Tungsten heavy alloy collimator, an important part of detector of SPECT system, is a collimator made of high density tungsten-based alloy with composition of W-Ni-Fe, W-Ni-Cu or W-Ni-Cu-Fe. There are a certain number of holes arranged on the collimator. According to the form of the drilled hole, the tungsten heavy alloy collimator is divided into tungsten alloy parallel-hole collimator, tungsten alloy focusing collimator, tungsten alloy converging collimator, and tungsten alloy pinhole collimator.

Compared with lead, tungsten alloy has higher density and better radiation shielding performance, so it is often used as a radiation protective material in medical electron linear accelerator. In addition, taking the factors of environmental protection, tungsten alloy shields are more and more popular and are gradually replacing lead shields in the field of radiation shielding.

Lead shield is a thing of past. Tungsten alloy X-ray shield, a newly developed poison-free shielding partition, is the future in hospitals or dental clinics, which can fully protect the medical workers and patients from different radiation resources such as X-rays. It has been reported that tungsten alloy X-ray shield is safe as it is non-toxic, fire-resistant and anti-corrosion with premium stability. Also, it features excellent sound insulation properties. And it can create an excellent and robust surface.

It has been reported that the linear accelerator can emit high energy X-rays or electrons to conform to a tumor's shape and destroy cancer cells while sparing surrounding normal tissue. So, tungsten alloy, as a radiation shielding material, is often used to medical linear accelerators to shield the high-energy X-rays generated by the accelerator during clinical radiotherapy treatment.