhancement - methods
Male
Middle Aged
Myocardial Perfusion Imaging - methods - statistics & numerical data
Prevalence
Reproducibility of Results
Rest
Risk factors
Sensitivity and specificity
Sweden - epidemiology
Abstract
The American Society of Nuclear Cardiology and the Society of Nuclear Medicine conclude that incorporation of attenuation corrected (AC) images in myocardial perfusion scintigraphy (MPS) will improve diagnostic accuracy. The aim was to investigate the value of adding AC stress-only images for the decision whether a rest study is necessary or not.
1,261 patients admitted to (99m)Tc MPS were studied. The stress studies were interpreted by two physicians who judged each study as "no rest study necessary" or "rest study necessary", by evaluating NC stress-only and NC + AC stress-only images. When there was disagreement between the two physicians, a third physician evaluated the studies. Thus, agreement between 2 out of 3 physicians was evaluated.
The physicians assessed 214 more NC + AC images than NC images as "no rest study necessary" (17% of the study population). The number of no-rest-study-required was significantly higher for NC + AC studies compared to NC studies (859 vs 645 cases (p
Notes
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PubMed ID
23547878 View in PubMed
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Application of Molecular Typing Results in Source Attribution Models: The Case of Multiple Locus Variable Number Tandem Repeat Analysis (MLVA) of Salmonella Isolates Obtained from Integrated Surveillance in Denmark.

https://arctichealth.org/en/permalink/ahliterature278946
Source
Risk Anal. 2016 Mar;36(3):571-88
Publication Type
Article
Date
Mar-2016
Author
Leonardo V de Knegt
Sara M Pires
Charlotta Löfström
Gitte Sørensen
Karl Pedersen
Mia Torpdahl
Eva M Nielsen
Tine Hald
Source
Risk Anal. 2016 Mar;36(3):571-88
Date
Mar-2016
Language
English
Publication Type
Article
Keywords
Animals
Artifacts
Bacteriophage Typing
Chickens
Denmark
Disease Outbreaks
Ducks
Food Safety
Humans
Meat
Minisatellite Repeats
Models, Statistical
Multilocus Sequence Typing - methods
Salmonella Food Poisoning - diagnosis - microbiology
Salmonella Infections
Salmonella enteritidis - isolation & purification
Salmonella typhimurium - isolation & purification
Swine
Turkeys
Abstract
Salmonella is an important cause of bacterial foodborne infections in Denmark. To identify the main animal-food sources of human salmonellosis, risk managers have relied on a routine application of a microbial subtyping-based source attribution model since 1995. In 2013, multiple locus variable number tandem repeat analysis (MLVA) substituted phage typing as the subtyping method for surveillance of S. Enteritidis and S. Typhimurium isolated from animals, food, and humans in Denmark. The purpose of this study was to develop a modeling approach applying a combination of serovars, MLVA types, and antibiotic resistance profiles for the Salmonella source attribution, and assess the utility of the results for the food safety decisionmakers. Full and simplified MLVA schemes from surveillance data were tested, and model fit and consistency of results were assessed using statistical measures. We conclude that loci schemes STTR5/STTR10/STTR3 for S. Typhimurium and SE9/SE5/SE2/SE1/SE3 for S. Enteritidis can be used in microbial subtyping-based source attribution models. Based on the results, we discuss that an adjustment of the discriminatory level of the subtyping method applied often will be required to fit the purpose of the study and the available data. The issues discussed are also considered highly relevant when applying, e.g., extended multi-locus sequence typing or next-generation sequencing techniques.
PubMed ID
27002674 View in PubMed
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Breaking Conventions: How the Smithsonian's Arctic Studies Center Makes a Difference in the Community

https://arctichealth.org/en/permalink/ahliterature257249
Source
First Alaskans. 2013 Feb/Mar; (): 56-60.
Publication Type
Article
Date
2013
  1 website  

Childhood leukaemia and socioeconomic status.

https://arctichealth.org/en/permalink/ahliterature160053
Source
Int J Epidemiol. 2007 Oct;36(5):1155; author reply 1156
Publication Type
Article
Date
Oct-2007

Clinical utility of ultra high pitch dual source thoracic CT imaging of acute pulmonary embolism in the emergency department: are we one step closer towards a non-gated triple rule out?

https://arctichealth.org/en/permalink/ahliterature113301
Source
Eur J Radiol. 2013 Oct;82(10):1793-8
Publication Type
Article
Date
Oct-2013
Author
Daniel J Hou
David K Tso
Chris Davison
Joao Inacio
Luck J Louis
Savvakis Nicolaou
Anja J Reimann
Author Affiliation
Department of Radiology, Faculty of Medicine, University of British Columbia, 3350-950 W 10th Avenue, Vancouver BC V5Z 4E3 Canada. danieljameshou@gmail.com
Source
Eur J Radiol. 2013 Oct;82(10):1793-8
Date
Oct-2013
Language
English
Publication Type
Article
Keywords
Acute Disease
Adult
Aged
Aged, 80 and over
Angiography - statistics & numerical data
Artifacts
British Columbia - epidemiology
Emergency Medical Services - statistics & numerical data
Emergency Service, Hospital - statistics & numerical data
Female
Humans
Male
Middle Aged
Prevalence
Pulmonary Embolism - epidemiology - radiography
Radiation Dosage
Radiography, Dual-Energy Scanned Projection - statistics & numerical data
Radiography, Thoracic - statistics & numerical data
Reproducibility of Results
Respiratory-Gated Imaging Techniques - statistics & numerical data
Risk assessment
Sensitivity and specificity
Tomography, X-Ray Computed - statistics & numerical data
Young Adult
Abstract
Aim of this study was to retrospectively compare the image quality and the radiation dose of an ultra high pitch CT scan for the evaluation of pulmonary embolism and visualization of cardiac structures in comparison to our institution's standard pulmonary embolism protocol.
The study cohort consisted of 115 consecutive patients, 57 underwent CT pulmonary angiography on a dual source 128 slice scanner (Siemens Somatom Definition FLASH) via an ultra high pitch mode (Pitch 2.8) while 58 were scanned on a dual source 64 slice scanner (Siemens Somatom Definition Dual Source) with standard pitch (Pitch 0.9). Qualitative image assessment was determined by two blinded radiologists with 3 and 15 years' experience in chest and cardiac CT. Quantitative image assessment was determined by the signal to noise ratio (SNR) and contrast to noise ratio (CNR). Effective radiation dose was calculated via the product of the dose length product.
For the ultra high pitch protocol, 14% (8/57) were positive for pulmonary embolus compared to 13.7% (8/58) for the standard pitch group. 98.2% of the ultra high pitch scans were diagnostic for pulmonary embolus vs. 94.8% of the standard protocol. Visualization of cardiac structures was significantly improved with the ultra high pitch protocol (p
PubMed ID
23743054 View in PubMed
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Comparative multicentre study of a panel of thyroid tests using different automated immunoassay platforms and specimens at high risk of antibody interference.

https://arctichealth.org/en/permalink/ahliterature196698
Source
Clin Chem Lab Med. 2000 Aug;38(8):785-93
Publication Type
Article
Date
Aug-2000
Author
J. Martel
N. Després
C E Ahnadi
J F Lachance
J E Monticello
G. Fink
A. Ardemagni
G. Banfi
J. Tovey
P. Dykes
R. John
J. Jeffery
A M Grant
Author Affiliation
Centre for Research and Evaluation in Diagnostics, Department of Clinical Biochemistry, Centre Hospitalier Universitaire de Sherbrooke, Qc, Canada.
Source
Clin Chem Lab Med. 2000 Aug;38(8):785-93
Date
Aug-2000
Language
English
Publication Type
Article
Keywords
Antibodies - immunology
Artifacts
Automation
Canada
Cross Reactions
Humans
Immunoassay - methods
Italy
Reagent kits, diagnostic
Regression Analysis
Reproducibility of Results
Thyroid Function Tests
Thyrotropin - analysis
Thyroxine - analysis
Triiodothyronine - analysis
Wales
Abstract
The introduction of automation for immunoassays in recent years has brought about important and evident improvements in assay precision. Increasing standardization and comparability between platforms should enable the development of clinical guidelines and diagnostic algorithms for appropriate clinical decision making. A continuing source of variation between different automated immunoassay platforms is the sporadic effect of interfering antibodies or substances, thus causing aberrant results not supporting the patient's clinical status. The aim of this study was to describe current thyroid panel variation between automated immunoassay platforms including population specimens at risk of antibody interference. A multisite design with laboratories in three different countries using four different automated immunoassay platforms (Roche-Boehringer Mannheim Elecsys (Italy), Roche-Boehringer Mannheim ES300 (Wales), Bayer Immuno 1 and the Bayer ACS:180 evaluated the thyroid panel of thyrotropin (TSH), triiodothyromine (T3), free thyroxine (FT4) and free triiodothyronine (FT3). A common set of 158 randomly selected patient samples of non-thyroid and thyroid disorders, with and without treatment, was tested. Included were 62 patient samples at risk for endogenous antibody interference with high antimicrosomal antibody, anti-TSH receptor antibody and increased rheumatoid factor sub-populations. Across all controls and between platforms, precision measurements were comparable and varied between 0.7% and 12.8% for TSH, 2.8% and 13% for FT4, 1.8% and 10.5% for FT3 and 3.1% and 16% for T3 assay. Acceptable correlation and reproducibility were found between the three Bayer Immuno 1 platforms at each country's site with all four thyroid panel assays demonstrating r-values of 0.989 to 1.000 and slopes of 0.915 to 1.078. Comparisons between the different platforms showed acceptable correlation for all thyroid panel assays. Specimens containing rheumatoid factor were associated with a significantly increased variation between systems for the FT4 and FT3 assays (p
PubMed ID
11071074 View in PubMed
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Comparison of analytical techniques for dynamic trace metal speciation in natural freshwaters.

https://arctichealth.org/en/permalink/ahliterature82565
Source
Environ Sci Technol. 2006 Mar 15;40(6):1934-41
Publication Type
Article
Date
Mar-15-2006
Author
Sigg Laura
Black Frank
Buffle Jacques
Cao Jun
Cleven Rob
Davison William
Galceran Josep
Gunkel Peggy
Kalis Erwin
Kistler David
Martin Michel
Noël Stéphane
Nur Yusuf
Odzak Niksa
Puy Jaume
Van Riemsdijk Willem
Temminghoff Erwin
Tercier-Waeber Mary-Lou
Toepperwien Stefanie
Town Raewyn M
Unsworth Emily
Warnken Kent W
Weng Liping
Xue Hanbin
Zhang Hao
Author Affiliation
Eawag, Swiss Federal Institute for Aquatic Science and Technology, P.O. Box 611, CH-8600 Duebendorf, Switzerland. laura.sigg@eawag.ch
Source
Environ Sci Technol. 2006 Mar 15;40(6):1934-41
Date
Mar-15-2006
Language
English
Publication Type
Article
Keywords
Artifacts
Denmark
Environmental Monitoring - instrumentation - methods
Fresh Water - analysis
Reproducibility of Results
Sensitivity and specificity
Time Factors
Trace Elements - analysis
Water Pollutants, Chemical - analysis
Abstract
Several techniques for speciation analysis of Cu, Zn, Cd, Pb, and Ni are used in freshwater systems and compared with respect to their performance and to the metal species detected. The analytical techniques comprise the following: (i) diffusion gradients in thin-film gels (DGT); (ii) gel integrated microelectrodes combined to voltammetric in situ profiling system (GIME-VIP); (iii) stripping chronopotentiometry (SCP); (iv) flow-through and hollow fiber permeation liquid membranes (FTPLM and HFPLM); (v) Donnan membrane technique (DMT); (vi) competitive ligand-exchange/stripping voltammetry (CLE-SV). All methods could be used both under hardwater and under softwater conditions, although in some cases problems with detection limits were encountered at the low total concentrations. The detected Cu, Cd, and Pb concentrations decreased in the order DGT > or = GIME-VIP > or = FTPLM > or = HFPLM approximately = DMT (>CLE-SV for Cd), detected Zn decreased as DGT > or = GIME-VIP and Ni as DGT > DMT, in agreement with the known dynamic features of these techniques. Techniques involving in situ measurements (GIME-VIP) or in situ exposure (DGT, DMT, and HFPLM) appear to be appropriate in avoiding artifacts which may occur during sampling and sample handling.
PubMed ID
16570618 View in PubMed
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54 records – page 1 of 6.