[Value of the functional neural tractography in the reconstruction of the visual pathways in DTMRI].
OBJECTIVE
This article shows that functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) are very useful in the in vivo description of the visual pathways using today's most advanced techniques and allowing fusion between fMRI and tractography. Two complementary techniques were combined: (1) DTI coupled with the tractography and (2) fMRI.


METHODS
A group of 205 cases, normal and pathological, children and adults, were studied for tractographic reconstitution of visual pathways. In addition, 11 patients underwent an acquisition in fMRI (BOLD effect), with a stimulation of a black-and-white flickering checkerboard. Acquisition was carried out on a 3.0 Tesla GEHC MRI unit. Activated arrays of fMRI are overlaid with those of neurotractography (neural tractography) having like results a functional neurotractography.


CONCLUSIONS
The main components of the visual pathways were successfully reconstructed in tractography: the optic nerves, optic chiasm, optic tracts, and optic radiations. It was also possible to visualize fiber decussation within the chiasma (possible direct pathways to the hypothalamus and thalamus were also identified).


CONCLUSIONS
The tensor of diffusion is increasingly used and is a promising technology to improve the diagnosis of neurological diseases. Sophisticated algorithms contribute a new vision of the anatomy, with the possibility of isolating distinct anatomical entities. With the software used, the charts of fMRI activation are overlaid on the anisotropy charts. The tractograms that link two regions of the same functional network thus provide information on subjacent structural connectivity. Consequently, one speaks about functional neurotractography.
UFR 927 Pitié-Salpêtrière, CNRS UMR 6569, service de neuro-imagerie et radiologie, centre hospitalier national d'ophtalmologie des XV-XX, université Pierre-et-Marie-Curie Paris-6, 28, rue de Charenton, 75571 Paris cedex 12, France. adiistoc@yahoo.com
A
A
Istoc
C
C
Habas
M-T
MT
Iba-Zizen
T H
TH
Nguyen
A
A
Abanou
M
M
Yoshida
L
L
Bellinger
J-F
JF
Le Gargasson
E A
EA
Cabanis
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D038524:Diffusion Magnetic Resonance Imaging; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D014795:Visual Pathways / Q000033:anatomy & histology*; D055815:Young Adult