What Medical Imaging Techniques Use Ionizing Radiation?

1. Radiography: They use X-rays to capture a single image of the body tissues for the diagnosis of health conditions. Mammography is a special type of radiography performed on the breasts. It is used to screen for breast cancer.
2. Computed tomography scan (CT scan): A CT scan uses a higher radiation dosage than conventional radiography. It creates several images taken from various angles and tissue depths of the target site. The resultant images are of higher resolution and provide more detailed information than radiography.
3. Angiography: It involves the examination of the blood vessels. In this technique, contrast is injected into a blood vessel and X-rays are used to ascertain the health of the blood vessels, such as an abnormal narrowing, blockage, or thickening of the blood vessels.
4. Fluoroscopy: This procedure makes a real-time video of the movements inside a part of the body (such as the heart or gut) by passing X-rays through the body over a period. It can be used to diagnose diseases and guide during certain procedures (such as an implant or stent placement or injections into the joints or spine).
5. PET-CT: This test combines a positron emission tomography (PET) scan and a CT scan. A PET scan uses a radioactive substance called a tracer to detect the metabolic or biochemical functioning of tissues or organs. It is a highly sensitive test and helps detect several health conditions (such as cancer and brain and heart conditions) quite earlier than a conventional CT scan.

The radiation exposure varies according to the type of imaging technique. The exposure may differ from one lab to another depending on the type of equipment used and the modifications or settings are done (for example, many labs adjust the radiation dose at a lower level for children than adults).

To comprehend the amount of radiation exposure better, one must note that an average American is exposed to about 3 mSv of radiation from natural sources annually.

Ionizing radiations carry high energy and can damage the cells and tissues, leading to various health conditions. They are highly penetrating in the body and can damage the genetic material (DNA) of the cells besides causing other chemical changes in the cell.

The exposure can occur through natural (such as radon or cosmic rays in the environment) and manmade sources (such as during medical imaging or radiation therapy).

Exposure to ionizing radiation can result in various conditions, such as:

• Skin rashes or redness (erythema)
• Cancer (such as leukemia, lung cancer, breast cancer, liver cancer, multiple myeloma, ovarian cancer, and stomach cancer)
• Cataract (opacification of the eye lens)
• Infertility (temporary or permanent)
• Harm the unborn baby in case the woman is pregnant and undergoes radiographic imaging
• Genetic changes that may be passed on to future generations

Some imaging tests involve consuming a contrast or dye orally or administered through an intravenous line. Some people may develop an allergic reaction to the dye. Always inform your doctor if you have any known allergies before going for the test.

Radiation exposure during medical imaging is generally kept at the lowest possible dose. The doctor ensures that the benefit of using the imaging test far outweighs the possible risk of radiation exposure.

Accidental exposure to a huge quantity of radiation can occur during situations, such as nuclear power plant accidents or the use of atomic weapons. Such heave and sudden exposure results in severe damage that may lead to serious skin and other tissue damage, acute radiation syndrome, and even death.

Acute radiation syndrome, also called radiation toxicity or acute radiation sickness, can damage various tissues, such as the bone marrow, gut, brain, and heart of the affected person. In severe cases, it can even cause the death of the person.