ChinJClinNeurosurg,Mar2009,Vol14,No3MELAS型线粒体脑肌病的MRI诊断李国雄阳昱恒*王凤鸣**●论著●【摘要】目的探讨合并乳酸血症和卒中样发作的线粒体脑肌病(MELAS)的磁共振成像(MRI)影像学特点。方法收集经临床病理证实的MELAS型线粒体脑肌病共6例,回顾性分析其MRI和磁共振波谱(MRS)资料。结果脑MRI检查,MELAS表现为大脑半球各叶大小不等片状病灶;病变位于脑皮质区,病灶的分布与脑血供分布不一致;自旋回波T1加权像呈低信号、T2加权像呈高信号;扩散加权成像(DWI)呈高信号。MRS分析显示病灶区见典型的乳酸盐峰,N-乙酰天门冬氨酸盐/肌酸值正常或略降低。扩散张量成像(DTI)显示病灶区脑皮质下白质纤维束破坏、中断、稀少。结论MELAS型线粒体脑肌病的病变形态、分布具有特征性,常规MRI与DWI、DTI及MRS等磁共振技术,对MELAS的定性诊断具有很高的价值。【关键词】线粒体脑肌病;磁共振成像;诊断【文章编号】1009-153X(2009)03-0144-04【文献标识码】A【中图分类号】R742.8+9;R685.5DiagnosisofMitochondrialEncephalomyopathywithLacticAcidosisandStrokebyMRILIGuo-xiong*,YANGYu-heng,WANGFeng-ming.*DepartmentofNuclearMedicine,WuhangeneralHospital,GuangzhouCommand,PLAWuhanHubei430070,China【Abstract】ObjectiveToinvestigatetheappearancesofmitochondrialencephalomyopathywithlacticacidosisandstroke(MELAS)onMRI.MethodMRIandmagneticresonancespectroscopy(MRS)dataof6patientswithMELASconfirmedbypathologicalexaminationwereanalyzedretrospectively.ResultsThemultipleflakylesionswithvariedsizewereobservedindifferentlobeofbrainonbrainMRIofallthepatientswithMELAS.Thelesionsmainlylocatedinthecerebralcortexes,andnotdistributedinaccordancewithcerebralvesselsrun.AllthelesionsshowedlowsignalintensityonT1-weightedimage,andhighsignalintensityonT2-weightedimageanddiffusionweightedimage(DWI).MRSshowedatypicalcrestoflactateinMELASlesions.TheratioofN-acetyl-aspartatetocreatinewasnormalordecreasedslightlyonMRS.Diffusiontensorimaging(DTI)showedthatthenervefiberbundlesofthewhitematterunderthecerebralcortexeswerebrokenoffanddegenerated.ConclusionsTheMELASlesionsappearancetheonMRIanddistributionofMELASlesionsinthebrainwerecharacteristic.RoutineMRIandfunctionalMRtechniquessuchasDWI,DTIandMRSareofanimportantvaluetodiagnosisofMELAS.【KeyWords】Mitochondrialencephalomyopathy;Magneticresonanceimaging;Magneticresonancespectrum;Diagnosis线粒体脑肌病指由于线粒体基因或细胞核基因缺失或发生点突变导致的线粒体结构和功能异常,引起机体能量代谢障碍,主要累及脑和横纹肌的一类少见疾病[1~5],以线粒体脑肌病合并乳酸血症和卒中样发作(mitochondrialencephalomyopathywithlac-ticacidosisandstroke,MELAS)最常见。线粒体脑肌病临床表现复杂且缺乏特异性,常误诊为癫痫、脑炎及脑梗死。本组收集6例经临床及病理证实的MELAS,在常规磁共振成像(magneticresonanceimaging,MRI)的基础上行扩散加权成像(diffusionweightedimaging,DWI)、扩散张量成像(diffusionten-sorimaging,DTI)、磁共振血管成像(magneticreso-nanceangiography,MRA)及磁共振波谱(magneticresonancespectroscopy,MRS)研究,旨在进一步加深对本病的认识,提高诊断水平。1临床材料1.1一般资料本组收集了我院2006年7月至2008年1月间,经临床及病理证实的MELAS型线粒体脑肌病患者6例,其中男、女各3例,年龄20~55岁,平均约36.5岁;病程2.5~4年,平均约3年。6例MELAS中,4例由于起病急,表现为卒中样发作,误诊为癫痫,另外2例在外院误诊为颅内感染。6例均有头痛、恶心呕吐及肢体抽搐症状,发作时伴有短作者单位:广州军区武汉总医院核医学科(湖北武汉,4300700)*放射科**放疗中心144--中国临床神经外科杂志2009年3月第14卷第3期暂意识丧失或浅昏迷。住院期间血液及脑脊液常规及生化检查,4...