Midterm ch. 3

Question 1

Which of the following is not a type of interaction between x-radiation and biologic matter?

Answer 1

Bremsstrahlung

Question 2

The symbol Z indicates

Answer 2

atomic number of an atom.

Question 3

The probability of occurrence of photoelectric absorption _________ as the energy of the incident photon decreases and the atomic number of the irradiated atoms _________.

Answer 3

increases markedly; increases

Question 4

Which of the following is not another term for coherent scattering?

Answer 4

Characteristic

Question 5

If two anatomic structures have the same density and atomic number but one is twice as thick as the other, the thicker structure will absorb

Answer 5

twice as many x-ray photons.

Question 6

1. Exit, or image-formation, radiation is composed of which of the following?

A. Primary photons and wide-angle Compton scattered photons

B. Non-interacting and small-angle scattered photons

C. Very low energy photons

D. Auger electrons

Answer 6

B.

B. Non-interacting and small-angle scattered photons

Question 7

2. Which of the following contributes significantly to the exposure of the radiographer?

A. Positrons

B. Electrons

C. Compton scattered photons

D. Compton scattered electrons

Answer 7

C.

C. Compton scattered photons

Question 8

3. Which of the following defines attenuation?

A. Absorption and scatter

B. Absorption only

C. Scatter only

D. Weakened only

Answer 8

A.

A. Absorption and scatter

Question 9

4. In the radiographic kilovoltage range, which of the following structures undergoes the most photoelectric absorption?

A. Air cavities

B. Compact bone

C. Fat

D. Soft tissue

Answer 9

B. Compact bone

Question 10

5. In which of the following x-ray interactions with matter is the energy of the incident photon partially absorbed?

A. Compton

B. Photoelectric

C. Coherent

D. Pair production

Answer 10

A. Compton

Question 11

6. When a high atomic number solution is either swallowed or injected into human tissue or a structure to visualize it during an imaging procedure, which of the following occurs?

Answer 11

B. Photoelectric interaction becomes significantly enhanced, leading to an increase in the absorbed dose in the body tissues or structures that contain the contrast medium.

Question 12

7. Which of the following characteristics primarily differentiates the probability of occurrence of the various interactions of x-radiation with human tissue?

Answer 12

A. Energy of the incoming photon

Question 13

8. Which of the following influences attenuation?
9. Effective atomic number of the absorber
10. Mass density
11. Thickness of the absorber

Answer 13

D. 1, 2, and 3

Question 14

9. A decrease in contrast of the image by adding an unwanted additional exposure (radiographic fog) results from which of the following interactions between x-radiation and matter?

Answer 14

1. Compton scattering

Question 15

10. The interactions of x-ray photons with any atoms of biologic matter are:

Answer 15

C. Random, so the effects of such interactions cannot be predicted with certainty