7 Applications of radioactivity Flashcards
How are radioactive isotopes used?
As tracers to help doctors identify diseased organs.
Which organs are we referring to?
Kidneys or the liver.
What is a radioactive tracer?
It is a chemical compound that emits gamma radiation.
How is the tracer taken?
The tracer is taken orally by the patient or injected.
How can you tell that the tracer is working?
The tracer’s journey around the body can be traced using a gamma ray camera.
How are compounds chosen for diagnostic tasks?
Different compounds are chosen for different diagnostic tests.
What is an example of how different compounds are chosen for the thyroid gland?
The isotope iodine-123 is absorbed by the thyroid gland in the same way as the stable form of iodine.
How does this isotope work in the thyroid?
The isotope decays and emits gamma radiation.
How can we then actually look at the thyroid gland?
A gamma ray camera can then be used to form a clear image of the thyroid gland.
What is the half life of iodine-123?
It is about 13 hours.
Why is the fact that its half-life is so short?
A short half-life is important as this means that the activity of the tracer decreases to a very low level in a few days.
What are the other isotopes that are used to image specific parts of the body?
Technetium-99 is the most widely used isotope in medical imaging.
What exactly does technetium do?
It is the most widely used isotope in medical imaging. It is used to help identify medical problems that affect many parts of the body.
Why are imaging techniques useful?
They enable doctors to produce three-dimensional computer images of a patient’s body.
What is said about radiation from isotopes and its effects on our bodies?
Radiation from isotopes can have various effects on the cells that make up our bodies.
What effect does a low dose of radiation have on us?
Low doses of radiation may have no lasting effects.
What effect does a high dose of radiation have on us?
May cause the cells to stop working properly as the radiation damages the DNA in these cells.
What can these high doses of radiation lead to?
Abnormal growths and cancer.
What effect do very high doses of radiation have on us?
They will kill living cells,
How can cancer be treated?
By surgery that involves cutting out cancerous cells.
What is another way of treating cancer?
Another way of treating cancer is to kill the cancer cells inside the body.
How is the treatment of cancer by killing the cells inside the body done?
This can be done with chemicals containing radioactive isotopes.
What is a disadvantage of using chemicals containing radioactive isotopes for cancer treatment?
The radiation kills healthy cells as well as diseased ones.
How can this disadvantage be limited?
To reduce the damage to healthy tissue, chemicals are used to target the location of the cancer in the body.