X ray physics

1. X-ray physicsX-ray physics
By By
Dr. Tarek MansourDr. Tarek Mansour

2. Content Content
Introduction, history and basic physics.Introduction, history and basic physics.
How radiograph produce.How radiograph produce.
Interaction of x-ray with patient.Interaction of x-ray with patient.
Formation of the image.Formation of the image.
Processing the film.Processing the film.

3. Introduction, history Introduction, history
and basic physics.and basic physics.

4. Discovery of x-raysDiscovery of x-rays
Discovered in 1895 by German physicist named Discovered in 1895 by German physicist named
Wilhelm Roentgen.Wilhelm Roentgen.
He found shadow of his bone on fluorescent He found shadow of his bone on fluorescent
screen.screen.

6. X-rays are a form of electromagnetic radiation X-rays are a form of electromagnetic radiation
similar to visible light but with short wave similar to visible light but with short wave
length.length.

7. Radiation physicsRadiation physics

8. Electromagnetic spectrumElectromagnetic spectrum
Electromagnetic radiation consists of energy in Electromagnetic radiation consists of energy in
small packets called photons.small packets called photons.
They are grouped according to there wave They are grouped according to there wave
length and frequency.length and frequency.

10. Properties of x-raysProperties of x-rays
Are electromagnetic Are electromagnetic
radiations composed of radiations composed of
small packets of energy small packets of energy
called photons.called photons.
Travel at speed of light.Travel at speed of light.
Travel in straight lines.Travel in straight lines.
Highly penetrating.Highly penetrating.
Invisible.Invisible.
Blacken radiographic Blacken radiographic
films.films.
Produce scatter.Produce scatter.

11. Atoms structuresAtoms structures
Positively charged Positively charged
protons in nucleus.protons in nucleus.
Neutrons of no charge Neutrons of no charge
also in the nucleus.also in the nucleus.
Negatively charged Negatively charged
electrons in various electrons in various
orbits around the orbits around the
nucleus.nucleus.

12. Atomic numberAtomic number
Lighter elements have fewer number of protons Lighter elements have fewer number of protons
such as oxygen.such as oxygen.
Heavier elements have more such as lead.Heavier elements have more such as lead.
The number of protons is called the atomic The number of protons is called the atomic
number.number.

13. Density of matter.Density of matter.
Low density matter is loosely packed with large Low density matter is loosely packed with large
spaces between each atom like air. spaces between each atom like air.
High density matter is tightly packed with atoms High density matter is tightly packed with atoms
sitting close to each other like lead.sitting close to each other like lead.

14. How radiographs are How radiographs are
producedproduced

15. Production of radiographProduction of radiograph
X-ray are produced in the machine.X-ray are produced in the machine.
X-ray interact with the patient.X-ray interact with the patient.
Image is recorded in the x-ray plate.Image is recorded in the x-ray plate.

16. Production of the x-ray Production of the x-ray
radiations on the radiations on the
machine.machine.

17. The x-ray tube.The x-ray tube.
The tube head consists of a pair of electrodes.The tube head consists of a pair of electrodes.
- A negatively charged cathode with - A negatively charged cathode with
include a heater filaments.include a heater filaments.
- A positively charged a node with a - A positively charged a node with a
tungsten target.tungsten target.

18. Steps in x-ray production.Steps in x-ray production.
Filament is heated and gives off cloud of Filament is heated and gives off cloud of
electrons.electrons.
A large electrical charge is placed in the A large electrical charge is placed in the
cathode/anode space causing the electrons to cathode/anode space causing the electrons to
race toward the anode.race toward the anode.
When they crush into the anode it causes x-ray When they crush into the anode it causes x-ray
to be given off. to be given off.

19. X-ray machine components.X-ray machine components.
The tube headThe tube head where the x-rays are generated. where the x-rays are generated.
The control panelThe control panel which regulate the strength which regulate the strength
and amount of the x-rays produced and trigger and amount of the x-rays produced and trigger
the exposure.the exposure.
The power supplyThe power supply which provide the energy to which provide the energy to
creates the x-rays. creates the x-rays.

26. X-ray tube headX-ray tube head
Stationary anode.Stationary anode.
Found in smaller Found in smaller
machines.machines.
The target is fixed in The target is fixed in
block of copper.block of copper.
Only capable of low Only capable of low
output.output.
mA to 30mA to 30
Rotating anode.Rotating anode.
Found in large machines.Found in large machines.
The target is rotate in The target is rotate in
tungsten disc.tungsten disc.
Higher output Higher output
producing.producing.
mA up to 300mA up to 300

27. The control panel.The control panel.
The three factors that can be varied during The three factors that can be varied during
producing radiograph areproducing radiograph are
-The kilovoltage (KV) difference applied between The kilovoltage (KV) difference applied between
the anode and cathode during exposure. the anode and cathode during exposure.
-The milliamperage (mA) applied to the filament.The milliamperage (mA) applied to the filament.
-The duration of exposure. The duration of exposure.

28. Control panelControl panel
Higher kv attract the electrons toward the anode by Higher kv attract the electrons toward the anode by
greater force.greater force.
They smash the anode harder and produce x-ray with They smash the anode harder and produce x-ray with
higher energy and greater tissue penetrating power.higher energy and greater tissue penetrating power.
Increasing mA increase the number of electrons cloud Increasing mA increase the number of electrons cloud
around the filament. Result in higher number of x-ray around the filament. Result in higher number of x-ray
produced per second.produced per second.

31. How x-ray interact How x-ray interact
with patients.with patients.

32. Three things occuredThree things occured
Some x-rays absorbed.Some x-rays absorbed.
Some pass straight through the patient.Some pass straight through the patient.
Some scattered.Some scattered.

33. Depend on three thingsDepend on three things
X-ray energy. In high kv most of x-rays pass to X-ray energy. In high kv most of x-rays pass to
the film through the patient.the film through the patient.
Atomic number of the absorber.Atomic number of the absorber.
Thickness and density of the object.Thickness and density of the object.

34. How image is formedHow image is formed

35. As an x-ray beam leave the tube head, it fans out As an x-ray beam leave the tube head, it fans out
and become weaker.and become weaker.
As the distance double, the strength is reduced.As the distance double, the strength is reduced.

36. Formation of the imageFormation of the image
The distance from the anode target to the film is The distance from the anode target to the film is
called the film focal distance.called the film focal distance.
Changing the distance affect the quantity of the Changing the distance affect the quantity of the
x-ray reaching the film.x-ray reaching the film.
Increasing the distance means that less x-rays Increasing the distance means that less x-rays
reaches the film.reaches the film.

37. Formation of imageFormation of image
Low density or low Low density or low
atomic number tissues atomic number tissues
allow more x-rays allow more x-rays
through causing more through causing more
blackening of film.blackening of film.
High density or high High density or high
atomic number tissues atomic number tissues
allow less x-ray through allow less x-ray through
causing less blackening causing less blackening
of the film.of the film.

38. Effect of kilovoltage.Effect of kilovoltage.
Increasing kV, increases the penetrating ability Increasing kV, increases the penetrating ability
of the x-rays photons.of the x-rays photons.
More x-ray photons get through to darken film.More x-ray photons get through to darken film.
High kv produces darker images but poor High kv produces darker images but poor
contrast.contrast.

39. Effect of milliamperage and time.Effect of milliamperage and time.
Increasing the mA and mAs, increases the Increasing the mA and mAs, increases the
number of x-rays production.number of x-rays production.
It does not affect the penetrating power of the It does not affect the penetrating power of the
photons.photons.
Increase mA will increase overall blackness of Increase mA will increase overall blackness of
the film.the film.

40. X-ray film composition.X-ray film composition.
Polyester base that provide support has bluish Polyester base that provide support has bluish
tint.tint.
Film emulsion is a thin layer of chemicals Film emulsion is a thin layer of chemicals
coating the base composed of.coating the base composed of.
- Light sensitive silver halide (mainly Bromide - Light sensitive silver halide (mainly Bromide
AgBr) crystals.AgBr) crystals.
- gelatins that keep the silver bromide grains - gelatins that keep the silver bromide grains
evenly dispersed. evenly dispersed.

55. Recording imageRecording image
When x-ray hits the atoms in the film emulsion When x-ray hits the atoms in the film emulsion
it causes it to change leaving a latent (hidden), it causes it to change leaving a latent (hidden),
image.image.

56. The cassette filmThe cassette film
Light proof container for film.Light proof container for film.
Lead backed to absorb transmitted radiations Lead backed to absorb transmitted radiations
and prevent scatter.and prevent scatter.
Intensifiers to use lower exposure.Intensifiers to use lower exposure.
Calcium tungstate. Calcium tungstate.

58. Grids Grids
Composed of hundreds of alternating thin lead Composed of hundreds of alternating thin lead
strips with aluminum or fiber interspaces. strips with aluminum or fiber interspaces.
X-ray can pass through the interspaces without X-ray can pass through the interspaces without
interaction.interaction.
Lead strips absorb weak energy scatter x-ray that Lead strips absorb weak energy scatter x-ray that
hit them.hit them.
Strips is encased in protective cover. Strips is encased in protective cover.

61. Processing filmsProcessing films

62. Processing the filmProcessing the film
There are five stepsThere are five steps
Developing.Developing.
Rinsing,Rinsing,
Fixing.Fixing.
Washing.Washing.
Drying.Drying.

63. Development Development
Chemical convert the exposed AgBr in to Chemical convert the exposed AgBr in to
metallic silver.metallic silver.
The bromine goes into solution.The bromine goes into solution.
Unexposed AgBr is less affected. Unexposed AgBr is less affected.

64. RinsingRinsing
Essential to rinse of the developer solution so Essential to rinse of the developer solution so
that the fixer solution is not contaminated.that the fixer solution is not contaminated.
Contamination leads to faster exhaustion of the Contamination leads to faster exhaustion of the
fixer. fixer.

65. Fixing Fixing
Stops development.Stops development.
Washes away unexposed and undeveloped silver Washes away unexposed and undeveloped silver
halide crystals.halide crystals.
Hardens the emulsion.Hardens the emulsion.

66. Washing Washing
To wash all traces of fixer from emulsion.To wash all traces of fixer from emulsion.

67. Draying Draying
Hang up in dust free area to dry.Hang up in dust free area to dry.
Automatic processors by it by using hot air.Automatic processors by it by using hot air.