Table 3. Diagnostic ability of gray-scale ultrasonography, shear wave elastography, and computed tomography in patients with suspected appendicitis.

	Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)
Gray-scale ultrasonography
Diameter (≥6 mm)	100	82	94	100
Echogenicity of periappendiceal fat	100	82	94	100
Thickening of appendiceal wall	100	73	91	100
Appendicolith	33	100	100	35
Diameter (≥6 mm), Echogenicity of periappendiceal fat, thickening of appendiceal wall	100	82	94	100
Shear wave elastography
Elastic modulus scale (≥12.5 kPa)	93	100	100	85
Computed tomography
Diameter (≥6 mm)	100	100	100	100
Enhancement of periappendiceal fat	100	73	91	100
Thickening of appendiceal wall	100	82	94	100
Appendicolith	33	100	100	35
Diameter (≥6 mm), enhancement of periappendiceal fat, thickening of appendiceal wall	100	100	100	100

PPV, positive predictive value; NPV, negative predictive value; kPa, kilopascal.