X-Ray Production

Question 1

describe the relationship between wavelength and frequency.

Answer 1

shorter the wavelength, the higher the frequency = higher energy

Question 2

describe the properties of X-rays.

Answer 2

1. they travel in straight lines until they interact with matter
2. X-rays pass thru space at speed of light
3. X-rays are capable of exposing photographic film

Question 3

describe how x-ray is produced. what is how the source of electrons?

Answer 3

1. source of electrons- heated tungsten filament
2. source of high voltage- imparts high energy to electrons
3. target for the electrons to strike

Question 4

what is the anode? cathode?

Answer 4

anode- tungsten metal target

cathode- filament that heats up and imparts energy to electrons

Question 5

describe the production and targeting of electrons.

Answer 5

electrons are produced at the filament (cathode) by miliamps and fired at the metal targe (anode).

Question 6

how can you increase the # of electrons produced?

Answer 6

increase the milliamps

Question 7

how can you increase the speed of electrons?

Answer 7

increase the voltage

Question 8

high speed electrons means what for wavelength?

Answer 8

shorter wavelength x-rays

Question 9

why does bone appear white?

Answer 9

because bone absorbs a lot of x-ray, so no x-ray actually got to the film to expose it –> so it appears white

Question 10

what color does underexposure/overexposure appear?

Answer 10

underexposure- white/ very light

overexposure- black/ very dark

Question 11

what color does soft tissue appear on x-ray?

Answer 11

grayish/black

Question 12

What is a Rad?

Answer 12

(radiation absorbed dose)

-ionization absorbed by patient

Question 13

What is Rem?

Answer 13

(occupational radiation exposure )

-radiation dose absorbed by worker

Question 14

what is the average # of millirads exposed per year?

Answer 14

for a terrestrial- 96 mrads/yr

for medical- 93 mrads/yr

Question 15

what is LD 50/30? what is it for humans?

Answer 15

dose of radiation to the whole body that will result in death within 30 days to 50% of subjects
*for humans, it is 300 rads (or 300,000 millirads)

Question 16

what is the term for the portion that is closest to the film cassette?

Answer 16

view

Question 17

what is the term for the portion which the X-ray beam enters?

Answer 17

projection

Question 18

What is the “Lisfrancs joint”?

Answer 18

joint btwn tarsal bones and 5 metatarsals

Question 19

what are the 3 standard images of the foot?

Answer 19

1. AP projection
2. lateral projection
3. medial oblique view

Question 20

what are the 3 standard images of the ankle?

Answer 20

1. ankle mortis
2. lateral projection of ankle
3. AP projection of ankle

Question 21

what x-ray position should you use to decrease overlap of the hallux with the other digits?

Answer 21

raised lateral hallux

Question 22

what x-ray position can decrease overlap between tibia and fibula?

Answer 22

ankle mortise (vs. AP projection which is poor visual)

Question 23

what are the Ottawa rules?

Answer 23

(designed to minimize the use of ankle radiographs)
only needed if: patient has inability to walk 4 steps; pain in posterior edge or tip of malleoli; pain at navicular or base of 5th met

Question 24

what is the measurement of radiation in the air?

Answer 24

roentgen