  Diffusion magnetic resonance imaging (dMRI) and tractography provide means to
study the anatomical structures within the white matter of the brain. When
studying tractography data across subjects, it is usually necessary to align,
i.e. to register, tractographies together. This registration step is most often
performed by applying the transformation resulting from the registration of
other volumetric images (T1, FA). In contrast with registration methods that
"transform" tractographies, in this work, we try to find which streamline in
one tractography correspond to which streamline in the other tractography,
without any transformation. In other words, we try to find a "mapping" between
the tractographies. We propose a graph-based solution for the tractography
mapping problem and we explain similarities and differences with the related
well-known graph matching problem. Specifically, we define a loss function
based on the pairwise streamline distance and reformulate the mapping problem
as combinatorial optimization of that loss function. We show preliminary
promising results where we compare the proposed method, implemented with
simulated annealing, against a standard registration techniques in a task of
segmentation of the corticospinal tract.
