Question

One of the methods used to limit radiation dose to the patient in medical imaging is to employ isotopes with short half-lives. How would this limit the dose?

a) Short half-lives reduce the amount of radiation emitted.

b) Short half-lives result in longer exposure times.

c) Short half-lives increase the radiation dose.

d) Short half-lives have no effect on radiation dose.

Answer 1

Isotopes with short half-lives decay quickly and emit radiation for a shorter period, reducing the cumulative radiation dose to the patient. Short half-lives lead to a reduction in the amount of radiation emitted, which limits the patient's radiation exposure.

Step-by-step explanation:

Employing isotopes with short half-lives in medical imaging limits the radiation dose to the patient because isotopes with shorter half-lives decay more quickly. This means they emit radiation for a shorter period of time. In contrast, isotopes with longer half-lives emit radiation over a more extended period, resulting in a higher cumulative radiation dose. Short half-lives ensure that the radioactive material does not remain active in the patient's body for long, hence reducing the total radiation exposure.

The correct answer to the question is: a) Short half-lives reduce the amount of radiation emitted. This is because the rate of decay is more rapid, which leads to a reduction in the overall time radiation is being emitted from the isotope. Rapid decay ensures that the radioactive substance becomes non-radioactive more quickly, minimizing the duration of the patient's exposure to radiation.