Assessment of Internal Jugular Vein Size in Healthy Subjects with Magnetic Resonance and Semiautomatic Processing

Table 2

Intrarater and interraters variability of IJVl and IJVr CSA for all cervical levels from C1 to C7. The concordance correlation coefficient (ρc), expressed also as precision (ρ) and accuracy (Cb), is reported. The intraclass correlation coefficient (ICC) is represented with its 95% lower (ci l) and upper (ci u) confidence interval bounds. Data shows almost perfect agreement (ρc > 0.90) and no systematic differences (ICC > 0.9) between raters at each cervical level.

			C1	C2	C3	C4	C5	C6	C7
Intrarater	IJVl CSA	ρc	0.989	0.989	0.982	0.907	0.961	0.971	0.960
		ρ	0.994	0.990	0.983	0.912	0.967	0.978	0.966
		Cb	0.995	0.999	0.999	0.995	0.994	0.993	0.994
		ICC	0.990	0.990	0.984	0.917	0.965	0.974	0.964
		95% ci l	0.960	0.956	0.934	0.686	0.857	0.891	0.859
		95% ci u	0.998	0.998	0.996	0.980	0.992	0.994	0.992
	IJVr CSA	ρc	0.988	0.983	0.978	0.977	0.971	0.986	0.978
		ρ	0.989	0.984	0.983	0.979	0.979	0.987	0.989
		Cb	0.998	0.998	0.994	0.998	0.992	0.999	0.988
		ICC	0.989	0.984	0.980	0.979	0.974	0.987	0.980
		95% ci l	0.958	0.942	0.920	0.923	0.899	0.954	0.923
		95% ci u	0.997	0.996	0.995	0.995	0.994	0.997	0.995
Interraters	IJVl CSA	ρc	0.969	0.992	0.994	0.975	0.964	0.955	0.934
		ρ	0.986	0.996	0.997	0.979	0.971	0.964	0.963
		Cb	0.983	0.996	0.997	0.996	0.993	0.991	0.969
		ICC	0.973	0.993	0.995	0.978	0.968	0.960	0.941
		95% ci l	0.770	0.972	0.970	0.911	0.873	0.843	0.763
		95% ci u	0.995	0.998	0.999	0.995	0.993	0.991	0.986
	IJVr CSA	ρc	0.983	0.985	0.952	0.966	0.979	0.974	0.983
		ρ	0.992	0.987	0.969	0.977	0.985	0.988	0.988
		Cb	0.991	0.998	0.983	0.989	0.995	0.986	0.995
		ICC	0.985	0.986	0.957	0.969	0.981	0.977	0.985
		95% ci l	0.892	0.948	0.844	0.886	0.931	0.910	0.940
		95% ci u	0.997	0.997	0.989	0.992	0.995	0.994	0.996