Table 4: Observer concordance and 2 × 2 table values for Extended ASL cohort with both 3.0 T and 1.5 T systems. Observer concordance is defined as in table 1. The left 2 × 2 table is for the entire extended cohort of ASL studies, while the right table is censored, excluding 5 study results that were ambiguous, i.e., outcome was not be definitive by the study's end.
A
Observer concordance | |||||
Overall agreement | Fleiss' free margin kappa | Complete agreement | Partial discordance (1 v. 2 or 2 v. 3) | Complete discordance (1 v. 3) | |
ASL total | 76% | 0.69 | 52/75 69% |
23/75 31% |
0/70 0% |
ASL censored | 80% | 0.7 | 49/70 70% |
21/70 30% |
0/71 0% |
B
ASL extended cohort | ||||
Cond. + | Cond. - | Sum | PPV, NPV | |
Test + | 14 | 4 | 18 | 0.78 |
Test - | 8 | 49 | 57 | 0.86 |
Sum | 22 | 53 | 75 | |
Sens., Spec. | 0.64 | 0.92 | 0.84 |
C
ASL extended cohort censored | ||||
Cond. + | Cond. - | Sum | PPV, NPV | |
Test + | 14 | 2 | 16 | 0.88 |
Test - | 8 | 46 | 54 | 0.85 |
Sum | 22 | 48 | 70 | |
Sens., Spec. | 0.64 | 0.96 | 0.86 |