Intravoxel incoherent motion diffusion-weighted magnetic resonance imaging for predicting histological grade of hepatocellular carcinoma: Comparison with conventional diffusion-weighted imaging

Table 1 Intravoxel incoherent motion diffusion-weighted imaging parameters of different pathologic grades of hepatocellular carcinoma

Parameter	Observer	Edmondson-Steiner grade			P value
		1 (n = 14)	2 (n = 24)	3 (n = 24)
ADC (× 10-3 mm2/s)1	R1	1.496 ± 0.312	1.210 ± 0.186	1.003 ± 0.247	< 0.001
	R2	1.503 ± 0.306	1.214 ± 0.186	1.001 ± 0.236	< 0.001
D (× 10-3 mm2/s)1	R1	1.186 ± 0.214	0.910 ± 0.151	0.775 ± 0.188	< 0.001
	R2	1.193 ± 0.226	0.910 ± 0.148	0.771 ± 0.187	< 0.001
D* (× 10-3 mm2/s)2	R1	37.400 (43.900)	29.000 (71.700)	7.980 (63.590)	0.057
	R2	32.200 (44.600)	28.400 (74.363)	7.885 (61.640)	0.054
f (%)2	R1	27.250 (14.925)	20.675 (11.225)	31.300 (12.267)	0.149
	R2	26.550 (20.200)	21.200 (11.725)	31.550 (11.325)	0.214

¹Data are mean ± SD, one-way analysis of variance;

²data are median (interquartile range), Kruskal-Wallis Test. A P-value < 0.05 was considered statistically significant. R1: Radiologist 1; R2: Radiologist 2; ADC: Apparent diffusion coefficient; D: Pure diffusion coefficient; D*: Pseudo-diffusion coefficient; f: Perfusion fraction.

Table 2 Diagnostic value of intravoxel incoherent motion diffusion-weighted imaging and conventional diffusion-weighted imaging parameters in differentiating the low-grade group (G1) from the high-grade groups (G2 and G3)

Parameter	Observer	AUC (95%CI)	Optimal cutoff value	Youden index	Sensitivity (%)	Specificity (%)	Accuracy (%)
ADC	R1	0.843 (0.718, 0.968)	1.285	0.619	78.6(11/14)	83.3(40/48)	82.3(51/62)
	R2	0.852 (0.730, 0.974)	1.275	0.649	85.7(12/14)	79.2(38/48)	80.6(50/62)
D	R1	0.909 (0.834, 0.985)	0.962	0.741	92.9(13/14)	81.3(39/48)	83.9(52/62)
	R2	0.911 (0.832, 0.990)	0.977	0.804	92.9(13/14)	87.5(42/48)	88.7(55/62)
D*	R1	0.632 (0.489, 0.776)	17.75	0.378	85.7(12/14)	52.1(25/48)	59.7(37/62)
	R2	0.636 (0.495, 0.777)	17.90	0.378	85.7(12/14)	52.1(25/48)	59.7(37/62)
f	R1	0.523 (0.348, 0.698)	0.216	0.182	78.6(11/14)	39.6(19/48)	48.4(30/62)
	R2	0.518 (0.332, 0.704)	0.246	0.173	71.4(10/14)	45.8(22/48)	51.6(32/62)

R1: Radiologist 1; R2: Radiologist 2; ADC: Apparent diffusion coefficient; D: Pure diffusion coefficient; D*: Pseudo-diffusion coefficient; f: Perfusion fraction. ADC, D, and D* are in units of × 10^-3 mm²/s; f is in units of 100%; 95%CI: 95% confidence intervals.

Table 3 Apparent diffusion coefficient and intravoxel incoherent motion derived parameters: Spearman correlation coefficients of the parameters with the histopathological grades

Spearman correlation			ADC	D	D*	f
R1	Grade	Correlation coefficient	-0.619	-0.628	-0.299	0.130
		P-value	< 0.001	< 0.001	0.018	0.313
R2	Grade	Correlation coefficient	-0.622	-0.633	-0.303	0.121
		P-value	< 0.001	< 0.001	0.017	0.349

P-value < 0.05 was considered statistically significant. ADC: Apparent diffusion coefficient; D: Pure diffusion coefficient; D*: Pseudo-diffusion coefficient; f: Perfusion fraction.