An average CT brain image is constructed to serve as reference frame for inter-subject registration. A set of 96 clinical CT images is used. Registration includes translation, rotation, and anisotropic scaling. A temporary average based on a subset of 32 images is constructed. This image is used as reference for the iterative construction of the average CT image. This approach is computationally efficient and results in a consistent registration of the 96 images. Registration of new images to the average CT is more consistent than registration to a single CT image. The use of the average CT image is illustrated. © 2003 Elsevier Ltd. All rights reserved.
Jongen, C., Pluim, J. P. W., Nederkoorn, P. J., Viergever, M. A., & Niessen, W. J. (2004). Construction and evaluation of an average CT brain image for inter-subject registration. Computers in Biology and Medicine, 34(8), 647-662. https://doi.org/10.1016/j.compbiomed.2003.10.003