The difference in mutual information after registration of the merged volumes to the mutual information of the XFAST input volumes is computed.
The mean unweighted image was used to compute the co-registration parameters to the anatomical T1 image (SPM5 mutual information co-registration), which were then applied to all diffusion weighed images and derivates.
3) The T1-weighted (structural) image was co-registered to the first EPI volume using a mutual information co-registration algorithm.
In short, each PWI was co-registered to a reference EPI (without labeling), which in turn was co-registered to the corresponding T1-weighted image using affine transformations with 9 degrees of freedom and the normalized mutual information co-registration algorithm available in the Statistical Parametric Mapping (SPM2) program (Welcome Department of Imaging Neuroscience; London, UK).
Ictal and interictal SPECT studies were co-registered using an automatic registration algorithm based on mutual information using the registration module of Statistical Parametric Mapping (SPM version 8; Wellcome Trust Centre for Neuroimaging, London, UK), implemented in Matlab (R2012; The MathWorks Inc., MA, USA) [20, 21].
Diffusion-weighted data and B0 data, as well as diffusion-weighted and T1-weighted data were matched using a mutual information-based registration technique.
8 The diffusion-weighted images were first corrected for eddy current distortion using a mutual information-based registration scheme, and then masked using locally written software plus the Brain Extraction Tool (BET) in the Functional Software Library package (Oxford Centre for Functional Magnetic Resonance Imaging of the Brain, Oxford University, UK).
To make up for the lack of concern on the spatial information in the conventional mutual information based image registration framework, this paper designs a novel spatial feature field, namely the maximum distance-gradient (MDG) vector field, for registration tasks.
This procedure integrates a distortion-tolerant mutual information MR-CT registration, a new tissue classification exploiting global spatial cues, a simplex-based surface meshing model to identify and triangulate the relevant anatomical boundaries, and a final almost-regular tetrahedralization of tissue volumes surrounded by these boundaries.
This black-and-white perspective leads to well-known answers and results in the selection of correlation coefficient (CC) for mono-modal registration and mutual information (MI) for multi-modal registration.
