亚急性和慢性心肌梗塞的MRI诊断和评价

MRIdiagnosisandevaluationinpatientswithsubacuteandchronicmyocardialinfarction

目的：确定自旋回波（ＳＥ）和电影动态ＭＲＩ（ｃｉｎｅＭＲＩ）评价亚急性和慢性心肌梗塞信号变化、室壁节段运动和其他合并症的价值。材料和方法：对心肌梗塞亚急性期５例和慢性期１３例进行ＭＲ横断面、左室长／短轴Ｔ１ＷＩ，其中１３例还经Ｔ２ＷＩ，５例经Ｇｄ－ＤＴＰＡ增强。结果：前壁（包括前间壁）受累６例，下壁、侧壁和后壁受累各２例，前壁和下壁均受累６例。Ｔ１ＷＩ显示４例梗塞室壁信号略低，４例亚急性期注射Ｇｄ－ＤＴＰＡ后强化，慢性期１１例室壁厚度变薄；ｃｉｎｅＭＲＩ显示１５例室壁节段运动减低；发现合并二尖瓣返流６例、主动脉瓣返流４例、心包积液４例。结论：ＳＥ和ｃｉｎｅＭＲＩ能较好地显示心肌梗塞的部位、范围和室壁厚度。

Purpose:TodeterminethevalueofSEandcinegradientechotechniqueinthedemon-strationofthesignalcharacteristics,regionalwalmotionabnormalitiesandotherassociatedmanifes-tationsincaseswithsubacuteandchronicmyocardialinfarction.Materialsandmethods:Thestudygroupconsistedof15malesand3femalesagingfrom45to81yearsexaminedonaGEVectra0.5Tsuperconductivemagnetsystem.Fivepatientswerestudiedinsubacuteperiod[3 6weeksaftera-cutemyocardialinfarction(AMI)],13patientswereexaminedinchronicperiod(6weeksafterAMI).Alcasesacquiredtransaxial,long-axisandshort-axisECGgatedSET1WI(5caseswithin-travenousGd-DTPAinjection)、T2WI(10withFSE,3withVE)andcinegradientechoimages.Re-sults:Thecombinationoftransaxial、long-axisandshort-axisimagesdemonstratedthesegmentalanatomyofLVverywelandshowedthattheanteriorwalwasinvolvedin6cases,theinferiorwalin2,boththeanteriorandinferiorwalin6,thelateralwalin2andtheposteriorwalin2cases.ThefindingsoftheMRIexaminationwereasfolows:(1)Thesignalcharacteristics:In14casestheinfarctedwalshowednormalsignalinSET1WIandonlyin4casestherewasaslighthypointensitysignal.4of5subacutemyocardialinfarctiondemonstratedmildtomoderateGd-DTPAenhancement.(2)LVwalthicknessandregionalwalmotionabnormalities:Decreasedwalthicknesswasob-servedin11caseswithtwoLVwalaneurysms.Regionalwalmotionabnormalitieswereshownin15of18cases.In10caseswiththeechocardiographyexaminationcineMRIhadthesamesensitivityasechocardiographyinevaluatingthewalmotionchanges,andtheresultsalsoshowedthatcineMRIwasbetterthanSEtechniqueinevaluatingthisfinding.(3)Otherassociatedmanifestations:cineMRIdemonstratedmitralvalveregurgitationin6casesfrommildtomoderatedegree,aorticre-gurgitationin2cases,andpericardialefusionin4cases.Conclusion:SEandcineMRIwereusefulindemonstratingthelocation,sizeandwalthicknessinsubacuteandchronicmyocardialinfarctions.CineMRIwasbeterinevaluatingtheregionalwalmotionabnormalitiesandvalveregurgitation.