Added value of ratio of cross diameters of the appendix in ultrasound diagnosis of acute appendicitis

Table 2 Diagnostic performances of different criteria for evaluating acute appendicitis

Item	Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)	AUC (95%CI)
RATIO (1.18)	91.0	83.0	91.8	81.6	0.870 (0.830-0.904)
MOD (> 6 mm)	99.1	31.3	75.0	94.6	0.652 (0.599-0.702)
RATIO + MOD > 6 mm	90.1	92.0	95.9	81.7	0.910 (0.875-0.938)

RATIO: Ratio of the cross diameters of the appendix; MOD: Maximum outer diameter on the transverse section of the appendix; PPV: Positive predictive value; NPV: Negative predictive value; AUC: Area under the receiver operating characteristic curve.