Exam 1 (Radiation & Laser)

Question 1

• What is mechanical radiation?

Answer 1

Only travels thru substances

Question 2

• What is nuclear radiation?

Answer 2

Unstable atom nuclei

Question 3

• What is cosmic radiation?

Answer 3

• Electrons only.
• Sun rays.
• Almost speed of light.

Question 4

• What is ionizing radiation?

Answer 4

Electrons knocked off atoms create ions

Question 5

• What is more harmful, non-ionizing or ionizing radiation?

Answer 5

Ionizing, d/t electrical charges causing chemical reactions

Question 6

• What are x-rays carried by?

Answer 6

By photons

Question 7

• A shorter wavelength means _____ energy?

Answer 7

Higher

Question 8

• What must happen for an electron to move back into its original orbit?

Answer 8

The orbit must release a photon

Question 9

• Which atom size is more likely to absorb photons?

Answer 9

Larger atoms (bones)

Question 10

• What is an example of small atoms & large atoms in the human body?

Answer 10

• Small= soft tissue.
• Large= bones

Question 11

• Explain the Anode in an x-ray machine?

Answer 11

• Positive charge.
• Made of tungsten
• Attaches electrons across the tube

Question 12

• Explain the Cathode in an x-ray machine?

Answer 12

• Filament in the center.
• Current heats filament.
• Heat causes electrons to fly off filament

Question 13

• What are the most common side effects of radiation therapy?

Answer 13

• N/V: (brain, pelvis, abdomen)
• Hair loss: (brain, breast, chest).
• Diarrhea: (pelvis, rectum, abdomen)

Question 14

• What are radiation doses measured in?

Answer 14

millirem (mrem) or rads

Question 15

• What are the annual allowable doses for radiation?

Answer 15

• Whole body: 5,000 mrem
• Extremities: 50,000 mrem
• Eye: 15,000 mrem
• Pregnancy: 500 mrem

Question 16

• An angioplasty exposes one to how many mrem?

Answer 16

5,700 mrem

Question 16

• A CXR exposes one to how many mrem?

Answer 16

5-10 mrem

Question 16

• An angiogram exposes one to how many mrem?

Answer 16

1,500 mrem

Question 17

• A CT exposes one to how many mrem?

Answer 17

5,000 mrem

Question 18

• A narrow collimation leads to _____ scatter?

Answer 18

Decreased

Question 19

• Moving from 2 feet to 4 ft from radiation source affects your exposure by what?

Answer 19

Only exposed to ¼ of mrem (20 mrem to 5 mrem)

Question 20

• MRI principles are based of?

Answer 20

• Static magnetic field &
• individual atom nuclei

Question 21

• What does an MRI use the magnetic field for?

Answer 21

To orient nuclei of Hydrogen molecules to north-south poles

Question 22

• How does fat & water appear using T1 MRI view/technique & what is a T1 used for?

Answer 22

• Fat= bright. Water= dark.
• T1 used for anatomy

Question 23

- What is a T2 MRI view used for?

Answer 23

- Pathology & - identifies edema easily

Question 24

- What is the MRI contrast material made of & what are the side effects?

Answer 24

- Gadolinium. - Side effects: itching, rash, abnormal skin sensation

Question 25

- How long does it take for Gadolinium to clear the system?

Answer 25

24hrs with normal GFR

Question 26

- Which vaporizer is MRI safe?

Answer 26

Sevoflurane

Question 27

- What body part is at risk for injury during MRI abdominal scans?

Answer 27

Brachial plexus d/t arms being over the head

Question 28

- How long does one have to wait to be MRI safe after endovascular or biliary stents, what about coronary stents?

Answer 28

- 8 weeks. - Coronary stents are safe immediately

Question 29

- What happens to the electrons when the laser is in use?

Answer 29

Electrons become excited & move to higher orbit

Question 30

- What are the properties of lasers?

Answer 30

- Monochromatic: same wavelength. - Coherence: photons travel synchronized in time & space. - Collimation: beam photons are nearly parallel

Question 31

What are the mediums used in lasers?

Answer 31

- Argon - CO2 - Nd YAG (neodymium-doped yttrium aluminum garnet)

Question 32

- What is the advantage of a CO2 laser & what locations are they great for?

Answer 32

- Minimal scatter. - Great for vocal cord, oropharynx

Question 33

- What is the advantage of an Argon laser & what is it used for?

Answer 33

- Modest tissue penetration. - Used in dermatology

Question 34

- What is a Nd YAG laser used for?

Answer 34

Tumor debulking (oncology)

Question 35

- What are the hazards of lasers?

Answer 35

- Atmospheric contamination - Perforation of vessel or structure - Embolism - Inappropriate energy transfer - Airway fire

Question 36

- Atmospheric contamination can lead to what & what are the S/S?

Answer 36

- Lead to interstitial PNE, bronchiolitis, emphysema, carciogenic. - S/S: HA, nausea after inhalation

Question 37

- What is needed for the fire triad?

Answer 37

- Ignition source - Fuel - Oxidizer

Question 38

- What are the two major sources for OR fires?

Answer 38

- ESU (Electrosurgical units) (Cautery, etc) - Laser

Question 39

- What are pledgets?

Answer 39

Soaked cotton like device placed around ETT

Question 40

- What should be avoided in laser procedures?

Answer 40

- Nitrous - Keep O2 < 30%