Ultrasomics in liver cancer: Developing a radiomics model for differentiating intrahepatic cholangiocarcinoma from hepatocellular carcinoma using contrast-enhanced ultrasound

Table 1 Basic characteristics of patients and lesions

Characteristics	HCC, n = 140	ICC, n = 140	P value
Age in yr	53.39 + 11.85	57.46 + 11.39	0.58
	26-79	33-86
Sex			0.311
Male	126	120
Female	14	20
HBV (+)	126	106	0.562
Lesion size in cm	66.37 + 27.38	69.04 + 32.68	0.271
AFP in μg/L			0.001
> 20	91	18
< 20	49	122
CA19-9 in U/mL			0.001
> 34	15	83
< 34	125	57

AFP: Alpha-fetoprotein; CA19-9: Carbohydrate antigen 19-9; HBV: Hepatitis B virus; HCC: Hepatocellular carcinoma; ICC: Intrahepatic cholangiocarcinoma.

Table 2 Radiomic features in the radiomic analysis

Types	Features
Shape (n = 9)	Elongation, MajorAxisLength, MaximumDiameter, MeshSurface, MinorAxisLength, Perimeter, PerimeterSurfaceRatio, PixelSurface, Sphericity
First order (n = 18)	10Percentile, 90Percentile, Energy, Entropy, InterquartileRange, Kurtosis, Maximum, MeanAbsoluteDeviation, Mean, Median, Minimum, Range, RobustMeanAbsoluteDeviation, RootMeanSquared, Skewness, TotalEnergy, Uniformity, Variance
GLCM (n = 22)	Autocorrelation, JointAverage, ClusterProminence, ClusterShade, ClusterTendency, Contrast, Correlation, DifferenceAverage, DifferenceEntropy, DifferenceVariance, JointEnergy, JointEntropy, Imc1, Imc2, Idm, Idmn, Id, Idn, InverseVariance, MaximumProbability, SumEntropy, SumSquares
GLRLM (n = 16)	GrayLevelNonUniformity, GrayLevelNonUniformityNormalized, GrayLevelVariance, HighGrayLevelRunEmphasis, LongRunEmphasis, LongRunHighGrayLevelEmphasis, LongRunLowGrayLevelEmphasis, LowGrayLevelRunEmphasis, RunEntropy, RunLengthNonUniformity, RunLengthNonUniformityNormalized, RunPercentage, RunVariance, ShortRunEmphasis, ShortRunHighGrayLevelEmphasis, ShortRunLowGrayLevelEmphasis
GLSZM (n = 16)	GrayLevelNonUniformity, GrayLevelNonUniformityNormalized, GrayLevelVariance, HighGrayLevelZoneEmphasis, LargeAreaEmphasis, LargeAreaHighGrayLevelEmphasis, LargeAreaLowGrayLevelEmphasis, LowGrayLevelZoneEmphasis, SizeZoneNonUniformity, SizeZoneNonUniformityNormalized, SmallAreaEmphasis, SmallAreaHighGrayLevelEmphasis, SmallAreaLowGrayLevelEmphasis, ZoneEntropy, ZonePercentage, ZoneVariance
GLDM (n = 14)	DependenceEntropy, DependenceNonUniformity, DependenceNonUniformityNormalized, DependenceVariance, GrayLevelNonUniformity, GrayLevelVariance, HighGrayLevelEmphasis, LargeDependenceEmphasis, LargeDependenceHighGrayLevelEmphasis, LargeDependenceLowGrayLevelEmphasis, LowGrayLevelEmphasis, SmallDependenceEmphasis, SmallDependenceHighGrayLevelEmphasis, SmallDependenceLowGrayLevelEmphasis
NGTDM (n = 5)	Busyness, Coarseness, Complexity, Contrast, Strength

Imagetype: Original, Log-sigma-2-0-mm-3D, Log-sigma-3-0-mm-3D, Log-sigma-4-0-mm-3D, Wavelet-H, wavelet-L, lbp-2D, square, squareroot, logarithm, exponential. GLCM: Gray Level Concurrence Matrix; GLDM: Gray Level Dependence Matrix; GLRLM: Gray Level Run-Length Matrix; GLSZM: Gray Level Size-one Matrix; NGTDM: Neighborhood Gray-Tone Difference Matrix.

Table 3 Area under the receiver operating characteristic curve, sensitivity, specificity, accuracy, positive predict value, and negative predict value of radiomics models in different cohorts

Parameter	Training				Validation				Test
	US	AE + PE	US + AE + PE	US + AE + PE + CL	US	AE + PE	US + AE + PE	US + AE + PE + CL	US	AE + PE	US + AE + PE	US + AE + PE + CL
AUC (95%CI)	0.885 (0.825, 0.889)	0.955 (0.919, 0.962)	0.966 (0.934, 0.972)	0.975 (0.941, 0.975)	0.822 (0.738, 0.863)	0.956 (0.856, 0.962)	0.964 (0.907, 0.977)	0.973 (0.933, 0.983)	0.816 (0.690, 0.825)	0.919 (0.876, 0.959)	0.955 (0.907, 0.967)	0.971 (0.916, 0.980)
Sensitivity	0.766	0.933	0.900	0.911	0.727	0.909	0.818	0.863	0.607	0.714	0.928	0.892
Specificity	0.853	0.842	0.876	0.921	0.681	0.818	0.909	0.954	0.857	0.857	0.857	0.928
Accuracy	0.810	0.888	0.888	0.916	0.704	0.863	0.863	0.909	0.732	0.785	0.892	0.910
PPV	0.841	0.857	0.880	0.921	0.695	0.833	0.900	0.950	0.809	0.833	0.866	0.925
NPV	0.783	0.925	0.896	0.911	0.714	0.900	0.833	0.875	0.685	0.750	0.923	0.896

AE: Arterial enhancement; AUC: Area under the receiver operating characteristic curve; CI: Confidence interval; CL: Clinical data; NPV: Negative predict value; PE: Portal enhancement; PPV: Positive predict value; US: Ultrasound.