MRI在诊断MS的作用

1、The role of MRI in the diagnosis of Multiple Sclerosis,MS-主要讨论问题,典型MRI发现 McDonald标准：MRI在诊断的应用 鉴别诊断： MS-其他常见白质病变,当我们见下面病例，首先考虑是什么病？MS？高血压性小血管病？或其他更少见病,白质脑病: 许多神经系统疾病在临床和放射学均与MS相似 多数意外发现WMLs常为血管性 白质病变鉴别诊断太难,white matter lesions (WMLs,Typical MRI findings in MS,多发性硬化特征性发现胼胝体病灶和胼胝体周围白质病灶,PDWI,Common -co

2、rpus callosum,T2WI,characteristic finding multiple hypointense lesions in the corpus callosum,T1WI,Common -corpus callosum,Juxtacortical lesions are specific for MS,involvement of U-fibers in MS,subcortical lesion-a larger area of white matter almost reaching the ventricles,Hypertension- U-fibers ar

3、e not involved,Juxtacortica lesions,高信号白质病变与皮层间 有暗带,Common - Juxtacortical lesions,adjacent to the cortex and must touch the cortex,与皮质 接触,T2,特异性差,特征性MS灶：Juxtacortical MS lesion located in the U-fiber,近皮质灶难以与长T2 皮质区别，放大更清楚,近皮质灶,脑室周多发灶，含Dawson finger(箭,同时有2类病灶,Common - Juxtacortical lesions,Common -

4、Juxtacortical lesions,Juxtacortical lesions（旁正中矢状位更清楚,Common - Juxtacortical lesions,Cortical lesions in a patient with relapsingremitting MS on 3 T MRI,注意：常规序列无法显示这些皮质灶,皮质2个高信号灶,3D FLAIR,相应区域低信号,3D double-inversion recovery,cross-referenced 3D T1WI,MS传统认为是白质病变，近年来超高场MRI清晰显示大脑灰质也存在病灶,sometimes - Cor

5、tical lesions,MS常见病灶-幕下病灶,typical - infratentorial lesions,bright foci in the brainstem and cerebellum,PDWI: highly sensitive for the detection of plaques in MS, especially in the posterior fossa,typical - infratentorial lesions,注意MS典型分布,多灶邻近脑室,脑干和小脑多发灶,Multiple WMLs with a typical distribution for

6、MS,卵圆形垂直灶,typical - infratentorial lesions,常见幕下病灶,Infratentorial lesions,桥脑左侧，右中脑角,T2,仅仅左侧病灶增强,增强,dissemination in time,两个病灶，一个增强,typical - infratentorial lesions,MS典型灶-脑室周围白质高信号,a highly sensitive sequence for lesion detection, particularly supratentorially,FLAIR,typical - periventricular lesions,m

7、ultiple lesions in a distribution characteristic of MS,PDWI,Specifically, the periventricular lesions and the more peripheral white matter lesions near the gray matterwhite matter junction are typical MRI findings in MS,typical - periventricular lesions,多发性脊髓灶-MS另一个典型特征,脊髓病灶很少见于其他CNS病，除了ADEM, Sarcoi

8、d, Lyme和SLE,病灶同时见于脊髓，小脑或 脑干高度提示MS,PDWI:显示MS脊髓最佳序列：脊髓均匀低信号，MS斑反差强更清楚,相对小，周围性，好发颈髓，小于2节段,SE PDW,a patient with MS,typical Spinal cord,24岁,单眼视力数年后四肢运动感觉损害 双下肢感觉损害就诊MS可能,横切-背部典型三角形,边界模糊,无增强效应,脊髓活动灶可增强,但远不如脑常见,边界清楚,典型病史,typical Spinal cord,T2WI: a 27-year-old woman,axial : a multiple sclerosis plaque loc

9、ated in the left dorsolateral region of the left hemicord,a fusiform area of increased signal intensity representing a MS plaque,typical Spinal cord,非特异深白质灶,胼胝体,典型MS灶：胼胝体，颞叶，近皮质，脑室旁,近皮质,Coronal PD image of a brain specimen with MS involvement,小血管病灶仅见于额顶，少见于枕，不会在颞叶,颞叶白质病变好发于MS或CADASIL早期 不见于血管病,Dawson

10、 fingers,typical Dawson fingers,Dawson fingersare a radiographic feature depicting demyelinating plaques through corpus callosum, arranged at right angles along medullary veins (callososeptal location) They are a relatively specific sign forMS, which presents as T2 hyperintensities,typical Dawson fi

11、ngers,Typical findings a 35-year-old man with relapsing remitting MS,Ovoid lesions perpendicular to the ventricles surface are common,MRI reveals multiple lesions with high T2 signal intensity and one large white matter lesion. These demyelinating lesions may sometimes mimic brain tumors because of

12、the associated edema and inflammation,typical Dawson fingers,MS切片：perivenous inflammation,淋巴细胞浸润见于小静脉周围，这些淋巴细胞攻击髓鞘,MS病变始于静脉周围炎症，在前4周内BBB受损初期均匀增强，可以变为环型增强,Lymphocytic infiltration,小静脉,typical Dawson fingers,MS斑三种增强类型,见于疾病急性（活动）期或亚急性斑块 三种增强类型 Solid “开环征”(open-ring sign)或称为“弓形征”(arclike sign) Ring 环形,s

13、olid enhancement,The C-shaped or arclike enhancement, which is fairly characteristic of multiple sclerosis,右颞枕增强斑,arclike enhancement,ring enhancement,女，36岁，双下肢麻木7月，无力4月,多数病灶周边轻至中度异常强化，呈环形(白箭头)或开环样强化(长箭头)，提示为急性或亚急性病灶,FSE T2WI,侧脑室旁深部白质、左额皮层下多发类圆形长T2灶,Fried Egg sign,增强,DWI上的高信号环，ADC略低，提示扩散受限，称为“晕环征”(箭

14、头,左额皮层下卵圆形灶，周围水肿，称“煎蛋征,DWI,急性期斑块周边的环形高信号(箭头,ADC,Halo sign,ring-like or open ring-like enhancement,MS Variants and Differential diagnosis,A 39 year old male presented with subacute onset of hemianopsia.He was referred for biopsy to differentiate between a glioma or demyelination,Tumefactive MS,右颞枕瘤样脱

15、髓鞘病，活检证实,T2W,增强,T2WI低信号环,灶周水肿 占位征相对轻,周围部分增强 (不完全环,活检处,anincomplete ring,MS Variants,Tumefactive MS特征,MS变异型 较大脑实质灶，占位征不如其他性质同样大小灶 增强 周围增强，常呈不完全环状，可以与表现为封闭环样增强的胶质瘤或脑脓肿区别 部分增强(开放环）+ 低信号T2环+ CBF低均提示脱髓鞘,瘤样,MS Variants,Balos Concentric Sclerosis,少见脱髓鞘病，脱髓鞘灶和髓鞘呈带状交替出现,螺纹样,左侧巨大灶 T2高/等信号交替出现,交替性线性增强,右侧较小类似灶,

16、Differential diagnosis,Neuromyelitis Optica,脊髓肿，病变广 (3节以上,大脑少数 T2病灶,诊断线索是AQP4-抗体滴度是1:1024,横切累及 大部脊髓,单侧视神经炎,Differential diagnosis,Acute Disseminated Encephalomyelitis (ADEM,选择性累及皮质，基底节和丘脑,广泛皮层灰质受累,特征性丘脑灶,Differential diagnosis,不会发生在MS,Here another case of ADEM,注意基底节受累,未增强,小脑,可以增强,Differential diagno

17、sis,Here another case of ADEM,弥漫，幕上下 白质，较对称,Differential diagnosis,模糊,脊髓,Differential diagnosis,The McDonald criteria for MS,McDonald criteria,Poser- Diagnosis conclusions,The criteria can yield five conclusions: Clinically definite MS. Needs two attacks and some clinical or paraclinical evidences L

18、aboratory supported definite MS, showing oligoclonal bands and clinical or paraclinical evidences Clinically probable MS, with less restrict combinations. Laboratory supported probable MS. Only two attacks is enough to enter this category No MS There is no clinical evicence of having MS,Poser CM, et

19、 al. New diagnostic criteria for multiple sclerosis: Guidelines for research protocols. Annals of Neurology 1983 13 (3): 22731,2001提出McDonald标准，用MRI代替原Poser标准，在2005，2010修改,2010年5月在爱尔兰都柏林，国际MS诊断小组第三次会晤（2011简化版,Diagnosis,2010年5月，一个国际专家小组在爱尔兰都柏林修订McDonald criteria， 简化病灶空间和时间弥散标准，并在某些情况下，仅一次扫描就可以确定 随着时间

20、的推移，如果MRI显示新病灶形成，容许MRI参与诊断，使尽早些诊断成为可能 即使有了这些进展，由于MS的复杂性和变异，仍然有些患者多年诊断不确定 2011简化的修订版使早期诊断具有高度的特异性及敏感性，让患者更好的咨询和早期治疗,2010年5月在爱尔兰都柏林，国际MS诊断小组第三次会晤（2011简化版,进一步修订MS麦当劳诊断标准。简化影像学证实CNS病变空间和时间播散，并在某些情况下，仅一次扫描就可以确定时间和空间播散 保留原诊断敏感性和特异性，满足实际应用，更一致使用，更早诊断 标准包括临床和亚临床实验室检查，强调需要证明病变空间和时间播散和排除其他诊断 虽然MS仅仅单靠临床诊断，但是CN

21、S的MRI能支持、补充，甚至替换某些临床标准 2011简化的修订版使早期诊断具有高度的特异性及敏感性，让患者更好的咨询和早期治疗,dissemination in place,2005 Mc Donald criteria,以及被2010版代替,4条中有3条才能诊断,2005 Mc Donald criteria,1 T2灶 至少2区域 不需增强,一次阅片：增强+非增强灶 前后两次比较：新T2灶或增强灶 等候再次发作,下面任一条可以诊断,2010年5月-爱尔兰都柏林,For dissemination in space (DIS) lesions in two out of four typi

22、cal areas of the CNS are required,periventricular juxtacortical infratentorial spinal cord,For dissemination in time (DIT) there are two possibilities,任何时间-同时存在无症状增强灶和非增强灶,再次检查 发现新T2 和/或增强灶,非增强灶,增强灶,新T2,新T2,Dawson finger：与脑室垂直卵形灶，是与脑室表面垂直的穿透小静脉周围炎症引起,增强灶周水肿，水肿最终 消退，仅留中央长T2灶,增强和非增强灶同时存在,脑室旁 多发灶,增强灶仅持

23、续一月,增强,a 36-year-old woman - relapsing-remitting MS, just about 2 years ago,dissemination in time- Dawson fingers,增强的意义,同时存在增强和非增强病变主要有两层含义： 证明急性炎症病变 证明疾病的时间传播,增强,dissemination in time,Periventricular, callosal /subcallosal, and ovoid lesions,胼胝体/皮质下2个增强灶 左脑室旁非增强灶,T2-weighted image,4个高信号灶,3个卵圆形,T1增强

24、,右侧非增强低信号,Frederik Barkhof ，Brain (1997), 120, 20592069,dissemination in time,典型表现 多发增强灶，均为新灶（增强灶仅见于一月内），为时间播散证据 许多灶近皮质，且位于U-fibers,T1增强,MS:首次发作+3月后随访(前后2次比较,多发增强灶：dissemination in time,首次,三月后,dissemination in time,New lesions on T2W images （前后比较,仅有一个灶,T2WI,首次临床发作,3月后,发现2个新灶,dissemination in time,De

25、monstration of dissemination in time (DIT,3 months later,满足2005麦当劳诊断标准第2点（复诊至少30天发现新病灶 和至少3月发现新增强灶），使临床医生能够较早诊断MS,新病灶,新增强灶,dissemination in time,脑室周围3病灶 其中一个增强灶,满足2010麦当劳诊断标准点（任何时间发现无症状新病灶 和增强灶），使临床医生能够较早诊断MS,dissemination in time,Juxtacortical lesions in the frontal and parietal lobes,T2,T1增强,其中2个增

26、强,Frederik Barkhof ，Brain (1997), 120, 20592069,dissemination in time,多发近皮质灶（箭头,FLAIR image,T2 image,MS-Diagnosis（要点,神经学检查-脑脊髓损害征 MRI-本身并不能确诊，仅显示可能为MS病灶 CSF-支持诊断，表明脑脊髓免疫系统处于活动状态 诱发电位-可协助诊断 医生-分析上述检查和实验室结果，确定MS是否是实际的诊断 甚至当所有测试完成，有些人可以出现症状多年后仍然无法确诊 McDonald 标准仅仅针对MS,如果要使用MRI诊断，必须确保病人确定是MS，不能有任何疑问而治疗,D

27、isease Modifying Agents,FDA Approves Agent每种药都有副作用和风险 Interferon beta-1a weekly (Avonex)阿沃纳斯 Interferon beta-1b every other day (Betaseron) Interferon beta-1a three days a week (Rebif) Copolymer (Copaxone)克帕松 Mitoxantrone (Novantrone) Natalizumab (Tysabri)珠单抗注射液 FDA Approves Third Oral Agent for the

28、 treatment of relapsing-remitting multiple sclerosis (MS) （2012-03） 2010-芬戈莫德 Fingolimod (Gilenya, Novartis诺华 ) 2013-特立氟胺 Tiflunomide (Aubagio, Genzyme/Sanofi赛诺菲 ) 富马酸二甲酯 Mar,2013- Dimethyl fumarate (Tecfidera, Biogen Idec生物技术公司艾迪克,http:/,The episode can be monofocal or multifocal,a first neurologic

29、 episode that lasts at least 24 hours,Clinically isolated syndrome,caused by inflammation/demyelination in one or more sites in CNS,The McDonald criteria for MS were recommended in 2001 by an international panel and revised in 2005 and 2010,An Attack is: Neurological disturbance of kind seen in MS S

30、ubjective report or objective observation At least 24 hours duration in absence of fever or infection Excludes pseudoattacks, single paroxysmal symptoms (multiple episodes of paroxysmal symptoms occurring over 24 hours or more are acceptable as evidence) Some historical events with symptoms and patt

31、ern typical for MS can provide reasonable evidence of previous demyelinating events, even in the absence of objective findings Time Between Attacks: 30 days between onset of event 1 and onset of event 2 Positive CSF is: Oligoclonal IgG bands in CSF (and not serum) or elevated IgG index,满足,The McDona

32、ld criteria for MS,The diagnosis is either: MS : all criteria fulfilled possible MS : not all criteria fulfilled not MS : no criteria fulfilled The McDonald criteria make use of the clinical presentation and the advances of MR imaging When a patient presents with 2 or more attacks with clinical evid

33、ence of 2 or more neurological deficits, there is no need for additional requirements to make the diagnosis of MS, because there is dissemination in place and time In all other cases (less than 2 attacks or less than 2 clinical lesions) there is a role for MRI to fulfill the diagnostic criteria by d

34、emonstrating dissemination in space, in time or both. McDonald 标准仅仅针对MS,如果要使用MRI诊断，必须确保病人确定是MS，不能有任何疑问而治疗,Coronal and midsagittal scout views are needed for reproducible positioning of the slices, so you are able to compare follow up studies. Use the coronal scout to plan the true midsagittal image

35、parallel to the falx and other midline structures.On a true midsagittal image a line is drawn through the hypophysis and the roof of the fourth ventricle (fastigium).This is called the HYFA: hypophysis-fastigium line. Subsequently the slices are positioned with the middle slice at the lower border o

36、f the splenium of the corpus callosum,WMLs患病率-发生率差别相当大,遗传病：每种病尽管罕见，但作为一组疾病并非少见，但仍远比MS少 Lymes disease：尽管目前流行，但仍是一个少见疾病 血管病：往往是意外发现WMLs的病因，在所有MRI（不管何原因）中，高达50%为血管性，尤其是老人和有血管病危险因素者（如动脉硬化,高血压，高胆固醇,糖尿病,淀粉样血管病,高同型半胱氨酸血症, 房颤。,Reporting,如果在临床上怀疑MS而且MR支持该诊断, 那么鉴别诊断就不应当考虑Lymes 病和神经SLE等少见病，因为这些少见病发病率相当低，除非临床表现

37、支持这些少见病,Reporting,下列情况不应将MS作为鉴别诊断 临床医生没有怀疑MS 意外发现白质脑病 因为血管病WMLs发病率是MS斑的50-500倍，其概率不支持诊断MS 如果临床医生怀疑MS ，并且发现多个WMLs，主要鉴别是血管病，并且应用McDonald criteria,Differential diagnosis of WMLs,WMLs鉴别诊断广泛 存在正常老人，多数为获得性和缺血缺氧性 最常见炎症是MS 最常见病毒感染是PML和HIV 遗传病常表现对称性异常，必须与中毒鉴别,多发灶鉴别诊断要点,Borderzone infarction单侧，分为内/外分水岭，本例为內分水

38、岭区，MCA/与ACA ADEM白质和基底节多灶，感染或疫苗后 ，与MS同：脊髓, U纤维和胼胝体），有时增强，与MS不用：病灶较大，儿童，单相 Lyme2-3mm病灶，与MS相似，同时有皮疹和类流感征，其他：脊髓高信号，CN7 增强 Sarcoid病灶分布酷似MS，难鉴别 PMLJC 病毒所致脱髓鞘病，免疫抑制患者 占位，非增强WMLs ，位于U-fibers (unlike HIV or CMV).可以为单侧，双侧不对称更常见 Virchow Robin spacesT2WI亮，FLAIR黑 Small vessel diease位于深白质。不位于胼胝体, 近脑室或近皮质,鉴别： mult

39、iple enhancing lesions,Vasculitis 好发于SLE, PAN, Behcet, syphilis, Wegener, Sjogren 和 Primary angiitis of CNS 大多数为点状增强 Behcet 好发土耳其人 典型发现：脑干病灶+急性期结节性增强 Metastases 灶周常有显著水肿 Borderzone infarction A peripheral border zone infarction may enhance in the early phase,Virchow Robin spaces,典型VR spaces（特征位置+信号）

40、 位置：基底节 信号：所有序列信号同CSF（T1低信号,T2WI,FLAIR,基底节多发T2高信号灶,FLAIR黑色,Differential diagnosis of WMLs,Virchow Robin腔：穿通软脑膜支周围含CSF的空腔 常见位置：基底节，三角区周围，前连合附近，脑干中央 信号特征：在所有序列与CSF相同，FLAIR黑色（与WMLs不同） 空腔常常较小（前联合周围空腔例外） 随年龄增加及高血压血管周围结构萎缩 VR腔增大,FLAIR,特殊病例：非常宽VR腔和融合高信号灶共存,清楚显示VR空腔与白质病变不同,白质融合高信号,宽VR腔（筛孔状态,Differential dia

41、gnosis of WMLs,正常老人的发现,在正常老人，可以发现: Periventricular caps and bands Periventricular caps：围绕侧脑室前后极的高信号区，与myelin pallor和血管周围腔同时存在 Periventricular bands or rims ：是沿着侧脑室体部薄薄的线状区，与有关subependymal gliosis有关 脑轻度萎缩（脑室和脑沟增宽） 深白质斑点样改变或融合灶（Fazekas I and II） 临床意义尚未完全清楚 一些脑血管危险因素与白质变化有关，除了高血压外，其中一个最显著的危险因素是年龄,Diffe

42、rential diagnosis of WMLs,老人白质变化,白质疏松（Leukoaraiosis，LA） 放射学的用语 指脑非特异性白质改变，并没有特定的病理学特征与之对应 常见于65岁以上老年人 病理变化包括 轴索丧失（loss of axon） 白质苍白化（myelin pallor） 胶质增生（gliosis） 室管膜细胞丧失（loss of ependymal cells） 血管周围间隙扩张（enlarged perivascular spaces,Differential diagnosis of WMLs,Typical differences in vascular bra

43、instem lesions compared to MS,T2WI,桥横纤维中央部受累,桥脑外周白质受累，常在三 叉神经附近，或接近四脑室,血管灶：脑干中央，对称,MS灶脑干周围,Differential diagnosis of WMLs,Normal Aging,some punctate WMLs in the deep white matter,periventricular caps,脑沟脑 室扩大,深白质点状白质改变,描述深白质改变：Fazekas分类,Periventricular bands（正常,斑点样深白质改变,正常,轻,中,重,融合WMLs（75岁正常,广泛融合WMLs

44、（异常,病例分析：高血压患者，发现多发白质病变,病灶特点： 白质深部，不接触脑室，不接触皮质，不在胼胝体：不符合MS 高血压史：有利于诊断血管病 感染，中毒等：临床不支持这些病,Vascular disease,SE- T2WI,病例分析：明显是血管病,深白质广泛病变，U纤维和胼胝体未受累,前面已经显示MRI,50岁以上患者：脑动脉粥样硬化高达50%，它可见于正常血压，但更常见于高血压,缺血性白质脑病 ：表现腔梗，分水岭梗塞或深白质弥散高信号,遗传性小血管病-Cadasil,临床：migraine, dementia and family history 典型发现 青壮年人 皮质下腔梗，伴有小

45、囊（small cystic lesions）和白质脑病 病灶位置有高度诊断特异性：前颞极（anterior temporal pole）和外囊,病灶位置有高度诊断特异性,MRI -Most specific finding,Most specific finding to differentiate CADASIL from ischemic leukoaraiosis T2 hyperintenisties in anterior temporal pole,A characteristic finding on the MRI in patients with CADASIL,hyperintensities involving the temporal poles,FLAIR MRI,FLAIR MRI,hyperintensities involving Bilateral external capsules,MRI in CADASIL w/characteristic MRI findings of involvement of the external capsule and anterior temporal lobe