MELAS综合征的MRI和ASL及~1H-MRS特征

MRI,ASL and ~1H-MRS features of MELAS syndrome

目的 :探讨MRI常规扫描和ASL及~1H-MRS对线粒体脑肌病伴高乳酸血症和脑卒中样发作(Mitochondrial encephalopathy with lactic acidosis and stroke-like episodes,MELAS)综合征的诊断价值。方法 :对9例MELAS综合征患者(男6例,女3例,年龄7~35岁)行头部MR常规轴位、冠状位、矢状位平扫及增强扫描,ASL灌注成像和~1H-MRS检查。结果 :9例患者中2例双侧发病,7例单侧发病。1例累及小脑半球,MRI平扫示顶叶、枕叶、颞叶皮层肿胀,T_1WI呈稍低信号,T_2WI呈稍高信号,FLAIR呈高信号,DWI呈高信号,ADC图呈低信号,增强扫描呈脑回样强化。ASL病变区呈高灌注。~1H-MRS扫描当TE为35 ms时,NAA峰降低,Cho峰略升高,并见Lac双峰,当TE为144 ms时,见倒置Lac双峰。结论 :MELAS综合征的MRI和ASL及~1H-MRS表现具有特征性,MRI和ASL及~1H-MRS对其诊断及鉴别诊断有重要价值。

Objective： To discuss diagnosis value of mitochondrial encephalopathy with lactic acidosis and stroke-like episodes（MELAS） syndrome by MRI routine scan, ASL and 1H-MRS. Methods： A total of 9 patients with MELAS syndrome（6 males, 3 females, age 7-35 years old） were selected. MR routine and enhanced scan, ASL perfusion imaging and 1H-MRS were performed. Results： In 9 cases, 2 cases of bilateral disease, 7 cases of unilateral disease. One case involved the cere- bellar hemisphere. MRI routine scan （parietal lobe, occipital lobe, temporal lobe） cortex were swelling, cortical and subcortical white matter was slightly lower signal on TIWI, brain-like high signal was showed on TtWI of 1 case cortex, T2WI was slight- ly higher signal. FLAIR showed high signal, DWI showed high signal, and ADC map showed hypointensity. Brain-like en- hanced was showed on post contrast images of cerebral cortex. Lesions were significantly higher perfusion on ASL. 1H-MRS： when TE was 35 ms, the NAA peak decreased, Cho peaks raised slightly, and Lac bimodal was showed, when TE was 144 ms, inverted Lac bimodal was observed. Conclusion： MRI routine scan and ASL, 1H-MRS is characterized, MRI and ASL and 1H-MRS is important for diagnose and differential diagnose.