Article Figures & Data
Figures
- FIGURE 1.
GUI used in ROC studies. Top 3 panels display SA, HLA, and VLA slices, from top to bottom, for interpretation by observer. Three pull-down buttons shown on polar map marking 3 arterial territories (middle panel at bottom) allowed user to assign score to each vascular territory (LAD, LCx, and RCA). During training, feedback regarding presence or absence of defect would appear in right panel at bottom of interface after observer completed assigning scores as described in text. Instructions for observer were given in left panel at bottom.
- FIGURE 2.
Comparison of SA slices of FBP (first row), OSEM with AC (second row), OSEM with AC + SC (third row), and OSEM with AC + SC + RC (fourth row) reconstructions for patient with low likelihood of CAD. Note that inferior wall cooling artifact associated with subdiaphragmatic attenuation and presence of extracardiac activity, although present in FBP images, is absent in corrected images. Enhanced levels of extracardiac activity were seen in OSEM images with AC alone, in contrast to OSEM images with both AC + SC and AC + SC + RC.
- FIGURE 3.
Comparison of ROC curves for overall detection of CAD (averaged over 7 observers) for FBP, OSEM with AC, OSEM with AC + SC, and OSEM with AC + SC + RC. TPF = true-positive fraction; FPF = false-positive fraction.
- FIGURE 4.
Average ROC curves for LAD localization for FBP, OSEM with AC, OSEM with AC + SC, and OSEM with AC + SC + RC. TPF = true-positive fraction; FPF = false-positive fraction.
- FIGURE 5.
Average ROC curves for LCx localization for FBP, OSEM with AC, OSEM with AC + SC, and OSEM with AC + SC + RC. TPF = true-positive fraction; FPF = false-positive fraction.
- FIGURE 6.
Average ROC curves for RCA localization for FBP, OSEM with AC, OSEM with AC + SC, and OSEM with AC + SC + RC. TPF = true-positive fraction; FPF = false-positive fraction.
Tables
- TABLE 1
Aggregate Az Values for Detecting CAD and Arterial Defects and Significance of Differences Between Reconstruction Methods
Disease or defect location Mean ± SD Az (P value*) for: FBP AC AC + SC AC + SC + RC CAD 0.808 ± 0.023 0.845 ± 0.010 (0.011) 0.868 ± 0.009 (<0.001) 0.894 ± 0.014 (<0.001†) LAD 0.746 ± 0.026 0.784 ± 0.024 0.781 ± 0.025 0.803 ± 0.024 (0.007) LCx 0.809 ± 0.013 0.837 ± 0.024 0.845 ± 0.022 0.863 ± 0.021 (0.036) RCA 0.744 ± 0.032 0.775 ± 0.023 0.801 ± 0.019 (0.022) 0.785 ± 0.014 - TABLE 2
Aggregate Sensitivity for Detecting CAD and Arterial Defects at 80% Specificity and Significance of Differences Between Reconstruction Methods
Disease or defect location Mean ± SD % sensitivity (P value*) for: FBP AC AC + SC AC + SC + RC CAD 65.9 ± 4.9 74.8 ± 2.6 (0.034) 77.0 ± 2.1 (0.007) 82.2 ± 2.7 (<0.001) LAD 57.1 ± 4.5 60.1 ± 5.6 61.9 ± 4.8 64.9 ± 4.8 (0.025) LCx 64.6 ± 3.0 70.3 ± 5.7 69.5 ± 5.7 75.5 ± 4.8 RCA 56.4 ± 6.1 57.4 ± 5.3 64.3 ± 3.8 58.3 ± 3.1 ↵* P values are for comparisons between indicated method and FBP. Only significant and nonredundant P values are shown. No significant differences were noted for LCx and RCA territories.
- TABLE 3
Aggregate Specificity for Detecting CAD and Arterial Defects at 80% Sensitivity and Significance of Differences Between Reconstruction Methods
Disease or defect location Mean ± SD % specificity (P value*) for: FBP AC AC + SC AC + SC + RC CAD 66.7 ± 4.5 73.1 ± 2.3 (0.016) 78.0 ± 1.6 (<0.001) 82.6 ± 3.0 (0.001†) LAD 52.5 ± 4.8 63.0 ± 4.0 (0.019) 61.2 ± 5.1 66.5 ± 4.9 (0.0017) LCx 67.2 ± 2.2 76.1 ± 4.2 76.9 ± 3.5 79.2 ± 3.2 (0.0164) RCA 53.4 ± 6.1 62.1 ± 3.8 (0.024) 65.5 ± 3.6 (0.002) 63.6 ± 2.4 (0.007) - TABLE 4
Comparison of Average Az Values Obtained by Attending Physicians (AP) and Cardiology Fellows (CF)
Disease or defect location Observers Mean ± SD Az for: FBP AC AC + SC AC + SC + RC CAD AP 0.819 ± 0.010 0.852 ± 0.005 0.870 ± 0.005 0.892 ± 0.011 CF 0.800 ± 0.015 0.840 ± 0.010 0.867 ± 0.012 0.896 ± 0.006 LAD AP 0.729 ± 0.023 0.799 ± 0.019 0.775 ± 0.009 0.799 ± 0.007 CF 0.759 ± 0.004 0.772 ± 0.012 0.786 ± 0.013 0.807 ± 0.019 LCx AP 0.829 ± 0.016 0.866 ± 0.016 0.849 ± 0.010 0.840 ± 0.023 CF 0.793 ± 0.015 0.815 ± 0.012 0.842 ± 0.009 0.880 ± 0.012 RCA AP 0.759 ± 0.004 0.769 ± 0.026 0.817 ± 0.010 0.790 ± 0.007 CF 0.733 ± 0.017 0.779 ± 0.022 0.790 ± 0.018 0.781 ± 0.007
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