Chapter 9

Question 1

interact with the whole atom.

Answer 1

Low energy X-rays

Question 2

interact with electrons

Answer 2

Moderate energy X-rays

Question 3

interact with nuclei.

Answer 3

High energy X-rays

Question 4

the incident x-ray interacts with a target atom, causing it to become excited.

Answer 4

Coherent scattering

Question 5

Other name for coherent scattering

Answer 5

Classical Scattering or
Thompson Scattering.

Question 6

general graying of an image; reduces image contrast.

Answer 6

IMAGE NOISE

Question 7

• occurs between moderate-energy x-rays and outer-shell electrons.

• interaction with outer-shell electrons that not only scatters the x-ray but reduces its energy and ionizes the atom as well.

Answer 7

COMPTON SCATTERING

Question 8

the ejected electron from the atom.

Answer 8

COMPTON/SECONDARY ELECTRON

Question 9

X-ray scattered back in the direction of the incident x-ray beam.

Answer 9

BACKSCATTER RADIATION

Question 10

reduces image contrast.”

Answer 10

Compton scattering

Question 11

• x-rays undergo ionizing interactions with inner-shell electrons.

• result: the x-ray is not scattered, but it is totally absorbed

• characteristic radiation is produced.

Answer 11

Photo electric effect

Question 12

• the interaction between the x-ray and the
nuclear field (causes the x-ray to disappear)

• result: two electrons appear, with opposite charge (neutrons)

Answer 12

PAIR PRODUCTION

Question 13

• very important for positron emission tomography imaging in nuclear medicine.

Answer 13

PAIR PRODUCTION

Question 14

when a positron unites with a free electron, and the mass of both particles is converted to energy in a process.

Answer 14

ANNAHILATION RADIATION

Question 15

does not occur during x-ray imaging.”

Answer 15

Pair production

Question 16

• incident x-rays can escape interaction with electrons and the nuclear field and be absorbed directly by the nucleus.

• the nucleus is raised to an excited state and instantly emits a nucleon or other nuclear fragment.

Answer 16

PHOTO DISINTEGRATION and PAIR PRODUCTION

Question 17

an x-ray image results from the difference between those x-rays absorbed photoelectrically in the patient and those transmitted to the image receptor.

Answer 17

Differential absorption

Question 18

a generalized dulling of the image by x-rays not representing diagnostic information.

Answer 18

IMAGE NOISE

Question 19

• results from approximately 0.5% of the x-rays emitted by the x-ray tube.

Answer 19

RADIOGRAPHIC IMAGE

Question 20

compounds used as an aid for imaging internal organs with x-rays.

Answer 20

CONTRAST AGENT

Question 21

produces excellent, high-contrast radiographs of the organs of the gastrointestinal tract.

Answer 21

LOW-KVp TECHNIQUE

Question 22

examinations not only to outline the organ under investigation but also to penetrate the contrast medium so the lumen of the organ can be visualized more clearly.

Answer 22

HIGH-KVp TECHNIQUE

Question 23

uses air for contrast in some examinations of the colon along with barium.

Answer 23

DOUBLE CONTRAST EXAMINATION

Question 24

•an interaction wherein the x-ray disappears

Answer 24

ABSORPTION PROCESS

Question 25

• the removal of an x-ray from a beam through a photoelectric effect.

• all-or-none condition for x-ray interaction.

Answer 25

ABSORPTION

Question 26

• total reduction in the number of x-rays remaining in an x-ray beam after penetration through a given thickness of tissue.

Answer 26

ATTENUATION

Question 27

•when a broad beam of x-rays is incident on any tissue, some of the x-rays are absorbed, and some are scattered.
• result: reduced number of x-rays

Answer 27

X-RAY ATTENUATION