MELAS综合征患者脑灌注异常的MRI特征

MRI evaluation of cerebral perfusion changes in patients with MELAS syndrome

目的探讨MELAS综合征患者的MR脑血流灌注异常特征。方法对13例确诊的MELAS综合征患者和13名对照组受试者行流速敏感交替反转恢复免除独立T，测量（FAIREST）序列扫描，通过后处理生成脑血流量（CBF）图，分别测量他们的双侧基底节区、丘脑、颞叶和枕叶的相对脑血流量（rCBF）值，采用多元回归法分析对照组中测量部位和侧别对rCBF值的影响，将对照组、MELAS综合征组非病灶区和病灶区的rCBF值采用单因素方差分析进行比较。结果对照组左侧基底节区、丘脑、颞叶和枕叶的rCBF值分别为0．83±0，23、1．17±0．30、0．93±0．28和1．11±0．25，右侧基底节区、丘脑、颞叶和枕叶的rCBF值分别为0．77±0.15、1．03±0．34、1．06±0．23和1．09±0．23，多元回归分析结果显示，对照组不同测量部位和侧别对于rCBF值的影响无统计学意义（P〉0．05）。对照组感兴趣区的rCBF值为1．00±0．28，MELAS组综合征非病灶区和病灶区的rCBF值分别为1．01±0．31和1．95±0.43，MELAS综合征组病灶区的rCBF值大于非病灶区和对照组，差异有统计学意义（F=54．99，P〈0．01）。结论MR灌注成像能够显示MELAS综合征患者发作期的脑血流改变，提示病灶区处于高灌注状态。

Objective To detect the changes of cerebral perfusion in patients with MELAS syndrome by using MR perfusion technique. Methods Thirteen patients with MELAS syndrome and 13 controls with normal neurological conditions were scanned with the sequence of flow-sensitive alternating inversion recovery exempting separate T1 measurement （FAIREST）. Their rCBF values were obtained in regions of bilateral basilar nuclei and thalami, as well as bilateral temporal lobes and occipital lobes. Regression analysis was carried out to determine the effect of location and side on the measurement of rCBF in controls. One-way ANOVA was conducted to compare rCBF values among the control group, the lesion ROIs and normal ROIs of the MELAS syndrome group. Results The values of rCBF were 0. 83 ± 0. 23, 1.17±0. 30, 0. 93 ± 0. 28, and 1.11±0. 25 for the left basilar ganglia, thalamus, temporal lobe, and occipital lobe respectively, while they were 0. 77±0. 15,1.03±0. 34,1.06±0. 23, and 1.09±0. 23 for the right basilar ganglia, thalamus, temporal lobe, and occipital lobe respectively. Regression analysis revealed no effect of location and side on the rCBF （P 〉0. 05）. The rCBF value for control group was 1.00 ± 0. 28, while it was 1.01± 0. 31 for the normal ROIs and 1.95± 0.43 for the lesion ROIs in the MELAS syndrome group （F=54. 99,P〈0.01）. The rCBF of the lesion ROIs in the MELAS syndrome group was significantly higher than the normal ROIs and the control group. Conclusion CBF maps can reveal changes of cerebral blood flow in patients with ictal MELAS, which suggests increased perfusion in the stroke-like lesions.