多发性硬化白质脱髓鞘斑块的磁敏感加权成像及动态磁敏感增强灌注成像研究  

Longitudinal study of multiple sclerosis plaques by using susceptibility weighted imaging and dynamical susceptibility contrasted MR perfusion imaging

作　　者：苗延巍[1] 蔡兆诚[1] 张清[1] 伍建林[1] 胡伽尼[1] 

机构地区：[1]大连医科大学附属第一医院放射科,116011

出　　处：《中华放射学杂志》2011年第5期426-431,共6页Chinese Journal of Radiology

基　　金：辽宁省高校优秀人才支持计划（2009R16）

摘　　要：目的探讨多发性硬化（MS）脱髓鞘斑块的磁敏感加权成像（SWI）特征表现、MS斑块形态及微循环的演变过程。方法对31例临床确诊的MS患者进行MR检查，扫描序列包括T2WI、液体衰减反转恢复（FLAIR）序列T2WI、T1WI及SWI。其中21例进行了MRI随访，间隔时间为2．0～20．0个月，并且15例随访患者在第2次MR检查时行动态磁敏感增强灌注成像（DSC—PI）。观察MS斑块在“滤过”后相位图（FPI）的特征，测量斑块相位值和灌注参数，包括脑血流量（CBF）和脑血容量（CBV），并动态分析其演变规律。不同序列检测出的斑块个数采用配对t检验进行对照分析；采用Pearson相关分析法评价斑块相位值与灌注参数的相关性。结果在FPI上，全部患者298个MS斑块呈3种表现：（1）低信号灶，无小血管穿行（109个，37％）；（2）低信号灶，有小血管穿行（169个，57％）；（3）病灶区仅有“异常血管区”而无明显信号降低（20个，7％）。21例随诊病例中，前后2次检查经FLAIR T2WI检出的斑块总数及均数分别为452（22±8）、439（21±7）个，T1WI检出的斑块数分别为205（10±3）、206（10±3）个，SWI检出的斑块数分别为211（10±3）、219（10±3）个，FLAIR T2WI检出的病灶均数减少（t=2．28，P=0．03），FPI检出的病灶均数增加（t=-2．61，P=0．02），而T1WI检出的病灶均数无明显变化（t=-1．00，P=0．33）。21例随访患者中，6例发现有9个脱髓鞘斑块从仅表现为异常血管区演变到出现明确的低信号灶，其相位值变化（-0．031±0．012）与CBF值的变化[（-13．92±7．99）ml·100g^-1·min^-1]以及CBV值的变化[（-2．54±1．33）ml·100g^-1]具有负相关（r值分别为-0．73、-0．84，P值均〈0．05）。结论SWI相位图上低信号伴有小静脉穿行是MS脱髓鞘斑块的特征性表现；联合运用SWI和DSC-PI有助于进一步理解MS斑块的病理生理演变[ Abstract] Objective To identify the imaging characteristics of demyelinating plaques in multiple sclerosis （MS） by using susceptibility weighted imaging （SWI）, and further explore their morphologic and micro-hemodynamic evolvements. Methods Thirty-one cases with clinically proven MS received SWI and dynamical susceptibility contrasted MR perfusion imaging （DSC-PI）. And 21 cases received MR again in the follow-up period, with a time interval of 2. 0-20. 0 months [ mean （ 7.5 ± 4. 8） months ]. Features of MS plaques in filtered phase images （FPI） were assessed, and the number of MS plaques detected in T1 WI, T2 FLAIR and FPI images were counted respectively. The measurements of phase values and perfusion parameters （including CBF and CBV） were acquired and their variation over time was also evaluated. The number of plaques detected by different MR sequences was compared by using paired t test, and the correlation between phase values and peffusion parameters was evaluated by using Pearson correlative analysis. Results Three types of MS plaques were observed in FPI images, including （ 1 ） round or oval hypointense foci without small veins （109 of 298, 37% ） , （2） hypointense foci with small veins （169 of 298, 57% ） , （ 3 ） abnormal vessels alone without hypointense foci （ 20 of 298, 7% ）. In the 21 cases received MR follow-up, the total and mean plaque numbers identified on T2 FLAIR images were 452 and （22±8） in the first MR examination, and 439 and （21 ±7）in the second MR examination; and on T1-weithed images, they were 211 and（ 10 ±3 ） in the first MR examination, and 219 and （ 10 ±3 ） in the second MR examination; as well as those on FPI images were 205 and （10 ±3 ）, and 206 and （10 ±3 ）, respectively. Compared between the first and second MR scan, the mean of number on T2 FLAIR images decreased （t =2.28 ,P =0. 03）, and that on FPI images increased（t = -2. 61 ,P =0. 02） , and then that on T1-weight images keep invariable （t

关 键 词：多发性硬化 磁敏感加权成像 

分 类 号：R445.2[医药卫生—影像医学与核医学]