Diagnostic accuracy of dual-layer spectral computed tomography virtual monoenergetic imaging with multiplanar reformation for T-staging of colorectal cancer

Table 7 Diagnostic performance of 40-70 keV virtual monoenergetic images and polyenergetic images in preoperative staging of T1-2 and T3-4 colorectal cancer

Images	CT T-staging	Pathological staging		Accuracy (%)	Sensitivity (%)	Specificity (%)	Youden index
		T1-2 (n = 31)	T3-4 (n = 126)
Axial PEIs	T1-2	12	19	70.7	38.71	78.56	0.17
	T3-4	27	99
PFS	T1-2	17	14	68.79	54.84	72.22	0.27
	T3-4	35	91
Axial PEIs and PFS	T1-2	12	19	70.7	38.71	78.56	0.17
	T3-4	27	99
OA PEIs	T1-2	14	17	76.43	45.16	84.13	0.29
	T3-4	20	106
PFS	T1-2	25	6	73.89	80.65	72.22	0.53
	T3-4	35	91
OA PEIs and PFS	T1-2	14	17	77.07	45.16	84.92	0.30
	T3-4	19	107
40 keV OA VIMs	T1-2	26	5	94.27	83.87	96.83	0.81
	T3-4	4	122
PFS	T1-2	25	6	73.25	80.65	71.43	0.52
	T3-4	36	90
40 keV OA VMIs and PFS	T1-2	25	6	93.63	80.65	96.83	0.77
	T3-4	4	122
50 keV OA VMIs	T1-2	26	5	94.27	83.87	96.83	0.81
	T3-4	4	122
PFS	T1-2	25	6	76.43	80.65	76.19	0.57
	T3-4	36	96
50 keV OA VMIs and PFS	T1-2	25	6	93.63	80.65	96.83	0.77
	T3-4	4	122
60 keV OA VMIs	T1-2	18	13	84.08	58.06	90.48	0.49
	T3-4	12	114
PFS	T1-2	25	6	73.25	80.65	71.43	0.52
	T3-4	36	90
60 keV OA VMIs and PFS	T1-2	18	13	84.08	58.06	90.48	0.49
	T3-4	12	114
70 keV OA VMIs	T1-2	16	15	80.25	51.61	87.30	0.39
	T3-4	16	110
PFS	T1-2	25	6	73.25	80.65	71.43	0.52
	T3-4	36	90
70 keV OA VMIs and PFS	T1-2	16	15	80.25	51.61	87.30	0.39
	T3-4	16	110

PEI: Polyenergetic image; VMI: Virtual monoenergetic image; PFS: Peritumoral fat stranding; OA: Oblique axial.