脑梗死DTI分型及其与临床分期相关性的研究

The Correlation Between the Types of DTI and Clinical Stages in Cerebral Infarction

目的应用MR扩散张量成像(diffusion tensor imaging,DTI)分析脑梗死不同临床时期的信号特征并分型,探讨DTI分型与临床分期的相关性。资料与方法采用盲法分析79例脑梗死病灶的平均扩散(average diffusion co-efficient,DCavg)图和部分各向异性(fractional anisotropic,FA)图的信号特点并分型,测量梗死区及健侧DCavg值和FA值,并对DTI分型与临床分期进行相关性分析。结果将79例脑梗死分为以下4型:Ⅰ型(11例):梗死区DCavg图呈等或低信号,FA图呈等、略高或高信号;梗死区DCavg值降低,FA值升高;Ⅱ型(40例):梗死区DCavg图呈低信号,FA图呈略低信号;梗死区DCavg值降低,FA值降低;Ⅲ型(11例):梗死区DCavg图呈略高信号,FA图呈低信号;梗死区DCavg值略升高,FA值降低;Ⅳ型(17例):梗死区DCavg图呈明显高信号(接近脑脊液信号),FA图呈明显低信号(接近脑脊液信号);梗死区DCavg值明显升高,FA值明显降低。DTI分型与临床分期存在正相关性。结论 DTI分型可更直观、简便地揭示脑梗死的病理生理过程,且DTI分型越高,临床发病时间越长。

Objective To discuss the signal types of the diffusion tensor imaging（DTI）in cerebral infarction at different stages,and investigate the relationship between the types of DTI and the clinical stages.Materials and Methods Signal characteristics of average diffusion coefficient（DCavg）and fractional anisotropic（FA）were observed and classified with double blind method in 79 patients.The DCavg and FA of the infracted area and the unaffected side were measured.The relationships between the types of DTI and the clinical stages were analyzed.Results Four types of the signal characteristics of DTI were classified as follows.Type I（11 cases）：the infraction lesions showed isointensity or hypointensity on DCavg map and isointensity or slight hyperintensity or hyperintensity on FA map,where the DCavg decreased and FA increased;Type Ⅱ（40 cases）：the infraction lesions showed hypointensity on DCavg map and slight hypointensity on FA map,where the DCavg decreased and FA decreased;Type Ⅲ（11 cases）：the infraction lesions showed slight hyperintensity on DCavg map and hypointensity on FA map,where the DCavg increased slightly and FA decreased;Type Ⅳ（17 cases）：the infraction lesions showed obvious hyperintensity on DCavg map（closing to the signal of cerebrospinal fluid）and obvious hypointensity on FA map（closing to the signal of cerebrospinal fluid）,where the DCavg increased and FA decreased significantly.Positive correlation was found between the types of DTI and clinical stages.Conclusion The types of DTI can intuitively reveal the pathophysiological procedure of the cerebral infarction,the higher of the types are,the longer of the onset time are.