Radiology

Question 1

X-Rays

Answer 1

A form of electromagnetic radiation

Question 2

Highest to lowest attenuation

Answer 2

Metal, bone, soft tissue, fat, air

Question 3

Ionizing energy

Answer 3

Energy high enough to completely knock electrons out of orbit

Question 4

The main target of ionizing radiation is

Answer 4

DNA

Question 5

DNA damage may be repaired or may produce cellular __________ and _________

Answer 5

Mutation, death

Question 6

Direct effect of radiation

Answer 6

Cleaved DNA or altered base pairs

Question 7

Indirect effect of radiation

Answer 7

Production of free radicals that can diffuse far enough to reach and damage critical target

Question 8

Radio sensitivity

Answer 8

relative susceptibility of cells, tissues, organs, or organisms to the harmful effect of ionizing radiation

Question 9

Most radio sensitive cells

Answer 9

Stem cells

Question 10

Most radio sensitive tissues

Answer 10

Young tissue, tissue with high metabolic activity

Question 11

ALARA

Answer 11

As Low As Reasonably Possible

Question 12

Three basic principles of ALARA

Answer 12

Distance, time, shielding

Question 13

Inverse square law

Answer 13

Doubling distance reduces exposure by 1/4

Question 14

Personnel protection only protects you from ______________ radiation

Answer 14

Scatter

Question 15

MPD

Answer 15

Maximum Permissible Dose

Question 16

For general public, MPD is ____ of the occupational level

Answer 16

2%

Question 17

Occupational worker minimum age

Answer 17

18

Question 18

MAD

Answer 18

lifetime maximum accumulative dose= age in yrs x 1 rem

Question 19

Whole body occupational dose limit

Answer 19

5,000 mrem/yr

Question 20

mA selector

Answer 20

Number of X-rays in beam (quantity)

Question 21

Focal spot selector

Answer 21

Trade off between resolution and quantity of radiation

Question 22

mAs selector

Answer 22

mA x time (msec)

Question 23

kVp Selector

Answer 23

Energy of beam (quality)

Number of x-rays (quantity)

Question 24

Prep phase

Answer 24

Electrons are generated by electrical current through the filament in the cathode

Question 25

Expose phase

Answer 25

X-rays produced when electrons interact with metal in the anode

Question 26

Metal in anode

Answer 26

Tungsten

Question 27

mA selector controls the _______ to the filament

Answer 27

Current, therefore X-ray quantity

Question 28

Small filament in focal spot selector

Answer 28

Used for low output exposures when high detail is needed

Question 29

Large filament in focal spot selector

Answer 29

Used for high output exposures

Question 30

kVp selector determines _______ of an image

Answer 30

Contrast

Question 31

kVp selector controls

Answer 31

Voltage across X-ray tube, therefore penetrating power of the generated X-ray, therefore X-ray quality and quantity

Question 32

Factors that increase scatter

Answer 32

Greater body area exposed to radiation

Question 33

Collimated beam

Answer 33

Limits beam to just area of interest to decrease amount of scatter

Question 34

Collimates are located

Answer 34

Outside tube housing

Question 35

Scatter radiation decreases film quality by reducing image __________

Answer 35

Contrast

Question 36

Grids

Answer 36

Used to prevent scatter radiation from reaching the film, composed of hundreds of alternating lead strips

Question 37

LUT

Answer 37

Look up table

Question 38

Radio graphic opacities are ________

Answer 38

Relative

Question 39

Summation effect

Answer 39

When two objects are superimposed over each other the overlapping portions of the object will appear more opaque

Question 40

Silhouetting effects

Answer 40

When two objects of the same density are in contact,they will appear to blend together radiographically (border effacement)

Question 41

Magnification

Answer 41

Enlargement of the image relative to the actual size of the object being imaged

Question 42

Distortion

Answer 42

Unequal magnification if the object is not in the center of the beam

Question 43

Orientation of radiographs

Answer 43

Head to left, tail to right

Question 44

Orientation of VD/DV radiographs

Answer 44

Patients right on your left and vice versa

Question 45

Radiograph labeling

Answer 45

Client name, patient name/number, name of clinic/location, date of exam, limb examined