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CT attenuation correction improves specificity and normalcy rate: A multicenter trial
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Abstracts Friday, October 1, 2004
Journal of Nuclear Cardiology July/August 2004
$151,000/ per death. For resting chest pain, it was $28,720/per event and $747,000/death. Conclusion: In angina patients with low risk, myocardial nuclear imaging enhances risk stratification and is useful in cutting expense by selecting patients for coronary angiography and intensive treatment. 31.59 HYBRID SPECT/CT ATTENUATION CORRECTION IMPROVES SPECIFICITY AND NORMALCY RATE: A MULTICENTER TRIAL Y-H Liu1*, F Wackers1, D Natale1, G DePuey2, R Taillefer3, L Araujo4, E Kostacos4, S Allen5, D Delbeke6, F Anstett7 1 Yale University, New Haven, CT; 2St. Luke’s Roosevelt Hospital, New York, NY; 3Centre Hospitalier de l’Universite´ de Montre´ al, QUE; 4 Hospital of University of Pennsylvania, Philadelphia, PA; 5Mercy Medical Center, Springfield, MA; 6Vanderbilt University, Nashville, TN; 7 GE Medical Systems, Waukesha, WI Objective: The aim of this multicenter study was to evaluate the diagnostic performance of a hybrid SPECT/CT attenuation correction system for the detection of angiographic coronary artery disease (CAD). Methods: One hundred and fifty-two patients were included in this study. Eighty-three had angiographic CAD ⱖ50%, 32 patients (pts) had angiographic insignificant CAD (of whom 24 pts had 0% stenosis), and 37 subjects were normal volunteers with ⬍ 3% likelihood of CAD. All pts had exercise-rest Tc-99m-Sestamibi SPECT imaging using a hybrid SPECT/CT gamma camera system. SPECT and CT images were acquired sequentially without patient movement. Images were reconstructed using filtered back projection method without attenuation correction (NC) and ordered subset expectation maximization method with non-uniform attenuation correction (AC). Reconstructed images were smoothed using a conventional Butterworth filter. All images were interpreted by two expert readers (GD, RT) who were blinded to the pts’ clinical information. Images were scored by consensus on a 5-point scale (1:definitely normal; 5:definitely abnormal) for construction of receiver operating characteristic (ROC) curves. Coronary
stenosis ⱖ50% was considered abnormal (CAD⫹) and ⬍ 50% normal (CAD-). Normalcy rate was determined in the normal volunteers (NL). Results: Fig. 1 shows the ROC analysis for NC and AC. Using NL as normal reference, specificity was higher as compared to CAD- as normal. Sensitivity, specificity, predictive accuracy and normalcy were improved using AC (Fig. 2). However, specificity was relative low due to referral bias. Conclusion: CT-based AC SPECT performs better in detecting CAD than NC SPECT, with improved specificity and normalcy rate and preserved sensitivity and predictive accuracy.
Abstracts Friday, October 1, 2004
Journal of Nuclear Cardiology July/August 2004
$151,000/ per death. For resting chest pain, it was $28,720/per event and $747,000/death. Conclusion: In angina patients with low risk, myocardial nuclear imaging enhances risk stratification and is useful in cutting expense by selecting patients for coronary angiography and intensive treatment. 31.59 HYBRID SPECT/CT ATTENUATION CORRECTION IMPROVES SPECIFICITY AND NORMALCY RATE: A MULTICENTER TRIAL Y-H Liu1*, F Wackers1, D Natale1, G DePuey2, R Taillefer3, L Araujo4, E Kostacos4, S Allen5, D Delbeke6, F Anstett7 1 Yale University, New Haven, CT; 2St. Luke’s Roosevelt Hospital, New York, NY; 3Centre Hospitalier de l’Universite´ de Montre´ al, QUE; 4 Hospital of University of Pennsylvania, Philadelphia, PA; 5Mercy Medical Center, Springfield, MA; 6Vanderbilt University, Nashville, TN; 7 GE Medical Systems, Waukesha, WI Objective: The aim of this multicenter study was to evaluate the diagnostic performance of a hybrid SPECT/CT attenuation correction system for the detection of angiographic coronary artery disease (CAD). Methods: One hundred and fifty-two patients were included in this study. Eighty-three had angiographic CAD ⱖ50%, 32 patients (pts) had angiographic insignificant CAD (of whom 24 pts had 0% stenosis), and 37 subjects were normal volunteers with ⬍ 3% likelihood of CAD. All pts had exercise-rest Tc-99m-Sestamibi SPECT imaging using a hybrid SPECT/CT gamma camera system. SPECT and CT images were acquired sequentially without patient movement. Images were reconstructed using filtered back projection method without attenuation correction (NC) and ordered subset expectation maximization method with non-uniform attenuation correction (AC). Reconstructed images were smoothed using a conventional Butterworth filter. All images were interpreted by two expert readers (GD, RT) who were blinded to the pts’ clinical information. Images were scored by consensus on a 5-point scale (1:definitely normal; 5:definitely abnormal) for construction of receiver operating characteristic (ROC) curves. Coronary
stenosis ⱖ50% was considered abnormal (CAD⫹) and ⬍ 50% normal (CAD-). Normalcy rate was determined in the normal volunteers (NL). Results: Fig. 1 shows the ROC analysis for NC and AC. Using NL as normal reference, specificity was higher as compared to CAD- as normal. Sensitivity, specificity, predictive accuracy and normalcy were improved using AC (Fig. 2). However, specificity was relative low due to referral bias. Conclusion: CT-based AC SPECT performs better in detecting CAD than NC SPECT, with improved specificity and normalcy rate and preserved sensitivity and predictive accuracy.