Quantitative parameters in novel spectral computed tomography: Assessment of Ki-67 expression in patients with gastric adenocarcinoma

Table 1 Inter-reader agreement of spectral parameters measurement

Parameters	ICC (95%CI)
	AP	VP
Zefflesion	0.88 (0.71, 0.95)	0.86 (0.69, 0.94)
Zeffaorta	0.94 (0.85, 0.97)	0.95 (0.88, 0.98)
IClesion (mg/mL)	0.86 (0.56, 0.95)	0.87 (0.73, 0.95)
ICaorta (mg/mL)	0.98 (0.94, 0.99)	0.95 (0.86, 0.98)
CT40 kev (HU)	0.95 (0.88, 0.98)	0.96 (0.79, 0.99)
CT70 kev (HU)	0.92 (0.78, 0.97)	0.91 (0.50, 0.98)
CT100 kev (HU)	0.86 (0.69, 0.94)	0.89 (0.70, 0.96)

ICC: Intraclass correlation coefficient; Z^eff_lesion and Z^eff_aorta: The effective atomic number of lesion and aorta; CT_{40 kev,} CT_{70 kev} and CT_{100 kev}: The computed tomography attenuation value of 40 kilo electron volt (kev), 70 kev and 100 kev monochromatic images; IC_lesion and IC_aorta: The iodine concentration of lesion and aorta; HU: Hounsfield unit; AP: Arterial phase; VP: Venous phase; 95%CI: 95% confidence interval.