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Insights into Imaging

Table 4 Performance of each CT finding in differentiating complicated from uncomplicated appendicitis

From: Predictive ability of CT findings in the differentiation of complicated and uncomplicated appendicitis: a retrospective investigation of 201 patients undergone appendectomy at initial admission

CT findings

Sensitivity

Specificity

Accuracy

PLR

NLR

PPV

NPV

p value

Appendiceal diameter ≥ 12 mma

61.7

65.1

63.5

1.8

0.6

61.1

65.7

< 0.001

(51.1–71.5)

(55.2–74.1)

(56.4–70.2)

(1.3–2.4)

(0.4–0.8)

(53.6–68.0)

(58.9–72.0)

Tip appendiceal diameter ≥ 10 mmb (n = 186)

68.3

54.8

60.8

1.5

0.6

54.4

68.7

< 0.001

(57.1–78.1)

(44.7–64.7)

(53.3–67.8)

(1.2–2.0)

(0.4–0.8)

(47.9–60.7)

(60.4–75.9)

Mucosal hyperenhancement

10.9

57.6

35.5

0.3

1.6

18.7

41.9

0.396

(4.1–22.3)

(47.6–67.1)

(28.1–43.4)

(0.1–0.6)

(1.3–1.9)

(9.5–33.6)

(37.4–46.5)

Mucosal enhancement defect

83.2

79.3

81.1

4.0

0.2

78.2

84.0

< 0.001

(74.1–90.0)

(70.3–86.5)

(75.0–86.3)

(2.7–5.9)

(0.1–0.3)

(71.0–84.0)

(76.9–89.2)

Intraluminal appendicolith

52.6

77.4

65.7

2.3

0.6

67.5

64.6

< 0.001

(42.1–63.0)

(68.2–84.9)

(58.7–72.2)

(1.6–3.5)

(0.5–0.8)

(58.3–75.7)

(59.0–69.8)

Appendicolith causing obstruction

41.5

82.9

63.3

2.4

0.7

68.4

61.3

< 0.001

(31.4–52.1)

(74.3–89.5)

(56.2–70.0)

(1.5–3.9)

(0.6–0.9)

(57.2–77.9)

(56.6–65.7)

Fat stranding; moderate–severe

96.8

42.5

68.2

1.7

0.1

60.1

93.8

< 0.001

(91.1–99.3)

(32.9–52.4)

(61.2–74.5)

(1.4–2.0)

(0.0–0.2)

(56.1–64.1)

(82.8–97.9)

Phlegmon

10.5

99.1

57.2

11.2

0.9

90.9

55.3

0.003

(5.2–18.5)

(94.9–100.0)

(50.1–64.2)

(1.5–85.6)

(0.8–1.0)

(56.6–98.7)

(53.5–57.0)

Fluid collection

24.2

99.1

63.7

25.7

0.8

95.8

59.3

< 0.001

(16.0–34.1)

(94.9–100.0)

(56.6–70.3)

(3.5–186.4)

(0.7–0.9)

(76.0–99.4)

(56.5–62.1)

Extraluminal appendicolith

6.3

100.0

55.7

N/A

0.9

100.0

54.4

0.010

(2.4–13.2)

(96.6–100.0)

(48.6–62.7)

(0.9–1.0)

 

(53.1–55.7)

Periappendiceal air

43.2

100.0

73.1

N/A

0.6

100.0

66.3

< 0.001

(33.0–53.7)

(96.6–100.0)

(66.5–79.1)

(0.5–0.7)

 

(62.2–70.0)

Periappendiceal fluid

76.8

71.7

74.1

2.7

0.3

70.9

77.6

< 0.001

(67.1–84.9)

(62.1–80.0)

(67.5–80.0)

(2.0–3.8)

(0.2–0.5)

(63.8–77.1)

(70.2–83.6)

Ascites

46.3

84.9

66.7

3.1

0.6

73.3

63.8

< 0.001

(36.0–56.9)

(76.7–91.1)

(59.7–73.1)

(1.9–5.1)

(0.5–0.8)

(62.5–81.9)

(59.0–68.4)

Small bowel dilatation

15.8

98.1

59.2

8.4

0.9

88.2

56.5

< 0.001

(9.1–24.7)

(93.4–99.8)

(52.1–66.1)

(2.0–35.7)

(0.8–0.9)

(63.8–97.0)

(54.3–58.8)

Small bowel thickening

49.5

87.7

69.7

4.0

0.6

78.3

66.0

< 0.001

(39.1–59.9)

(79.9–93.3)

(62.8–75.9)

(2.3–7.0)

(0.5–0.7)

(67.6–86.2)

(61.1–70.5)

  1. aArea under ROC curve 0.687 (0.613–0.760)
  2. bArea under ROC curve 0.658 (0.580–0.736)
  3. PLR: Positive likelihood ratio, NLR: negative likelihood ratio, PPV: positive predictive value, NPV: negative predictive value, N/A: not available
  4. Those in brackets represent 95% confidence interval
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