中枢神经系统影像-颅脑损伤分类课件

1、1Central Nervous System2Classification of Head InjuryExtracerebral lesions: Subdural hematoma Subdural effusion Epidural hematomaIntracerebral lesions: Brain contusion (edema, hemorrhage.) Subarachnoid hemorrhage (SAH) Intraventricular hemorrhage (IVH)Open cranial injury. Skull fracture Pneumoenceph

2、alus3颅脑外伤brain trauma硬膜外血肿(epidural hematoma)硬膜下血肿（subdural hematoma）脑挫裂伤（laceration and contusion of brain）蛛网膜下腔出血Subarachnoid haemorrhage4硬膜外血肿(extradural hematoma)These arise between the inner table of the skull and the dura. They usually develop from injury to the middle meningeal artery or one

3、of its branches, and therefore are usually temporoparietal in location. A temporal bone fracture is often the cause, but is not essential. The expanding haematoma strips the dura from the skull; this attachment is quite strong such that the haematoma is confined, giving rise to its characteristic bi

4、convex shape, with a well defined margin.5CT征象颅板内侧梭形(双凸透镜)高密度影(与脑实质比)，CT值5090Hu；(范围小而厚)密度一般较均匀边缘清楚、光滑锐利局部常见脑水肿征局部蛛网膜下腔常见出血征局部有颅骨骨折征具有占位征：局部脑回受压内移，中线结构向对侧移位6biconvex shape, with a well defined margin.78血块内含较灰区(箭)， 代表正在出血中，有未凝结的血块 EDH：纺垂型，高浓度血块头皮肿(箭)，撞击处 9外伤后外伤后16小时外伤后40小时1011123月28日4月15日5月18日Male/16,

5、 delayed EDH, and spontaneous resorption迟发性硬外硬膜下血肿，自行吸收13硬膜外血肿MRI平扫、Gd-DTPA增强14硬膜下血肿（subdural hematoma）These arise between the dura and arachnoid, often from ruptured veins crossing this potential space. The space enlarges as the brain atrophies and so subdural haematomas are more common in the elde

6、rly.15CT征象颅内板内侧新月状(或带状)高密度影(与脑实质比)，CT值5090Hu，范围广而薄密度一般较均匀边界清楚，但不光滑锐利局部可有或无脑水肿局部可有或无蛛网膜下腔出血局部一般无颅骨骨折，常为对冲伤出血较多时具有占位效应，局部脑实质受压内移，中线结构向对侧移位16the crescentic high density collection typical of a acute subdural haematoma, with associated midline shift. 17急性硬膜下血肿（SDH）SDH：新月型(A.B)SDH可能在大脑镰内(C)。SDH也可在幕下(D) (

7、不要误为脑內出血)ABCD18A. SDH，明显占位效应B. 术后，占位效应消失Acute subdural hematoma with mass effectAB19等密度Plain CTIV contrast202120080209术后2008021922同一个病人，2008072823Note the crescentic low density collection typical of a chronic subdural haematoma, with associated midline shift.24subdural hematoma25脑挫裂伤（laceration and

8、 contusion of brain）These occur due to stretching and shearing injury, often due to impaction of the brain against the skull on the side opposite to the injury. Thus they may be seen directly opposite the impact site, subcutaneous haematoma, fracture, or extradural haematoma (contre coup injury). Th

9、e inferior frontal lobes and anterior temporal lobes are common sites after a blow to the back of the head.26CT低密度水肿区,散在高密度出血灶,伴有占位效应。有的表现为广泛的脑水肿或脑内血肿27MRI脑水肿T1WI呈等低信号,T2WI高信号脑血肿T1WI,T2WI多呈高信号28There is a focal area of haemorrhagic contusion in the right frontal lobe, with surrounding low density du

10、e to infarction or oedema. This is a frequent location for a contre-coup injury following a blow to the back of the head.29Intracerebral Haemorrhage 30Subarachnoid haemorrhage This may occur alone or in association with other intracerebral or extracerebral haematomas. Increased attenuation is seen i

11、n the CSF spaces, over the cerebral hemispheres (look closely at the Sylvian fissure), in the basal cisterns or in the ventricular system. SAH may be complicated by hydrocephalus. Confusion can sometimes arise between SAH due to trauma and due to a ruptured aneurysm or arteriovenous malformation (AV

12、M); the patient may collapse and hit their head as a result of a bleed and the history (from the patient or a witness) is important.31This patient has an acute extradural haematoma on the right side, and acute traumatic subarachnoid haemorrhage on the left side.32Delayed hemorrhage, several hours or

13、 days after head injury8 小时随访脑外伤后33Head injury with EDH and delayed contusion hemorrhages6月22日6月20日34Contusion hemorrhages and SAHA. 9月29日 B. 9月30日延迟性出血在脑挫伤极常见。脑挫伤：小血块及脑水肿混杂在一起 AB35Vault fractures 36颅脑外伤后遗症 1. 脑萎缩 2. 交通性脑积水，多由于蛛血、脑室内出血 3. 脑软化或脑穿通性囊肿，多由于脑挫伤3786,5,14Acute SDH &contusionhemorrhage86,5,

14、16Post-craniotomy,the SDH disappeared,delayed hemorrhage; SAHin Rt. tentorium86,8,13Encephalomalaciachange with mild hydrocephalusDecompression hemorrhagewith encephalomalacia change3886,9,10: Communicating hydrocephalus86,2,6: Traumatic SAH in the sulci, interhemispheric fissureSAH caused communica

15、tinghydrocephalus391st day4 months later-brain atrophy5th dayComa after head injury4 months later, semi-vegetate stageMultiple punctate hemorrhagesDiffuse axonal injury (DAI) caused brain atrophy40DAIMRI41DAIDWIAJNR 199942DAISWI4344DAI-DWI4546CT of Head InjuryNegative finding of CT of head injury1.

16、True negative2. False negativeDiffuse axonal injuryBrainstem injury3. Delayed hemorrhage. Clinincally, closed observation of the patient is mandatory 4748495051颅内感染性疾病（infectious processes of the brain）化脓性脑脓肿（cerebral abscess）颅内结核（intracranial tuberculosis）病毒性脑炎（viral encephalitis）脑囊虫病（cerebral cyst

17、icercosis）52脑脓肿cerebral abscess Brain abscesses may be related to infections of the paranasal sinuses, mastoids, middle ears as well as hematogenous seeding, but in 20% of cases a source is not discovered. Presenting symptoms of a cerebral abscess include headache, drowsiness, confusion, seizures an

18、d focal neurologic deficits. Fever and leukocytosis are common during the invasive phase of a cerebral abscess but may resolve as the abscess becomes encapsulated. 53成熟期脑脓肿CT表现CT平扫脑实质内片状低密度影像，CT值约20Hu低密度区主要位于脑髓质内，呈枫叶状低密度影内隐约显示等密度环状影占位效应较明显CT增强原来等密度环明显增强呈环状，余不增强呈张力性薄壁环，环厚约34mm，厚度均匀54the cerebritis st

19、age high signal intensity on T2WI, both centrally from inflammation and peripherally from edema Areas of low signal are variably imaged on T1WI. 55cerebral abscess5657cerebral abscess585960颅脑先天畸形及发育障碍（congenital anomalies of the brain）胼胝体发育不全（hypoplasia of corpus callosum）小脑扁桃体疝（Chiaris malformation

20、）蛛网膜囊肿（arachnoid cyst）结节性硬化（tuberous sclerosis）6162Chiaris畸形（II型）63胼胝体发育不良64胼胝体发育不良65胼胝体发育不良6666孕30周，双侧侧脑室后角扩大，胼胝体缺如6767孕30周，双侧侧脑室后角扩大，胼胝体缺如6868孕30周，双侧侧脑室后角扩大，胼胝体缺如69脑膜脑膨出70Chiaris畸形伴脊髓空洞症71蛛网膜囊肿（arachnoid cyst）72结节性硬化（tuberous sclerosis）7374757677结节性硬化（tuberous sclerosis）78Categories of White Matte

21、r DiseaseDemyelinatingNormal myelin is injured or destroyed Further divided into primary and secondaryDysmyelinatingIntrinsic abnormality of myelin formation or maintenanceRare, usually seen in pediatric population79Demyelinating DisordersPrimary demyelinating diseaseMultiple sclerosisSecondary demy

22、elingating diseaseAcute disseminated encephalomyelitisProgressive multifocal leukoencephalopathyOsmotic demyelinationDisseminated Necrotizing LeukoencephalopathyChemotherapy and radiation80Multiple Sclerosis: EpidemiologyMost common demyelinating disease encountered in practiceFirst described in 186

23、8 by CharcotFemale predominanceSecond to fifth decades of lifeNorthern European extractionTemperate climates81Multiple Sclerosis: Clinical PresentationEvidence of two or more white matter lesions separated by time and in different locationsRange of symptomsCranial nerve palsyOptic neuritisVague sens

24、ory complaintsParesisVariable pattern of presentationExacerbations and remissionsChronic progressiveAttack followed by absence of clinical diseaseRapidly progressive82Multiple Sclerosis: DiagnosisSchumachers criteria: two or more white matter lesions with eitherTwo or more episodes of worsening, eac

25、h lasting at least 24 hrs and each at least a month apartSlow stepwise progression of signs or symptoms for at least six monthsMR plays role in confirming clinical diagnosisPossitive study with appropriate clinical data strongly supports diagnosis of MS83Multiple Sclerosis: PathologyMyelin breakdown

26、 with associated lymphocyte and macrophage infiltration of affected areaAstrocyte proliferation and infiltration of demyelinated area, with continued signs of inflammationGliotic regions with decreased cellularity and no myelin84Multiple Sclerosis: Dawsons FingerInflammatory lesions along periventri

27、cular medullary veinsRadiate from ventricular surfaceLesions preceed demyelination85Multiple Sclerosis: ImagingAdjunct to clinical signs and symptomsConfirm or fail to confirm clinical suspicion of MSSuggest plausible alternative diagnosisSensitivity of MR surpasses that of all non-invasive tests.Ty

28、pical appearance on MRT1: isointense to low intensityT2: high intensityFLAIR: high intensity86Multiple Sclerosis: ImagingLocation is criticalPeriventricular white matter87Multiple Sclerosis: ImagingLocation is criticalPeriventricular white matterCorpus callosum88Multiple Sclerosis: ImagingLocation is criticalPeriventricular white matterCorpus callosumVisual pathway89Multi