Statistical results: | Low-dose CT (45 mAs) | Ultra-low-dose CT (22 mAs) | ||||||
---|---|---|---|---|---|---|---|---|
Observer 1 | Observer 2 | Observer 1 | Observer 2 | |||||
Value | 95% CIa | Value | 95% CI | Value | 95% CI | Value | 95% CI | |
Sensitivity | 97.84% | 93.82 to 99.55% | 97.84% | 93.82 to 99.55% | 93.53% | 88.06 to 97.00% | 96.40% | 91.81 to 98.82% |
Specificity | 42.86% | 9.90 to 81.59% | 42.86% | 9.90 to 81.59% | 42.86% | 9.90 to 81.59% | 42.86% | 9.90 to 81.59% |
Positive predictive value (PPV) | 97.14% | 94.71 to 98.48% | 97.14% | 94.71 to 98.48% | 97.01% | 94.47 to 98.41% | 97.10% | 94.63 to 98.45% |
Negative predictive value (NPV) | 50.00% | 19.64 to 80.36% | 50.00% | 19.64 to 80.36% | 25.00% | 10.32 to 49.12% | 37.50% | 15.13 to 66.88% |
Positive likelihood ratio | 1.71 | 0.90 to 3.25 | 1.71 | 0.90 to 3.25 | 1.64 | 0.86 to 3.11 | 1.69 | 0.89 to 3.21 |
Negative likelihood ratio | 0.05 | 0.01 to 0.21 | 0.05 | 0.01 to 0.21 | 0.15 | 0.05 to 0.44 | 0.08 | 0.02 to 0.28 |
Accuracy | 95.21% | 90.37 to 98.05% | 95.21% | 90.37 to 98.05% | 91.10% | 85.26 to 95.17% | 93.84% | 88.62 to 97.14% |