Hemodynamic and Metabolic Changes of Acute Cerebral Infarction Evaluated by Flow-sensitive Alternating IR (FAIR) image and Spectroscopic Imaging(CSI), and Comparison with Dynamic Cerebral Perfusion SPECT M.Harada,T.Okada,S.Hisao& K. Yon&, H.Nishitani,M. Uno*, amiT. Matsuda**, Department of Radiology and Neurosurgery*, School ofMedicine,University ofTo~~~~-l8-15,Kur~oto,To~s~, 0 : We evaluated hemodynamic change of acute ca infarction using FAIR sequence(References 12) and comparedto the result of dynamic perfusion SPECI which was obtainedwithin 24 hours after MRI study.In addition,diffusionweightedimages@MlW and proton spectroscopicimaging(CSI) or MRS wert: measuredto find changesof ditlusion statusaud metabolites.The purposesof this study are 1)To comparesemiquautitativeresultsof FAIR and cerebralperfusionSPECT,2)To comparediffusion abnormalityof wateraud unaerobicmetabolism appearingelevationof l&ate. The subjectswem ten patientawho were evaluatedby MRI within 8 hours after onset of apoplexy.The informedconsentswereobtainedfrom patientsor patient’sfamily. The MRI instrumentwas Signa Horizon (GE,l.ST).Immediately after the measurement of dMRI, FAIR and CSI wereobtainedat the samepotion asshowingabnormalityon dMRI. The seaquence of dMRI wasmadeon the basisof SE-EPIwith motion-probing gradients at three axis @=lOtBs&mm2). The measurement condition of FAIR was following; TR=2s,‘IlUOms, inversion time(TIj=QOOms,slice thickuess=lOmm,FGV=24cm thickness of inversion pulse =4 times thicker than slice selectivepulse, matrix=96x%, number of excitation@?EX)=lOO. The spectmscopic imageswereobtainedby PRESSunderthecondition of TR=l2ooms, TE=135ms, Matrix=24x24, spectral data poiuts=2400. The post-processingcontaining 2DFFK O-order phasecorrectionand correctionof D-C offsetwas conductedon U/GE softwaresuppliedby GE. The perfusionscintigraphyof Tc-99m EXD including dynamic scan was measuredwithin 24 hours after MRI measmment, and the time activity curve of dynamicscanwas calculated.The perfusionvalue of FAIR and SPECI in theinfarct areawascalibratedsemiquautitativelyby the normalsidevalue. &&&The imagesof FAIR showeddecreasedperfnsionin the iufatct areaof all patients,which waswell-correlatedwith cerebral perfusionSPEKT(Fig.1).The semiquantitativevalue of FAIR in the infarct areahasthe good linear correlationwith that of SPFCC (@X78, Fig.2). Howeverthe lesion/normalratios of FAIR had a tendencyof higher vahre than those of SPEKT (slope of the correlationline =0.54in Fig2), and this meansthat the decreaseof perfusionobservedby FAIR may be more underestimatedthan that by SPECT.The surroundingareaof infarctionon two patients showedhigh intensity by FAIR, aud this areaswere depictedas high activity by earlyphaseof dynamicSPECI(Fig.3). The time activity curve in this area was gradually decreasedafter rapid increaseof earlyphase,suggestinga hyper-perfusionstatusBg.4). The remarkableelevationof lactate(lactateKr ratioAI.6) was seenin the core of infamtion with hyper intensity by dMRI, but lactatesignal was ciezulyobservedstill in the surroundingarea which showedno abnorn& intensity by dMRl and low perfusion by FAlR(Fig.S), though lactate elevation level was much lowe@ctate/Crratio&4) thanthat in thecoreof it&r&on. JWOihlh0n cod- 770-8503 , **GE-W% JawI . :l)FAIR images offered the ahuost identical informationclinically with e&y SPECTimagesof Tc-99mECD, even though the semiquantitativeanalysisshoweda tendencyof underestimateof low perfusion by FAIR. Furthenuore hyperperfusionwill be evaluatedby not only dynamicSPECTbut also FAIR 2&actatesignalwill be observedin the isehemicpenumbra by CSI, and thresholdof lactatelevel might be determinedto discriminateviablecerebralareafrom irreversiblelesion. :l)Kim SG, TsekosNV, Magn ResonMed 37;p4254351997 2)TsekosNV, et al. MagnResonMed 39;p564-573,199s FAIR DWI m SPECT Fig.2 Ns.3 DWI FAIR SPECT(eariyj