Hyperintensity on diffusion weighted image along ipsilateral cortical spinal tract after cerebral ischemic stroke: a diffusion tensor analysis.
OBJECTIVE
Hyperintensity along the ipsilateral cortical spinal tract (CST) on a diffusion weighted imaging (DWI) has been reported to may be associated with motor disability after brain infarction and can be misdiagnosed as a new infarction. However, the underlying patho-physiology related to this finding is not clear. The goal of our study was to analyze the diffusion tensor imaging (DTI) changes in patients with this hyperintensity.


METHODS
Eight patients (50 ± 10 years) who exhibited hyperintensity on DWI along ipsilateral CST from 3 to 21 days after stroke onset were reviewed as positive group, including 5 patients with serial DTI examinations. Twelve patients without hyperintensity during the matched examination time were classified as reference group. The apparent diffusion coefficient (ADC), fractional anisotropy (FA), and eigenvalues and their ratios (ipsilateral/contralateral value) in cerebral peduncle were measured, their correlation with motor function scale at eight months after stroke onset were evaluated.


RESULTS
The serial examinations showed that hyperintensity could eventually disappear. Both the ipsilateral ADC and FA values were significantly decreased (p<0.05) compared to the contralateral side. The ipsilateral FA significantly correlated with motor function scale in both groups (r = 0.875, 0.738; p = 0.004, 0.006 respectively).


CONCLUSIONS
The hyperintensity on DWI is a transient pathological process of Wallerian degeneration after ischemic stroke, its diffusion characteristics include concurrent significant decrease of ipsilateral ADC and FA. The ipsilateral FA value has the potential to predict neurological motor function outcome in such patients.
Department of Neuroradiology, Beijing Tiantan Hospital, #6 Tiantan Xili, Beijing, China. Xiang Liu@URMC.Rochester.edu
Xiang
X
Liu
Wei
W
Tian
Lilin
L
Li
Balasubramanya
B
Kolar
Xing
X
Qiu
Feng
F
Chen
Vikram S
VS
Dogra
D000328:Adult; D002545:Brain Ischemia / Q000150:complications* / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011712:Pyramidal Tracts / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020521:Stroke / Q000209:etiology* / Q000473:pathology*