Application Of Diffusion Tensor Imaging In The Evaluation Of Prognosis In Patients With Acute Middle Cerebral Artery Infarction

Objective: Cerebral infarction is a cerebrovascular disease with high morbidity and disability rate, which seriously affect the health and life quality of the elderly population.Early damage degree evaluation of cerebral infarction and the accurate prediction of the prognosis of the patients are always difficult problems in medical field.Nuclear magnetic resonance diffusion tensor imaging is a noninvasive method to study the morphology and structure of brain white matter fiber in living conditons, and is mainly used in diseases of the central nervous system,especially in cerebral infarction, and have important significance in early diagnosis of cerebral infarction, defining lesions, early evaluation of prognosis.The study used 1.5T diffusion tensor magnetic resonance imaging scanning in the patients with actute middle cerebral artery territory cerebral infarction to analysis of the relationship between the degree of the corticospinal trcat(CST) and clinical prognosis.Methods: Twenty- three patients with middle cerebral artery infarction were prospectively examined with 1.5T diffusion tensor imaging within a 72-hour mean interval onset. Measure the fractional anisotropy(FA) and the apparent diffusion coefficient(ADC) in ischemic lesion and the oppsite area in nonaffected hemisphere, the fringe area of infarcts, cerebral peduncle.According to the extent of CST destruction, the affacted CST was divided into three grades.The twenty patients were graded by NIHSS and FMS at different time points. All date were analyzed using SPSS16.0, and spearman correlation analysis was applied to reveal the relationships betwen the extent of CST destruction and clinical prognosis.The comparison of FA or ADC values in the ipsiateral and contralateral side was used T paired test,P <0.05 was considered statistically significance. Comparison of two different enumeration variables between the groups using x2 test, P <0.05 was considered statistically significance.Result: FA and ADC values notably decreased in infraction lesions verses nonaffected hemisphere( P < 0.001),which revealed that the tissue in infarction lesions have been damaged in different extent. Negative correlation was found between the extent of CST destruction and motor dysfunction grading according to FMS(r=-0.843,P<0.001), which revealed that the more serious CST was damaged, the lower motor dysfunction grading, the heavier degree of motor impairment, the worse prognosis. Positive correlation was found between the extent of CST destruction and recovery of neurological function according to NIHSS(r=0.819,P<0.001),which revealed that the more serious CST was damaged, the higher neurological function score, the worse prognosis of neurological function.conclusions: Diffusion tensor imaging provide a way for the quantitative analysis of acute middle cerebral artery territory lesions and the degree of CST damage, and provide reliable basis for early accurately judging the clinical prognosis and guiding clinical treatment, also open a new way for the ischemic penumbra and Wallerian degeneration research.