Table 3. Diagnostic Performance of the Individual US Findings for Appendicitis.
| Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) | Accuracy (%) | |
|---|---|---|---|---|---|
| Non-compressible appendix | 95.45 (77.16–99.88) | 16.13 (5.45–33.73) | 44.68 (40.30–49.14) | 83.33 (38.53–97.55) | 49.06 (35.06–63.16) |
| Appendiceal wall thickening | 100 (84.56–100.00) | 35.48 (19.23–54.63) | 52.38 (45.87–58.82) | 100 | 62.26 (47.89–75.21) |
| US-guided tenderness | 95.45 (77.16–99.88) | 6.45 (0.79–21.42) | 42.00 (38.87–45.19) | 66.67 (16.19–95.39) | 43.40 (29.84–57.72) |
| Peri-appendiceal fat infiltration | 77.27 (54.63–92.18) | 51.61 (33.06–69.85) | 53.12 (42.48–63.50) | 76.19 (57.95–88.14) | 62.26 (47.89–75.21) |
| Increased vascularity of the appendiceal wall | 77.27 (54.63–92.18) | 64.52 (45.37–80.77) | 60.71 (47.73–72.34) | 80.00 (63.94–90.02) | 69.81 (55.66–81.66) |
| Peri-appendiceal fat infiltration + increased vascularity of the appendiceal wall | 59.09 (36.35–79.29) | 83.87 (66.27–94.55) | 72.22 (52.02–86.18) | 74.29 (63.08–83.01) | 73.58 (59.67–84.74) |
Data in parentheses are the 95% confidence interval.
NPV = negative predictive value, PPV = positive predictive value, US = ultrasound