Diagnostic efficacy, imaging characteristics, and detection accuracy of transabdominal superficial ultrasonography for various types of appendicitis

Table 2 Comparison of diagnostic efficacy of two ultrasonography methods for detecting acute simple appendicitis

Diagnostic method	Nature	Gold standard (units)		Sensitivity (%)	Specificity (%)	Accuracy (%)	Positive predictive value (%)	Negative predictive value (%)
		Positive	Negative
Conventional abdominal ultrasonography	Positive	13	11	59.09	78.00	72.22	54.17	81.25
	Negative	9	39
Transabdominal superficial ultrasonography	Positive	20	3	90.91	94.00	93.06	86.96	95.92
	Negative	2	47
χ2	-	-	-	5.939	5.316	10.891	6.038	5.189
P value	-	-	-	0.015	0.021	0.001	0.014	0.023