the xray machine and radiation characteristics

control panel, extension arm, tubehead

x-ray machine components

control panel

x-ray machine components

• On/off switch, exposure button, and beam control devices

extension arm

x-ray machine components

• Supports the tubehead, contains electrical wires for movement and positioning.

tubehead

x-ray machine components

• Sealed metal housing with essential parts for x-ray production

metal housing, insulating oil, x-ray tube, lead collimator, position-indicating device

tubehead components

metal housing

tubehead components

• Protects the x-ray tube and grounds high-voltage parts

insulating oil

tubehead components

• Absorbs heat to prevent overheating.

x-ray tube

tubehead components

• Core component for generating x-rays

lead collimator

tubehead components

• Restricts x-ray beam size.

position indicating device

tubehead components

• Shapes and directs the x-ray beam.

cathode, anode

X-ray Tube Components

cathode

X-ray Tube Components

• Supplies electrons using a tungsten filament.

anode

X-ray Tube Components

• Converts electrons into x-ray photons with a tungsten target.

Electricity

X-ray Generation Process:

• — powers the machine, activating circuits

thermionic emission

X-ray Generation Process:

• Electrons are released when the filament is heated

cathode

X-ray Generation Process:

• Electrons are directed from the — to the anode, producing x-rays (only 1% energy converted to x-rays; 99% lost as heat).

primary

Types of Radiation:

• Penetrating beam from the anode.

secondary

Types of Radiation:

• Created when the primary beam interacts with matter.

scatter radiation

Types of Radiation:

• Deflected radiation, harmful to both patient and radiographer

no interaction

X-ray Interactions with Matter

• Photon passes through unchanged (produces image).

absorption

X-ray Interactions with Matter

• Photon energy absorbed, creating contrast.

  
  

compton scatter

X-ray Interactions with Matter

• Photon loses energy after ejecting an electron.

coherent scatter

X-ray Interactions with Matter

• Low-energy photon changes direction without energy loss.

quality (kVp)

Radiation Characteristics

• Controls beam’s penetrating ability. Higher kVp = more penetrating x-rays

quantity (mA)

Radiation Characteristics

• Determines the number of x-rays produced. Higher mA = more x-rays

intensity

Radiation Characteristics

• Combination of quantity and quality per unit area and time.

kilovoltage (kVp)

Factors Affecting Intensity:

• Higher kVp = more energy, greater intensity

milliamperage (mA)

Factors Affecting Intensity:

• More mA = more electrons, increased x-ray production.

exposure time

Factors Affecting Intensity:

• Longer exposure = more x-rays.

distance

Factors Affecting Intensity:

• Intensity decreases as distance increases (Inverse Square Law).

inverse square law

Key Laws:

• Intensity ∝ 1/(distance²).

kVp rule

Key Laws:

• Increasing kVp by 15 requires halving exposure time, and vice versa