磁化传递成像对脑部多发性硬化患者正常表现脑白质内微观病变的诊断价值

Value of magnetization transfer imaging in judging microchanges lesions in normal-appearing white matter of multiple sclerosis

目的 探讨磁化传递成像 (MTI)方法及其在判断脑部多发性硬化患者正常表现脑白质内微观病变中的价值。方法 对 4 1例脑部多发性硬化及 2 1名健康对照者进行磁化传递扫描。应用三维扰相梯度回波 ( 3D SPGR)序列 ,分别扫描打开及关闭饱和脉冲的全脑横断面近质子像图像 ,磁化传递率 (MTR)应用公式MTR =(M0 Ms) /M0 × 10 0 % ,其中M0 代表关闭饱和脉冲成像时兴趣区的信号值 ,Ms代表打开饱和脉冲成像时兴趣区的信号值 ,计算MTR值。参照T2 加权成像图像 ,测量脑内正常表现白质内 17个兴趣区的MTR ,包括脑干、两侧小脑脚、两侧内囊膝部、胼胝体膝部及压部、两侧侧脑室前后角旁、两侧脑室体部旁、两侧额顶叶深部白质。用 17个兴趣区MTR的平均值代表全脑正常表现脑白质的MTR值并与健康对照组进行统计学比较。结果 多发性硬化病例组每一不同部位的MTR平均值与健康对照组相比均有不同程度的降低 ,其中 ,胼胝体压部、侧脑室旁及顶叶MTR值差别较大。多发性硬化病例组全脑MTR值范围 19 4 5 %～ 2 4 15 % ,平均 2 2 4 4 %。健康对照组全脑MTR值范围 2 2 76 %～ 2 5 4 2 % ,平均 2 3 97%。二者全脑MTR值比较 ,差异有显著意义 (P <0 0 5 )。结论 MTI可以检测多发性硬化患者正常表现脑白质内的微观病变 。

Objective To explore the value of magnetization transfer imaging (MTI) in judging microscopic lesions in normal appearing white matter of multiple sclerosis (MS). Methods Forty one patients with brain MS, 17 males and 24 females, aged 13～65, and 21 healthy people, 8 males and 13 females, aged 18～57, used as controls underwent magnetic resonance imaging (MRI) using 3D spoiled grass (3D SPGR) series, to scan the whole brain with saturated pulses on and off respectively. The signal values were measured directly in the pictures of these 2 series. The formula MTR=(M 0 MS)/ M 0×100% was used, where M0 represents the signal value of region of interest with the saturated pulses off, and Ms represents signal value of region of interest with the saturated pulses on, to calculate the MTR value. With reference to T 2WI imaging, the MTR values of 17 regions of interest (ROI) in the normal appearing brain white matter, including the white matter of pons, bilateral cerebellar peduncles, knees of internal capsules, splenium and genu of corpus callosum, and the white matter by the anterior horn and posterior horn of lateral ventricle, body of lateral ventricle, and deep in the frontal and parietal lobes, were measured. The average MTR value of the 17 ROI was used to represent the MTR value of the whole normal appearing brain and used to make comparison with that of the healthy samples statistically. Results Compared with those of the healthy samples, the average MTR values of each ROI of the MS patients were lower at different degrees. The difference in the MTR values of the white matter of splenium of corpus callosum, and by lateral ventricle and deep in parietal lobe were especially bigger. The MTR value of the whole brain white matter in the healthy persons ranged from 22.76% to 25.42%, with an average value of 23.97%, both significantly higher than those of the MS patients (19.45% to 24.15%, and 22.44% respectively, both P <0.05). Conclusion MTI can be used to detect the microchange of normal appearing white matter in MS. MTR is a sensitive indicator to reflect the damage of structure of tissues.