Both MRI and CT are cross-sectional imaging, but the two imaging principles are different: CT stands for X-ray computed tomography, which uses X-rays for imaging and has a certain amount of radiation; MRI is an MR examination, which is based on the amount of protons in the body, i.e., hydrogen atoms, and other properties, without X-ray radiation. Both are capable of examining various parts of the body, but CT and MRI have their own advantages and disadvantages. First of all, MRI shows the cranial brain and spinal cord, that is, the nervous system and ligaments and muscles, more clearly; MRI can directly perform multi-directional imaging, and the images in each direction are equal and of high quality; MR uses more parameters, which is better for determining the origin of the tissue of the lesion and is conducive to the determination of the nature of the lesion; the contrast agent used in MR is also relatively safe. The MR scan can be used instead of the CT scan if there are contraindications to the use of CT contrast. These are the advantages and disadvantages of MRI. Now let’s talk about CT. CT is better for bone cortical calcification and gas, but it is not as good for soft tissue differentiation as MR; CT examination time is shorter, generally 2-10 minutes, and it is more suitable for emergency medical treatment; radiation is the biggest disadvantage of CT examination, and it cannot be applied to pregnant women and newborns. The above are the advantages and disadvantages of CT.