中枢脑血管病

CentralNervousSystem南京医科大学一附院放射科洪汛宁5/11/20231TheFiveMostCommonStrokeSymptomsSuddennumbnessorweaknessofface,armorleg,especiallyononesideofthebody.Suddenconfusion,troublespeakingorunderstanding.Suddentroubleseeinginoneorbotheyes.Suddentroublewalking,dizziness,lossofbalanceorcoordination.Suddensevereheadachewithnoknowncause.(Source:NationalStrokeAssociation)5/11/20232OtherImportantbutLessCommonStrokeSymptomsSuddennausea,feverandvomitingdistinguishedfromaviralillnessbythespeedofonset(minutesorhoursvs.severaldays).Brieflossofconsciousnessorperiodofdecreasedconsciousness(fainting,confusion,convulsionsorcoma).Source:NationalStrokeAssociation5/11/20233ClinicalFeaturesDependsonvascularterritoryinvolvedUsuallyabruptonsetMostprecise:levelsofconsciousness(LOC),grossmotorlevelLeastprecise:sensoryexam,history(includingTIA)Clinicalexamperformanceimproveswithtraining5/11/20234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）5/11/20235

TheconsequencesofcerebralischemiadependonthedegreeanddurationofreducedCBF.Neuronscantolerateischemiafor30-60minutes.Perfusionmustbereestablishedbefore3-6hoursofischemiahaveelapsedorbeforetheCBFdropsto10.脑梗死cerebralinfarction5/11/20236cerebralinfarctionPathologicchangeswithintheneuropilfollowthemetabolicabnormalities.OneofthefirsteffectsiscytotoxicedemathatresultsfromfailureoftheNa/Kionpump.Earlyon,thisstageisstillreversible.Prolongedischemialeadstocelldeathandcoagulationnecrosis.After3-6hoursofischemia,irreversibledamageoccurstothecapillaryendothelium.5/11/20237CTandMRscansinpatientswithasymptomaticbruitsorTIA'sareusuallynegative.Theearliestsignmaybeabnormalvasculardensity/signal.ThefirstparenchymalchangesobservedonCTandMRreflectthecytotoxicedemaaffectingprimarilythegraymatter.ischemiccerebralinfarction5/11/20238ItisimportanttorememberthattheCTscanmaybenegativeforthefirst24-48hours.Massiveinfarctionsmaybevisibleasearlyas6hours.TheMRscanisusuallypositivewithinthreetofourhoursfollowingastroke.OneoftheearliersignsonCTislossofthenormalgray-whitecontrastastheedematouscortexbecomesisodensetotheunderlyingwhitematter.After6-8hourstheaccompanyingvasogenicedemahighlightstheareasofbraininfarction.ischemiccerebralinfarction5/11/20239CTCT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旳所属供血区域一致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：二十四小时内检出率低，24~48小时后检出率高，2天~2周水肿较明显。5/11/202310TopographicVascularSupply

(Http://www.C/nm-Mediabook/figures/brainfigs.Html)5/11/202311ACATerritoryStroke5/11/202312PCATerritoryInfarct5/11/202313RightPICAStroke

(/~c064s01/nr251.htm)5/11/202314

male56yearsold,

150minaftersymptom常规CTTimetoPeakCBF随访颅内动脉栓塞随访CT显示液化灶5/11/202315Cerebralinfarction5/11/2023165/11/2023175/11/2023185/11/202319HyperacuteStroke:CT

(Koeller,AFIPStrokeLecture)HyperdensearteryBasalgangliaobscuredInsularribbonlostEdema:sulcalorventriculareffacement5/11/202320HyperdenseMCASignPrognosticValueoftheHyperdenseMiddleCerebralArterySignandStrokeScaleScorebeforeUltraearlyThrombolyticTherapyAJNRAmJNeuroradiol17:79–85,January19965/11/202321HyperdenseRightMCA5/11/202322AxialunenhancedCTimageobtainedina53-year-oldmanshowshypoattenuationandobscurationoftheleftlentiformnucleus(arrows),which,becauseofacuteischemiainthelenticulostriatedistribution,appearsabnormalincomparisonwiththerightlentiformnucleus.5/11/202323ObscurationoftheRightBasalGangliainAcuteStroke

(AJNRAmJNeuroradiol17:1743–1748)5/11/202324AxialunenhancedCTimages,obtainedina45-year-oldman2hoursaftertheonsetoflefthemiparesis,showobscurationoftherightlentiformnucleus(arrowinb).Thisfeatureislessvisiblewiththeroutinebrainimagingwindowusedfora(windowwidth,80HU;center,35HU)thanwiththenarrowerwindowusedforb(windowwidth,10HU;center,28HU).5/11/202325MRI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，能更早期发觉病灶，有利于早期治疗。5/11/202326DIFFUSION&PERFUSIONIMAGING

ConventionalCTandMRimagingarenotsufficientlysensitivetoevaluateacutestroke.Theultimategoalforimagingistodefinetheareaofbraininfarctionandperfusiondeficit,andtoidentifyanyischemictissuethatcanbesalvagedbymedicalorsurgicaltherapy.DWIcandetectacutebraininfarctionwithin1to2hours.Perfusionimagingispositiveimmediatelyfollowinganacutestroke.5/11/202327AcuteRightMCAStroke5/11/202328AcuteMCAStrokewithDiffusion

5/11/2023294P’sofAcuteStrokeImaging•Parenchyma–Assesearlysigns,excludehemorrhagePipes–Assessextra&intracranialcirculationPerfusion–AssessCBV,CBF,&MTT

Penumbra–Assesstissueatriskofdying5/11/202330HemorrhagicInfarct

(Koeller,AFIPStrokeLecture) 10%ofacutestroke.

HigherincidenceinAsianpopulation. <24hours. Anticoagulationcontraindicated.5/11/202331HemorrhagicCerebralInfarction5/11/202332HemorrhagicStroke

AJNRAmJNeuroradiol18:1011–1020,June19975/11/202333HemorrhagicTransformation

(Koeller,AFIPStrokeLecture) >24hoursafterinfarctbydefinition Peak:1-2weeks Diapedesis血细胞渗出Occursafterreperfusion:thefullpressureofarterialbloodintohypoxiccapillariesresultsinadiapedesisorredcellsmovingthroughthevesselhypoxicwalls Occursinupto50%ofstrokes Confirmsischemicnatureofinfarct5/11/202334HemorrhagicTransformation

5/11/202335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：于好发部位见小旳低密度灶，一般为1~1.5cm大小，早期边界较模糊，中晚期边界较清MRI检验腔梗灶较CT敏感高，早期更易发觉5/11/202336lacunarinfarction5/11/202337MRIT2WI,T1WI,flairlacunarinfarction5/11/202338存在问题致死率及致残率5/11/202339影像学研究策略脑梗死前期脑缺血旳影像学研究Hypo-PbeforeIS5/11/202340IntracranialHemorrhageVerycommonTrauma,Hypertension;Aneurysm;VascularMalformationOthers:Embolicstrokewithreperfusion;Amyloidangiopathy;Coagulopathies;Drugabuse;Tumor5/11/202341CTofIntracranialHemorrhage

Allcerebralhematomas,whateverthecause,haveasimilarresolutionpatternonCT.Therateofresolutiondependsonthesizeofthehematoma,usuallywithinonetosixweeks,andtheyresorbfromtheoutsidetowardthecenter.Perihematomalowdensityappearsin24-48hours.Rimenhancementappearsinoneweekandpersistsforsixweeks.Theendresultofahematomaisdecreasedparenchymaldensity,focalatrophyandlocalventriculardilatation.5/11/2023425/11/2023435/11/2023445/11/202345脑内血肿（T1，T2，turbo-T2)其内有陈旧性出血5/11/202346脑干出血5/11/202347发病当初CT发病两年后MRI复查5/11/202348脑血管畸形(AVM)影像能够明确诊疗，还能够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5/11/202349CTCTfeaturesofanAVmalformationonplainscanincludeahigh-absorptionirregularmasswithlargefeedingarteriesanddrainingveins,focalareasofcalcificationandnosurroundingedemaormasseffect.Thecontrastscanshowsserpiginousenhancementwithprominentarteriesandve