Table 2.

Agreement between US and intraoperative diagnosis of AC

Factor	Intraoperative AC	No intraoperative AC	Total	PPV/NPV (%)
US AC	134	9	143	PPV 93.7
No US AC	49	53	102	NPV 52.0
Total	183	62	245	—
Sensitivity/specificity, %	Sensitivity 73.2	Specificity 85.5		—

AC = acute cholecystitis; NPV = negative predictive value; PPV = positive predictive value; US = ultrasonography.