自从 CT 问世以来,它在临床诊断方面显示出了很大的优越性,这是众所承认的。但是,目前,有一些国家的科学家又在探索用其它放射性物质或能源来摄取人体各部位断层连续摄影的新方法。核磁共振断层摄影就是其中的一种。最近,它在临床应用上已取得了一定的进展。普通 CT 摄影的象素是利用物质对 X 射线的吸收因素为特征的。核磁共振的影象则是根据组织内“自由活动”的氢原子(即质子)的分布情况而取得的。这样,用普通 CT 无 It has been acknowledged that CT has shown great superiority in clinical diagnosis since the advent of CT. However, at present, scientists in some countries are also exploring new methods for taking continuous tomographic images of various parts of the human body using other radioactive materials or energy sources. Magnetic resonance tomography is one of them. Recently, it has made some progress in clinical application. Ordinary CT photography of the pixel is the use of substances on the X-ray absorption factor is characterized. MRI images are based on the distribution of “freely moving” hydrogen atoms (ie protons) in the tissue. In this way, with ordinary CT no