Three elements of magnetic resonance imaging principle

The three elements of magnetic resonance imaging are proton density and proton relaxation time constants (T 1 and T2) in body tissues, especially the latter two play a leading role in imaging.

Magnetic * * vibration imaging is an imaging technology that uses the signal generated by the vibration of the nucleus in a strong magnetic field to reconstruct the image, which is a nuclear physical phenomenon.

It uses radio frequency pulses to excite non-zero spin nuclei placed in a magnetic field. After the RF pulse stops, the nucleus relaxes. During the relaxation process, the signal is collected by the induction coil, and the mathematical image is reconstructed according to a certain mathematical method.

Preparation before inspection:

Before the magnetic vibration inspection, remove the mobile phone, pager, magnetic card, watch, coin, key, lighter, metal belt, metal necklace, metal earrings, metal buttons and other metal ornaments or electronic items.

Otherwise, it may affect the uniformity of magnetic field, cause image interference and form artifacts, which is not conducive to the display of lesions; Moreover, due to the strong magnetic field, metal objects may be sucked into the nuclear magnetic vibration frame, thus causing damage to the very expensive magnetic vibration machine.

In addition, mobile phones, pagers, magnetic cards, watches and other items may also be damaged by strong magnetic fields, causing unnecessary personal property losses.