X-rays are used in medicine for medical analysis. Dentists use them to find complications, cavities and impacted teeth. Soft body tissue are transparent to the waves. Bones also block the rays.
2. Content
Introduction
Uses Of X-ray
Parts Of X-ray Machine
How X-ray Interact With Patients?
How Image Is Formed?
Biological Effects Of Radiation
X-ray Protection
Prevention Of X-ray
3. Introduction
• X-Ray discovered in 1895 by German physicist named
Wilhelm Roentgen. He found shadow of his bone on
fluorescent screen.
• X-rays are a form of electromagnetic radiation similar to
visible light but with short wave length.
4. USES OF X-RAY
Medicine: X-rays are used in medicine for
medical analysis. Dentists use them to find
complications, cavities and impacted teeth. Soft
body tissue are transparent to the waves. Bones
also block the rays.
Industry: X-rays are used in industry to inspect
products made by various kinds of materials. X-
ray machines are used in airports to check
luggage etc.
5. Science: In Science x-rays are used to analyze the
arrangement of atoms in many kinds of substances,
particularly crystals. Archaeologists used X-rays to
examine ancient objects covered by a crust of dirt.
Consumer Goods: X-rays are also used in
consumer goods the manufactures treat certain
kinds of plastic to check the quality of many mass
produced products.
Used in research involving quantum mechanics
theory, crystallography(examine arrangement of
atoms in solid) and cosmology(study of the origins
and eventual fate of the universe).
6. PARTS OF X-RAY MACHINE
1. X-Ray tube.
2. Operating Console.
3. High Voltage transformer.
4. Tube Head or Protective Housing.
5. Collimator.
6. Patient Table.
7. Grid.
8. Bucky.
9. Radiographic film.
7. X-Ray Tube
It is an important
component of x-ray
machine which is
inaccessible as it is
contained in a
protective housing.
The X-ray tube can be
classified as
Internal
External
8. External Part:
The external part includes:
Tube Support.
Protective Housing.
Glass or Metal Envelope.
9. Internal Part:
The internal parts include
Cathode : The filament that causes thermionic emission
Anode: A flat disc made of tungsten that draws the
electrons across the tube.
The inside of the tube is vacuumed so that the X-rays are
produced isotropic ally.
10. Operating Console
It is an apparatus in X-Ray machine that allows to control
the x-ray tube current and voltage.
The Console Controls: -
Line compensation.
kVp.
mA.
Exposure time.
11. High Voltage transformer
The high voltage transformer is a step-up transformer.
There will be more winding on the secondary side
compared to the primary side.
The ratio of windings is referred to as the turns ratio.
The only difference between the primary and secondary
waveforms is the amplitude.
The turn ratio for most x-ray high voltage transformers is
between 500 and 1000.
The primary voltage is measured in volts, and secondary
in kilovolts
13. Tube Head or Protective
Housing
X-ray tube is always mounted inside a lead-lined protective
housing that is designed to:
Prevent excessive radiation exposure.
Prevent electric shock to the patient and operator
(technologist)
Incorporates specially designed high-voltage receptacles.
Provides mechanical support for the x-ray tube and protects
it from damage.
Some tube housings contain oil in which the tube is bathed.
Some tube housings contain a cooling fan to air-cool the
tube.
When properly designed, they reduce the level of leakage
radiation to less than 100 mR/hr at 1 meter when operated
at maximum conditions
14. Collimator
• The Collimator is attached to
the x-ray tube below the glass
window where the useful beam
is emitted.
• Lead shutters are used to
restrict the beam.
• Its purpose is to minimize field
of view, to avoid un necessary
exposure by using lead plates
15. Grid
• By virtue of function and
material, collimator and
grid are same but they
have different location.
• It is made up of lead.
• It is located just after
patient.
16. Grid.
• It is used to destroy scattered
radiation from the body.
• Some of the X-Rays entering
the body of a patient are
actually scattered and no
longer travel in a straight line,
this scattering can cause
blurring of X-Ray image.
• The rays which are at 90’ can
be passed .
17. Bucky
• A Bucky is a component of x-ray units that holds the x-
ray film cassette and moves the grid during x-ray
exposure.
• The motion keeps the lead strips from being seen on the
x-ray picture.
• The name refers to Dr. Gustave Bucky who invented the
use of filter grids in 1913.
18. Radiographic film
Two types of x-ray photon are responsible for density,
contrast and image on a radiograph.
Those that pass through the patient without interacting
and those that are scattered in the patient through
Compton interaction.
Together these x-rays that exit from the patient and
intersect the film are called Remnant x-rays.
19. Film Construction
Radiographic Film has two basic parts.
Base
Emulsion
Most film has two layers of emulsion so it is referred to
as Double Emulsion Film .
20. The Emulsion
• The emulsion is the heart of the film.
• The x-rays or light from the intensifying screens interact
with the emulsion and transfer information to the film.
21. HOW X-RAY INTERACT
WITH PATIENTS?
Three things occurred
Some x-rays absorbed.
Some pass straight through the patient.
Some scattered.
Depend on three things
X-ray energy : In high kv most of x-rays pass to the film
through the patient.
Atomic number of the absorber.
Thickness and density of the object.
22. HOW IMAGE IS FORMED?
• As an x-ray beam leave the tube head, it fans out and
become weaker.
• As the distance double, the strength is reduced.
• The distance from the anode target to the film is called
the film focal distance.
• Changing the distance affect the quantity of the x-ray
reaching the film.
23.
24.
25. BIOLOGICAL EFFECTS
OF RADIATION
Deterministic effects
• There is a threshold dose below which no effect is
observed
• Above this threshold the severity of the effect increases
with dose.
• Examples:
o Temporary Sterility
o Epilation
o Nausea, Vomiting and Diarrohea (NVD)
o Erythema
o Cataract
o Skin burn
26. Stochastic /Probabilistic effects
• There is no established threshold dose
• The probability of the effect increases with dose
• Example:
o Cancer
o Leukemia
o Hereditary effect
27. Effects Classified To:
Somatic
• Affects cells originally exposed (cancer)
• Affects blood, tissues, organs, possibly entire body
• Effects range from slight skin reddening to death (acute
radiation poisoning)
Genetic
• Affects cells of future generations
• Reproductive cells most sensitive
30. Cardinal Principles of
Protection
Triad of Radiation Safety
1. Time
2. Distance
3. Shielding: Types of shielding
• Contact
• Shaped
• Shadow
*Apply to the patient & Technologist *
31. PREVENTION OF X-RAY
• X-ray check should be done on the advice of the doctor only.
• Children and women must take special care while undergoing
any x-ray check.
• Children are more sensitive to x-rays.
Due to their small physical size children are especially at risk
because the x- rays may badly affect their genitals.
• Wear x-ray prevention clothes.
• prohibited to the eighth to the fifteenth week of pregnancy.
• Remove out the jeweler.
• Tell the doctor if you are pregnant and has IUD(intrauterine
device)planted.
32. Reference
1) MEDICAL IMAGING PHYSICS- Fourth edition [William R.
Hendee, Ph.D. - E. Russell Ritenour, Ph.D.].
2) Problems and Solutions in Medical Physics Diagnostic
Imaging Physics [Kwan Hoong Ng - Jeannie Hsiu Ding Wong
- Geoffrey D. Clarke].
3) MEDICAL IMAGING (Principles, Detectors, and
Electronics)[Edited by Krzysztof Iniewski].
4) https://www.slideshare.net/tarekhegazy/x-ray-physics.
5) https://www.slideshare.net/khyzra/x-rays-28870165.
6) https://www.slideshare.net/HuzaifaOxford/introduction-to-the-
parts-of-x-ray-machine.
7) http://www.sprawls.org/resources/DIGRAD/module.htm#4.