Table 4.
Number and percentage of patients considered true positive (TP), false positive (FP) and false negative (FN) after FNAB and MIBI. The sensitivity and positive predictive value (PPV) are also reported for both FNAB and MIBI
| TP | FP | FN | PPV | sensitivity | |
| FNAB | 20/24 (84%) | 1/24 (4%) | 3/24 (12%) | 94% | 83% |
| MIBI | 9/18 (50%) | 5/18 (28%) | 4/18 (22%) | 71% | 69% |
| Significance | P=0.04 | ns | ns | ||
Sensitivity=TP/(TP+FN); PPV=n 1/(n 1+n 2), where n 1 is the number of patients with correspondence between pre-operative result and post-surgical histology in locating parathyroid adenoma (PA); n 2 is the number of patients with positive pre-surgical localization but PA in a different location on surgery. ns: not significantly