17804
document
Registration accuracy of 153Gd transmission images of the brain . PURPOSE The aim of the study was to determine the accuracy of non-rigid nine-parameter image registrations based on 153Gd transmission computed tomography ( TCT ) images as compared with those based on 99mTc-ethyl cysteinate dimer ( ECD ) images and to assess whether normalised mutual information ( NMI ) or count difference ( CD ) should be used . METHODS TCT and ECD data were acquired in 25 randomly selected patients . Emission images were registered to an ECD template with a CD cost function . The same registration parameters were applied to the transmission images to create a TCT template . All TCT images were registered to the TCT template and the same registration parameters were applied to the ECD images . The procedure was repeated with NMI as cost function . Accuracy of both ECD-based and TCT-based registrations was assessed by comparing the normalisation parameter values and regional activities in the spatially normalised ECD images , using a mixed-model analysis of variance ( ANOVA ) . Scheffe post hoc tests were performed . RESULTS No significant differences were found between ECD/CD , ECD/NMI and TCT/CD , suggesting that ECD registration can be done with either CD or NMI , and that TCT registration using CD is equally as accurate as ECD registration . The accuracy of TCT registration with NMI was lower , with discrepancies occurring in the frontal inferior region and the cerebellum . The analysis of normalisation parameters indicated that z-scaling is underestimated and yz-rotation overestimated with TCT/NMI registration . CONCLUSION We conclude that ECD registrations with CD or NMI are as accurate as TCT registrations with CD and that TCT registrations with NMI should be avoided .
17805
Intervention_Physical
153Gd transmission computed tomography
17806
Intervention_Physical
99mTc-ethyl cysteinate dimer ( ECD ) images
17807
Intervention_Physical
ECD
17808
Intervention_Physical
TCT
17809
Intervention_Physical
ECD
17810
Intervention_Physical
ECD-based
17811
Intervention_Physical
TCT-based
17812
Intervention_Physical
ECD/CD
17813
Intervention_Physical
ECD/NMI
17814
Intervention_Physical
TCT/CD
17815
Intervention_Physical
ECD
17816
Intervention_Physical
CD
17817
Intervention_Physical
NMI
17818
Intervention_Physical
TCT
17819
Intervention_Physical
TCT
17820
Outcome_Other
No significant differences
17821
Outcome_Other
accuracy of TCT registration
17822
Outcome_Other
lower