摘要
目的应用MR扩散张量成像(DTI)技术对急性脑梗死行动态观察,研究其扩散变化规律,推断缺血半暗带的治疗时间窗,并通过扩散张量纤维束成像(DTT)技术论证皮质脊髓束与肌力的相关关系。方法对71例不同时间窗的脑梗死病例行常规MRI、扩散加权成像(DWI)及DTI检查,测定各期病灶的平均扩散系数(DCavg)、部分各向异性系数(FA)、相对各向异性系数(RA)及容积比(1-VR)值,并对10例行三维白质纤维重建。结果梗死不同时期的DCavg均值分别为[(0·275±0·022),(0·349±0·019),(0·465±0·023),(0·538±0·035)]×10-3mm2/s,随时间变化呈明显减低、逐渐回升、假正常化的趋势(P<0·001);FA、RA、1-VR值在超急性期轻度升高,以后呈不可复性减低的趋势;超急性期、急性期病灶中心区与边缘区的DCavg、FA、RA、1-VR值差异有统计学意义(P<0·001)。皮质脊髓束表现为无受压、受压无中断及中断、破坏,其临床肌力表现为无减退、治疗后肌力恢复、无恢复。结论梗死灶的DCavg、FA、RA、1-VR值具有特征性演变规律;超急性期、急性期病灶边缘区可能为缺血半暗带组织,其治疗时间窗可扩展为24h。DTT技术对临床及判断预后有重要价值。
Objective To reveal the transmiting discipline of parameters and define time window for therapy of ischemia penumbra by continuous detection of diffusion tensor imaging(DTI), and evaluate the relations between cortical spinal tracts(CST) and myodynamia by diffusion tensor tract(DTT). Methods 71 patients of cerebral infarction with different timing were imaged with conventional MRI, DWI and DTI, measuring DCavg, FA, RA , 1-VR of different ROI and performing DTT in ten patients. Results DCavg of lesions in different phases were [(0.275±0.022),(0.349±0.019),(0.465±0.023),(0.538±0.035)]×10~ -3mm^2/s, respectively. DCavg value showed tendency of reducing obviously, elevating gradually and false-normalizing (P<0.001). FA/RA/1-VR of lesions elevated in hyperacute stroke and showed tendency of unrecovered decline afterwards. Difference of DCavg, FA, RA, 1-VR between central and peripheral parts of lesions were significant in hyperacute and acute stroke (P<0.001).CST showed not compressed, compressed but not disrupted and disrupted, whose myodnamia was normal, recovered after therapy and not recovered. Conclusion There is characteristic discipline in changes of DCavg, FA, RA and 1-VR. The peripheral parts of lesions in hyperacute and acute stroke maybe ischemic penumbra, and its time window for therapy could extend to 24 hours. DTT has important value to clinical management and prognosis.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2005年第7期677-681,共5页
Chinese Journal of Radiology
基金
国家自然科学基金(30370434)
