Production of X-Rays

Question 1

What is diagnostic imaging?

Answer 1

The taking of good quality images of patients with disease or injury to assist with vet professionals in the diagnosis/tx of patient.

Question 2

Examples of things that use x-radiation

Answer 2

x-ray machine, CT, fluoroscopy, scintigraphy

Question 3

Examples of things that don’t use x-radiation

Answer 3

ultrasound and MRI.

Question 4

What is ionising radiation and non ionising radiation?

Answer 4

Ionising: radiation which has enough energy to remove electrons from the atoms in the medium in which is passes through, hazard
Non ionising: does not produce enough energy to do the above.

Question 5

What are the properties of X rays?

Answer 5

• Have very short wavelength
• Cause ionization
• Travel in straight lines
• They are absorbed (stopped) by bone metal
• They are transmitted (pass through) tissue
• Can react to photographic film (cause blackening)
• Can cause biological damage

Question 6

What is the metal casing function of the x ray tube?

Answer 6

• Lead lined to prevent radiation leakage
• Supports glass envelope and surrounds it with oil
• Insulated and earthed from high voltage

Question 7

What is the cathode in an x ray tube? function?

Answer 7

• Negative electrode made of tungsten
• Coiled filament in a focusing cup
• Cloud of electrons are produced when the filament of the cathode is heated (THERMIONIC EMISSION), this focuses a beam of elecs onto anode

Question 8

How is the temperature of the filament in the cathode determined?

Answer 8

By the mA on the control panel. The mA determines the amount of radiation produced (quantity).

Question 9

Why is tungsten used as a material for the cathode filament and the material of the anode target?

Answer 9

Because of its high melting point

Good heat conductor

Question 10

What is the anode in an x ray tube? function?

Answer 10

• Positive electrode made of tungsten
• Anode target in a copper block
• Electron energy converted to 99% heat 1% x ray photons
• The kVp will determine the energy (quality) of the x ray beam

Question 11

Give some characteristics for the x ray room and what should be in it

Answer 11

• Large enough to be able to stand away from tube
• Radiation sign must be placed on door
• Walls may be lined with barium plaster
• No windows
• Ground floor
• PPE for staff