RT Journal Article
SR Electronic
T1 Diffusion Tensor Imaging in Chronic Subdural Hematoma: Correlation between Clinical Signs and Fractional Anisotropy in the Pyramidal Tract
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 1159
OP 1163
DO 10.3174/ajnr.A1001
VO 29
IS 6
A1 K. Yokoyama
A1 M. Matsuki
A1 H. Shimano
A1 S. Sumioka
A1 T. Ikenaga
A1 K. Hanabusa
A1 S. Yasuda
A1 H. Inoue
A1 T. Watanabe
A1 M. Miyashita
A1 R. Hiramatsu
A1 K. Murao
A1 A. Kondo
A1 H. Tanabe
A1 T. Kuroiwa
YR 2008
UL http://www.ajnr.org/content/29/6/1159.abstract
AB BACKGROUND AND PURPOSE: Diffusion tensor imaging (DTI) was introduced as a good technique to evaluate structural abnormalities in the white matter. In this study, we used DTI to examine anisotropic changes of the pyramidal tracts displaced by chronic subdural hematoma (CSDH).MATERIALS AND METHODS: Twenty-six patients with unilateral CSDH underwent DTI before and after surgery. We measured fractional anisotropy (FA) values in pyramidal tracts of bilateral cerebral peduncles and calculated the ratio of the FA value on the lesion side to that on the contralateral side (FA ratio) and compared the ratios with motor weakness. Moreover, the relationships between FA ratios and clinical factors such as age, sex, midline shift, interval from trauma, and hematoma attenuation on CT were evaluated.RESULTS: FA values of pyramidal tracts on the lesion side were significantly lower than those on the contralateral side (0.66 ± 0.07 versus 0.74 ± 0.05, P < .0001). The FA ratio was correlated to the severity of motor weakness (r2 = 0.32, P = .002). FA ratios after surgery improved significantly compared with those before surgery (0.96 ± 0.08 versus 0.89 ± 0.07, P = .0004). Intervals from trauma and the midline shift were significantly associated with decreased FA ratios (P = .0008 and P = .037).CONCLUSIONS: In patients with CSDH, a reversible decrease of FA in the affected pyramidal tract on DTI was correlated to motor weakness. These anisotropic changes were considered to be caused by a reversible distortion of neuron fibers and vasogenic edema due to the hematoma.