Focal lesions of the corticospinal tract demonstrated by diffusion tensor imaging in patients with diffuse axonal injury.
OBJECTIVE
Diffusion tensor imaging (DTI) with fiber tractography (FT) could be useful for exploration of the state of the corticospinal tract (CST) at the subcortical white matter level. The purpose of this study was to demonstrate focal lesions of the CST in patients with diffuse axonal injury (DAI), using DTI with FT.


METHODS
Two patients with DAI and six normal control subjects were recruited to this study. DTI was performed using 1.5-T with a synergy-L Sensitivity Encoding (SENSE) head coil. Fractional anisotropy (FA) and apparent diffusion coefficients (ADC) were measured using a region of interest (ROI) method. FTs were obtained with FA <0.3 and an angle change >45 degrees as termination criteria.


RESULTS
On the DTI with FT, the focal lesions, which could not observed using routine brain MRI, were detected in the left brainstem of patient 1 and in the right pons and the left and right medulla of patient 2. The patients showed significantly decreased FA values in the focal lesions compared to normal controls.


CONCLUSIONS
DTI with FT demonstrated focal lesions at the brainstem that had not been revealed by conventional brain MRI; these focal lesions explained the weaknesses of the patients. We conclude that DTI with FT may be a useful modality for use in investigating the status of CST in patients with DAI.
Ahn
Young Hwan
YH
Department of Neurosurgery, School of Medicine, Ajou University, Suwon city, Republic of Korea.
Kim
Seong Ho
SH
Han
Bong Soo
BS
Kim
Oh Lyong
OL
Ahn
Sang Ho
SH
Cho
Yoon Woo
YW
Kwon
Yong-Hyun
YH
Jang
Sung Ho
SH
D000328:Adult; D016880:Anisotropy; D020833:Diffuse Axonal Injury / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D011712:Pyramidal Tracts / Q000473:pathology*