MR Imaging Grade Grouping to Indicate NPC | FP | FN | TP | TN | Sen % | Spec % | PPV % | NPV % | Accuracy % |
---|---|---|---|---|---|---|---|---|---|
Grades in the current system | |||||||||
Primary tumor 3, 4a | 140 | 1 | 382 | 243 | 99.74 | 63.45 | 73.18 | 99.59 | 81.59 |
Primary tumor only 4 | 8 | 48 | 335 | 375 | 87.47 | 97.91 | 97.67 | 88.65 | 92.69 |
Grades in the modified system | |||||||||
Primary tumor 3, 4, 5 | 140 | 1 | 382 | 243 | 99.74 | 63.45 | 73.18 | 99.59 | 81.59 |
Primary tumor 4, 5 | 31 | 14 | 369 | 352 | 96.34 | 91.91 | 92.25 | 96.17 | 94.13 |
Primary tumor 4, 5 + node 5a | 40 | 8 | 375 | 343 | 97.91 | 89.56 | 90.36 | 97.72 | 93.73 |
Grades in the plain scan system | |||||||||
Primary tumor 4, 5 | 45 | 17 | 366 | 338 | 95.56 | 88.25 | 89.05 | 95.21 | 91.91 |
Primary tumor 4, 5 + node 5a | 52 | 9 | 374 | 331 | 97.65 | 86.42 | 87.79 | 97.35 | 92.04 |
Note:—FP indicates false-positive; FN, false-negative; TP, true-positive; TN, true-negative; Sen, sensitivity; Spec, specificity; PPV, positive predictive value; NPV, negative predictive value.
↵a Combination of grades in the respective current, modified, and plain scan systems in Table 2.