CentralNervousSystem南京醫(yī)科大學(xué)一附院放射科洪汛寧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腦血管疾病

（cerebrovasculardisease）腦梗死（cerebralinfarction）腦出血（intracranialhemorrhage）動靜脈畸形（aterio-venousmalformation）蛛網(wǎng)膜下腔出血（subarachnoidhemorrhage）和顱內(nèi)動脈瘤（intracranialaneurysm）2/3/20235

TheconsequencesofcerebralischemiadependonthedegreeanddurationofreducedCBF.Neuronscantolerateischemiafor30-60minutes.Perfusionmustbereestablishedbefore3-6hoursofischemiahaveelapsedorbeforetheCBFdropsto10.腦梗死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掃描見低密度灶。常呈扇形，基底貼近顱內(nèi)板，尖指向顱腦中心。早期（1~2天）邊界較模糊，中后期（2~7天）邊界較清，無占位征或略有占位征。病灶部位和范圍與閉塞血管的所屬供血區(qū)域一致1~3周時可出現(xiàn)模糊效應(yīng)（側(cè)支循環(huán)建立）增強(qiáng)掃描可呈輕度腦回狀強(qiáng)化（血腦屏破壞及側(cè)循建立）1~2月后可出現(xiàn)低密度腦軟化或伴腦萎縮。注：24小時內(nèi)檢出率低，24~48小時后檢出率高，2天~2周水腫較明顯。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

常規(guī)CTTimetoPeakCBF隨訪

顱內(nèi)動脈栓塞

隨訪CT顯示液化灶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檢出腦梗塞較CT敏感。梗塞6小時內(nèi)，細(xì)胞毒性水腫，梗塞區(qū)含水量高，T1、T2時間延長。6小時后漸出現(xiàn)血管源性腦水腫，血腦屏障破壞。較高檔MR應(yīng)用MRI彌散成像和灌注成像，能更早期發(fā)現(xiàn)病灶，有利于早期治療。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血細(xì)胞滲出Occursafterreperfusion:thefullpressureofarterialbloodintohypoxiccapillariesresultsinadiapedesisorredcellsmovingthroughthevesselhypoxicwalls

Occursinupto50%ofstrokes Confirms

ischemicnatureofinfarct2/3/202334HemorrhagicTransformation

/AANLIB/cases/case42/mr1/012.html2/3/202335腔隙性腦梗死lacunarinfarction丘腦基底節(jié)區(qū)或深部腦髓質(zhì)小血管(A)閉塞所致CT征象：于好發(fā)部位見小的低密度灶，一般為1~1.5cm大小，早期邊界較模糊，中晚期邊界較清MRI檢查腔梗灶較CT敏感高，早期更易發(fā)現(xiàn)2/3/202336lacunarinfarction2/3/202337MRIT2WI,T1WI,flairlacunarinfarction2/3/202338存在問題致死率及致殘率2/3/202339影像學(xué)研究策略腦梗死前期腦缺血的影像學(xué)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腦內(nèi)血腫（T1，T2，turbo-T2)其內(nèi)有陳舊性出血2/3/202346腦干出血2/3/202347發(fā)病當(dāng)時CT發(fā)病兩年后MRI復(fù)查2/3/202348腦血管畸形(AVM)影像可以明確診斷，還可以觀察大小及血供情況，常有腦萎縮目前主要是血管成像(DSA、CTA、MRA等)可直接顯示畸形血管2/3/202349CTCTfeaturesofanAVmalformationonplainscanincludeahigh-absorptionirregularmasswithlargefeedingarteriesanddrainingveins,focalareasofcalcificationandnosurroundingedemaormasseffect.Thecontrastscanshowsserpiginousenha