Table 2.
The maximum inverse computing error (ICE) and the number of points (out of 27 262 976 points) with inverse computing errors greater than the error tolerance set in the PIDVF algorithm (0.01 cm) for the DVFs between the six lung images (Phase 0, Phase 1, … Phase 5) generated by the DIR implemented in ITK and the DIR in Ref. 25. The maximum and average differences are evaluated between DVFS–R and PIDVFS–R. For the ITK Demons DVFs, the reverse field (DVFS–R) is generated by running the DIR algorithm with reference and study images exchanged. SICLE autogenerates the reverse field. The number of DVFR–S elements with nonpositive Jacobians is also listed for each registration.
| R and S | ITK Demons DVFs | SICLE DVFs | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| No. of nonpositive Jacobians | Max. ICE (cm) | No. of points with ICE>0.01 cm | Max. difference (cm) | Ave. difference (cm) | No. of nonpositive Jacobians | Max. ICE (cm) | No. of points with ICE>0.01 cm | Max. difference (cm) | Ave. difference (cm) | |
| Phases 0 and 1 | 575 314 | 0.034 | 61 | 2.03 | 0.064 | 0 | 0.01 | 0 | 0.169 | 0.0024 |
| Phases 0 and 2 | 657 154 | 0.032 | 95 | 2.90 | 0.12 | 0 | 0.01 | 0 | 0.28 | 0.0027 |
| Phases 0 and 3 | 668 586 | 0.043 | 121 | 3.11 | 0.13 | 0 | 0.01 | 0 | 0.995 | 0.0498 |
| Phases 0 and 4 | 670 976 | 0.035 | 127 | 3.29 | 0.14 | 0 | 0.01 | 0 | 0.322 | 0.0029 |
| Phases 0 and 5 | 671 638 | 0.029 | 119 | 3.16 | 0.14 | 0 | 0.01 | 0 | 0.26 | 0.0029 |