Table 3.

Sonographic indicators predictive of intraoperative diagnosis of AC

Sonographic indicator	No.	Sensitivity,%	Specificity, %	PPV, %	NPV, %
Diagnosis of AC
Cholelithiasis	245	90.0	4.6	75.3	12.5
Thick wall	172	71.4	72.3	89.3	43.9
Murphy sign	137	59.5	86.2	93.3	39.7
Stone in neck	84	36.2	87.7	90.5	29.8
Distended	80	34.3	87.7	90.0	29.2
Pericholecystic fluid	35	15.7	96.9	94.3	26.3
Diagnosis of difficult operation*
Cholelithiasis	245	93.6	9.3	22.9	83.3
Thick wall	172	71.0	41.4	25.9	83.2
Murphy sign	137	50.0	51.2	22.8	78.0
Stone in neck	84	48.4	74.9	35.7	83.4
Distended	80	33.9	72.6	26.3	79.2
Pericholecystic fluid	35	14.5	87.9	25.7	78.1
Diagnosis of gangrenous AC
Cholelithiasis	245	85.2	8.1	9.2	83.3
Thick wall	172	77.8	40.7	12.5	94.4
Murphy sign	137	70.4	53.6	14.2	94.3
Stone in neck	84	37.0	70.2	11.9	91.1
Distended	80	44.4	72.6	15.0	92.3
Pericholecystic fluid	35	18.5	87.9	14.3	90.8

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

^*Difficult operation: fundus-down dissection, drain, partial cholecystectomy, conversion, or fifth port insertion.