Radiomic analysis based on multi-phase magnetic resonance imaging to predict preoperatively microvascular invasion in hepatocellular carcinoma

Table 1 Comparison of patient characteristics according to microvascular invasion

Characteristic	MVI+ (n = 73)	MVI- (n = 40)	P value
Age (yr)1	56.82 ± 13.38	57.50 ± 11.98	0.790
Gender, n (%)			0.374
Male	57 (78.1)	34 (85.0)
Female	16 (21.9)	6 (15.0)
Tumor number, n (%)			0.152
1	58 (79.5)	36 (90.0)
≥ 2	15 (20.5)	4 (10.0)
AFP, n (%)			0.023
≤ 20	23 (31.5)	23 (57.5)
20-400	22 (30.1)	9 (22.5)
> 400	28 (38.4)	8 (20.0)
HBsAg, n (%)			0.267
Negative	13 (17.8)	4 (10.0)
Positive	60 (82.2)	36 (90.0)
Pathologic grade, n (%)			0.042
Well	0 (0.0)	1 (2.5)
Moderate	39 (53.4)	28 (70.0)
Poor	34 (46.6)	11 (27.5)
Location, n (%)			0.891
Left lobe	21 (28.8)	13 (32.5)
Right lobe	51 (69.9)	27 (67.5)
Caudate lobe	1 (1.3)	0 (0.0)

¹Data are the mean ± SD.

AFP: Alpha-fetoprotein; HBsAg: Hepatitis B surface antigen; MVI: Microvascular invasion.

Table 2 Comparison of different imaging features according to microvascular invasion

MRI feature	MVI+ (n = 73)	MVI- (n = 40)	P value
MTD (cm)1	7.23 ± 4.30	3.80 ± 2.43	< 0.001
Arterial rim enhancement (%)			0.002
Absent	37 (50.7)	32 (80)
Present	36 (49.3)	8 (20)
Arterial peritumoral enhancement (%)			0.134
Absent	53 (72.6)	34 (85)
Present	20 (27.4)	6 (15)
Tumor margin (%)			0.004
Smooth	36 (49.3)	31 (77.5)
Non-smooth	37 (50.7)	9 (22.5)
Radiological capsule (%)			0.303
Absent	19 (26.0)	7 (17.5)
Present	54 (74.0)	33 (82.5)
Tumor hypointensity in the HBP (%)			0.336
Absent	2 (2.9)	3 (8.3)
Present	67 (97.1)	33 (91.7)
Peritumoral hypointensity in the HBP (%)			0.016
Absent	17 (24.6)	34 (94.4)
Present	52 (75.4)	2 (5.6)

¹Data are the mean ± SD.

There were eight patients who had no HBP images. HBP: Hepatobiliary phase; MVI: Microvascular invasion; MTD: Maximum tumor diameter; MRI: Magnetic resonance imaging.

Table 3 Receiver operating characteristic results of radiomic analysis based on most discriminant factors in arterial phase and histogram parameters to discriminate between microvascular invasion+ and microvascular invasion- groups

	MVI (-)	MVI (+)	AUC	Sensitivity	Specificity	P value	Cut-off value
MDF	(-4.80 ± 6.14) × 10-2	(2.63 ± 4.74) × 10-2	0.84 (0.80-0.88)	87%	66%	< 0.001	1.97 × 10-2
Histogram parameters
Mean	(1.27 ± 0.28) × 102	(1.09 ± 0.26) × 102	0.68 (0.63-0.74)	78%	52%	< 0.001	1.06 × 102
Variance	(5.28 ± 4.24) × 102	(4.57 ± 3.21) × 102	0.54 (0.48-0.61)	68%	45%	0.204	3.32 × 102
Skewness	(-9.71 ± 58.46) × 10-2	(2.52 ± 5.79) × 10-1	0.68 (0.62-0.74)	76%	58%	< 0.001	1.30 × 10-1
Kurtosis	(-5.24 ± 91.73) × 10-2	(4.06 ± 11.19) × 10-1	0.60 (0.53-0.66)	90%	25%	0.004	-5.96 × 10-1
Perc.01%	(0.80 ± 0.20) × 102	(0.68 ± 0.20) × 102	0.68 (0.62-0.74)	78%	50%	< 0.001	64.5
Perc.10%	(0.99 ± 0.23) × 102	(0.84 ± 0.22) × 102	0.68 (0.62-0.74)	96%	32%	< 0.001	69.5
Perc.50%	(1.28 ± 0.30) × 102	(1.08 ± 0.27) × 102	0.69 (0.63-0.74)	76%	47%	< 0.001	105.5
Perc.90%	(1.54 ± 0.34) × 102	(1.35 ± 0.31) × 102	0.65 (0.59-0.71)	57%	70%	< 0.001	148.5
Perc.99%	(1.73 ± 0.39) × 102	(1.57 ± 0.35) × 102	0.62 (0.55-0.68)	48%	74%	< 0.001	177.5

AUC: Area under the receiver operating characteristic curve; MDF: Most discriminant factor; MVI: Microvascular invasion.

Table 4 Receiver operating characteristic results of radiomic analysis based on most discriminant factors in portal venous phase and histogram parameters to discriminate between microvascular invasion+ and microvascular invasion- groups

	MVI (-)	MVI (+)	AUC	Sensitivity	Specificity	P value	Cut-off value
MDF	(7.84 ± 9.26) × 10-3	(-4.30 ± 7.00) × 10-3	0.85 (0.81-0.90)	67%	90%	< 0.001	4.17 × 10-3
Histogram parameters
Mean	(1.24 ± 0.24) × 102	(1.08 ± 0.24) × 102	0.69 (0.63-0.75)	78%	54%	< 0.001	106.6
Variance	(3.07 ± 4.11) × 102	(4.30 ± 3.59) × 102	0.67 (0.61-0.74)	80%	50%	< 0.001	165.9
Skewness	(1.93 ± 6.11) × 10-1	(1.87 ± 5.85) × 10-1	0.50 (0.44-0.57)	16%	88%	0.09	7.76 × 10-1
Kurtosis	(0.60 ± 1.20)	(0.62 ± 1.19)	0.51 (0.44-0.57)	57%	51%	0.787	1.62 × 10-1
Perc.01%	(91.84 ± 30.33)	(67.16 ± 24.85)	0.74 (0.68-0.80)	50%	90%	< 0.001	101.5
Perc.10%	(1.06 ± 0.29) × 102	(0.84 ± 0.25) × 102	0.72 (0.67-0.78)	56%	81%	< 0.001	107.5
Perc.50%	(1.25 ± 0.24) × 102	(1.07 ± 0.24) × 102	0.69 (0.64-0.75)	78%	55%	< 0.001	106.5
Perc.90%	(1.44 ± 0.27) × 102	(1.32 ± 0.27) × 102	0.62 (0.56-0.68)	63%	61%	< 0.001	137.5
Perc.99%	(1.61 ± 0.31) × 102	(1.56 ± 0.34) × 102	0.55 (0.49-0.61)	35%	77%	0.179	176.5

AUC: Area under the receiver operating characteristic curve; MDF: Most discriminant factor; MVI: Microvascular invasion.

Table 5 Univariate analysis of risk factors for most discriminant factors and patient characteristic

Variable	OR	95%CI	P value
MDFT1	11.200	4.346-28.861	< 0.001a
MDFT2	6.066	2.334-15.765	< 0.001a
MDFAP	8.552	2.967-24.650	< 0.001a
MDFPVP	0.050	0.017-0.143	< 0.001a
MDFEP	0.095	0.037-0.244	< 0.001a
MDFHBP	8.800	3.222-24.032	< 0.001a
MTD	1.351	1.146-1.593	< 0.001a
AFP	3.818	1.375-10.605	0.028a
Pathologic grade			0.105
Arterial rim enhancement	5.683	1.977-16.340	0.001a
Arterial peritumoral enhancement			0.215
Tumor margin	4.024	1.555-10.414	0.004a
Radiological capsule			0.275
Tumor hypointensity in HBP			0.215
Peritumoral hypointensity in HBP	52.000	11.287-239.569	< 0.001a

^aP < 0.05, statistically significant results from logistic regression analysis. Variables with ^aP < 0.05 in univariate logistic regression analysis were applied to a multivariate logistic regression analysis.

MDF: Most discriminant factor; AFP: Alpha-fetoprotein; AP: Arterial phase; CI: Confidence interval; EP: Equilibrium phase; HBP: Hepatobiliary phase; MTD: Maximum tumor diameter; OR: Odds ratio; PVP: Portal venous phase.