This paper describes a method to infer the connectivity induced by white ma
tter fibers in the living human brain. This method stems from magnetic reso
nance tensor imaging (DTI), a technique which gives access to fiber orienta
tions. Given typical DTI spatial resolution, connectivity is addressed at t
he level of fascicles made up by a bunch of parallel fibers. We propose fir
st an algorithm dedicated to fascicle tracking in a direction map inferred
from diffusion data. This algorithm takes into account fan-shaped fascicle
forks usual in actual white matter organization. Then, we propose a method
of inferring a regularized direction map from diffusion data in order to im
prove the robustness of the tracking. The regularization stems from an anal
ogy between white matter organization and spaghetti plates. Finally, we pro
pose a study of the tracking behavior according to the weight given to the
regularization and some examples of the tracking results with in vivo human
brain data. (C) 2001 Elsevier Science B.V. All rights reserved.