中枢神经系统影像学诊断

第十八章第十八章中枢神经系统影像学诊断中枢神经系统影像学诊断RADIOLOGYOFCENTRALNERVOUSSYSTEML河北医科大学第三医院河北医科大学第三医院LHEBEIMEDICALUNIVERSITY3RDHOSPITALL中枢神经系统中枢神经系统L脑L脊髓检查方法检查方法MODALITIESL头颅头颅MRIL头颅头颅CTLECT，EMISSIONCOMPUTEDTOMOGRAPHYSPECT,SINGLEPHOTONEMISSIONCOMPUTEDTOMOGRAPHYPET,POSITRONEMISSIONTOMOGRAPHYL脑血管造影,CEREBRALANGIOGRAPHYL经颅DOPPLER,TRANSCRANIALDOPPLER，TCDL头颅平片,PLAINFILM最好的检查方法，为首选最好的检查方法，为首选FIRSTCHOICE检查方法检查方法MODALITIESL显示脑实质显示脑实质PARENCHYMAMRI，MAGNETICRESONANCEIMAGINGCT,COMPUTEDTOMOGRAPHY检查方法检查方法MODALITIESL显示脑实质显示脑实质PARENCHYMAMRIL是颅脑最好的检查方法是颅脑最好的检查方法FIRSTCHOICEL优点优点ADVANTAGE软组织分辨率最高任意面成像，有利于观察解剖关系检查序列多T1WI,T2WI,PDWI等L缺点缺点DISADVANTAGE钙化、骨化、早期出血灶显示不如CT价格贵检查方法检查方法MODALITIESL显示脑实质显示脑实质PARENCHYMACTL是最常用的检查方法L优点优点显示骨和钙化一般比MRI好显示早期出血比MRI好L缺点缺点对脑组织的分辨率不如MRI检查方法检查方法MODALITIESL显示脑血管显示脑血管BLOODVESSEL脑血管造影脑血管造影CEREBRALANGIOGRAPHYLDSA，DIGITALSUBSTRACTIVEANGIOGRAPHYMRA,MAGNETICRESONANCEANGIOGRAPHYCTA,COMPUTEDTOMOGRAPHYANGIOGRAPHYTCD,TRANSCRANIALDOPPLERDSAMRATRANSCRANIALDOPPLER，TCDCTANGIOGRAPHY检查方法检查方法L显示脑功能显示脑功能BRAINFUNCTIONDWI,DIFFUSIONWEIGHTEDIMAGINGPWI,PERFUSIONWEIGHTEDIMAGINGBOLD,BLOODOXYGENATIONLEVELDEPENDENTECT,EMISSIONCOMPUTEDTOMOGRAPHYDWIINCEREBRALINFARCTABSOLUTECBFADTIMEFORTHELOWEREDGEOFTHEBOLUSTOREACHTHETISSUEBAPATIENTWITHRIGHTCAROTIDOCCLUSIONANDSMALLRIGHTSIDEINFARCTIONARROWPERFUSIONIMAGINGBOLDTOSHOWTHEVISUALCORTEX检查方法检查方法L显示脑代谢显示脑代谢BRAINMETABOLISMECTLSPECTLPETTRACERMOSTCOMMONIS18FDG，ANALOGUEOFGLUCOSEMRSSPECTSINGLEPIXELMRS正常影像解剖正常影像解剖NORMALIMAGINGANATOMYL平片平片PLAINFILMCT扫描技术及正常影像解剖扫描技术及正常影像解剖TECHNIQUEANDNORMALIMAGINGANATOMY以听眦线为基线向上连续扫描以听眦线为基线向上连续扫描912层层层厚层厚10MM正常影像解剖正常影像解剖NORMALIMAGINGANATOMYLMRIL定位像TOPOGRAPHY，SCOUTIMAGET1WIAXIALT2WIAXIALT1WICORONALT2WISAGITAL基本病变表现基本病变表现BASICIMAGINGSIGNL颅骨平片颅骨平片颅骨破坏颅板增厚颅板变薄骨折线DEPRESSEDSKULLFRACTURESKULLDESTRUCTIONTHINNINGZTABLETHICKNESSOFSKULLTABLE基本病变表现基本病变表现BASICIMAGINGSIGNLCTL平扫密度改变DENSITYCHANGES占位效应MASSEFFECT,SPACEOCCUPYINGEFFECT脑水肿BRAINEDEMA,CEREBRALEDEMA脑积水HYDROCEPHALUS脑萎缩BRAINATROPHY,CEREBRALATROPHY病灶的强化表现FEATURESAFTERCONTRASTINJECT基本病变表现基本病变表现BASICIMAGINGSIGNLCT平扫密度改变L高密度灶钙化（肿瘤、血管畸形）、出血出血的演变L低密度灶坏死、水肿、液体、气体和脂类L等密度灶肿瘤、出血某一阶段L混杂密度灶多种成分病变，多见L钙化正常生理钙化、血管畸形、少枝胶质瘤等等密度ISODENSITY低密度水肿LOWDENSITY占位效应高密度HIGHDENSITY占位效应混杂密度MIXEDDENSITY钙化CALCIFICATIONL占位效应占位效应SPACEOCCUPYINGEFFECT,MASSEFFECTCOMMONDISEASEL肿瘤TUMORL出血BLEEDINGL显著肿胀EDEMAMANIFESTATIONL中线结构移位DISPLACEMENTOFMIDLINESTRUCTURESL脑室与脑池移位变形L脑室、脑池扩大ENLARGEMENTOFVENTRICLEANDCISTERNL脑沟变化FUCIL脑体积的改变ENLARGEMENTOFBRAINVOLUME脑水肿脑水肿CEREBRALEDEMAL炎症性水肿INFLAMMATORYSWELLING感染INFECTION出血BLEEDING挫伤CONTUSION等L血脑通透性增加INCREASINGPERMEABILITYOFBBB肿瘤TUMOR感染INFECTION等脑积水脑积水HYDROCEPHALUSL原因ETIOLOGY脑积液产生和吸收失衡脑脊液循环通路障碍所致脑室系统异常扩大L类型TYPE交通性脑积水COMMUNICATIVEHYDROCEPHALUS阻塞性脑积水OBSTRUCTIVEHYDROCEPHALUS代偿性脑积水COMPENSATORYHYDROCEPHALUS梗阻性脑积水正常脑压性脑积水NORMALPRESSUREHYDROCEPHALUS脑萎缩脑萎缩CEREBRALATROPHYL描述DESCRIPTION各种原因引起脑组织减少而继发的脑室和蛛网膜下腔扩大L分类TYPE广泛性DIFFUSE局限性LOCAL皮质CORTEX白质WHITEMATTER增强扫描特征增强扫描特征L机制MECHANISM血脑屏障通透性增加异常血管增生引起血流量增加L常见类型COMMONTYPE均一强化脑膜瘤、生殖细胞瘤等环状强化脑脓肿、脑转移瘤、星形细胞瘤等斑状强化血管畸形、炎症等不规则强化恶性胶质瘤等等等密度，均匀强化ISODENSITY,HOMOGENEOUSENHANCEMENT环形强化RINGRIMENHANCEMENT颅骨改变颅骨改变L增厚THICKNESSL变薄THINL破坏DESTRUCTIONL增生PROLIFERATIONGIANTCELLREPARATIVEGRANULOMATRAUMA颅骨破坏MRI基本病变表现基本病变表现BASICMRISIGNL与CT类似的表现THESIMILARSIGNASTOCT占位效应脑积水脑萎缩L信号改变复杂，与CT密度改变不同长T1、长T2信号肿瘤、脑梗死、炎症等脑脊液信号囊性变、囊肿（FLAIR序列变黑）短T1、长T2信号脂肪、黑色素瘤等无信号钙化、晚期疤痕组织血管流空信号多为无信号MRI基本病变表现基本病变表现L水肿EDEMAT1WI为低信号LOWSIGNALT2WI为略高信号SLIGHTLYHIGHINTENSITYL出血BLEEDING信号变化复杂THECHANGEOFSIGNALISCOMPLEX长T1、长T2病灶，肿瘤水肿EDEMA钙化无信号囊性病灶CYSTICT2WI高信号MRI基本病变表现基本病变表现L增强环状均匀不均匀脑回状脑内血肿脑内血肿INTRACEREBRALHEMATOMALCT分期分期STAGING急性期急性期ACUTESTAGE1周L高密度HYPERDENSITYL周围水肿SURROUNDINGEDEMA吸收期吸收期ABSORPTIONSTAGE2周2个月L始于37天，密度逐渐减低囊变期囊变期CYSTICCHANGESTAGE2个月L水样低密度WATERLIKEDENSITYLMRI分期分期STAGING超急性期超急性期（HYPERACUTEHEMATOMA）6小时LT1WI等信号，T2WI为等信号急性期急性期（ACUTEHEMATOMA）7小时3天LT1WI呈等信号，血肿内缘可见低信号强度的硬膜，T2WI呈低信号亚急性期和慢性期亚急性期和慢性期（SUBACUTEHEMATOMA）3天4周L高信号METAHEMOGLOBIN囊变期囊变期（REMOTEHEMATOMA）4周L液体信号L周围有低信号（HEMOSIDERIN血肿影像学表现血肿影像学表现IMAGINGPRESENTATIONOFHEMATOMATHEEVOLUTIONOFHEMATOMAHYPERACUTEHEMATOMACTT1WIT2WICTT2WISUBACUTETOCHRONICHEMATOMAACUTEHEMATOMAGRET1WI常见疾病诊断常见疾病诊断COMMONDISEASEOFCNSL脑外伤脑外伤TRAUMAOFBRAINL脑血管病脑血管病CEREBRAOVASCULARDISEASE脑梗死CEREBRALINFARCTION脑出血CEREBRALHEMORRHAGEL脑肿瘤脑肿瘤CEREBRALTUMOR脑外伤脑外伤TRAUMAOFBRAINLCT为首选为首选FIRSTCHOICE显示骨折、早期出血好方便快速多螺旋可快速形全身检查LMRI的适应症的适应症INDICATIONCT检查阴性亚急性期慢性期L平片已少用平片已少用CT未普及的地区脑外伤脑外伤TRAUMAOFBRAINL脑挫裂伤脑挫裂伤CEREBRALCONTUSIONL脑内血肿脑内血肿INTRACEREBRALHEMATOMAL硬膜下血肿硬膜下血肿SUBDURALHEMATOMAL硬膜外血肿硬膜外血肿EPIDURALHEMATOMAL蛛网膜下腔出血蛛网膜下腔出血SUBARACHNOIDHEMORRHAGE脑挫裂伤脑挫裂伤L名词的含义名词的含义脑挫伤脑挫伤CEREBRALCONTUSION脑内散在出血灶，静脉淤血、脑血肿和肿胀脑裂伤脑裂伤LACERATIONOFBRAIN伴有脑膜、脑或血管撕裂L发病部位LOCATION着力点附近COUPSITE着力点对冲部位CONTRECOUPL病理PATHOLOGY脑水肿坏死液化散在小出血点脑挫裂伤脑挫裂伤LCT低密度病灶内散在斑点状高密度出血灶边缘模糊ILLDEFINEDRIM占位效应MASSEFFECTLMRI脑水肿LT1WI呈低或等信号LT2WI高信号出血BLEEDINGL表现与血肿期龄有关THEREISAFOCALAREAOFHAEMORRHAGICCONTUSIONINTHERIGHTFRONTALLOBE,WITHSURROUNDINGLOWDENSITYDUETOINFARCTIONOROEDEMATHISISAFREQUENTLOCATIONFORACONTRECOUPINJURYFOLLOWINGABLOWTOTHEBACKOFTHEHEAD弥漫性轴索损伤弥漫性轴索损伤DIFFUSEAXONALINJURY,DAIL其他名称SYNONYMY剪切伤SHEARINJURYL机制MECHANISM头受到旋转暴力致大脑绕中轴发生旋转运动白质、灰白质交界区、胼胝体、脑干及小脑等受到剪切力损伤弥漫性轴索断裂、点片状出血和水肿L临床CLINICALFEATURES伤后意识立即丧失，多数立即死亡部分持续昏迷，后果严重弥漫性轴索损伤弥漫性轴索损伤DIFFUSEAXONALINJURYTHISIMAGEDEMONSTRATESASMALLPETECHIALHAEMORRHAGEINATYPICALLOCATIONATTHEGREYWHITEMATTERINTERFACEARROWASISOFTENTHECASE,THEREWEREMULTIPLESUCHLESIONSONOTHERSLICES硬膜下血肿硬膜下血肿SUBDURALHEMATOMAL出血部位出血部位LOCATION硬脑膜与蛛网膜之间L发生率发生率INCIDENCE颅脑外伤的56L临床临床CLINICALFEATURES急性硬膜下血肿L多与脑挫裂伤同时存在L症状重慢性硬膜下血肿L轻微头痛L有或无明确外伤史EPIDURALSPACESUBIDURALSPACEDURALMATTER硬膜下血肿硬膜下血肿SUBDURALHEMATOMAL颅骨下方新月形高密度影L占位效应等密度硬膜下血肿低密度硬膜下血肿硬膜外血肿硬膜外血肿EPIDURALHEMATOMAL部位部位LOCATION颅骨与硬膜之间L发生率发生率INCIDENCE占颅脑外伤的23L临床临床CLINICALFEATURES急性85亚急性12慢性少见硬膜外血肿硬膜外血肿EPIDURALHEMATOMA颅板下梭形或半圆形高密度影多位于骨折附近不跨越颅缝蛛网膜下腔出血蛛网膜下腔出血SUBARACHNOIDHEMORRHAGEL颅内血管破裂进入蛛网膜下腔L病因ETIOLOGY外伤TRAUMA自发性SPONTANEOUSLYL动脉瘤51L高血压动脉硬化15L动静脉畸形6L临床CLINICALFEATURES好发年龄3040岁三联征L剧烈头痛L脑膜刺激征L血性脑脊液蛛网膜下腔出血蛛网膜下腔出血SUBARACHNOIDHEMORRHAGE蛛网膜下腔蛛网膜下腔出血出血脑血管病脑血管病CEREBROVASCULARDISEASEL脑出血脑出血INTRACEREBRALHEMORRHAGEL脑梗死脑梗死INFARCTOFBRAINL动脉瘤动脉瘤ANEURYSML血管畸形血管畸形VASCULARMALFORMATION脑出血INTRACRANIALHEMORRHAGEL病因ETIOLOGY高血压HYPERTENSIVEINTRACEREBRALHEMORRHAGE占40动脉瘤破裂脑血管畸形出血出血性脑梗死外伤脑肿瘤血液病等高血压性脑出血高血压性脑出血HYPERTENSIVEINTRCEREBRALHEMORRHAGEL机制微小动脉瘤破裂脑血管玻璃样变L好发部位好发部位PREDOMINATEDLOCATION基底节、丘脑、脑桥和大脑半球白质内易破溃入脑室L并发症并发症COMPLICATIONS脑水肿脑组织受压坏死脑出血INTRACRANIALHEMORRHAGEL脑内血肿破入脑室破入蛛网膜下腔脑积水脑梗死脑梗死CEREBRALINFARCTIONL原因原因ETIOLOGY脑血栓形成脑血栓形成THROMBOSIS脑栓塞脑栓塞EMBOLIC血压过低血压过低LOWBLOODPRESSUREL发病率INCIDENCE为脑血管病首位脑梗塞脑梗塞脑梗死脑梗死CEREBRALINFARCTIONLPATHOLOGY缺血性脑梗死缺血性脑梗死ISCHEMICINFARCTION出血性脑梗死出血性脑梗死HEMORRHAGEINFARCTION腔隙性脑梗死腔隙性脑梗死LACUNARINFARCTIONL好发于基底节区、脑干、小脑等L病灶大小515MM脑梗死脑梗死LCT低密度灶低密度灶，其部位和范围与闭塞血管供血区一致，可有占位效应23周时可出现“模糊效应模糊效应（FOGGINGEFFECT）”增强脑回样强化脑回样强化12个月形成边界清楚的低密度囊腔低密度囊腔脑梗死脑梗死CT演变过程演变过程L024HRNORMALORSUBTLEHYPODENSITYSULCAEFFACEMENTL17DAYSMASSEFFECTPEAKAT34DAYSLDAYSTOMONTHS/YEARSHYPODENSITYL18WEEKSCONTRASTENHANCEMENTLWEEKSTOYEARSATROPHY脑梗死脑梗死LMRI显著优于显著优于CTL急性期急性期ACUTEPHASE和超急性期和超急性期SUPERACUTEPHASEDWI,PWI6HOURS传统MRI，FLAIR8HOURSL亚急性期亚急性期SUBACUTEPHASEL慢性期慢性期CHRONICPHASET1WIT2WIFLAIRADCMAPDWIMRAMULTIPHASICPERFUSIONCTOBTAINED3HOURSAFTERTHESUDDENONSETOFRIGHTHEMIPARESISANDAPHASIAINA76YEAROLDWOMANF2DAYSFOLLOWUPT1WIT2WIDWIMALE,60YEARSOLDONSET6HOURS血管畸形血管畸形VASCULARMALFORMATIONL为胚胎期血管的发育异常，分为动静脉畸形动静脉畸形ARTERIOVENOUSMALFORMATION,AVM静脉畸形VENOUSMAFORMATION毛细血管扩张症CAPILLARYTELANGIECTASIA海绵状血管瘤海绵状血管瘤CAVERNOUSHEMANGIOMA等动静脉畸形动静脉畸形AVMCT不规则混杂密度灶钙化斑点或弧线形强化无水肿和占位效应不敏感不敏感MALE,65YR动静脉畸形动静脉畸形（AVM）LMRI扩张流空的畸形血管团邻近脑质混杂低信号（HEMOSIDERIN）非常敏感非常敏感MALE,48YRMALE,48YR海绵状血管瘤CAVERNOUSHEMANGIOMAM，31YR颅内动脉瘤颅内动脉瘤INTRACRANIALANEURYSML描述描述为血管的局限性扩张为血管的局限性扩张L病因先天性80后天性20L常见年龄PREDOMINATEDONSETAGE3060YEARSOLDLPREDOMINATEDLOCATIONINTERNALCAROTIDARTERY90VERTEBRALANDBASILARARTERYSYSTEM10L并发症并发症L蛛网膜下腔出血THEWHITEARROWONTHEBLACKCARDMARKSTHESITEOFARUPTUREDBERRYANEURYSMINTHECIRCLEOFWILLISTHECIRCLEOFWILLISHASBEENDISSECTED,ANDTHREEBERRYANEURYSMSARESEEN脑肿瘤脑肿瘤BRAINTUMORL概况概况恶性恶性L胶质瘤GLIOMA4050L转移瘤METASTASIS3191292良性良性L脑膜瘤MENINGIOMA1520L垂体瘤PITUITARYADENOMA10L颅咽管瘤CRANIOPHARYNGIOMAL听神经瘤ACOUSTICNEURINOMA脑肿瘤脑肿瘤BRAINTUMORL胶质瘤胶质瘤（GLIOMA）星形细胞瘤ASTROCYTOMA40少突胶质细胞瘤OLIGODENDROGLIOMA515室管膜瘤EPENDYMOMA髓母细胞瘤MEDULLOBLASTOMA48星形细胞瘤星形细胞瘤ASTROCYTOMAL临床临床CLINICALFEATURES局灶性或全身性癫痫发作为最重要表现神经功能障碍颅内压增高星形细胞瘤星形细胞瘤ASTROCYTOMALCT级级L低密度灶，分界清楚，占位效应轻，无或轻度强化级级L高、低或混杂密度，可呈囊性L斑点钙化和瘤内出血L形态不规则，边界不清L占位效应和瘤周水肿明显L不规则环形伴壁结节强化，或不均匀强化星形细胞瘤星形细胞瘤LMRIT1WI稍低或混杂信号T2WI均匀或不均匀性高信号L恶性程度越高，其T1、T2值愈长，囊壁和壁结节强化越明显局灶性弥漫型星局灶性弥漫型星形细胞瘤形细胞瘤（WHO2级）级）间变型星形细胞瘤（间变型星形细胞瘤（WHO3级）级）F/68平扫瘤体内低信号平扫瘤体内低信号及条状高信号，累及条状高信号，累及基底节及颞叶周及基底节及颞叶周围明显水肿，增强围明显水肿，增强后明显不均匀强化后明显不均匀强化OLIGODENDROGLIOMAMALE,43YR脑膜瘤脑膜瘤MENINGIOMALSEXPREDOMINATION,GENDER中年女性多见中年女性多见L起源于起源于ORIGINATEDIN蛛网膜粒帽细胞多居于脑外脑外，与硬脑膜粘连L好发部位好发部位LOCATION矢状窦旁、脑凸面、蝶骨嵴、嗅沟、桥小脑角、大脑镰或小脑幕等，与硬脑膜相邻硬脑膜相邻部位少数脑室、眼眶脑膜瘤脑膜瘤（MENINGIOMA）L大体病理大体病理GRASSPATHOLOGY肿瘤包膜完整，多由脑膜动脉供血，血运丰富，常有钙化，少数有出血、坏死和囊变L组织学分型组织学分型HISTOLOGICTYPE上皮型纤维型过渡型砂砾型血管瘤型L等15型脑膜瘤脑膜瘤MENINGIOMALCT平扫平扫PLAINSCANL等或略高密度L常见斑点状钙化L广基底