磁共振（MRI）和CT有什么区别 贾晓峰 贵阳市第二人民医院 скачать в хорошем качестве

磁共振（MRI）和CT有什么区别 贾晓峰 贵阳市第二人民医院

磁共振（MRI）和CT有什么区别 贾晓峰 贵阳市第二人民医院 区别在于：1、磁共振是把人体放置在一个强大的磁场中，通过射频脉冲激发人体内氢质子，发生核磁共振，然后接受质子发出的核磁共振信号，经过梯度场三个方向的定位，构成各方位的图像。CT由于X线球管和探测器是环绕人体某一部位旋转，所以只能做人体横断面的扫描成像，而磁共振可做横断、矢状、冠状和任意切面的成像。2、磁共振由不同的扫描序列可形成各种图像，CT只能辨别有密度差的组织，对软组织分辨力不高而磁共振对软组织有较好的分辨力，所以CT与磁共振是截然不同的检查方法。虽然MRI有多方位成像、对人体无伤害，对软组织有较好的分辨力，但是在氢质子缺乏或含量很少的组织如致密的骨骼、钙化、含气的肺部等，皆无法成像。由于MRI成像时间较长，昏迷、躁动病人不能获得清晰的图像，体内有金属异物的患者也不能进入磁场，此为禁忌症。所以MRI检查也有不可克服的缺点，它不能取代CT，当然CT也不能取代MRI，两者应相辅相成。 What is the difference between MRI and CT The difference is: 1. MRI is to place the human body in a strong magnetic field, Hydrogen protons in human body are excited by RF pulses, Nuclear magnetic resonance, And then it receives the nuclear magnetic resonance signal from the proton, After three orientations of gradient field, Make up images in all directions. Because X-ray tube and detector rotate around a certain part of human body, So we can only do cross-sectional scanning of human body, MRI can be used in transverse, sagittal, coronal and arbitrary sections. 2. MRI can form various images by different scanning sequences, CT can only distinguish tissues with density difference, The resolution of soft tissue is not high, while that of MRI is good, So CT and MRI are very different examination methods. Although MRI has multi-directional imaging and no harm to human body, It has good resolution to soft tissue, However, in the tissue lacking or containing little hydrogen protons, such as dense bone, calcification, gas-containing lung, etc, No imaging. Because MRI takes a long time, Coma and restlessness patients can not get clear images, Patients with metal foreign bodies in their bodies cannot enter the magnetic field, This is contraindication. So MRI also has insurmountable shortcomings, It can't replace CT, Of course, CT can't replace MRI, The two should complement each other.