生物醫(yī)學(xué)工程基礎(chǔ)四—生物醫(yī)學(xué)圖象2ppt課件

1、（2019.11）Imaging technologies are changing the way science is done(R.P. Crease, Science, Vol. 261, July 1993) First Observation of Nuclear Magnetic Resonance in condensed matterShared 1952 Nobel prize in physics for their independent discoveries1946Felix BlochStanford University1945Edward PurcellHar

2、vard UniversityNSPurcells Experiment With magnet off, signal attenuator and phase adjuster match output from resonant cavity When magnet passed through right field strength, output from cavity decreasesRF signal generator(30 MHz)+-+-Signal attenuator,phase adjustorResonant cavity (30 MHz) filled wit

3、h waxVariable-strength MagnetDifferencedetectorPaul C. Lauterbur保羅保羅勞特布爾勞特布爾University of Illinois Urbana, IL, USA Peter Mansfield 彼得彼得曼斯菲爾德曼斯菲爾德University of Nottingham, School of Physics and Astronomy Nottingham, United Kingdom Paul C. Lauterbur Prize Award Photo Sir Peter Mansfield Prize Award Ph

4、oto10/6,2019第一臺(tái)第一臺(tái)MRIMRI裝置裝置 19771977世界上第一張世界上第一張 MRI MRI 圖象圖象19781978年年 英國(guó)取得了第一幅人體頭部的磁共振圖英國(guó)取得了第一幅人體頭部的磁共振圖像；像；T1 ContrastTE = 14 msTR = 400 msT2 ContrastTE = 100 msTR = 1500 msProton DensityTE = 14 msTR = 1500 ms100mm100mm體積分辨率需提體積分辨率需提高高 109 倍倍CT MRT1T2T1T2CTThe Induced signal in the coilmmdBdt0dMMBdtiiM微觀宏觀0B00B0BKxKyABCDEABCDERF pulseGzGxGydttGtkdttGtktyytxx00)()()()(This animation shows the rotating frame coordinates.The two RF pulses (p/2 & p) tip about the rotating x axis.The arrows are magnetization at various points