Chapter 9: Basic Radiation Protection and Radiobiology

Question 1

Who discovered X-rays?

Answer 1

Wilhelm Rongten

Question 2

When were X-rays discovered?

Answer 2

November 8th, 1895

Question 3

What was the name of Rongten’s report?

Answer 3

On a New Kind of Rays

Question 4

Name the 3 common natural sources of ionizing radiation.

Answer 4

Radium, Uranium, and Cosmic Rays

Question 5

Name sources of man made ionizing radiation.

Answer 5

Nuclear, Radionuclides, and Diagnostic Xrays

Question 6

What does Roentgen measure?

Answer 6

exposure in the air, below 3MeV

Question 7

What does RAD stand for?

Answer 7

Radiation Absorbed Dose

Question 8

What do RAD’s measure?

Answer 8

amount of radiation a person/body part absorbs as xrays pass through body.

Question 9

What does REM stand for?

Answer 9

Radiation Equivalent Man (Gy is the SI unit) 1 Gy=100 rad

Question 10

What does REM measure?

Answer 10

The biological response. (Sv is the SI unit) 1 Sv= 100 rem

Question 11

Curie (Ci) measures what?

Answer 11

measures rate of radionuclide decay (Bq is the SI unit) 1 Ci= 3.7x10^10 Bq

Question 12

What is the speed Xrays travel?

Answer 12

They travel at the speed of light!

Question 13

A “bundle of energy,” or group of photons is called what?

Answer 13

Quantum

Question 14

What 3 things must be present to create xrays?

Answer 14

Cathode (containing a filament made of thoriated tungsten), A current to move electrions (mAs), and an Anode which stops them rapidly from positive charge.

Question 15

What is thermionic emission?

Answer 15

When the filament in the cathode heats up and emits electrons.

Question 16

When electrons strike anode, what is produced?

Answer 16

99% heat and 1% xrays.

Question 17

Name 3 types of scattering.

Answer 17

Classic Coherent, Photoelectric Effect, and Compton Scattering.

Question 18

Explain Classic Coherent.

Answer 18

An incoming xray photon strikes atom and is absorbed which excites atom, releasing another photon with SAME energy. No energy transfer to patient.

Question 19

Explain Photoelectric Effect.

Answer 19

Xray photon strikes INNER SHELL ELECTRON, creating ion pair. Energy is completely consumed causing greatest hazard to patient.

Question 20

Explain Compton scattering.

Answer 20

Incoming xray photon strikes OUTER SHELL ELECTRON, which deflects in another direction (scatter). Most occupational exposure happens here.

Question 21

CDRH stands for….

Answer 21

Center of Devices and Radiologic Health

Question 22

NCRP stands for…

Answer 22

National Council on Radiation Protection and Measurement.

Question 23

MPD stands for…

Answer 23

Max Permissible Dose, which no longer is in use.

Question 24

ADL stands for…

Answer 24

Affective Dose Limit, which is now in use because there is always a chance of biological effect.

Question 25

Dose Limits

Answer 25

Occupational worker: 50 mSv (5 rem) annually. Public: 1/10 of worker so 5 mSv (.5 rem) annually. To get Occ workers whole body dose: 10 mSv x age of worker.

Question 26

What is the difference between somatic cells and germ cells?

Answer 26

Somatic cells: (regular function 46 chromosomes divide through mitosis) Germ cells: reproductive cells 23 chromosomes reproduce through meiosis.

Question 27

Direct Hit Theory is when...

Answer 27

radiation hits DNA which can re-arrange genetic info.

Question 28

Indirect Hit Theory is when...

Answer 28

radiation hits cytoplasm, causing: ion pairs, excited state, chemical change. *This one is more likely to occur.

Question 29

Bergonie and Tribondeau (B&T) theory says what?

Answer 29

Cells are most sensitive to radiation during active division, therefore cells that undergo division often are more sensitive.

Question 30

What are the 4 examples of radiosensitive cells?

Answer 30

Ball cells, Crypt cells, Germ cells, and Blood cells.

Question 31

Which cells do not undergo repeated mitosis and are therefore resistant to radiation?

Answer 31

Never cells, Muscle cells, and Brain cells.

Question 32

3 acute radiation syndromes:

Answer 32

Bone marrow: occur at doses 2-10 Gy leading to infection, hemorrhage, and anemia. Gastrointestinal: doses 10-50 Gy leading to DNV CNS: doses above 50 Gy leading to convulsions, coma, and eventually death.

Question 33

3 stages of acute radiation syndrome:

Answer 33

Prodromal: NVD Latent: feeling of well-being. Manifest: feeling full effect of exposure.. either leads to curing, or death.

Question 34

Late Effects:

Answer 34

Somatic effect: cataracts, cancer | Genetic effect: future generations affected

Question 35

Dose limits for pregnant tech:

Answer 35

Per month: .05 rem (.5mSv) For entire pregnancy: .5 rem (5mSv) *wear fetal badge

Question 36

OSL badge stands for...

Answer 36

Optically Stimulated Luminescence Dosimeter (reads between 1 mRem to 1000 rem)

Question 37

Film badges detect doses below...

Answer 37

10 mRem

Question 38

TLD...

Answer 38

thermo-luminescent dosmiter

Question 39

Pocket Dosimeters

Answer 39

have a metal electrode that's positively charged, exposing it to radiation neutralizes electrode. Immediate reading is available.