Diffusion tensor imaging of the corticospinal tract in patients with brain neoplasms.
OBJECTIVE
To maximize the extent of tumor resection and minimize postoperative neurological deficits in patients with brain neoplasms, it is very important to evaluate the integrity of the corticospinal tract (CST) before surgery. We attempted to determine whether CST abnormality in these patients correlates with clinical motor weakness.


METHODS
We retrospectively evaluated 19 patients (16 men, 3 women, aged 39 to 70 years) with pathologically proven brain neoplasms with lesions adjacent to the posterior limb of the internal capsule and categorized their motor function as normal or abnormal based on clinical assessment. After correcting raw diffusion tensor image (DTI) data for motion and eddy-current artifacts, we computed fractional anisotropy (FA) and apparent diffusion coefficient (ADC) maps. We manually segmented the CST from the level of the cerebral peduncle to the internal capsule, used the segmented CST as the mask for FA and ADC measurements, and compared normalized FA (nFA) and ADC (nADC) values relative to the contralateral normal side using a 2-tailed, unpaired t-test.


RESULTS
Compared with the normalized values for patients with normal motor function, patients with abnormal motor function demonstrated significantly decreased FA (P<0.001, 0.65±0.09 versus 0.85±0.08) and significantly increased ADC (P<0.01, 1.49±0.17 versus 1.23±0.22).


CONCLUSIONS
DTI metrics can be used for preoperative evaluation of the integrity of the CST microstructure.
Department of Radiology, Tokushima University Hospital, Japan. nmorita@clin.med.tokushima-u.ac.jp
Naomi
N
Morita
Sumei
S
Wang
Paulomi
P
Kadakia
Sanjeev
S
Chawla
Harish
H
Poptani
Elias R
ER
Melhem
D000328:Adult; D000368:Aged; D016880:Anisotropy; D016477:Artifacts; D001932:Brain Neoplasms / Q000473:pathology / Q000503:physiopathology*; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011712:Pyramidal Tracts / Q000473:pathology / Q000503:physiopathology*; D012189:Retrospective Studies