Objective: To evaluate the crossing fiber trajectory through the corpus callosum using distortion-corrected diffusion tensor tractography in the human brain.
Methods: After correcting distortion associated with large-diffusion gradients, T2-weighted echo planar images (EPIs) acquired from 10 right-handed healthy men were coregistered into T2-weighted fast spin echo images using linear through sixth-order nonlinear, 3-dimensional, polynomial warping functions. The optimal transformation parameters were also applied to the distortion-corrected diffusion-weighted EPIs. Diffusion tensor tractography through the corpus callosum was reconstructed, employing the “1 or 2 regions of interest” method.
Results: Compared with the lines through the genu, those through the rostrum ran more inferiorly and seemed to enter the orbital gyrus. Those lines entering posterior temporal white matter (tapetum) crossed through the ventral portion of the splenium and were clearly distinguished from lines that reached parieto-occipital white matter (forceps major).
Conclusion: Diffusion tensor tractography is a feasible noninvasive tool to evaluate commissural fiber trajectory.
From the *Department of Radiology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan, and †Department of Neuropsychiatry, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
Supported in part by a Grant-in-Aid for Scientific Research (C) (2) 15591259 of the Ministry of Education, Science, Sports, and Culture of Japan.
Reprints: Dr Osamu Abe, Department of Radiology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-8655, Japan (e-mail: email@example.com).