Table 2.

Repeatability and diagnostic performance of the ADC parameter

No	b-value distribution	ICC (95% CI)	CV (%)	bias (%, ±1.96SD)	AUC (95% CI)	ρ (95% CI)	α
2	0,1000	0.984(0.967–0.992)	3.840	−1.1 (− 11.0–8.9)	0.901 (0.743–0.978)	− 0.745(− 0.868 - -0.535)	2.581
2	0,1500	0.970(0.938–0.985)	4.063	0.8 (− 10.1–11.6)	0.829 (0.655–0.939)	− 0.629(− 0.802 - -0.359)	2.379
2	0,2000	0.968(0.933–0.984)	3.729	1.2 (− 8.7–11.2)	0.837 (0.664–0.943)	− 0.629(− 0.802 - -0.359)	2.385
2	50,1000	0.978(0.955–0.989)	3.333	0.6 (− 8.7–10.0)	0.877 (0.713–0.966)	− 0.710(− 0.849 - -0.480)	2.526
2	50,1500	0.977(0.954–0.989)	3.531	− 0.1 (− 10.2–10.0)	0.813 (0.637–0.929)	− 0.618(− 0.795 - -0.343)	2.372
2	100,1000	0.985(0.970–0.993)	3.514	− 1.8 (− 10.4–6.8)	0.730 (0.545–0.871)	−0.494(− 0.719 - -0.175)	2.156
2	100,2000	0.984(0.966–0.992)	3.762	0.4 (− 9.7–10.5)	0.837 (0.664–0.943)	− 0.598(− 0.783 - -0.314)	2.377
2	200,1000	0.976(0.952–0.989)	3.582	−0.9 (− 10.1–8.3)	0.734 (0.549–0.874)	−0.462(− 0.698 - -0.135)	2.127
2	200,2000	0.988(0.975–0.994)	2.991	0.4 (− 8.5–9.2)	0.766(0.583–0.897)	− 0.511(− 0.730 - -0.197)	2.231
3	0,100,1000	0.990(0.979–0.995)	2.407	−0.6 (− 7.3–6.1)	0.825(0.651–0.936)	−0.635(− 0.805 - -0.368)	2.420
3	0,200,2000	0.980(0.959–0.990)	2.963	− 1.1 (− 9.0–6.7)	0.766(0.583–0.897)	−0.525(− 0.739 - -0.216)	2.230
3	50,1000,2000	0.989(0.978–0.995)	2.857	0.4 (− 7.7–8.6)	0.865(0.698–0.959)	−0.644(− 0.810 - -0.380)	2.465
3	100,1000,1500	0.958(0.914–0.979)	5.568	− 1.7 (− 16.1–12.7)	0.933(0.785–0.991)	−0.751(− 0.871 - -0.544)	2.569
3	200,500,1500	0.966(0.929–0.983)	3.613	−2.2 (− 11.3–6.9)	0.802(0.623–0.921)	−0.572(− 0.767 - -0.278)	2.282
3	500,1500,2000	0.922(0.840–0.962)	4.374	−0.3 (− 11.2–10.7)	0.937(0.791–0.992)	−0.759(− 0.876 - -0.558)	2.571
4	0,100,1000,1500	0.989(0.977–0.995)	3.077	−2.6 (− 10.4–5.2)	0.750(0.549–0.874)	−0.496(− 0.706 - − 0.149)	2.178
4	0,200,1000,2000	0.990(0.980–0.995)	2.143	-0.1 (− 6.0–5.8)	0.833(0.660–0.941)	−0.595(− 0.781 - -0.310)	2.396
4	0,500,1000,1500	0.983(0.965–0.992)	3.703	− 1.4 (− 10.0–7.1)	0.829(0.655–0.939)	−0.574(− 0.769 - -0.282)	2.335
4	100,200,500,1000	0.994(0.988–0.997)	2.554	−2.7 (− 7.9–2.6)	0.804(0.625–0.922)	−0.567(− 0.765 - -0.272)	2.312
4	500,1000,1500, 2000	0.920(0.835–0.961)	4.892	− 1.9 (− 13.5–9.7)	0.938(0.793–0.993)	−0.748(− 0.870 - -0.540)	2.538
5	0,50,200,500,1000	0.998(0.996–0.999)	1.475	−1.6 (− 4.5–1.2)	0.714(0.528–0.859)	−0.407(− 0.662 - -0.068)	2.088
5	0,200,500,1000,1500	0.995(0.990–0.998)	1.933	−1.6 (− 6.0–2.9)	0.774(0.592–0.902)	−0.496(− 0.720 - -0.179)	2.230
5	0,500,1000,1500,2000	0.984(0.968–0.992)	3.349	−1.4 (− 9.7–6.8)	0.871(0.705–0.963)	−0.664(− 0.822 - -0.410)	2.472
5	50,200,500,1500,2000	0.982(0.962–0.991)	2.735	−0.9 (− 7.9–6.0)	0.865(0.698–0.959)	−0.664(− 0.810 - -0.380)	2.475
5	100,200,500,1000,2000	0.990(0.979–0.995)	2.263	−1.6 (− 6.8–3.6)	0.861(0.693–0.957)	−0.626(− 0.800 - -0.355)	2.438
6	0,100,200,500,1000,1500	0.996(0.992–0.998)	1.784	−1.4 (− 5.6–2.8)	0.829 (0.655–0.939)	−0.609(− 0.790 - -0.331)	2.402
6	50,200,500,1000,1500,2000	0.988(0.976–0.994)	2.520	−1.7 (− 7.6–4.3)	0.825(0.651–0.936)	−0.589(− 0.778 - -0.302)	2.360
7	0,100,200,500,1000,1500,2000	0.993(0.985–0.996)	2.137	−1.5 (−6.4–3.5)	0.821(0.646–0.934)	−0.597(− 0.783 - -0.314)	2.375
8	0,50,100,200,250,500,1000,1500	0.995(0.991–0.998)	1.966	−1.6 (− 6.2–3.0)	0.817(0.641–0.931)	−0.597(− 0.783 - -0.314)	2.373
9	0,50,100,150,200,500,1000,1500,2000	0.988(0.975–0.994)	2.811	−1.9 (−8.6–4.8)	0.857(0.688–0.955)	−0.618(− 0.795 - -0.343)	2.416
10	All b values	0.991(0.981–0.996)	2.566	−2.0 (− 7.7–3.6)	0.774(0.592–0.902)	−0.471(− 0.704 - -0.146)	2.190

ICC intraclass correlation coefficient, SD standard deviation, CI confidence interval, CV coefficient of variation, AUC area under receiver operating characteristic curve, ρ: Spearman correlation coefficient, α: = ICC + AUC + |ρ|- CV - |bias|