Quantitative and clinical analysis of SPECT image registration for epilepsy studies.
This study reports quantitative measurements of the accuracy of two popular voxel-based registration algorithms--Woods' automated image registration algorithm and mutual information correlation--and compares these with conventional surface matching (SM) registration.


METHODS
The registration algorithms were compared (15 different matches each) for (a) three-dimensional brain phantom images, (b) an ictal SPECT image from a patient with partial epilepsy matched to itself after modification to simulate changes in the cerebral blood flow pattern and (c) ictal/interictal SPECT images from 15 patients with partial epilepsy. Blinded visual ranking and localization of the subtraction images derived from the patient images were also performed.


RESULTS
Both voxel-based registration methods were more accurate than SM registration (P < 0.0005). Automated image registration algorithm was more accurate than mutual information correlation for the computer-simulated ictal/interictal images and the patient ictal/interictal studies (P < 0.05). The subtraction SPECTs from SM were poorer in visual ranking more often than the voxel-based methods (P < 0.05).


CONCLUSIONS
Voxel intensity-based registration algorithms provide significant improvement in ictal/interictal SPECT registration accuracy and result in a clinically detectable improvement in the subtraction SPECT images.
Department of Neurology, Mayo Foundation, Rochester, Minnesota 55905, USA.
B H
BH
Brinkmann
T J
TJ
O'Brien
S
S
Aharon
M K
MK
O'Connor
B P
BP
Mullan
D P
DP
Hanson
R A
RA
Robb
D000465:Algorithms; D001921:Brain / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation / Q000502:physiology; D003545:Cysteine / Q000031:analogs & derivatives; D004828:Epilepsies, Partial / Q000000981:diagnostic imaging*; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D015609:Organotechnetium Compounds; D019047:Phantoms, Imaging; D019275:Radiopharmaceuticals; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C059659:technetium Tc 99m bicisate; D003545:Cysteine