一、前言自从1946年美国哈佛大学的E.M.Putcell和斯坦福大学的F.Bloch发现核磁共振(NMR)至今已过去了四十二个年头。自从R.Damadian提出将NMR应用于医学诊断的可能性和P.Lauterbur提出核磁共振成像(MRI)原理以来,”也已有十五年的历史。七十年代末到八十年代初,美国、西德的一 I. INTRODUCTION Since 1946 E.M. Putcell of Harvard University and F. Bloch of Stanford University have found that nuclear magnetic resonance (NMR) has passed for forty-two years. It has been fifteen years since R.Damadian proposed the possibility of applying NMR to medical diagnosis and P.Lauterbur proposed the principle of magnetic resonance imaging. "In the late seventies and the early eighties, the United States, One of West Germany