Clinical Application Of Magnetic Resonance Diffusion Tensor Imaging In Cerebral Ischemic Stroke

Part I Analysis different b values on DTI of normal adultObjective:To investigate the relationship between various b-values and DTI．Materials and Methods:15healthy adult male volunteers underwent DTIscanning,b-values selected(100,300,500,1000,1500,2000,2500,3000s/mm2)． All theimages were measured ADC and FA value,And calculated SNR and contrast of theGW and WM．Results:Different b values in different parts of ADC were significantly different（P＜0.05），ADC decreases with increasing b values；FAvalue of the mean，median，standard deviation and coefficient of variation was not with the b-value changed(P＞0.05)；image SNR and contrast of the GW and WM were affected by the strength of b－value．Conclusion:FA is a relatively stable value,unaffected by the strength of b-value；when b=1000s/mm2,SNR and the contrast of gray and white matter were better,canbe used as a routine clinical applications. Part II Clinical application of magnetic resonance diffusiontensor imaging in cerebral ischemic strokeObjective:To investigate the variation law of apparent diffusion coefficient andfractional anisotropy values in patients with cerebral infarction.and to explore therelationship between the changes with the severity of clinical symptoms and theprognosis of cerebral infarct patients,To investigate the relationship between DTTscores with the severity of clinical symptoms and the prognosis of cerebral infarctpatients.Materials and Methods:patients met the inclusion criteria with cerebralinfarction were recruited and divided into3groups:acute phase group,sub-acute phasegroup and early chronic group.ADC and FA values were calculated in infarct areasand control areas respectively,Then，The difference of ADC and FA values in patientsat the three stage between the two areas and the Relationship with NIHSS score、Rankin score were analyzed.All the patients were performed DTT.Results:The patients at acute stage and sub-acute stage,The FA/ADC value ininfarct areas were lower than control areas(P＜0.05).At early chronic stage,The ADCvalue of the affected side and control side were no significant differences(P＞0.05)；rFA/rADC with the NIHSS score and Rankin score was no significant correlation（P＞0.05）.DTT scores with the NIHSS scores and Rankin scores was related（P＜0.05)。Conclusion:ADC and FA values can reflect the pathophysiological changes ofstrokes;DTT scores with the severity of clinical symptoms and prognosis wassignificant correlation.