Multi-leaf grating system consists of 120 tungsten alloy grating blades, in which the blades are made of tungsten alloy, which is much less harmful than the lead blade.

Multi-leaf grating system is mainly used to control the direction and scope of X ray of medical radiation, which replaces the irregular handmade lead block. During the treatment, the multi-leaf blade grating movements are controlled by computer to form irregular shape that required for clinical field irradiation.

 

Multi-leaf grating system is widely used in radiation therapy, which mainly based on tungsten alloy shielding effects on radioactive materials. Tungsten alloy is a kind of high density metal. The research shows that the high-density metal can shield the radioactive substance. Because metal tungsten has strong radiation shielding effects, the material of multi-leaf grating blade mostly is made of tungsten.

 

 

A whole multi-leaf grating includes two sets of blades, which are oppositely arranged on the bracket. The blade can move on the bracket and the direction of movement is perpendicular to the axis of the beam. Each blade is independently driven by a stepper motor. In order to reduce the mutual friction, there’s appropriate gap between two leaves. A movable baffle is mounted below each of the two sets of blades to reduce leakage of the radiation through the gap. 

 

As tungsten alloy material has the advantages of excellent X-ray shielding performance, it is very suitable for occasions that requires high spatial resolution like multi-leaf grating system. Besides, the size of the ray shield is reduced for tungsten alloy has high density. And tungsten alloy is environmental friendly, so it has been widely used in medical radiation technology.