MELAS患者MR脑氧代谢成像初步研究  

Application of MRI Oxygen Extraction Fraction Imaging in Patients with MELAS: A Preliminary Study

作　　者：于磊[1] 肖江喜[1] 谢晟[2] 张晓东[1] 侯超[1] 王朝霞[3] 

机构地区：[1]北京大学第一医院医学影像科,北京100034 [2]中日友好医院放射科,北京100029 [3]北京大学第一医院神经内科,北京100034

出　　处：《临床放射学杂志》2014年第5期652-656,共5页Journal of Clinical Radiology

摘　　要：目的利用磁共振氧摄取分数(OEF)成像方法探讨线粒体脑肌病伴高乳酸血症和卒中样发作(MELAS)患者脑组织氧代谢的异常。方法对42例MELAS患者(发作组19例,发作间期组23例)及26名正常对照组进行常规MR平扫及OEF成像。在MELAS患者卒中样发作组(19例)、发作间期组(23例)及正常志愿者(26例)OEF图像取6个感兴趣区并计算平均值;应用Krukal-Wallis秩和检验比较三组脑组织OEF平均值改变;应用Wilcoxon配对法对发作组的病灶区与对侧非病灶区的OEF值进行比较。对7例MELAS患者进行了随访,分别获得发作期和发作间期脑组织OEF平均值,应用Wilcoxon配对法对发作期与发作间期的脑组织OEF平均值进行比较。结果 (1)发作间期组、发作组及对照组的脑组织OEF平均值具有统计学差异(χ2=25.4,P<0.001),发作组及发作间期组MELAS患者脑组织OEF分别为0.271±0.007、0.293±0.002,低于对照组0.319±0.006(Z=-4.459,P=0.001;Z=-3.306,P=0.001)。(2)发作组中单侧受累病灶OEF值与对侧未受累区具有统计学差异,病灶组OEF值(0.261±0.010)低于对侧非病灶组OEF值(0.286±0.012)(Z=-2.20,P=0.028)。(3)7例随访患者发作期脑组织平均OEF值(0.271±0.007)低于发作间期组OEF值(0.310±0.009),差异具有统计学意义(Z=-2.366,P=0.018)。结论 MR的OEF成像可以定量测量不同时期MELAS患者脑组织OEF值,发作期MELAS患者脑组织线粒体氧利用率进一步减低,在病灶区减低尤其明显。Objective To investigate the abnormalities of cerebral oxygen metabolism in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke like episodes （MELAS） by using MRI oxygen extraction fraction （OEF） imaging. Methods Forty-two patients with MELAS were enrolled in this study, 19 of them were at the onset phase and 23 at the interictal phase. Twenty-six healthy volunteers were used as the control group. Conventional plain MRscanning and OEF imaging were performed in all subjects. On OEF images six regions of interest （ROI） were selected, and the mean values were estimated. Using Krukal Wallis method the mean OEF values of the ipsilateral lesions were compared with those of contralateral ROIs. With the help of Wilcoxon paired test the OEF values of the lesion in patients at the onset phase were compared with those of contralateral ROIs. Seven MELAS patients were followed up, and the mean OEF values at the onset phase as well as at the interictal phase were measured separately. Using Wilcoxon paired test the mean OEF values of the lesions obtained at the onset phase were compared with those obtained at the interictal phase. Results （ 1 ）Statistically significant differences in mean OEF values existed between each other of the three groups （ X^2 = 25.4, P 〈 0.001 ）. Cerebral OEF was reduced significantly in the brain of patients at both the onset phase （0. 271 ±0. 007） and theinterictal phase （0. 293 ± 0. 002）, which were significantly lower than those in the control group （0. 319 ±0. 006, Z = -4. 459 ,P = 0. 001 ;Z = -3. 306 ,P = 0. 001 ）. （2） In the brain at the onset phase of the episode, 17 ROIs were placedon the stroke like lesions, which showed lower OEF values （0. 261 ±0. 010） when compared with the OEF values in the contralateral spared brain regions （0.286 ＋ 0. 012,Z = -2.20,P = 0. 028）. （3） In 7 patients with follow-up MRI, thecerebral OEF values at the onset phase （0. 271 ＋ 0. 007 ） was significantly lower than those obt

关 键 词：线粒体脑肌病伴高乳酸血症和卒中样发作 脑氧摄取分数 磁共振成像 氧代谢 

分 类 号：R445.2[医药卫生—影像医学与核医学] R741[医药卫生—诊断学]