Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Principles > Lasers and radiation > Flashcards

Lasers and radiation Flashcards

1
Q

Who discovered X ray

A
  1. Wilhelm Roentgen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Radiation From motion of atoms; combine electricity and magnetism

A
  1. Electromagnetic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Radiation that Only travels through substances

A

Mechanical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Radiation that is Unstable atom nuclei

A

Nuclear (neutron)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Radiation that is electrons only such as sun rays that travels almost the speed of light

A

Cosmic (beta)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Non ionizing radition

A

Can’t knock electrons off atoms but is stable.
Doesn’t break molecular bonds
Harmful only due to heat energy (radio wave or microwaves)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

ionizing radiation

A

When electrons are knocked off atoms they create ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does Ion electrical charges cause what intracellular chemical reactions

A

Break DNA chains…cell apoptosis
Mutate DNA chains…cancer
Mutated sperm or egg cell… birth defects

can be additive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the similarity between x rays and light rays (2)

A

Both are electromagnetic energy
Carried by particles called photons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Term fo difference in energy level

A

wavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Radio wave length compared to visible light

A

longer wavelength/lower energyradio waves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

X ray wave length compared to visible light

A

shorter wavelength/higher energy X-ray waves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How light is emitted

A

Caused by the movement of electrons in atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How are small atoms affected by radiation

A

Electron orbitals are separated by low jumps in energy because their orbits aren’t as far apart and don’t need as much energy to jump from orbit to the next. As they go back to the OG orbit = putting out less energy.
Less likely to absorb xray photons
ie. Soft tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How to large atoms affect radiation

A

Greater energy differences between orbitals because their orbits are further apart = require more energy to jump to a new orbit and fall back releasing more energy/ photons = brighter light
More likely to absorb photons
ie. Bones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does that cathode on an xray machine work?

A

Is a Filament in center of machine that heats.
Current heats filament (like a fluorescent lamp)
Heat causes electrons to fly off of filament and go onto another orbital level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does the anode of a x ray machine work?

A

Positively charged and attracts the electrons. After the electrons fly off with the cathode the anode attracts the electron to move down the tube and release the photons
Made of tungsten
Attracts electrons across the tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Terms for electrode pairs in the x ray machine

A

A cathode and an anode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How do the photons reach the machine?

A

Thick shield surrounds entire machine

Window in shield allows a narrow beam of photons to escape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does the camera on the x ray machine do?

A

Camera on opposite side records the pattern of x-ray photons

Chemical reaction on film

Ambient light can darken or lighten

Intensity changes to beam (over/under exposure) alter appearance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Radiation dose times a weighting factor

A

Rem

Measured as millirem (mrem) or 1/1000 of a Rem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Annual allowable radiation doses/ year

A

5,000 mrem whole body
50,000 mrem extremities
15,000 mrem lens of eye
500 mrem for pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

When are we okay with pregnancy radiation exposure

A

in the 2nd and 3rd trimester after oganogenosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Direct sources of radiation from cxray, coronary angiogram, angioplasty, and CT

A

CXR: 5-10 mrem
Coronary angiogram: 1,500 mrem
Angioplasty: 5,700 mrem
CT: 5,000 mrem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Indirect sources of radiation

A

Scattered radiation
Reflected off tables, patients, other surfaces

25
Q

Kinds of ways that affect scatter and how much you get

A

Collimation, object thickness, air gap

26
Q

affects of body habitus with scatter

A

Skinny ppl will have less scatter, and heavier ppl will have more scatter because the broader habitus would allow the photons to shoot off at greater angles.

27
Q

Fetal dose of radiation and age of the effects

A

Fetal doses < 10,000 mrem unlikely to cause effects
After 20 weeks

28
Q

Transient erythema was seen at what dose of radiation?

A

200,000 mrem

29
Q

ALARA stands for

A

Radiation protection

As Low As Reasonably Achievable

30
Q

ALARA factors to consider

A

Time
Distance

31
Q

Distance from beam related to radiation exposure

A

if you double the distance from the beam, you ¼ the exposure rate

moving from 2 ft to 4 ft might change exposure from 20mrem/min to 5 mrem/min

32
Q

Distance to be from patient undergoing radiation

A

attempt to be > 6ft from patient

33
Q

dosimeters

A

1- outside the apron on the collar
2- inside the apron on the waist

34
Q

MRI is based on the interactions between______

A

Static magnetic field in the machine and the Individual atom nuclei

35
Q

How does MRI affect the cells

A

The Magnetic field in the machine is used to orient nuclei of hydrogen molecules in each at and causes them to north-south pole orient
Radio waves of the MRI pulses change orientation from North south of specific atoms which radiates energy. As the enrgy radiates off then we create image of white gray or black.
Creates image

36
Q

MRI contrast between tissues is generated by _____

A

Contrast is generated by the energy that’s occurring and the time till tissue relaxation when Radio Frequency waves being turned off and on

Different tissues have different energies/ different hydrogens in their nuclei and they have different chemical and physical properties, and when those waves are turned on and turned off then we see a picture/ brightness/ darkness differentieated in our pictures.

37
Q

T1 view of MRI

A

Magnetic vector relaxes

Fat appears bright; water dark….provides good grey-white matter contrast…anatomy

38
Q

T2 MRI view

A

Axial spin relaxes
Fat is darker than water…identifies tissue edema easily…pathology

39
Q

Most common contrast material

A

Gadolinium

40
Q

How does Gadolinium work?

A

Alters the magnetic properties of nearby water molecules which enhances the quality of MR images.

41
Q

Side effects of Gadolinium

A

Mild side effects: itching, rash, abnormal skin sensation
Rare severe reactions
Clears with normal GFR in 24 hours

42
Q

What kinds of objects are attracted to the magnetic field?

A

Ferro (iron) magnetic objects experience
Attractive force…pulled towards center of magnet
Torque…an attempt to line up with the field

43
Q

Risks in MRI (4)

A

Projectile risk
Radiofrequency energy cause tissue/device heating
Electromagnetic interference causes artifacts… interpretation of ECG
Acoustic noise ? 125 dB (as loud as a chainsaw)…. Hearing protectors for CRNA and patient

44
Q

What does Laser stand for

A

Light Amplification by Stimulated Emission of Radiation

45
Q

Characteristics of Laser (3)

A

A specific wavelength
Focused narrow beam
High-intensity

46
Q

How do we produce the radiation from lasters

A

If the electrons get energy/ excited/ heated then them move to the next higher orbit and then get rid of the energy/ heat dissipates and the go back to the orbit and then photons are produced

47
Q

Monochromatic

A

All the photons in the laser beam are the same wavelength

48
Q

Coherence

A

Travel of photons is synchronized in time and space
Don’t move randomly

49
Q

Collimation

A

The laser beam photons are nearly parallel
Allows beam to be focused on small area

50
Q

Argon Laser

A

Modest tissue penetration (0.05-2mm)
Used in derm

51
Q

Carbon dioxide laser

A

Scatter is minimal
Surrounding tissue damage is negligible…absorbed by water/disperses little heat
Great for vocal cords, oropharynx

52
Q

Nd:YAG Laser

A

Most Powerful
Deeper tissue penetration (2-6mm)
Used for tumor debulking

53
Q

Hazards of Laser (5)

A
  1. Atmospheric contamination
  2. Perforation of a vessel or structure
  3. Embolism
  4. Inappropriate energy transfer
  5. Airway fire
54
Q

Laser Plume and side effects

A

Fine particulates produced d/t vaporization of tissue

HA, nausea after inhalation
Could cause interstitial pneumonia, bronchiolitis, emphysema
Could be carcinogenic

55
Q

Fire triad

A

Ignition source
Fuel
Oxidizer

56
Q

Generic laser safety

A

Laser glasses for provider

Laser glasses for patient with eyes taped

Windows covered

Laser plume masks for vaporized viruses

Appropriate suction

Water/saline irrigation on back table

Don’t tent drapes/have pockets of oxygen

57
Q

Two major sources of OR fires

A

ESU
Laser

58
Q

Preoperative evaluation of airway with laser

A

Stridor,
flow volume loops,
CT,
fiberoptic eval/ brochoscopy

consider how narrow their airway is

Mutual planning with surgeon
Intermittent apneic oxygenation, jet ventilation

59
Q

Oxygen level and med to avoid for laser in the airway

A

O2 < 30%, avoid nitrous

Principles (34 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions