磁振扩散频谱造影之研发与其在大脑白质复杂结构之分析

ProgramforPromotingUniversityAcademicExcellenceAnnualPerformanceReportforYear__1__MagneticresonancediffusionspectrumimagingofcomplexwhitematterandconnectivitySerialNo-91-N-FA01-2-4-4OverallDuration:MonthMarchYear2002-MonthAprilYear20061stYearDuration:MonthMarchYear2002-MonthAprilYear2003NationalTaiwanUniversityJanuary20,2003III.(FORM2)PROJECTDESCRIPTION(Pleasestatethefollowingsconciselyandclearly,andsubmitformfortheOverallandSub-Project(s)separately.)1.ExecutiveSummary(inbothChineseandEnglish)Non-invasiveimagingofthebrainstructureandfunctionhasbroughtsignificantimpactsonneuroscienceresearchbysheddinginsightstotheworkingofhighcognitivefunction,processofcorticalreorganization,andstructuralabnormalityofAlzheimerdisease.Inthiscentury,MRItechniquesinfunctionalMRI(fMRI),perfusionanddiffusionMRIwillbedevelopedinconjunctionwithparallelacquisitionandcomputingtechniques,magnetoencephalography(MEG),andpositronemissiontomography(PET)tosurpasscurrentlimitsofresolutioninspaceandtime,andtissuespecificity.Theadvancementwillbenefitmoredirectlytopatientswithneurodiseaseintermsofprevention,treatmentandmonitoring.Thissubprojectaimstodevelopanadvancedmagneticresonanceimagingtechnique,calleddiffusionspectrumimaging(DSI),andtoapplythistechniquetothestudyofcerebralwhitematterconnectivity.Byprovidingcomprehensivesolutionstounravelingaxonalfibertracts,DSIwillbecomeanotherpowerfultoolinneuroscienceresearchasfMRIdidincorticalfunctionmapping.functionMRIperfusionanddiffusionMRImagnetoencephalogramPositronEmissionTomography踪diffusionspectrumimaging2.GeneralDescriptionoftheProject:includingObjectivesoftheProject.ThissubprojectaimstodevelopDSIandtoextebditsapplicationstoneuroscienceresearch.Toachieveourgoal,welistfivespecificgoalsthataremostcriticaltotheestablishmentofDSI.1)validation:tounderstandhowDSIrelatestomicrostructures.2)optimization:toobtainDSIatadquatespatialresolutionandSNRwithin30minutes.3)visualization:toreconstructcomplexDSIdataintosimpledisplay.4)quantification:toextractquantitativeresultsfromDSIdata.5)application:toidentifypotentialrolesofDSIinneurosciencestudy.3.InterfaceandIntegrationbetweenOverallandSub-Project(s),aswellasamongallSub-Projects.Bycollaboratingwithothersubprojects,thissubprojectservesasaplatformlinkingtechnologydevelopmentandinvivoapplications.TheultimategoalofthissubprojectistoapplyDSItechniquestoneuroscienceresearchandtopatientswithneurodisease.Tomeetthisgoal,thetechniquemusthavereliableandrobustcapabilitytoshowneuralfiberarchitecture.Inaddition,itsperformanceshouldalsobeenhancedin:1)imagingspeed,2)temporalresolution,3)tissuecontrast,and4)signal-to-noiseratio(SNR).Weseeksupportsfromsubproject1fornovelparallelimagingtechnology.Equippedwithreduceddatasamplingschemesdevelopedinoursubproject,theimagingspeedwillbeenhancedsothatthetotalscanningtimewillbereducedtomeettheclinicallimit.Subproject2iscurrentlysettinguptheSQUIDtechnologyformedicalapplications.OneofitsapplicationsisMEG.MEGcomplementsDSIbyprovidingtemporalresolutioninmappingoutfunctionalconnectivity.Wewillworkwithsubproject3ontissuecontrastenhancementindiffusionexperiments.WewillalsousetheirhighfieldNMRsystemstoperformq-spaceimaginginsmallanimals.Thede-noisealgorithmsdevelopedbysubproject5willhelpusenhanceSNRoftheDSIdata.Wewillalsoworkwithsubproject5onsimulationofspindynamicsinthepresenceoffinitediffusiongradientduration.4.ProjectManagement:themechanismtopromotecollaborationandintegrationamongtheschoolsinvolved.1)WewillholdinternationalsymposiumonadvancedMRItechnologiesevery1or2years.EachCo-PIproposesalistofinvitingspeakersfromthebench-marklabs.Inthesymposium,recentprogressofresearchwillbesharedandfeasibilityofinternationalcollaborationwillbediscussed.2)Regularmeetingswillbeheldevery3months.Thepurposeofthemeetingistofacilitateresearchprogressbyprovidingavailableadministrativeandacademicresources.Theprogressofthelastseasonwillbeevaluated,problemswillbeidentified,andremediesproposed.3)Toprovidestudentswithmulti-disciplinarytraining,Co-PIswillopenlecturesortrainingcoursesoftheirexpertise.ThestudentsofthecoursehavefullaccesstovariousNMRsystemsinCo-PIs’labsandfamiliarizethemselvesthefundamentaltheoriesofNMRandMRI,relatedhardwareorsoftware,in-vitroorin-vivoexperiments,dataanalysisandresultinterpretation.4)Wehaveafull-timeassistantwhoisresponsibleforkeepingCo-PIsinformedofrecentstatusofthetotalprojectthroughwebsiteannouncement,emails,telephonesorfax.Ourwebsitealsoenhancesourvisibilityandinteractionswiththeinternationalscientificcommunity.5.Describeindetailtheapproachesandmethodologiestoimplementtheresearchworks(forbothoverallandsub-projects).Goal1.TovalidatethatDSIcanmapcomplexfiberorientationsinbiologicaltissueWedevelopedanin-vivoandanex-vivomodeltoevaluatetheerrorsofDSI.Inthein-vivomodel,manganeseionswereinfusedintorats’optictracts.TheoptictractswereenhancedonT1-weightedimages(T1WI)andservedasareferenceforthetractorientation.Theex-vivomodelwasaphantomcomprisingsheetsofparallelcapillaries,I.D.=50µm,filledwithwater.Sheetswerestackedoneachotherwithcapillariesc