Chapter 14
Doses and risks in diagnostic radiology, interventional radiology and cardiology and nuclear medicine



1. The dose rate from potassium-40 in the human body is:

a. 0.1 mSv/y.

b. 0.2 mSv/y.

c. 0.5 mSv/y.

d. 1 mSv/y.



2. The annual dose from radon gas is:

a. 2 mSv.

b. 10 mSv.

c. 15 mSv.

d. 20 mSv.



3. The average effective dose from medical radiation is about:

a. the same as the dose from natural background radiation.

b. the same as the dose from natural background radiation excluding radon.

c. half of the total effective dose.

d. one third of the total effective dose.



4. The annual effective dose from all sources (natural background and ordinary medical examinations) is:

a. 1 mSv.

b. 1.5 mSv.

c. 3.5 mSv.

d. 6 mSv.



5. The doses relevant to diagnostic radiology cannot induce deterministic effects (with the exception of the irradiation of the embryo or fetus) but they can induce stochastic effects (carcinogenesis and hereditary effects).

a. True.

b. False.



6. Effective dose is the whole-body dose of x-rays that would have to be delivered to produce the same stochastic risk as the partial-body dose that is actually delivered.

a. True.

b. False.



7. The collective effective dose is:

a. the total dose a patient receives in a series of examinations.

b. the absorbed dose a patient receives in a single examination multiplied by the appropriate tissue weighting factors.

c. the product of effective dose that an individual in a given population receives and the numbers of exposed individuals.



8. The effective dose for a multiple-slice chest CT-scan is:

a. 1 mSv.

b. 2 mSv.

c. 4 mSv.

d. 8 mSv.



9. The effective dose for a single chest radiograph is:

a. 0.02 mSv.

b. 0.5 mSv.

c. 1 mSv.

d. 1.5 mSv.



10. In order to estimate the harm to an exposed population in terms of radiation induced cancers and hereditary effects, we use:

a. the average absorbed dose per patient.

b. the average effective dose per patient.

c. the average equivalent dose per patient.

d. the collective effective dose to the patients and to the radiation workers.



11. The risks for cancer or hereditary diseases caused by ionizing radiation are:

a. 1% per Sv for fatal cancer induction and 0.2% per Sv for severe hereditary effects.

b. 1% per Sv for fatal cancer induction and 5% per Sv for severe hereditary effects.

c. 4% per Sv for fatal cancer induction and 0.6% per Sv for severe hereditary effects.

d. 0.1% per Sv for fatal cancer induction and 0.6% per Sv for severe hereditary effects.



12. In interventional radiology and cardiology, the doses are much higher than in general diagnostic radiology, which:

a. increases the risk for stochastic effects, while there is still no risk for deterministic effects.

b. increases the risk for stochastic effects and implies a risk for deterministic effects as well.



13. Depending on the type of the examination, the effective dose in an interventional procedure is in the interval:

a. 0.2-10 mSv.

b. 0.2-20 mSv.

c. 0.2-40 mSv.

d. 0.2-80 mSv.



14. The effective dose in a diagnostic nuclear medicine investigation is in the interval:

a. 0.1-10 mSv.

b. 0.5-2 mSv.

c. 0.5-25 mSv.

d. 10-60 mSv.



15. The dose to the patient from a PET scan is relatively small because:

a. a small activity of radionuclide is used.

b. the radionuclide decays slowly.

c. the radionuclide decays quickly.



16. The use of iodine-131 for the treatment of hyperthyroidism has been considered to induce:

a. thyroid cancer in adults.

b. thyroid cancer in children.



17. Children are most sensitive than adults to radiation induced cancer, especially:

a. lung cancer.

b. breast and thyroid cancer.

c. brain cancer.

d. ovarian cancer.