X-ray Units

Question 1

Tungsten has a ______ atomic number which helps with an efficient production of x-rays.

Answer 1

High

Question 2

What is amperage?

Answer 2

Number of electrons moving through a circuit

Question 3

What is voltage?

Answer 3

Electrical force that causes electrons to move from a negative pole to a positive pole.

Question 4

How does collimation (collimator) filter out photons?

Answer 4

Collimator filters photons out based on specific size and shape of the collimator

Question 5

How does filtration work in the tube head?

Answer 5

Filtration filters out photons based on wavelength and frequency. Longer wavelength/low energy photons are filtered out only allowing high energy photons to pass through.

Question 6

Why is tungsten used in the X-ray unit?

Answer 6

It has the highest melting point of all metals in pure form thus it can withstand the high energy and heat that x-rays produce.

It also has a high atomic number (74), which helps with more electrons in the orbitals of the target in the anode.

Question 7

What are the components of an intraoral x-ray unit?

Answer 7

• Tube head
• Extension arm
• Control panel

Question 8

Where in the x-ray unit are x-rays produced?

Answer 8

X-rays will be produced in the x-ray tube inside the tube head

Question 9

What are the components of the x-ray tube?

Answer 9

• Cathode
• Anode
• Evacuated lead glass envelope (with a non-lead glass window)

Question 10

True or False: The tube head components of the intraoral x-ray unit are similar to the tube head on the extraoral tube head.

Answer 10

True

Question 11

In the x-ray tube, do electrons flow from the cathode to the anode, or from the anode to the cathode?

Answer 11

Cathode to the Anode

Cathode is the negative pole
Anode is the positive pole

Question 12

What property of copper makes it a good choice in x-ray equipment?

Answer 12

Copper has very good heat dissipation

Question 13

What are 2 functions for the insulating oil?

Answer 13

• Heat dissipation/transfer through convection
• Electric insulator

Question 14

An increase in x-ray quality leads to an increase in ____________?

Answer 14

Mean energy of the x-ray photons in the x-ray beam

Question 15

Does collimation care about the energy/wavelength of the photons being blocked?

Answer 15

No

Question 16

What are the 4 aspects of heat dissipation in the tube head?

Answer 16

Heated tungsten block, copper block, insulating oil and the tube metal housing

Question 17

What amount of kinetic energy dissipates as heat in x-ray production?

Answer 17

99% or more heat

Question 18

Why do you have to watch the patient when taking an x-ray?

Answer 18

To make sure they don’t move during x-ray exposure

Question 19

How do you increase the amount of x-rays produced?

Answer 19

• Increase electrical current (mA)
• Increase exposure time

Question 20

X-rays will be produced when electrons inside the tube start to accelerate and then collide against a target, thus turning the ____ energy of the electrons into x-rays.

Answer 20

Kinetic

Question 21

What is a position-indicating device (PID)?

Answer 21

A position-indicating device (PID) helps to adjust the direction, focal spot to object distance, and beam shape (cylindrical or rectangular) of the X-Ray.

Also called beam-indicating device (BID) or aiming cylinder

Question 22

What makes up total filtration?

Answer 22

Inherent filtration and additional filtration

Inherent
* X-ray tube glass
* Insulating oil

Additional
* Aluminum Filter
this is determined by manufacturer

Question 23

What are the different parts of the control panel?

Answer 23

Exposure button, indicator light, control devices, anatomical regions presets, Child/Adult presets

Question 24

What is a high-voltage transformer connected to?

Answer 24

cathode and anode

Question 25

What is a collimator and what does it do?

Answer 25

* Lead disc * Blocks the more divergent photons * Collimates the beam area

Question 26

What does the extension arm of the x-ray unit do?

Answer 26

* connects electrical wires * aids in horizontal and vertical movements

Question 27

What is the focusing cup made of?

Answer 27

The focusing cup is made of Molybdenum.

Question 28

What 3 unit types are there for intra-oral x-ray units?

Answer 28

* fixed on the wall * mobile stand * portable/hand-held

Question 29

What part of the intraoral x-ray unit contributes to inherent filtration?

Answer 29

x-ray tube glass and insulating oil

Question 30

Is a cathode a positive or negative electrode?

Answer 30

Negative electrode

Question 31

Are voltage and amperage interchangeable terms?

Answer 31

No. Voltage is the electrical force that causes electrons to move from a negative pole to a positive pole. Amperage is the number of electrons moving through a circuit.

Question 32

True or False: The Low-Voltage Transformer is connected to the anode only.

Answer 32

**False**. It is connected to the cathode only.

Question 33

True or False: Adults and children receive the same amount of radiation when taking X-rays to get a good quality image.

Answer 33

**False**. There is a button specifically for adult and child presets when taking X-rays. Children should receive less radiation because they are smaller; they need less exposure to get a good quality X-ray image.

Question 34

What does Insulating Oil do?

Answer 34

Acts as an electrical insulator and helps in heat dissipation

Question 35

What blocks the more divergent photons?

Answer 35

collimator

Question 36

What is used as additional filtration in the tube head?

Answer 36

aluminum filter

Question 37

When the focal spot of an x-ray is decreased and there are less divergent x-rays, what is the result?

Answer 37

increased image sharpness

Question 38

What were the two examples given of inherent filtration within the tube head?

Answer 38

* X-ray tube glass * Insulating oil

Question 39

Regarding the tube head, what is the difference between collimation and filtration?

Answer 39

* Collimation involves physically blocking wavelengths and form a collimated x ray beam. * Filtration specifically filters out the least energetic wavelengths.

Question 40

What is **mostly** generated in the process of producing x-ray photons?

Answer 40

Heat

Question 41

What is most commonly used in dental units: a stationary anode or a rotating anode?

Answer 41

Stationary anode

Question 42

What is the purpose of the aluminum filter in the X-ray tube head?

Answer 42

The aluminum filter removes low-energy, less-penetrating X-rays to ensure only the most energetic X-rays are used, reducing patient exposure and improving image quality.

Question 43

What is the function of the position-indicating device (PID) in an X-ray unit?

Answer 43

The PID directs the X-ray beam, determines the focal spot-to-object distance, and shapes the X-ray beam, typically in cylindrical or rectangular forms.

Question 44

True or False: the indicator light is on when the x-ray unit has power to it

Answer 44

False - the indicator light is one when the x-ray is being produced. The ready light is on when the unit has power to it.