Table 1.
Root mean square error (RMSE) calculated with standard images (convDKI-64)
| Number of encoding directions | 64 | 32 | 21 | 15 | 12 | 6 | |
|---|---|---|---|---|---|---|---|
| Required scan time (min : sec) | 61 : 08 | 30 : 55 | 20 : 32 | 14 : 52 | 12 : 02 | 6 : 22 | |
| Axial | ConvDKI | - | 0.185 | 0.249 | 0.461 | - | - |
| (min, max) | (0.173, 0.199) | (0.240, 0.270) | (0.451, 0.471) | ||||
| eDKI | 0.174 | 0.178 | 0.185 | 0.190 | 0.193 | 0.198 | |
| (min, max) | (0.161, 0.186) | (0.165, 0.189) | (0.173, 0.195) | (0.176, 0.200) | (0.182, 0.206) | (0.182, 0.278) | |
| P-value a | - | <0.01 | <0.01 | <0.01 | - | - | |
| Radial | ConvDKI | - | 0.277 | 0.396 | 0.986 | - | - |
| (min, max) | (0.253, 0.296) | (0.372, 0.418) | (0.965, 1.004) | ||||
| eDKI | 0.269 | 0.279 | 0.288 | 0.296 | 0.309 | 0.312 | |
| (min, max) | (0.232, 0.287) | (0.239, 0.292) | (0.251, 0.302) | (0.259, 0.310) | (0.270, 0.323) | (0.276, 0.424) | |
| P-value a | - | 0.27 | <0.01 | <0.01 | - | - | |
aWilcoxon signed-rank test. P-value under 0.05 was considered significant in this study
Numbers denote medians and ranges
DKI diffusional kurtosis imaging, convDKI conventional DKI, convDKI-64 convDKI obtained from 64 encoding directions, eDKI estimated DKI