Quantitative diffusion-weighted magnetic resonance enterography in ileal Crohn's disease: A systematic analysis of intra and interobserver reproducibility

Table 2 Intraobserver agreement and variability of apparent diffusion coefficient and signal ratio measurements between the two readers over two sessions

Group	CD (n = 21)						Normal (n = 23)
	1st session reader 1	2nd session reader 1	P-value	1st session reader 2	2nd session reader 2	P-value	1st session reader 1	2nd session reader 1	P-value	1st session reader 2	2nd session reader 2	P-value
ADC	1.50 ± 0.40	1.54 ± 0.45	0.201	1.52 ± 0.45	1.56 ± 0.47	0.125	2.55 ± 0.53	2.53 ± 0.53	0.772	2.57 ± 0.50	2.64 ± 0.57	0.450
ICC	0.952			0.977			0.736			0.711
CoV	6.28			4.71			10.47			10.64
Bias (%)	1.77			1.89			-1.07			-1.71
LoA (%)	-14.10 to 17.65			-10.65 to 14.42			-30.75 to 28.62			-28.30 to 24.86
SR	4.17 ± 1.43	4.20 ± 1.36	0.505	4.21 ± 1.34	4.23 ± 1.42	0.794	1.45 ± 0.54	1.44 ± 0.53	0.697	1.44 ± 0.52	1.45 ± 0.56	0.704
ICC	0.989			0.979			0.974			0.944
CoV	3.51			4.64			5.93			8.69
Bias (%)	1.39			-0.07			-0.58			0.45
LoA (%)	-9.22 to 12.01			-13.81 to 13.67			-19.16 to 17.99			-23.99 to 24.88

Apparent diffusion coefficient (ADC) and signal ratio parameters are expressed as the mean ± standard deviation, ADC units: ×10^-3 mm²/s. ADC: Apparent diffusion coefficient; SR: Signal ratio; CD: Crohn’s disease; ICC: Intraclass correlation coefficient; CoV: Coefficients of variation; LoA: Bland-Altman analysis with 95% limits of agreement.