| Objective: Diffusion tensor tractography(DTT) was stud- ied in the patients with cerebral infarction in order to evaluate extent of motor dysfunction and clinical prognosis. The relationship between infarcted focus and cortical spinal tract(CST)was analysed in patients through Diffusion tensor tractography(DTT)so as to investigate application of DTI in cerebral infarction.Methods: Forty-five patients (mean age 62.44±2.08 years, range 32 to 88years old; male 29, female 16) presenting from 3 hours to 3 years of the onset were studied. All the patients had suffered from motor dysfunction because of CST had been damaged . According to the staging method of Osborn AG, the patients were divided into hyperacute phase(<6h,n=5), acute phase(6h～3d,n=18),subacute phase(4d～8w,n=15),and Chronic phase(>8w,n=7) groups. Patients with primary cereb- ral hemorrhage assessed by computed tomography(CT) were excluded from the study. Conventional MRI ( anteroposterior axes T1WI T2WI, abscissa axis T1WI T2WI),MRA,DWI and DTI were performed on a Siemens Tim—avanto1.5T using a standard. Meantime, another twenty healthy volunteers of the similar age and sex (mean age 57.75±4.57. range 34 to 79years old; male 12, female 8 )had been chosen for contrast. The same examination was implemented. As was shown in the result of the examintaion, among the 45 patients, there were 25 cases of basal ganglia,10cases of body of lateral ventricle,7cases of brain stem,3cases of fronto and temporal lobe. According to different parts of infarction, the values of FA and ADC in the infarction and corresponding regions in uninjured side were measured. Meanwhile, the value of FA in the same ROIs as researched team in the contrast group was measured. The DTT was carried on the researched team and the contrasting group. We also got the normal direction of CST as well as got the damaging condition of CST of the researched team. CST could be devided into 3 grades according to its degree of damage. grade1:CST was complete, grade 2 was complete but compression shift, grade 3 was break. Meantime, all the patients were measured according to Activities of Daily Living (ADL) scale when on admissioa(ADL(1)) and two months after the onset(ADL(2)). The decreasing percents of FA value in infarctions were calculated in order to see whether there were any relationship between ADL(1)and ADL(2) Meanwhile, the damage grades of CST and their relationship with ADL(2)were also calculated to know the recovering state of the patients. The statisics were analyzed by SPSS13.0 and P<0.05 was considered to has statistical difference. The difference between measurement data was decided by compared t-test, and the correlation analysis was taken by spearman correlation. Result:1. The variation of FA in different parts of infarctionsIn researched team ,the value of FA in Basal ganglia,Body of lateral ventricle,Brain stem,Fronto and Temporal lobe were significantly lower than the value of FA in corresponding regions and in the same parts of contrast group (P <0.05). While the value of FA weren'significant in uninjured side of researched team and in contrast group (P >0.05).Neither do the contrast of the left sides and the right sides(P >0.05).2. The variation of the FA and ADCin different phases in infarctionsThe value of FA in infarction regions were significantly lower than the corresponding regions in acute,subacute and chronic phases(P <0.05). Though staticstics, we could see that the FA didn't change obviously in hyperacute phases.Followi- ng the development of the patient's conditions, the value of FA decreased gradually.The value of ADC in infarction regions were significantly lower than the corresponding regions in hyperacute and acute phases (P <0.05).However,in chronic phase, The value of ADC in infarctions were significantly higher than the corresponding. Though staticstics, we could see that during hyperacute and acute phases, the value of ADC in infarctions had decreased obviously. In subacute phase, it reached almost the same level on both sides. However in chronic, it increased again..3. DTT image formation The CST was buit in between researched team and contrast group. The shapes of 45 patients'CST in uninjured si- de were consistent with the contrast group with good continuity. However,the CST in infarctions performed discontinuity. They were devided into 9 cases of grade1; 24cases of grade2 and 12 cases of grade 3 .4.The result of ADLAll the patients' ADL score was average 53.5±5.83 (rage 5 to 95) when on admission(ADL(1)) and was average 68.25±5.60 (rage 30 to 100) two months after the onset(ADL(2)).5.The relationship among the decreasing percentage of FA, DTT and ADL.The decreasing percentage of FA assumed the inverse correlation relations withADL (1) (r=-0.826,P <0.05)and with ADL (2) (r=-0.851,P <0.05). The damage level of CST was shown by DTT assumed the inverse correlation rela tions with ADL(2)( r=-0.914, P <0.05).Conclusion:1.DWI and DTI are significant in identifing the position and the range of infarction regions in the early diagnosis of hyperacute phase in cerebral infarction.2. The variations of FA and ADC in different phases of cerebral infarction have invariably regularities. They can provide important imaging materials for clinical stage and judgement of pathogenetic condition's prognosis.3. The values of FA in infarctions are compareid with the correspongding's, the more obviously decreasing of the FA, the worse of the patients'prognosis.It can offer evidence for judgement of prognosis in the early stage.4. DTT can show the relationship between positions of infarctions and CST non-invasivly and analyze the influen- ce of theirs. It is early objective proof for judging the injury of the motor function and evaluating prognosis. |
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