三维增强T2*加权血管成像对多发性硬化脑内病灶铁沉积的分析

目的 探讨三维增强T2*加权血管成像(3D-ESWAN)在研究多发性硬化(MS)患者脑内病灶铁沉积中的价值.方法 选取22例复发-缓解型MS(RR-MS)患者和22名年龄、性别相匹配的健康志愿者行常规MRI和3D-ESWAN检查,患者扩展残疾状态量表(EDSS)评分为0～8.5分,病程为0.5 ～15.0年.ESWAN数据经后处理获得幅度图和相位图,由2名经验丰富的放射医师肓法评定MS病灶在常规MRI和ESWAN的表现,并在相位图分别测量患者半卵圆中心和正中侧脑室体旁之间层面的病灶和健康志愿者相应ROI的相位值.采用Wilcoxon秩和检验比较MS患者病灶和对照组相应ROI相位值的差异,相位值以“中位数±四分位间距(M±Q)”表示,Spearman等级相关分析MS病灶相位值与EDSS评分、病程之间的相关性.结果 (1)ESWAN后处理的幅度图和相位图分别观察MS病灶:共观察到650个病灶,其中213个(32.8％)病灶在幅度图和相位图同时显示,164个(25.2％)病灶单独在幅度图显示,273个(42.0％)病灶单独在相位图显示,较常规MRI(608个病灶)多观察到42个病灶.在相位图显示的486(273 +213)个病灶中,205个(31.5％)病灶表现为均匀低信号,45个(6.9％)病灶表现为环形低信号,236个(36.4％)病灶表现为不均匀低信号.(2)424个(65.2％)侧脑室体旁病灶显示有“穿通静脉”,其中,198个(30.5％)急性病灶内“穿通静脉”扩张、延长,208个(32.9％)慢性病灶内“穿通静脉”变细、变短,但在5例稳定期MS患者中,12个(1.8％)慢性病灶显示“穿通静脉”扩张、延长.(3)MS病灶和对照组相应ROI相位值分别为- 0.05±0.08、0.06±0.05,二者比较差异有统计学意义(Z =22.30,P＜0.01).(4)MS病灶相位值与MS患者EDSS评分和病程均具有相关性(r值分别为-0.98、0.99,P值均＜0.01).结论 ESWAN所测的相位值能量化MS病灶内铁含量,为研究MS的发病机制和病理改变提供重要价值.

Analysis of iron deposition in the brain lesions of patients with multiple sclerosis by three dimensional enhanced T2-star weighted angiography

Objective To explore the values of 3D enhanced T2-star weighted angiography (ESWAN) in detecting iron deposition of the brain in patients with multiple sclerosis ( MS).Methods Conventional MRI and 3D ESWAN were performed in 22 patients with released-remitting MS(RR-MS) and in 22 age- and gender-matched normal controls.Both the magnitude images and phase images were available after post processing of the original ESWAN data post processing.The expanded disability status scale (EDSS) scores of the patients were from 0 to 8.5,and the course of disease were between 0.5 year and 15 years.The manifestation of MS lesions was evaluated on conventional MR images and ESWAN images by two experienced radiologists with blind methods.The phase values were measured for MS lesions between the semioval center and periventricular white matter and the corresponding regions in the normal control group were measured as well The Wilcoxon rank test was used to compare the differences of phase values between MS patients and normal controls,and the Spearman rank correlation analysis were used to analyze the correlations among the phase values of MS lesions,EDSS scores and course of disease of MS patients.Results ( 1 ) MS lesions were observed on magnitude images and phase images,respectively and together.Two hundred and thirteen(32.8％ )lesions were detected on both the magnitude images and phase images,164 (25.2％)lesions were detected on the magnitude images only,and 273 (42.0％) lesions were detected on the phase images only.A total of 650 lesions were observed on the ESWAN,which showed more 42 lesions than conventional images(608).Among 486(273 + 213 )lesions observed on the phase images,205 (31.5％) lesions were homogeneously hypointense,45 (6.9％ ) lesions showed hypointense ring,and 236 (36.4％ ) lesions were inhomogeneously hypointense.(2) “ Penetrating veins” were showed in 424 (65.2％ ) periventricular lesions.The “penetrating veins” showed dilated and prolonged in 198 (30.5％ ) acute lesions,thin and short in 208 (32.9％ ) chronic lesions.However,the “penetrating veins” of 12 ( 1.8％ ) chronic lesions in 5 stable MS patients were expanded and prolonged slightly.( 3 ) The average phase value of the lesions ( - 0.05 ± 0.08) in patients with RR-MS was significantly lower than that of corresponding to regions (0.06 ± 0.05 ) in the normal control group( Z = 22.30,P ＜ 0.01 ).(4) The phase values of MS lesions were significantly correlated to the EDSS and course of disease of patients with RR-MS (r = -0.98,0.99 respectively,P ＜ 0.01 ).Conclusion ESWAN can be helpful in the evaluation and quantification of abnormal iron deposition in MS lesions,which provides important values for the pathogenesis and pathological study for MS patients.