Preoperatively Grading Rectal Cancer with the Combination of Intravoxel Incoherent Motions Imaging and Diffusion Kurtosis Imaging

Table 2

Diffusion parameters among different histologic grades.

	D (×10^−9 m^2/s)	f	D (×10^−9 m^2/s)	Dapp (×10^−9 m^2/s)	Kapp
All subjects (n = 58)	1.282 ± 0.164	0.237 ± 0.070	45.458 ± 11.801	1.440 ± 0.201	0.739 ± 0.127
WHO grade 1 (n = 11)	1.465 ± 0.081	0.292 ± 0.067	40.329 ± 7.399	1.699 ± 0.099	0.604 ± 0.058
WHO grade 2 (n = 29)	1.323 ± 0.105	0.244 ± 0.052	45.622 ± 11.187	1.460 ± 0.127	0.715 ± 0.091
WHO grade 3 (n = 18)	1.105 ± 0.103	0.192 ± 0.072	48.329 ± 14.239	1.250 ± 0.144	0.862 ± 0.099
Low grade (1 and 2) (n = 40)	1.362 ± 0.117	0.257 ± 0.059	44.166 ± 10.470	1.526 ± 0.161	0.684 ± 0.096
High grade (3) (n = 18)	1.105 ± 0.103	0.192 ± 0.072	48.329 ± 14.239	1.250 ± 0.144	0.862 ± 0.099
value (grade 1 vs. grade 2)	0.001	0.079	0.412	<0.001	0.003
value (grade 1 vs. grade 3)	<0.001	<0.001	0.182	<0.001	<0.001
value (grade 2 vs. grade 3)	<0.001	0.018	0.721	<0.001	<0.001
value (low grade vs. high grade)	<0.001	0.002	0.276	<0.001	<0.001

^※D: true diffusion coefficient, D: pseudodiffusion coefficient, D_app: apparent diffusion coefficient derived from DKI, f: perfusion fraction, K_app: apparent diffusion kurtosis coefficient.