医学领域的磁共振成像革命——2003年诺贝尔生理及医学奖主要工作介绍

Revolution of MRI in Medicine: The Introduction of The 2003 Nobel Prize in Physiology or Medicine

在磁场中 ,自旋的原子核会吸收频率与其自旋频率相同的电磁波 ,使自身能量增加 ,发生能级跃迁 ,当原子核迁移回原能级时 ,就会把多余的能量以电磁波的形式释放出来 ,称为核磁共振 (NMR) .磁共振成像(MRI)利用这一原理 ,依据所释放的能量在物质内部不同结构环境中不同的衰减 ,通过外加梯度磁场检测所发射出的电磁波 ,即可得知构成这一物体原子核的位置和种类 ,据此可以绘制成物体内部的结构图像 .将这种技术用于人体内部结构的成像 ,就产生出一种革命性的医学诊断工具 .快速变化的梯度磁场的应用 ,大大加快了磁共振成像的速度 ,使该技术在临床诊断、科学研究的应用成为现实 ,极大地推动了医学。

Atomic nuclei in a strong magnetic field rotate at a frequency that is dependent on the strength of the magnetic field. Their energy can be increased if they absorb radio waves with the same frequency ( resonance). When the atomic nuclei return to their previous energy level, radio waves are emitted, called nuclei magnetic resonance (NMR). Based on this principle, knowing that the energy released attenuates at different rate in different materials, images of internal structures of an object can be acquired using magnetic resonance imaging (MRI) by applying a gradient and detecting radio wave signals which reveal the positions and kinds of certain nuclei constituting the object. The attempts of utilizing this technique on human by P. Lauterbur and P. Mansfield have led to a revolutionary tool for medical diagnose. Extremely rapid imaging could be achieved by very strong and fast gradients, which helped realizing MRI in medical imaging and research, and promoted the development of medicine, neurophysiology as well as cognitive neuroscience remarkably.