Quantitative evaluation of the pyramidal tract segmented by diffusion tensor tractography: feasibility study in patients with amyotrophic lateral sclerosis.
OBJECTIVE
Diffusion tensor imaging can evaluate the cerebral white matter quantitatively using fractional anisotropy (FA) and also can extract a certain tract by tractography, but these two have been used separately and not combined. The purpose of this study was to assess the clinical feasibility of ROI analysis using diffusion tensor tractography (DTT) in patients with amyotrophic lateral sclerosis (ALS).


METHODS
Sixteen patients with ALS (9 limb-onset type, 7 bulbar-onset type) and nine age-matched volunteers were studied. DTT of the corticobulbar tract (DTT-CBT) and corticospinal tract (DTT-CST) were visualized by free software (dTV/VOLUME-ONE). Regions-of-interest (ROIs) were semi-automatically placed on the tracts defined by DTT methods, and FA values within the ROIs were measured.


RESULTS
Mean FA values of ALS patients in the ROIs along the DTT-CST (bulbar-onset: 0.574, limb-onset: 0.594) were significantly lower than those of controls (DTT-CST: 0.629) (p<0.05). The mean FA of DTT-CBT of the bulbar-onset type (0.509) was significantly lower than that of the limb-onset type (0.558) and that of volunteers (0.561).


CONCLUSIONS
DTT could segmentate certain white matter tracts and evaluate them quantitatively. It could depict the subtle changes between subtypes of ALS as well as the changes between the patients and volunteers.
Aoki
Shigeki
S
Department of Radiology, University of Tokyo Hospital, Tokyo 113-8655, Japan.
Iwata
Nobue K
NK
Masutani
Yoshitaka
Y
Yoshida
Mariko
M
Abe
Osamu
O
Ugawa
Yoshikazu
Y
Masumoto
Tomohiko
T
Mori
Harushi
H
Hayashi
Naoto
N
Kabasawa
Hiroyuki
H
Kwak
Shin
S
Takahashi
Seizou
S
Tsuji
Shoji
S
Ohtomo
Kuni
K
D000690:Amyotrophic Lateral Sclerosis / Q000473:pathology*; D016880:Anisotropy; D001931:Brain Mapping / Q000379:methods; D016022:Case-Control Studies; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011712:Pyramidal Tracts / Q000473:pathology*; D012984:Software