[临床医学]分水岭区梗死及影像学表现

《[临床医学]分水岭区梗死及影像学表现》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、分水岭区梗死WatershedInfarctsWatershedinfarctsoccurattheborderzonesbetweenmajorcerebralarterialterritoriesasaresultofhypoperfusion.Therearetwopatternsofborderzoneinfarcts:CorticalborderzoneinfarctionsInfarctionsofthecortexandadjacentsubcorticalwhitematterlocatedattheborderzoneofAC

2、A/MCAandMCA/PCAInternalborderzoneinfarctionsInfarctionsofthedeepwhitematterofthecentrumsemiovaleandcoronaradiataattheborderzonebetweenlenticulostriateperforatorsandthedeeppenetratingcorticalbranchesoftheMCAorattheborderzoneofdeepwhitematterbranchesoftheMCAandtheACA.Corticawat

3、ershedstrokes(CWS),orouterbraininfarcts,arelocatedbetweenthecorticalterritoriesoftheanteriorcerebralartery(ACA),middlecerebralartery(MCA),andposteriorcerebralartery(PCA).Internalwatershedstrokes(IWS),orsubcorticalbraininfarcts,arelocatedinthewhitematter,alongandslightlyabovet

4、helateralventricle,betweenthedeepandthesuperficialarterialsystemsoftheMCA,orbetweenthesuperficialsystemsoftheMCAandACA.Watershedsorborderzonesareareasthatlieatthejunctionoftwodifferentdrainageareas.Thevascularsupplyofthecerebralparenchymacanbeenvisionedinasimilarmanner,withde

5、finedboundariesbetweendifferentarterialsystems.Cerebralinfarctsinborderzoneswerefirstdiscussedin1883andweredefinedasischemiclesionsinanareabetweentwoneighboringvascularterritories.Theseterritoriescanbefurtherclassifiedintwobroadcategoriesas(a)external(cortical)or(b)internal(s

6、ubcortical)borderzones.Borderzoneinfarctsconstituteapproximately10%ofallcerebralinfarcts.Varioustheorieshavebeenproposedtoexplaintheirpathogenesis.Itisbelievedthatrepeatedepisodesofseveresystemichypotensionarethemostfrequentcause.Susceptibilityofborderzonestoischemiawasproved

7、inanautopsystudyofpatientswithborderzoneinfarcts.Variousneuropathologicstudieshaveshownneuronalnecrosisfromhypotensionintheseregionsandhaveadvancedourunderstandingofthepreferentialdistributionofborderzoneinfarcts.Theappearancesofborderzoneinfarctsdepictedbystandardimagingmoda

8、litiesarewelldescribed.Advancedimagingtechniquescanhelpidentifyareas