中枢脑血管病教材讲义

CentralNervousSystem南京医科大学一附院放射科洪汛宁hongxunning@2/3/20231TheFiveMostCommonStrokeSymptomsSuddennumbnessorweaknessofface,armorleg,especiallyononesideofthebody.Suddenconfusion,troublespeakingorunderstanding.Suddentroubleseeinginoneorbotheyes.Suddentroublewalking,dizziness,lossofbalanceorcoordination.Suddensevereheadachewithnoknowncause.(Source:NationalStrokeAssociation)2/3/20232OtherImportantbutLessCommonStrokeSymptomsSuddennausea,feverandvomitingdistinguishedfromaviralillnessbythespeedofonset(minutesorhoursvs.severaldays).Brieflossofconsciousnessorperiodofdecreasedconsciousness(fainting,confusion,convulsionsorcoma).Source:NationalStrokeAssociation2/3/20233ClinicalFeaturesDependsonvascularterritoryinvolvedUsuallyabruptonsetMostprecise:levelsofconsciousness(LOC),grossmotorlevelLeastprecise:sensoryexam,history(includingTIA)Clinicalexamperformanceimproveswithtraining2/3/20234脑血管疾病

（cerebrovasculardisease）脑梗死（cerebralinfarction）脑出血（intracranialhemorrhage）动静脉畸形（aterio-venousmalformation）蛛网膜下腔出血（subarachnoidhemorrhage）和颅内动脉瘤（intracranialaneurysm）2/3/20235

TheconsequencesofcerebralischemiadependonthedegreeanddurationofreducedCBF.Neuronscantolerateischemiafor30-60minutes.Perfusionmustbereestablishedbefore3-6hoursofischemiahaveelapsedorbeforetheCBFdropsto10.脑梗死cerebralinfarction2/3/20236cerebralinfarctionPathologicchangeswithintheneuropilfollowthemetabolicabnormalities.OneofthefirsteffectsiscytotoxicedemathatresultsfromfailureoftheNa/Kionpump.Earlyon,thisstageisstillreversible.Prolongedischemialeadstocelldeathandcoagulationnecrosis.After3-6hoursofischemia,irreversibledamageoccurstothecapillaryendothelium.2/3/20237CTandMRscansinpatientswithasymptomaticbruitsorTIA'sareusuallynegative.Theearliestsignmaybeabnormalvasculardensity/signal.ThefirstparenchymalchangesobservedonCTandMRreflectthecytotoxicedemaaffectingprimarilythegraymatter.ischemiccerebralinfarction2/3/20238ItisimportanttorememberthattheCTscanmaybenegativeforthefirst24-48hours.Massiveinfarctionsmaybevisibleasearlyas6hours.TheMRscanisusuallypositivewithinthreetofourhoursfollowingastroke.OneoftheearliersignsonCTislossofthenormalgray-whitecontrastastheedematouscortexbecomesisodensetotheunderlyingwhitematter.After6-8hourstheaccompanyingvasogenicedemahighlightstheareasofbraininfarction.ischemiccerebralinfarction2/3/20239CTCT扫描见低密度灶。常呈扇形，基底贴近颅内板，尖指向颅脑中心。早期（1~2天）边界较模糊，中后期（2~7天）边界较清，无占位征或略有占位征。病灶部位和范围与闭塞血管的所属供血区域一致1~3周时可出现模糊效应（侧支循环建立）增强扫描可呈轻度脑回状强化（血脑屏破坏及侧循建立）1~2月后可出现低密度脑软化或伴脑萎缩。注：24小时内检出率低，24~48小时后检出率高，2天~2周水肿较明显。2/3/202310TopographicVascularSupply

(Http://www.C/nm-Mediabook/figures/brainfigs.Html)2/3/202311ACATerritoryStroke2/3/202312PCATerritoryInfarct2/3/202313RightPICAStroke

(/~c064s01/nr251.htm)2/3/202314

male56yearsold,

150minaftersymptom

常规CTTimetoPeakCBF随访

颅内动脉栓塞

随访CT显示液化灶2/3/202315Cerebralinfarction2/3/2023162/3/2023172/3/2023182/3/202319HyperacuteStroke:CT

(Koeller,AFIPStrokeLecture)HyperdensearteryBasalgangliaobscuredInsularribbonlostEdema:sulcalorventriculareffacement2/3/202320HyperdenseMCASignPrognosticValueoftheHyperdenseMiddleCerebralArterySignandStrokeScaleScorebeforeUltraearlyThrombolyticTherapyAJNRAmJNeuroradiol

17:79–85,January19962/3/202321HyperdenseRightMCA2/3/202322AxialunenhancedCTimageobtainedina53-year-oldmanshowshypoattenuationandobscurationoftheleftlentiformnucleus(arrows),which,becauseofacuteischemiainthelenticulostriatedistribution,appearsabnormalincomparisonwiththerightlentiformnucleus.2/3/202323ObscurationoftheRightBasalGangliainAcuteStroke

(AJNRAmJNeuroradiol17:1743–1748)2/3/202324AxialunenhancedCTimages,obtainedina45-year-oldman2hoursaftertheonsetoflefthemiparesis,showobscurationoftherightlentiformnucleus(arrowinb).Thisfeatureislessvisiblewiththeroutinebrainimagingwindowusedfora(windowwidth,80HU;center,35HU)thanwiththenarrowerwindowusedforb(windowwidth,10HU;center,28HU).2/3/202325MRI检出脑梗塞较CT敏感。梗塞6小时内，细胞毒性水肿，梗塞区含水量高，T1、T2时间延长。6小时后渐出现血管源性脑水肿，血脑屏障破坏。较高档MR应用MRI弥散成像和灌注成像，能更早期发现病灶，有利于早期治疗。2/3/202326DIFFUSION&PERFUSIONIMAGING

ConventionalCTandMRimagingarenotsufficientlysensitivetoevaluateacutestroke.Theultimategoalforimagingistodefinetheareaofbraininfarctionandperfusiondeficit,andtoidentifyanyischemictissuethatcanbesalvagedbymedicalorsurgicaltherapy.DWIcandetectacutebraininfarctionwithin1to2hours.Perfusionimagingispositiveimmediatelyfollowinganacutestroke.2/3/202327AcuteRightMCAStroke2/3/202328AcuteMCAStrokewithDiffusion

2/3/2023294P’sofAcuteStrokeImaging•Parenchyma–Assesearlysigns,excludehemorrhagePipes–Assessextra&intracranialcirculationPerfusion–AssessCBV,CBF,&MTT

Penumbra–Assesstissueatriskofdying2/3/202330HemorrhagicInfarct

(Koeller,AFIPStrokeLecture) 10%ofacutestroke.

HigherincidenceinAsianpopulation. <24hours. Anticoagulationcontraindicated.2/3/202331HemorrhagicCerebralInfarction2/3/202332HemorrhagicStroke

AJNRAmJNeuroradiol

18:1011–1020,June19972/3/202333HemorrhagicTransformation

(Koeller,AFIPStrokeLecture) >24hoursafterinfarctbydefinition Peak:1-2weeks

Diapedesis血细胞渗出Occursafterreperfusion:thefullpressureofarterialbloodintohypoxiccapillariesresultsinadiapedesisorredcellsmovingthroughthevesselhypoxicwalls

Occursinupto50%ofstrokes Confirms

ischemicnatureofinfarct2/3/202334HemorrhagicTransformation

/AANLIB/cases/case42/mr1/012.html2/3/202335腔隙性脑梗死lacunarinfarction丘脑基底节区或深部脑髓质小血管(A)闭塞所致CT征象：于好发部位见小的低密度灶，一般为1~1.5cm大小，早期边界较模糊，中晚期边界较清MRI检查腔梗灶较CT敏感高，早期更易发现2/3/202336lacunarinfarction2/3/202337MRIT2WI,T1WI,flairlacunarinfarction2/3/202338存在问题致死率及致残率2/3/202339影像学研究策略脑梗死前期脑缺血的影像学研究Hypo-PbeforeIS2/3/202340IntracranialHemorrhageVerycommonTrauma,Hypertension;Aneurysm;VascularMalformationOthers:Embolicstrokewithreperfusion;Amyloidangiopathy;Coagulopathies;Drugabuse;Tumor2/3/202341CTofIntracranialHemorrhage

Allcerebralhematomas,whateverthecause,haveasimilarresolutionpatternonCT.Therateofresolutiondependsonthesizeofthehematoma,usuallywithinonetosixweeks,andtheyresorbfromtheoutsidetowardthecenter.Perihematomalowdensityappearsin24-48hours.Rimenhancementappearsinoneweekandpersistsforsixweeks.Theendresultofahematomaisdecreasedparenchymaldensity,focalatrophyandlocalventriculardilatation.2/3/2023422/3/2023432/3/2023442/3/202345脑内血肿（T1，T2，turbo-T2)其内有陈旧性出血2/3/202346脑干出血2/3/202347发病当时CT发病两年后MRI复查2/3/202348脑血管畸形(AVM)影像可以明确诊断，还可以观察大小及血供情况，常有脑萎缩目前主要是血管成像(DSA、CTA、MRA等)可直接显示畸形血管2/3/202349CTCTfeaturesofanAVmalformationonplainscanincludeahigh-absorptionirregularmasswithlargefeedingarteriesanddrainingveins,focalareasofcalcificationandnosurroundingedemaormasseffect.Thecontrastscanshowsserpiginousenha