How are radioactive isotopes used in medical imaging?

Radioactive isotopes are used in medical imaging to detect and diagnose diseases within the body.

Radioactive isotopes, also known as radioisotopes, play a crucial role in medical imaging. They are used in a variety of diagnostic techniques, including X-rays, computed tomography (CT) scans, and positron emission tomography (PET) scans. These isotopes emit radiation that can be detected by special cameras or scanners, creating images of the inside of the body.

The process typically involves introducing a small amount of a radioactive isotope into the body, often by injection. This isotope, or 'tracer', then travels through the body and accumulates in specific organs or tissues. As the tracer decays, it emits radiation. This radiation can be detected and measured, providing a detailed picture of the organ or tissue in question.

Different isotopes are used for different purposes, depending on the type of radiation they emit and how long they take to decay. For example, Technetium-99m is commonly used in nuclear medicine because it emits gamma radiation, which can be easily detected by medical equipment. It also has a short half-life, meaning it decays quickly and leaves the body rapidly, reducing the patient's exposure to radiation.

The images produced by these techniques can reveal a wealth of information about the body's internal workings. They can show how blood is flowing through the heart, how the kidneys are functioning, or whether a tumour is present. This makes radioactive isotopes an invaluable tool in the diagnosis and treatment of a wide range of diseases.

However, it's important to note that while these techniques are incredibly useful, they do involve exposure to radiation. Therefore, their use must be carefully controlled to ensure patient safety. The benefits of the diagnostic information gained must always be weighed against the potential risks of radiation exposure.