Table 5: Sensitivity, specificity, predictive values, and accuracy of duplex ultrasound findings in diagnosis of infrapopliteal arterial lesions.

 

Sensitivity

Specificity

PPV

NPV

Accuracy

Ultrasound finding

1. Color Doppler ultrasound

79.0%

(94/119)

66.7%

(42/63)

81.7%

(94/115)

62.7%

(42/67)

74.7%

(136/182)

2. Increased in PSV ≥ two-fold relative to the proximal segment

85.7%

(48/56)

46.8%

(59/126)

41.7%

(48/115)

88.1%

(59/67)

58.8%

(107/182)

3. Monophasic flow

and broadening spectrum at the examined segment

64%

(87/136)

39.1%

(18/46)

75.6%

(87/115)

26.9%

(18/67)

57.7%

(105/182)

 

4. Monophasic flow with reduced velocity at the distal segment

70%

(7/10)

44%

(33/75)

14.3%

(7/49)

91.7%

(33/36)

47.1%

(40/85)

Combining two ultrasound findings

1 + 2

84.9%

(45/53)

45.7%

(59/129)

39.1%

(45/115)

88.1%

(59/67)

57.1%

(104/182)

1 + 3

79.1%

(72/91)

53.3%

(48/90)

62.6%

(72/115)

71.6%

(48/67)

65.9%

(120/182)

Combining three ultrasound findings

1 + 2 + 3

87.6%

(85/97)

64.7%

(55/85)

73.9%

(85/115)

82.1%

(55/67)

76.9%

(140/182)