最新MAGNETIC RESONANCE IMAGING[磁共振成像](50)PPT课件.ppt

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1、MAGNETICRESONANCEIMAGING[磁共振成像](50)SummarySlideI.HISTORICALPERSPECTIVEII.MAGNETICNUCLEIIII.TISSUEMAGNETIZATIONANDRELAXATIONIV.RFPULSESEQUENCESANDIMAGINGMETHODSV.SPATIALCHARACTERISTICSOFTHEMRIMAGEVI.PROTOCOLFACTORSFORCONTRASTCONTROLVII.IMAGEDETAILANDNOISEVIII.BASICMRIEQUIPMENT1.1HistoricalPerspective

2、1.1.1NMRSpectroscopy-19461.1.1.1FelixBloch-Stanford1.1.1.2EdwardM.Purcell-Harvard1.1.1.3JointNobelPrize-19521.1.2MRIImaging1.1.2.1PaulLauterbur-1973-WaterImage1.1.2.2RaymondDamadian-1974-PatentGranted1.1.2.3PeterMansfield-1975-FingerImage2.3Nuclides2.3.1Hydrogen-12.3.2Phosphorus-312.3.3Carbon-122.3.

3、3.1Carbon-132.3.4Sodium-232.3.5Potassium-392.3.6Oxygen-162.3.6.1Oxygen-172.3.7Fluorine-192.4MagneticFields2.4.1Magnets2.4.2FieldCharacteristics2.4.2.1SizeandShape2.4.2.2Direction2.4.2.3StrengthUnits2.4.2.3.1TheTesla=10,000Gauss2.4.2.3.2TheGauss–MeasureofEarth’sfield2.4.2.3.2.1Atlanta=0.6Gauss2.5Magn

4、eticResonance2.5.1Resonant(Larmor)Frequency2.5.1.1FieldStrength2.5.1.2Nuclide-GyromagneticRatio(MagnetogyricRatio)2.5.2RadioFrequency(RF)Absorption2.5.3RadioFrequency(RF)EmissionIII.TISSUEMAGNETIZATIONANDRELAXATION3.1MaterialMagnetization3.1.1Production3.2MagneticCharacteristics3.2.1Direction(Vector

5、)3.2.2Strength3.2.2.1NuclearConcentration3.2.2.2FieldStrength3.2.3Stability3.2.3.1Permanent3.2.3.2Temporary3.3MagneticDirections3.3.1Longitudinal3.3.1.1Stable3.3.1.2Unstable3.3.2Transverse3.3.2.1Unstable3.3.2.2ProducesRFSignal3.4MagneticExcitation3.4.1RadioFrequencyEnergy3.4.290°Excitation3.4.3180°R

6、ephasing3.4.4ExcitationMethod3.4.4.1RFCoils3.4.4.2RFGenerator3.5MagneticRelaxation3.5.1EnergyExchange3.5.2RelaxationRates3.6LongitudinalRelaxation3.6.1Mechanism3.6.2RelaxationTime–T13.7TransverseRelaxation3.7.1Mechanism3.7.2RelaxationTime-T23.8TissueValues3.8.1FieldStrength3.8.2Temperature3.8.3Water

7、Content3.8.4ProteinContent3.8.5ParamagneticIons(ContrastMedia)SomeNeuralTissueCharacteristicsTissueProtonDensityT1T2Fat10029060GrayMatter8452095Whitematter7238085CSF1002700160OtherTissueCharacteristic