Brainscape's Knowledge GenomeTM

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


See full index

Oral Radiology > Exam 1 > Flashcards

Exam 1 Flashcards

1
Q

Who discovered the X-ray? What year did this take place?

A

Wilhelm Conrad Von Roentgen in 1895

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

Who was Otta Walkoff?

A

Dentist that produced first dental radiographs 2 weeks after discovery (25 min exposure time)

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

Who was Dr. Edmund Kells?

A

Invented surgical aspirator, and one of the first to hire a female dental assistant. First to expose a dental radiograph in the United States.
(Radiation burns on hands)

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

Who was William Coolidge?

A

Designed prototype for the enclosed X-ray tube

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

How many neutrons are in Tungsten if its atomic mass (A) is 184 and the atomic number (Z) is 74? Electrons?

A

110 neutrons. 74 if it is a neutral atom

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

Binding Energy vs. Ionization?

A

BE: Minimum amount of energy to remove an electron from its shell (eV)

Ionization: Forming ions from removing an electron through inputting enough energy to overcome the binding energy(positive ion is neutral atom losing electron, negative ion is the free electron

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

What is radiation?

A

Transmission of energy through SPACE (vacuum) and MATTER…
Sound waves cannot travel through a vacuum

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

Wave Theory vs Quantum Theory

A

Wave: Explains the propagation of radiation.
- NO MASS
-Electromagnetic fields control movement through space

Quantum: Explains the interaction of radiation (photons) with matter.
-MASS and travels in straight lines

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

Non-ionizing vs ionizing EM radiations…

A

Non-ionizing: Cannot eject electrons from the shells
Radio, microwave, infrared, visible light 3/4 UV

Ionizing: Can eject electrons from the shell
1/4 UV, X-rays, gamma rays

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

Energy is directly proportional to what? Inversely proportional?

A

Proportional to frequency - high frequency = high energy
Inversely proportional to wavelength - high frequency = short wavelength = high energy

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

What determines LET? What is meant by HIGH LET?

A

Velocity, size, charge
High LET = less penetration due to lower velocity, greater size and higher charge (alpha particles, used in radiation therapy)

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

What are the 7 properties of x-rays?

A
  1. Invisible, weightless***, no charge
  2. Straight lines (diverging)
  3. Travels at peed of light
  4. Highly penetrating (short wavelengths, high frequency)
  5. Differentially absorbed by matter
  6. Can ionize matter
  7. Causes biological changes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What two things make up the the x-ray machine? What makes up those parts? What make up those parts?

A
  1. CONTROL PANEL
  2. TUBE HEAD
    a) X-ray Tube
    i) Cathode (-)
    - Filament (tungsten)
    - Focusing cup (molybdenum)
    ii) Anode (+)
    - Tungsten Target
    - Copper Stem
    b) Power supply
    i) Step-Up Transformer
    ii) Step-Down Transformer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why is Tungsten a good target material?

A
  1. High Atomic number
  2. High Melting Point
  3. High thermal conductivity (dissipate heat)
  4. Low vapor pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Step-down vs Step-Up

A

Step-down
- Highly coiled to less coiled
- mA (number of electrons)

Step-up
- less coiled to highly coiled
-kV (energy of electrons traveling from cathode to anode)

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

What does kVp describe? keV?

A

kVp = energy of electrons
keV = energy of x-rays

17
Q

What is voltage? What is Current? What do they correlate to?

A

Voltage is the difference in electrical charge between two points in an electric circuit (kV)

Current is the amount of electrons traveling through a conductor per second (mA)

18
Q

What is self-rectification? Benefits?

A

Alternating current to direct current

Benefits of direct current are:
- Shorter exposure times
- More consistent beam intensity
- Higher mean energy of beam
- Decreased radiation dose

19
Q

Bremsstrahlung radiation vs Characteristic radiation

A

Bremsstrahlung: e- to nucleus interaction (70% of the time)
- More deviated the electron is high, the higher energy x-ray produced –> heterogenous beams

Characteristic Radiation: e- to e- interaction (30% of the time)
- ionize the tungsten target, and e- from outer shell have to fill in missing k shell e-, which emits an x-ray (M–> K produced more energy)

20
Q

What factors control the X-ray beam intensity?

A
  1. Tube voltage
  2. Exposure time
  3. Tube current
  4. Filtration
  5. Collimation
  6. Source-to-receptor distance
21
Q

Increasing Tube voltage…

A

Number of photons generated INCREASES
Mean energy of photons INCREASES
Maximum energy of photons INCREASES

22
Q

Increasing exposure time…

A

Number of photons generated INCREASES
Mean energy of photons UNCHANGED
Maximum energy of photons UNCHANGED

23
Q

Increasing the tube current (mA)…

A

Number of photons generated INCREASES
Mean energy of photons UNCHANGED
Maximum energy of photons UNCHANGED

24
Q

Increasing filtration…

A

Number of photons generated DECREASES
Mean energy of photons INCREASES
Maximum energy of photons UNCHANGED

25
Q

Increasing collimation (restricting size and shape of beam)…

A

Number of photons generated DECREASES
Mean energy of photons UNCHANGED
Maximum energy of photons UNCHANGED

26
Q

Increasing source-to-receptor distance…

A

Number of photons generated DECREASES
Mean energy of photons UNCHANGED
Maximum energy of photons UNCHANGED

27
Q
  1. Density is altered by factors affecting the _________ of the beam.
  2. Contrast is altered by factors affecting the _________ of the beam
A
  1. Quantity (“think density and quantity are both NUMERICAL”)
  2. Quality
28
Q

Density vs Contrast

A

Density is the amount of blackness (related to # of x-rays)
- controlled primarily by mA
- mA and exposure time are inversely related

Contrast is the differences in densities b/w light and dark images on the radiograph
- controlled by voltage (kVp)

29
Q

What is low contrast best for? High contrast?

A

Low: bone loss (high kVp, short wavelength)

High: Caries (low kVp, long wavelength)
- short gray scale

*low kVp=high contrast …………….. high kVp=low contrast

30
Q

Order of steps in a CMOS/CCD detector

A

X-ray —> photon to electron conversion (light) —> electron to voltage conversion —> software processing —> images

Oral Radiology (7 decks)

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