Tungsten needle is an elongated tungsten product made of pure tungsten or tungsten alloy, having the advantages of high temperature resistance, high hardness, and good conductivity. Tungsten needle can be used as an electrode material for argon arc welding (the fastest growing and most widely used welding technology at home and abroad), as a probe needle for detecting instrument, or as a dissection needle for various minimally invasive surgery.

Tungsten alloy is a safe and reliable radiation shielding material that can replace the traditional radiation shielding material lead for parallel-hole collimator - the most commonly used collimator for stationary SPECT imaging in hospitals. As a new type of radiation shielding material, tungsten alloy has many advantages such as high strength, good processability, no secondary bremsstrahlung radiation, and environmental protection for applications of parallel-hole collimator. Also, the thickness of tungsten alloy is only 2/3 of lead to obtain the same shielding effect. Wherein, SPECT is the short for single photon emission computed tomography.

Tungsten heavy alloy is also called tungsten alloy. The main component of tungsten alloy can be W-Ni-Fe, W-Ni-Cu or W-Ni-Cu-Fe, among which other metals such as cobalt, molybdenum, and chromium can also be added. The density of tungsten heavy alloy is twice that of steel, and 1.5 times of lead (conventional radiation shielding material). Moreover, tungsten alloy is an environmentally friendly material, which is non-toxic and pollution-free, so it is more suitable for collimator applications as a radiation protection material than heavy metal lead.

Tungsten alloy collimator is also known as tungsten heavy alloy collimator or high-density tungsten alloy collimator. Collimator is a key component of gamma camera - the most basic imaging equipment in nuclear medicine, and affects the imaging quality. So, it is very important to choose the raw material of collimator. Tungsten alloy has good absorption and shielding performance to 60Co, 137Cs and other strong gamma ray sources, and therefore, it is regarded as the best shielding material for collimators. And tungsten alloy collimator can prevent γ-ray omission from causing permanent harm to medical workers, patients and their family members.