. 2020 Feb 10;20:17. doi: 10.1186/s40644-020-0296-3

Table 2.

Texture features with significant difference obtained from virtual monochromatic CT images between lymph node metastases positive and negative groups of pancreatic ductal adenocarcinoma (155 cases)

Image subset	Texture feature	N+(n = 72)	N-(n = 83)	U/t	P value	AUC(95% CI)	P value	Cutoff value	+LR
1.25 mm-AP-60 keV	WavEnLH_s-2^b	244 (208, 313)	294 (242, 352)	2209	0.005	0.630(0.549–0.706)	0.005	270	2.08
1.25 mm-PVP-60 keV	S(5,-5)SumAverg^a	62.5 ± 2.0	63.4 ± 2.1	2.657	0.009	0.619(0.538–0.696)	0.009	63.3	1.45
	S(4,-4)SumAverg^a	62.5 ± 1.8	63.2 ± 1.9	2.303	0.023	0.600(0.518–0.677)	0.029	63.7	1.31
	S(4,4)SumAverg^a	62.4 ± 1.8	63.0 ± 1.8	2.019	0.045	0.589(0.500–0.679)	0.052	NA	NA
	S(4,0)SumAverg^a	62.7 ± 1.4	63.2 ± 1.6	1.995	0.048	0.594(0.512–0.672)	0.040	63.4	1.41
	S(3,3)SumAverg^a	62.6 ± 1.6	63.2 ± 1.6	2.283	0.024	0.607(0.525–0.684)	0.019	62.6	1.67
	S(2,2)SumAverg^a	62.9 ± 1.3	63.4 ± 1.3	2.216	0.028	0.615(0.534–0.692)	0.012	63.1	1.64
	S(1,1)SumAverg^a	63.5 ± 0.8	63.7 ± 0.9	2.021	0.045	0.608(0.526–0.685)	0.019	63.6	1.60
5 mm-AP-65 keV	135dr_LngREmph^a	1.24 ± 0.06	1.22 ± 0.06	−2.133	0.035	0.608(0.526–0.685)	0.019	1.23	1.57
	S(4,-4)SumOfSqs^a	100 ± 7	97 ± 9	−2.218	0.028	0.573(0.484–0.663)	0.110	NA	NA
	135dr_Fraction^a	0.929 ± 0.016	0.934 ± 0.015	2.088	0.038	0.612(0.530–0.689)	0.015	0.934	1.58
5 mm-PVP-65 keV	S(5,-5)SumAverg^b	62.2(61.1, 63.4)	62.8(61.1, 64.6)	2429	0.045	0.594(0.512–0.672)	0.041	63.0	1.36
	S(4,4)SumAverg^a	62.0 ± 1.8	62.6 ± 2.1	2.047	0.042	0.571(0.481–0.661)	0.121	NA	NA

^aData are mean ± standard deviation, independent samples t-test was used

^bData are median (quartile 1, quartile 3), Mann-Whitney test was used

Abbreviation: AP late arterial phase, AUC area under receiver operator characteristic curve, CI confidence interval, keV kilo electron voltage, +LR positive likelihood ratio, n number of cases, N+ lymph node metastasis positive, N- lymph node metastasis negative, NA not applicable, PVP portal venous phase, SD standard deviation, t independent samples t-test, U Mann-Whitney test; 1.25 mm/5 mm, slice thickness of the CT images analysed