脑干华勒氏变性的DTI研究

目的 应用弥散张量成像（diffusion tensor imaging,DTI）观察非脑干脑梗死后脑干华勒氏变性（Wallerian degeneration,WD）的特点,从而为临床早期治疗和预后评估提供准确的影像学信息.方法 收集54例非脑干梗死患者,其中非脑干梗死组中初发脑梗死按照病程分为三期,即急性期（n=16）、亚急性期（n=16）、慢性期（n=16）;非脑干梗死组按照病灶范围分为腔隙性梗死组（病灶直径＜1.5 cm,n=27）和梗死面积较大组（病灶直径＞1.5 cm,n =27）.另外选择脑实质未见异常的对照组40例.所有受试者应用美国GE1.5T磁共振进行脑部常规MRI及DTI成像.所有数据应用AW4.5 Functool软件分析处理,根据白质纤维示踪图观察脑干皮质脊髓束形态变化,分别测量ADC值和FA值,并进行统计学分析、比较.结果 与对照组比较,非脑干梗死组ADC值和FA值均降低（均P＜0.01）;而非脑干梗死组在不同病程和病灶范围大小不同的ADC值和FA值比较,均有统计学差异（P＜0.05）,其中FA值从急性期、亚急性期到慢性期呈逐步降低的趋势,ADC值在急性期及亚急性期降低,慢性期升高;与腔隙性梗死组对比,梗死面积较大组ADC值和FA值均降低（均P＜0.05）.结论 应用弥散张量成像可以判断非脑干梗死时脑干华勒氏变性皮质脊髓束形态变化,定量测定脑于FA值和ADC值.

Study on DTI of brainstem Wallerian degeneration

Objective To investigate the the characteristics of brainstem Wallerian degeneration caused by non-brainstem cerebral in- farction by diffusion tensor imaging for providing the accurate imaging information for early clinical treatment and prognosis. Methods Fifty-four non-brainstem cerebral infarction patients were collected and divided into lacunar infarction group（ size less than 1.5 cm, n = 27） and larger infarction area（ size more than 1.5 cm, n = 27） according to the lesion size. Forty-eight primary cerebral infarction patients were divided three groups：acute stage group（ n = 16）, subacute stage group （n = 16）and chronic stage group （n = 16）. Forty subjects with no abnormal brain parenchyma were chosen as control group. All subjects were performed cerebral imaging of conventional magnetic resonance imaging and diffusion tensor imaging with American GEl. 5 T MRI. All data were analyzed with AW 4.5 worksta- tion. The corticospinal tracts of brainstem were observed, and ADC value and FA value were measured and statistically analyzed. Re- suits ADC values and FA values in non-brainstem infarction group decreased compared with control group （ P 〈 0.01 ）. ADC values and FA values at the different stages and different lesion sizes in non-brainstem infarction group were statisticaly different（P 〈 0.05）. FA values gradually reduced from acute stage, subacute stage to chronic stages, while ADC values decreased from acute stage to suba- cute stage, but increased at chronic stage. ADC values and FA values in larger cerebral infarction group were significantly lower than tbese in lacunar cerebral infarction group（P 〈 0. 05）. Conclusion Diffusion tensor imaging can be used to evaluate the characteris- tics of corticospinal tracts of brainstem Wallerian degeneration and quantitatively detect FA values and ADC values.