Magnetic resonance-based total liver volume and magnetic resonance-diffusion weighted imaging for staging liver fibrosis in mini-pigs

Table 1 Mini-pigs with liver fibrosis at different stages confirmed on the follow-up weekends (n)

Weekend	S0	S1	S2	S3	S4
0 (16)	16	0	0	0	0
5 (16)	31	8	5	0	0
9 (15)	0	3	7	5	0
16 (13)	0	11	1	7	4
21 (9)	0	11	11	1	6

¹The liver fibrosis at this stage in the mini-pigs is similar to this disease at the immediately preceding stage during the follow-up. S0, S1, S2, S3 and S4 represent stage 0, stage 1, stage 2, stage 3 and stage 4, respectively.

Table 2 Total liver volume and apparent diffusion coefficient values corresponding to the stage of liver fibrosis

Fibrosis stage (n)	ADC value (×10-3 mm2/s), mean (SD), 95%CI			TLV (cm3), mean (SD), 95%CI
	b = 300 s/mm2	b = 500 s/mm2	b = 800 s/mm2
0 (16)	1.96 (0.19), 1.83-2.09	1.67 (0.21), 1.53-1.81	1.39 (0.15), 1.29-1.50	641.08 (99.22), 574.42-707.74
1 (11)	1.81 (0.19), 1.69-1.93	1.66 (0.23), 1.51-1.81	1.37 (0.11), 1.30-1.44	671.62 (106.12), 600.33-742.91
2 (13)	1.69 (0.17)1, 1.57-1.81	1.52 (0.17), 1.40-1.64	1.29 (0.11), 1.22-1.37	776.57 (156.91)1, 655.95-897.18
3 (13)	1.78 (0.21), 1.64-1.91	1.39 (0.13)2, 1.30-1.47	1.18 (0.15)2, 1.09-1.28	745.04 (155.51), 625.51-864.58
4 (10)	1.58 (0.17)1, 1.44-1.73	1.35 (0.15)2, 1.23-1.48	1.15 (0.12)3, 1.05-1.25	672.03 (145.33), 560.32-783.75
Grouped stages
0-1 (27)	1.88 (0.20), 1.79-1.97	1.66 (0.22), 1.57-1.76	1.38 (0.13), 1.32-1.44	656.35 (101.46), 611.36-701.34
0-2 (40)	1.82 (0.21), 1.75-1.90	1.62 (0.21), 1.54-1.70	1.35 (0.13), 1.31-1.40	691.25 (129.80), 643.64-738.86
2-4 (36)	1.69 (0.19)4, 1.62-1.77	1.42 (0.16)4, 1.36-1.48	1.21 (0.14)4, 1.16-1.26	731.21 (153.32)4, 670.56-791.81
3-4 (23)	1.70 (0.21), 1.60-1.80	1.37 (0.14)5, 1.31-1.44	1.17 (0.13)5, 1.10-1.23	708.54 (150.77), 633.56-783.51

¹Different from stage 0, P < 0.05;

²Different from stage 0, and from stage 1, P < 0.05;

³Different from stage 0, from stage 1, and from stage 2, P < 0.05;

⁴Different from stage 0-1, P < 0.05;

⁵Different from stage 0-2, P < 0.05. TLV: Total liver volume; ADC: Apparent diffusion coefficient.

Table 3 Receiver operating curve analyses of total liver volume and liver apparent diffusion coefficient values for prediction of fibrosis stage ≥ 2 and ≥ 3 (%)

Cut-off	Stage differentiations	AUC	Sensitivity	Specificity
TLV 656.25 cm3	Prediction of stage ≥ 2	0.682	74.1	73.7
ADC (b = 800 s/mm2)
1.82 × 10-3 mm2/s	Prediction of stage ≥ 2	0.743	69.6	73.3
1.75 × 10-3 mm2/s	Prediction of stage ≥ 3	0.646	63.6	60.0
ADC (b = 800 s/mm2)
1.51 × 10-3 mm2/s	Prediction of stage ≥ 2	0.803	82.6	76.7
1.44 × 10-3 mm2/s	Prediction of stage ≥ 3	0.847	78.8	80.0
ADC (b = 800 s/mm2)
1.29 × 10-3 mm2/s	Prediction of stage ≥ 2	0.848	78.3	80.0
1.23 × 10-3 mm2/s	Prediction of stage ≥ 3	0.887	84.8	81.2

TLV: Total liver volume; AUC: Area under the receiver operating curve curve; ADC: Apparent diffusion coefficient.