三维纤维束示踪成像评价急性脑梗死患者皮质脊髓束损伤的意义

Evaluation of cortical spinal tract injury in patients with acute cerebral infarction with three-dimension diffusion tensor tract

目的∶观察缺血性脑卒中急性期患者皮质脊髓束的状况,分析运动功能与皮质脊髓束受损情况的关系。方法∶采用GE1.5T磁共振成像系统,对2005-02/12解放军南京军区福州总医院就诊的15例缺血性脑卒中急性期患者进行磁共振弥散张量成像检查,用dTV.Ⅱ软件进行处理,显示部分各向异性图及彩色部分各向异性方向图;并采用种子方法重建双侧皮质脊髓束的三维纤维束成像图,观察纤维束的移位、连续性及破坏情况;同时采用Brunnstorm标准判断脑梗死患者患手肌力,应用Spearmen相关分析分析皮质脊髓束损伤程度与患手肌力的相关性。以15例健康志愿者为对照组进行比较。结果:30例受试者均进入结果分析。①脑卒中患者梗死白质区部分各向异性值显著低于健侧,两侧相比差异有显著性意义(t=4.570,P<0.001)。②对照组双侧皮质脊髓束重建,自中央前回下行至内囊并延续至脑桥和延髓,每条连续形态一致性良好。脑梗死患者健侧皮质脊髓束形态与对照组一致,连续性好;患侧皮质脊髓束因受梗死区不同程度的累及,表现为连续性中断及解剖结构形态一致性的丧失。表现为1级(皮质脊髓束完整)2例;2级(皮质脊髓束完整,但受压推移)5例;3级(皮质脊髓束中断)8例。③皮质脊髓束损伤程度与患手肌力明显相关(rs=0.888,P<0.05)。结论:①急性脑梗死患者患侧皮质脊髓束不同程度受损,且损伤程度与肌力相关,提示可用于判断康复治疗的预后。②三维纤维束示踪成像图可以更立体直观的显示锥体束状况。

AIM： To observe the condition of cortical spinal tract （CST） in acute cerebral ischemic stroke patients and analyze relationship between motor function and the impairment degree of CST. METHODS： Between February and December 2005, 15 patients with acute cerebral ischemic stroke in Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA received magnetic resonance diffusion tensor imaging （DTI） with GE 1.5 T nuclear magnetic resonance system, fiber tracking with the software of dTV-Ⅱ. Fractional anisotropy （FA） maps and 3D tractography of bilateral CST of all patients were created. Displacement, continuity and injured condition of fibrous bands were observed. At the same time, hand muscle strength of patients with cerebral infarction was measured with Brunnstorm standard. Injured degree of CST and correlation of hand muscle strength was analyzed with Spearmen correlation analysis. Totally 15 healthy volunteers were enrolled as control. RESULTS： A total of 30 testees were involved in the result analysis. ①The FA value in infarct area of white matter was significant lower than that in normal hemisphere, which had significant difference at the two sides （t=4.570,P 〈 0.001）. ②Reconstruction of bilateral CST in the control group, precentral gyrus to internal capsule and continued to pontine and medulla oblongata, and concordance was good in each. CST form in uninjured side in the cerebral infarction patients was coincident with that in the control group and the continuity was good. The injured CST expressed continuous break and the loss of anatomic structure, because it was involved by infarcted region to different degree. There were 2 cases of grade 1 （complete CST）, 5 cases of grade 2 （complete CST, but compression shift） and 8 cases of grade 3 （CST break）. ③Injured degree of CST was significantly associated with hand muscle strength （ra=0.888,P 〈 0.05 ）. CONCLUSION： ①CST is injured to different degree in acute cerebral infarction patients, and the degree of injury is associated with muscle strength. It is indicated that it can be used for prognosis of rehabilitative treatment. ②3D fiber tract maps can display the status of pyramidal tract more stereotacticly.