Results 211 to 220 of about 78,948 (263)

27. PET Image Interpretation Attenuation-Corrected (ATN) Vs Non-Attenuation Corrected (NATN) Images

Clinical Positron Imaging, 2000
Purpose: The purpose of this study was to evaluate the difference, if any, in lesion detection in ATN and NATN images.Methods: Sixty-one consecutive patients having clinical whole body FDG PET scans for oncologic indications were included. The patients were administered 10-20 mCi FDG intravenously, and imaging on the Advance (GE Medical Systems) was ...
, Wong, , Coleman, , Hagge, , Borges-Neto, , Hanson   +4 more
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SPECT Attenuation Correction

2015
Abstract Attenuation correction minimizes the impact of body habitus on the acquired myocardial count distribution. The superior diagnostic performance of corrected over uncorrected SPECT images is due to improved specificity and normalcy rate.
Fabio Peroba Esteves, James R. Galt
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Segmented attenuation correction for myocardial SPECT

Annals of Nuclear Medicine, 2004
One of the main factors contributing to the accuracy of attenuation correction for SPECT imaging using transmission computed tomography (TCT) with an external gamma-ray source is the radionuclide count. To reduce deterioration of TCT images due to inadequate radionuclide counts, a correction method, segmented attenuation correction (SAC), in which TCT ...
Yasuyuki, Takahashi, Kenya, Murase, Teruhito, Mochizuki, Hiroshi, Higashino, Yoshifumi, Sugawara, Akiyoshi, Kinda   +5 more
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PET/MRI: Attenuation Correction

2018
A well-known challenge in PET/MRI scanners is the correction of annihilation-photon attenuation introduced by both patient tissue and hardware within the field of view. Traditional methods of accounting for such attenuation—such as direct measurement with radioactive sources or estimation from computed tomography data—are impractical to implement due ...
Gaspar Delso, Johan Nuyts
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Regression Estimation after Correcting for Attenuation

Journal of the American Statistical Association, 1978
Abstract The limiting distribution of the regression coefficients calculated from a correlation matrix that has been corrected for attenuation is obtained. Methods of estimating the covariance matrix of the vector of regression coefficients are presented. Nonnormal regression variables and nondiagonal error matrices are considered.
Wayne A. Fuller, Michael A. Hidiroglou
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Comparative Accuracy of CT Attenuation-Corrected and Non–Attenuation-Corrected SPECT Myocardial Perfusion Imaging

Clinical Nuclear Medicine, 2012
The aim of the present study was to evaluate whether computed tomography based-attenuation correction (CT-AC) provides any advantage over non-attenuation-corrected (NAC) images for qualitative and quantitative analysis of single photon emission tomography (SPECT) myocardial perfusion imaging (MPI).We retrospectively evaluated data of 171 patients who ...
Punit, Sharma, Chetan D, Patel, Sellam, Karunanithi, Sagar, Maharjan, Arun, Malhotra   +4 more
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The Correction for Attenuation

Educational and Psychological Measurement, 1996
This article examines the statistical correction for attenuation and the controversies surrounding the procedure. Although originally developed for test construction purposes, the correction for attenuation is also used in meta-analysis and assessments of validity generalization. Since Spearman's classic article in 1904, correct use and interpretation
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A Semiparametric Correction for Attenuation

Journal of the American Statistical Association, 1994
Abstract A correction method is proposed for models including the generalized linear model when the covariate is measured with error. The method requires a separate validation data set that consists of the surrogate W and the true covariate X or an unbiased estimate X⊃ of X.
J. H. Sepanski, R. Knickerbocker, R. J. Carroll   +2 more
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Test Reliability and Correction for Attenuation

Psychometrika, 1950
Evidence is cited to show that specificity, or lack of equivalence, in the comparable forms of tests has a tendency to lower the value of reliability coefficients but has no tendency to lower the value of observed trait coefficients. This implies that the greater the lack of equivalence, the higher will be coefficients corrected for attenuation. Errors
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Attenuation Correction during Image Reconstruction

2014
The main goal of SPECT imaging is to determine the distribution of injected activity inside patient’s body. However, due to photon attenuation, a quantitative study is encountered with remarkable error. Using Monte Carlo method, it is possible to find the most precise relationship between activity distribution and its projections.
Shahla Ahmadi, Dariush Sardari, Hossein Rajabi, Farshid Babapour, Marzieh Rahmatpour   +4 more
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