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. 2024 Sep 29;14(19):2171. doi: 10.3390/diagnostics14192171

Table 4.

Performance with misclassified cases of AC-5M, AC-5A, and AC-3A for detecting S > 1 liver steatosis as defined by MRI-PDFF ≥ 17.1%.

Parameter Algorithm (Observations n) S0–S1 vs. S2–S3
AUROC AC-5M (overall) †

  • IQR/5M ≤ 5% (44)

  • IQR/5M ≤ 10% (135)

  • IQR/5M ≤ 15% (168)

  • IQR/5M > 15% (14)

AC-5A (overall) †

  • SD/5A ≤ 5% (162)

  • SD/5A ≤ 10% (178)

  • SD/5A ≤ 15% (182)

  • SD/5A > 15% (0)

AC-3A (overall) †

  • SD/3A ≤ 5% (116)

  • SD/3A ≤ 10% (173)

  • SD/3A ≤ 15% (178)

  • SD/3A > 15% (4)

 0.91 (0.87–0.96)
0.89 (0.79–0.98) p = 0.65 *
0.90 (0.85–0.95) p = 0.72 *
0.91 (0.86–0.96) p = 0.86 *
0.96 (0.85–1.00) p = 0.42 *
0.91 (0.87–0.96) p = 1 *
0.92 (0.87–0.96) p = 0.93 *
0.92 (0.87–0.96) p = 0.90 *
0.91 (0.87–0.96) p = 1 *
----
0.89 (0.81–0.96) p = 0.65 *
0.90 (0.85–0.96) p = 0.79 *
0.92 (0.87–0.96) p = 0.76 *
0.88 (0.81–0.96) p = 0.57 *
1.00 (1.00–1.00) p ≤ 0.01 *
Sensitivity % AC-5M (overall) †

  • IQR/5M ≤ 5%

  • IQR/5M ≤ 10%

  • IQR/5M ≤ 15%

  • IQR/5M > 15% ^

AC-5A (overall) †

  • SD/5A ≤ 5%

  • SD/5A ≤ 10%

  • SD/5A ≤ 15%

  • SD/5A > 15%

AC-3A (overall) †

  • SD/3A ≤ 5%

  • SD/3A ≤ 10%

  • SD/3A ≤ 15%

  • SD/3A > 15% §

 93.3 (77.9–99.2)
100 (76.8–100)
92.9 (76.5–99.1)
93.1 (77.2–99.2)
100 (2.5–100)
96.7 (82.8–99.9)
96.2 (80.4–99.9)
96.3 (81.0–99.9)
96.7 (82.8–99.9)
----
80.0 (61.4–92.3)
82.6 (61.2–95.1)
80.8 (60.7–93.5)
78.6 (59.1–91.7)
100 (15.8–100)
Specificity % AC-5M (overall) †

  • IQR/5M ≤ 5%

  • IQR/5M ≤ 10%

  • IQR/5M ≤ 15%

  • IQR/5M > 15% ^

AC-5A (overall) †

  • SD/5A ≤ 5%

  • SD/5A ≤ 10%

  • SD/5A ≤ 15%

  • SD/5A > 15%

AC-3A (overall) †

  • SD/3A ≤ 5%

  • SD/3A ≤ 10%

  • SD/3A ≤ 15%

  • SD/3A > 15% §

 73.7 (65.9–80.5)
66.7 (47.2–82.7)
69.2 (59.5–77.7)
71.9 (63.7–79.2)
92.3 (64.0–99.8)
71.7 (63.8–78.7)
71.3 (63.0–78.8)
71.5 (63.6–78.6)
71.7 (63.8–78.7)
----
86.2 (79.7–91.2)
85.0 (76.0–91.5)
85.7 (79.0–90.9)
86.0 (74.9–91.1)
100 (15.8–100)
PPV % AC-5M (overall) †

  • IQR/5M ≤ 5%

  • IQR/5M ≤ 10%

  • IQR/5M ≤ 15%

  • IQR/5M > 15% ^

AC-5A (overall) †

  • SD/5A ≤ 5%

  • SD/5A ≤ 10%

  • SD/5A ≤ 15%

  • SD/5A > 15%

AC-3A (overall) †

  • SD/3A ≤ 5%

  • SD/3A ≤ 10%

  • SD/3A ≤ 15%

  • SD/3A > 15% §

 41.2 (29.4–53.8)
58.3 (36.6–77.9)
44.1 (31.2–57.6)
40.9 (29.0–53.7)
50.0 (13.2–86.8)
40.3 (28.9–52.5)
39.1 (27.1–52.1)
37.7 (26.3–50.2)
40.3 (28.9–52.5)
----
53.3 (37.9–68.3)
57.6 (44.7–69.5)
50 (39.2%–60.8)
51.2 (40.3–62.0)
100 (15.8–100)
NPV % AC-5M (overall) †

  • IQR/5M ≤ 5%

  • IQR/5M ≤ 10%

  • IQR/5M ≤ 15%

  • IQR/5M > 15% ^

AC-5A (overall) †

  • SD/5A ≤ 5%

  • SD/5A ≤ 10%

  • SD/5A ≤ 15%

  • SD/5A > 15%

AC-3A (overall) †

  • SD/3A ≤ 5%

  • SD/3A ≤ 10%

  • SD/3A ≤ 15%

  • SD/3A > 15% §

 98.3 (93.8–99.8)
100 (83.2–100)
97.4 (90.8–99.7)
98.0 (93.1–99.8)
100 (73.5–100)
99.1 (95.0–100)
99.0 (94.5–100)
99.1 (95–100)
99.1 (95–100)
----
95.6 (90.7–98.4)
95.2 (89–98)
96.2 (92–98.2)
95.6 (91.3–97.8)
100 (15.8–100)
LR+ AC-5M (overall) †

  • IQR/5M ≤ 5%

  • IQR/5M ≤ 10%

  • IQR/5M ≤ 15%

  • IQR/5M > 15% ^

AC-5A (overall) †

  • SD/5A ≤ 5%

  • SD/5A ≤ 10%

  • SD/5A ≤ 15%

  • SD/5A > 15%

AC-3A (overall) †

  • SD/3A ≤ 5%

  • SD/3A ≤ 10%

  • SD/3A ≤ 15%

  • SD/3A > 15% §

 3.55 (2.67–4.71)
3.00 (1.81–4.98)
3.01 (2.23–4.07)
3.32 (2.50–4.41)
13 (1.98–85.46)
3.42 (2.63–4.44)
3.35 (2.54–4.42)
3.38 (2.60–4.40)
3.42 (2.63–4.44)
----
5.79 (3.75–8.95)
5.49 (3.27–9.21)
5.65 (3.65–8.76)
5.61 (3.61–8.73)
----
LR− AC-5M (overall) †

  • IQR/5M ≤ 5%

  • IQR/5M ≤ 10%

  • IQR/5M ≤1 5%

  • IQR/5M > 15% ^

AC-5A (overall) †

  • SD/5A ≤ 5%

  • SD/5A ≤ 10%

  • SD/5A ≤ 15%

  • SD/5A > 15%

AC-3A (overall) †

  • SD/3A ≤ 5%

  • SD/3A ≤ 10%

  • SD/3A ≤ 15%

  • SD/3A > 15% §

 0.09 (0.02–0.35)
0
0.10 (0.03–0.40)
0.10 (0.03–0.37)
0
0.05 (0.01–0.35)
0.05 (0.01–0.37)
0.05 (0.01–0.36)
0.05 (0.01–0.32)
----
0.23 (0.11–0.48)
0.20 (0.08–0.50)
5.65 (3.65–8.76)
0.25 (0.12–0.51)
0
Total misclassified cases, n (%) AC-5M (overall) †

  • IQR/5M ≤ 5%

  • IQR/5M ≤ 10%

  • IQR/5M ≤ 15%

  • IQR/5M > 15% ^

AC-5A (overall) †

  • SD/5A ≤ 5%

  • SD/5A ≤ 10%

  • SD/5A ≤ 15%

  • SD/5A > 15%

AC-3A (overall) †

  • SD/3A ≤ 5%

  • SD/3A ≤ 1 0%

  • SD/3A ≤ 15%

  • SD/3A > 15% §

 42 (2 FN + 40 FP) (23.1)
10 (0 FN + 10 FP) (22.7)
35 (2 FN + 33 FP) (25.9)
41 (2 FN + 39 FP) (24.4)
1 (0 FN + 1 FP) (14.3)
44 (1 FN + 43 FP) (24.2)
40 (1 FN + 39 FP) (24.7)
44 (1 FN + 43 FP) (24.7)
44 (1 FN + 43 FP) (24.2)
----
27 (6 FN + 21 FP) (14.8)
18 (4 FN + 14 FP) (15.5)
26 (5 FN + 21 FP) (15.0)
27 (6 FN + 21 FP) (15.2)
0

*, AUROC comparison with AC-5M AUROC; †, IQR/M and SD/A were ≤30% for all AC measurements; ^, only 14 individuals had IQR/M > 15%; §, only 4 individuals had SD/3A > 15%. AC-5M, attenuation coefficient (median of five measurements); AC-5A, attenuation coefficient (average of five measurements); AC-3A, attenuation coefficient (average of three measurements); dB/cm/MHz, decibel/centimeter/megahertz; CI, confidence interval; FN, false negative; FP, false positive; IQR/M, interquartile range to median ratio; SD/A, standard deviation to average ratio; LR+, positive likelihood ratio; LR, negative likelihood ratio; MRI-PDFF, magnetic resonance imaging proton density fat fraction; p, probability of α type I error; NPV, negative predictive value; PPV, positive predictive value; S, steatosis grade; SD, standard deviation.