Study Guide

Question 2

What is the anode heel effect?

Answer 2

A phenomenon that allows for better utilization of x-ray beams

The anode heel effect is significant in x-ray imaging as it enhances image quality by distributing radiation more favorably.

Question 3

What does electromagnetic radiation refer to?

Answer 3

Energy traveling through space at light speed, including x-rays

Electromagnetic radiation encompasses various forms of energy, such as visible light, radio waves, and x-rays.

Question 4

What is the speed of electromagnetic radiation in a vacuum?

Answer 4

3 x 10^8 meters per second or 186,000 miles per second

This speed is a fundamental constant of nature, often denoted as ‘c’ in physics.

Question 26

What charge is on the cathode?

Answer 26

Negative ## Footnote The cathode has a negative charge which is essential for the function of the x-ray tube.

Question 27

What are the two main parts of the cathode?

Answer 27

* Filament * Focusing cup ## Footnote The filament and focusing cup work together to produce and direct electrons.

Question 28

What is the filament made of?

Answer 28

Tungsten ## Footnote Tungsten is chosen for its high melting point and ability to withstand heat.

Question 29

What is the source of electrons in x-ray production?

Answer 29

Filament ## Footnote The filament heats up and emits electrons through thermionic emission.

Question 30

What is the main reason for tube failure?

Answer 30

Heat ## Footnote Excessive heat can damage the components of the x-ray tube, leading to failure.

Question 31

What charge is on the focusing cup?

Answer 31

Negative ## Footnote The negative charge helps to focus the electron beam towards the target.

Question 32

What is the focusing cup made of?

Answer 32

Nickel for general x-ray or molybdenum ## Footnote The materials used for the focusing cup are chosen for their electrical properties and heat resistance.

Question 33

What is the heel effect?

Answer 33

The heel effect refers to the variation in x-ray intensity across the field of the beam, which is caused by the angled geometry of the x-ray tube and the absorption of x-rays by the anode.

Question 34

What is the maximum setting we can use at the control panel?

Answer 34

120-150 KVP

Question 35

What are the three main parts of the anode?

Answer 35

* Target * Stator * Rotor

Question 36

What is the source of x-rays?

Answer 36

The target in the anode, where electrons collide and produce X-rays.

Question 37

What is the target made of?

Answer 37

Tungsten

Question 38

What does SID stand for and what are we measuring?

Answer 38

SID stands for Source-to-Image Distance, and we are measuring the distance between the x-ray tube and the image receptor.

Question 39

What is the purpose of the glass envelope in an x-ray tube?

Answer 39

The glass envelope houses the cathode and anode and maintains a vacuum environment for electron flow.

Question 40

What is the limitation of electron emission?

Answer 40

The limitation of electron emission is influenced by the temperature of the filament and the maximum voltage applied.

Question 41

Fill in the blank: The _______ charge effect refers to the behavior of electron emission based on the electric charge distribution.

Answer 41

[key learning term]

Question 42

What is the stationary anode made of?

Answer 42

Tungsten embedded in copper ## Footnote Tungsten is used for its high melting point and thermal conductivity, while copper provides efficient heat dissipation.

Question 43

What causes pitting of the anode?

Answer 43

Repeated high-energy exposures leading to surface damage ## Footnote Pitting can compromise the anode's performance and longevity.

Question 44

What is the purpose of tube warm-up and how do we do this?

Answer 44

Prevents thermal shock by gradually increasing exposure levels ## Footnote Warm-up helps to stabilize the anode temperature and avoid damage.

Question 45

What causes a crooked anode?

Answer 45

Rapid heating without proper warm-up or excessive exposure ## Footnote Both factors can lead to uneven wear and structural issues in the anode.

Question 46

What is the Line-Focus Principle?

Answer 46

Allows the anode to create a smaller effective focal spot while maintaining a larger actual focal spot ## Footnote This principle is essential for improving image quality in radiographic techniques.

Question 47

What change happens in the tube when we select the small focal spot instead of the large focal spot?

Answer 47

Better image resolution due to a smaller electron beam hitting the target ## Footnote Smaller focal spots can enhance detail and clarity in radiographic images.

Question 48

What is the anode heel effect?

Answer 48

Variation in X-ray intensity stronger on the anode side ## Footnote The anode heel effect refers to the phenomenon where X-ray intensity is not uniform across the beam, with the intensity being stronger on the cathode side and weaker on the anode side.

Question 49

What type of imaging benefits from the anode heel effect?

Answer 49

Thoracic spine or femur imaging ## Footnote The anode heel effect is particularly useful in imaging structures with varying thickness, such as the thoracic spine or femur, where optimal image quality is desired.

Question 50

What type of motor turns the anode?

Answer 50

Rotating induction motor ## Footnote A rotating induction motor is used to turn the anode in X-ray machines, allowing for the necessary speed and torque.

Question 51

What action do you do to start the anode?

Answer 51

Pressing the prep button ## Footnote The prep button initiates the spinning of the anode to prepare it for X-ray production.

Question 52

Why do we spin the anode?

Answer 52

Distributes heat, prevents damage ## Footnote Spinning the anode helps distribute the heat generated during X-ray production, reducing the risk of damage to the anode.

Question 53

How fast do we spin the anode?

Answer 53

3,000 to 10,000 RPM ## Footnote The speed at which the anode spins can range from 3,000 to 10,000 revolutions per minute (RPM), depending on the design of the X-ray tube.

Question 54

What causes a large hole in the anode?

Answer 54

Excessive heat or prolonged exposure ## Footnote A large hole in the anode can occur due to excessive heat build-up or prolonged exposure during X-ray production.

Question 55

What part of the X-ray tube lies outside the glass envelope?

Answer 55

Stator ## Footnote The stator is the component of the X-ray tube that is located outside the glass envelope and is responsible for generating the magnetic field necessary to rotate the anode.

Question 56

What is the gluss envelope made of?

Answer 56

purex gluss ## Footnote The material used for the gluss envelope is purex glass.

Question 57

What is the unit of the pouten of the envelope called?

Answer 57

Window-port ## Footnote The specific term used for the unit of measurement related to the envelope is 'Window-port'.

Question 58

What is the maximum housing leak allowed?

Answer 58

100 MR HR at 1 meter ## Footnote This refers to the permissible leakage rate from the housing, specified as 100 MR HR at a distance of 1 meter.