The overall service life of a plastic is dependent on the total amount of radiation absorbed. Materials like PEEK and polyimide show good resistance against gamma radiation and X-rays. By contrast, PTFE and POM are very sensitive and are therefore less suitable for applications that involve exposure to radiation.

A thin piece of paper, or even the dead cells in the outer layer of human skin, provides adequate shielding because alpha particles can’t penetrate it. Thick, dense shielding is necessary to protect against gamma rays. The higher the energy of the gamma ray, the thicker the shield must be.

In general, beta particles are lighter than alpha particles, and they generally have a greater ability to penetrate other materials. As a result, these particles can travel a few feet in the air, and can penetrate skin. Nonetheless, a thin sheet of metal or plastic or a block of wood can stop beta particles.

Gamma rays are a radiation hazard for the entire body. They can easily penetrate barriers that can stop alpha and beta particles, such as skin and clothing. Gamma rays have so much penetrating power that several inches of a dense material like lead, or even a few feet of concrete may be required to stop them.

beta particles

Gamma rays can be emitted from the nucleus of an atom during radioactive decay. They are able to travel tens of yards or more in air and can easily penetrate the human body. Shielding this very penetrating type of ionizing radiation requires thick, dense material such as several inches of lead or concrete.

Materials that are strongest at attenuation gamma radiation are tungsten and lead, while high density concrete and borated polyethylene are better materials for stopping neutrons.

As mentioned, x-rays expose you to ionizing radiation. MRI machines don’t emit this radiation. x-rays take mere minutes while MRIs can take 30 minutes or longer — up to a couple of hours — depending on what the doctor is looking for. x-rays are limited to scanning for only a few body ailments.

MRI is used to diagnose stroke, traumatic brain injury, brain and spinal cord tumors, inflammation, infection, vascular irregularities, brain damage associated with epilepsy, abnormally developed brain regions, and some neurodegenerative disorders.

The magnetic fields that change with time create loud knocking noises which may harm hearing if adequate ear protection is not used. They may also cause peripheral muscle or nerve stimulation that may feel like a twitching sensation. The radiofrequency energy used during the MRI scan could lead to heating of the body.

MRI might show brain atrophy long after the injury, which results when injured or dead brain tissue is reabsorbed after TBI. Since injured brain tissue might not fully recover after TBI, doctors might detect TBI-related changes many years following an injury.