摘要
目的结合动态回波平面Ｔ２血流灌注成像在颅脑疾病诊断中的初步应用，总结正常成人与颅脑疾病患者血流灌注成像的表现，阐明ＭＲ顺磁性对比剂血流灌注成像的基本原理及颅脑疾病灌注成像表现的磁共振基础，讨论磁共振脑血流定量研究中存在的问题及其进一步的研究方向。方法共４３例，其中健康成人８例，脑缺血或脑梗死病人２２例，病毒性脑炎２例，胶质瘤５例，脑膜瘤４例，神经鞘瘤２例。所有病例均行常规Ｔ２ＷＩ、Ｔ１ＷＩ、回波平面（ＥＰＩ）弥散加权像及动态ＥＰＩＴ２血流灌注成像。计算Ｔ２图像信号变化率（ΔＲ），计算ΔＲ时间曲线下面积，对比剂平均通过时间（ＭＴＴ）。结果健康成人灰质区脑血容量大于白质区（配对ｔ检验，ｔ＝９３４，Ｐ＜００１）。比值为２２３±０８９。灰质区ＭＴＴ较白质区为短，（配对ｔ检验，ｔ＝９３４，Ｐ＜００１），差值平均为（１１７±０７５）秒。颞顶叶局部脑血容量均值较额枕叶为低。基底节区以内囊后肢与膝部的局部脑血容量为低。脑梗死病灶中心区表现为脑血容量明显下降，ＭＴＴ延长。在超早期可见缺血灌注减低区范围大于或等于弥散加权像所显示的范围。脑炎的Ｔ２ＷＩ异常区相对脑血容量比率增加至１９９与２?
Objective To report the preliminary study of brain diseases by using MR dynamic EPIT2* perfusion imaging and summarize the perfusion status of normal adult brain and the perfusion changes in brain diseases Methods Totally 43 cases were studied including 8 healthy adults, ischemia or infarction 22 cases, viral encephalitis 2 case, glioma 5 cases, meningioma 4 cases, and Schwannoma 2 cases MR examinations were performed using T2 and T1 weightedimaging, EPI diffusion weighted imaging, dynamic EPIT2* perfusion imaging R* R*dt and MTT* were calculated in normal and abnormal brain lesions Results rrCBV of gray matter was greater than that of white matter in normal adult brain(paired test,t=934,P<001) The rrCBV ratio was 223089 MTT* was shorter in gray matter than in white matter with mean difference of 117075 seconds(paired test,t=460,P<001) rrCBV in the center region of ischemic lesions decreased significantly with delayed MTT* The area of decreased rrCBV shown on perfusion imaging was greater than that shown on diffusionweighted imaging in some of the hyperacute ischemic stage rrCBF ratio increased to 199 and 228 in cerebral encephalitis in the abnormal region on T2WI R*dt of glioma decreased or increased to different degrees R*dt of meningioma and schwannoma increased significantly with prolonged MTT* Signal base line in these lesions restored slowly with or without elevated base line Conclusions Dynamic susceptibility contrast EPIT2* imaging can demonstrate the hemodynamic status normal brain and pathological lesion Combined with routine MR imaging, dynamic EPIT2* perfusion imaging is an ideal method to show the morphological and functional changes of brain tissue simultaneously AIF is the basis for quantitative measurement of CBF.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
1999年第7期457-462,共6页
Chinese Journal of Radiology
关键词
磁共振成像
血液动力学
造影剂
脑缺血
Magnetic resonance imaging HemodynamicsContrast mediaEvaluation studies
