Optimal b value of diffusion-weighted imaging on a 3.0T magnetic resonance scanner in Crohn’s disease

Table 5 Overall diagnostic assessment of active Crohn's lesions on diffusion-weighted imaging

b value (s/mm2)	TP	FP	FN	TN	Sensitivity	Specificity	Lesion detection rate
800	71	20	12	145	83.53%	88.96%	87.10%
1500	69	8	16	155	81.18%	95.10%	90.32%
2000	62	9	23	154	72.94%	94.48%	87.10%
2500	55	8	30	155	64.71%	95.10%	84.68%

TP: True positive; FP: False positive; FN: False negative; TN: True negative. Unit of b value in diffusion-weighted imaging is s/mm².