CT灌注成像PPT课件VIP

1、精选,1,反映组织的血管化程度及血流灌注情况，获得血液动力学方面的信息。方法：快速造影剂团注后(5ml/s以上)，在首次经过受检组织的过程中对某一选定的层面进行快速动态扫描，获得一系列动态图像，分析造影剂通过每个像素所对应的体素密度的差异，从而得到反映血流灌注情况的参数。,CT灌注成像(Perfusion),精选,2,脑梗塞肝、肾血流灌注及肿瘤的诊断肾移植的血流灌注的评价，了解移植血管的情况电子束CT的灌注可了解心脏灌注，有助于缺血性心肌病的早期诊断,CTPerfusion应用,精选,3,由脑局部缺血而阻碍血液扩散是导致中风，占脑中风70%。用血纤维蛋白可溶解闭塞的血管。发生中风后，有效治疗的

2、时间为3小时左右。要尽快了解病情类型、发病时间和局部缺血的程度。在这段时间内常规CT检查较难发现，而灌注CT可应用于急性中风检查。,CT灌注,精选,4,前动脉供血区,中动脉供血区,后动脉供血区,外则内侧底面,脑动脉系统,精选,5,脑动脉系统,精选,6,在快速注射造影剂后，计算和脑的扩散有关的参数，从不同侧面提供中风的灌注分布情况：脑血液流量CerebralBloodFlow,CBF脑血液容量CerebralBloodVolume,CBV造影剂达到各点最大值的时间TimePeak，TP平均通过时间Meantransittime，MTT通过CBV与MTT可获得CBF,CTPerfusion,精选,

3、7,常规CT通过组织对X线不同衰减来显示图像CTA通过造影剂在血管内流动来显示血管结构灌注CT利用血液流动有关的参数CBF信号强示流速大；造影剂到达高峰的时间分布图TP，愈大意味着造影到达晚。CBF直接把它和向脑组织提供氧的总量联系起来，同时也与血液动力学方面有关。,CTPerfusion,精选,8,紫色区域为血流量少,大脑急性中风区域,红色区域血流量大,CBF,精选,9,71岁妇女在症状开始90分钟后进行检查。CT平扫示无反常情况，但CBF示脑左侧(中脑和左半动脉供血)大部分，(前脑动脉)提供地区严重局部缺血，示头颅内颈动脉的双枝闭塞。,CTPerfusion,精选,10,左半脑症状出现60

4、分钟后，CT平扫无脑异常血液流动，(b)示左侧半脑广泛性和右前部的局部缺血。原因：左颈内动脉闭塞。,精选,11,CBFCBVTime-to-peakimage,男44岁右脑中风约2小时，CBF在脑岛的脑皮层和豆状核后部，示严重扩散障碍(接近零)。与左边半球比较，中脑动脉血液供应相当少。CBV显示同样情况，但在右侧MCA其他地方血液容量接近正常。与左边区域比较，达到顶点时间图在延长(造影剂延迟到达)。MCAMI段栓塞和小脑膜血液供应良好，,精选,12,CBFTime-to-peakimage3天后CT,上述病例进行动脉血纤维蛋白溶解处理，治疗后一天，用扩散CT成像显示了治疗效果，3天以后CT平扫

5、，示梗塞形成，核心区域与CBF和CBV图像相似。,精选,13,在梗塞核心区域范围确定方面，CT灌注能提供重要信息，可绘局部缺血轮廓，用高密度来显示。用于辨认梗塞灶核心和周围梗塞局部缺血(阴影)，为外科提供治疗方法。通常CBV的梗塞灶小于CBF和TP，MRI也如此，一般认为CBV提供的信息较正确。早期CBV减少与随后梗塞形成程度较接近。,CTPerfusion应用,精选,14,与CBV(b)相比CBF(a)、TP(c)在MCA中局部缺血间不匹配。在脑岛脑皮层背部(箭)有一梗塞灶。再通治疗法后24小时(d)在MCA同样位置示受限梗塞区。,精选,15,71-year-oldfemalepatient

6、withright-sidedhemiplegia(偏瘫)andglobalaphasia(失语).PlainCT(90minuteslater)revealsnoearlysignsofanischemia(局部缺血).,Theparameterimagesdisplaytheentireextentoftheischemiawithahigh-gradereductionofCBFandCBV,alackingdetectionofthecontrastbolusinthetime-to-peakimage.Theinfarction(梗塞)includestheregionofthean

7、teriorcerebralarteryandlargeportionsoftheregionsuppliedbythemiddlecerebralartery,bothfeaturesindicativeofanocclusionoftheintracranialcarotidbifurcation.,Case1,精选,16,精选,17,Patient(male44)witharight-sidedischemiaintheregionofthemiddlecerebralartery(MCA)whichbegan160minutesago.Typicalfindingsofahigh-gr

8、adedisturbanceinperfusionintheinsularcortexandtheposteriorportionofthelentiformnucleuswithareductioninCBFandCBVasaresultofanembolicocclusioninthedistalM1segment.TheotherregionssuppliedbytheMCAdemonstratedgoodleptomeningealcollateralbloodsupplywhichonlyshowedmoderatelyreducedCBFandCBVvalues,aswellasa

9、prolongationofthetime-to-peak.,Case2,精选,18,InthecalculationofrelativeperfusionindicesfromCBFvaluesinischemicareasandinmirrorredROIswithintheunaffectedhemisphereprovedtobeavaluablemethodfortheprognosticevaluationofaregionwithreducedperfusion.Thecoreoftheinfarctandtheischemicmarginalzonesdemonstratecl

10、earlydifferentCBFperfusionindices(green-markedROI=0.17versusred-markedROI=0.69).,精选,19,ThefindingsofperfusionCTcouldbeverifiedbyDSAwithregardtothetypeofocclusionandtheconditionofthecollateralbloodsupply.Thefollow-upCTafterasuccessfulintra-arterialfibrinolysisshowstheinfarctindimensionscomparabletoth

11、einfarctcoreseenwithperfusionCT.,精选,20,70minutesaftertheoccurrenceoftheinfarction,theCBFimagerevealedahighgradeischemiainthefrontalregionofthesupplyareaoftheMCAandinthelentiformnucleus(Fig.3a)withaperfusionindexinthegreenmarkedROIof0.07(Fig.3b).Asaresultofthegoodcollateralflow,thedisturbanceinperfus

12、ionintheremainingregionoftheMCA,withaperfusionindexof0.82,isnotseentobeveryextensive(red-markedROIinFig.3b).,36-year-oldmalepatientwithanembolicocclusionintheM1segmentoftheleftMCAandasimultaneousocclusionoftheleftinternalcarotidarteryasaresultofdissection.,Case3,精选,21,Becauseofthepartiallyhigh-grade

13、ischemiaontheonehandandtheexcellentcollateralbloodsupplyofthemarginalregionontheother,fibrinolysiswasnotperformedinspiteoftheshorttimeinterval.Asexpected,thefollow-upCTrevealedthedevelopmentofaninfarctionintheareawhichhadprimarilydemonstratedahigh-gradeischemia.,精选,22,灌注CT与颅脑CT扫描和颅脑CT血管造影术结合为脑梗塞早期检查

14、提供了一种有用工具。常规CT可检查梗塞区域的形成灌注CT可决定局部缺血的区域，提供了局部缺血组织的位置和潜在病变区域CT血管造影术为诊断提供了相应病灶区域的形态。为临床工作人员决定进一步治疗的方案提供了重要信息。,精选,23,CTPerfusion前景,目前认为中风处理的最佳时间在60分钟。通过对造影剂注入位置与方式的研究，灌注CT在不到15分钟中完成中风评价过程。,精选,24,Inthecourseofaninvestigationperformedon33patients,anattemptwasmadetocarryoutaquantitativeevaluationofthesever

15、ityoftheischemiawiththeaidofanROI-evaluationoftheCBFimages.,thecalculationofrelativeperfusionindicesfromCBFvaluesinischemicareasandinmirrorredROIswithintheunaffectedhemisphereprovedtobeavaluablemethodfortheprognosticevaluationofaregionwithreducedperfusion.,精选,25,Ischemiaswithamildtomoderatedegreeofs

16、everity(CBFperfusionindex:0.35-0.9)progressedwellunderfibrinolytictherapy.EveninischemicregionswithaCBFindexof0.35,intra-arterialfibrinolysiscouldpreventthedevelopmentofaninfarctinmorethanhalfofthecases,aslongastheindexdidnotfallbelowacriticalvalueof0.2.Otherwise,ascouldbeverifiedwithfollow-upinvestigationscarriedoutwithcomputedtomographyandmagneticresonancetomography,ischemicnecroseswereseentodevelopwith