Apparent diffusion coefficient-based histogram analysis differentiates histological subtypes of periampullary adenocarcinoma

Table 2 Interobserver agreement for volumetric histogram parameters

	b = 800 s/mm2		b = 1000 s/mm2
ADC parameter	ICC	95%CI	ICC	95%CI
Mean	0.992	0.984-0.996	0.994	0.989-0.997
Entropy	0.959	0.922-0.978	0.952	0.910-0.975
Skewness	0.742	0.153-0.864	0.781	0.585-0.884
Kurtosis	0.399	-0.136-0.682	0.486	0.029-0.728
5th	0.954	0.912-0.976	0.978	0.959-0.989
10th	0.974	0.950-0.986	0.975	0.952-0.987
25th	0.988	0.976-0.993	0.991	0.983-0.995
50th	0.989	0.978-0.994	0.996	0.992-0.998
75th	0.984	0.969-0.991	0.992	0.985-0.996
90th	0.973	0.948-0.986	0.981	0.965-0.990
95th	0.975	0.950-0.987	0.977	0.966-0.988
ADCmin	0.981	0.965-0.990	0.984	0.970-0.992
ADCmax	0.951	0.908-0.974	0.948	0.901-0.972

ICC: Interclass correlation coefficient; CI: Confidence interval; ADC: Apparent diffusion coefficient.