2. X-rays were discovered by the German physicist Wilhelm Rontgen in
November 1895. He called the 'new kind of ray' or X-rays( X for the
unknown).their usefulness to visualize the internal anatomy of humans
was established.
Today, imaging with X-rays is perhaps the most commonly used
diagnostic tool with the medical profession, and the techniques from a
simple chest radiography to a digital subtraction angiography or
computer tomography depend on the use of X-rays.
Introduction
3. What is X-ray?
X-radiation (composed of X-rays) is a form of
electromagnetic radiation.
X-rays have a wavelength in the range of 0.01 to 10
nanometers.
X-ray photons carry enough energy to ionize atoms
and disrupt molecular bonds.
4. Types
X-rays is of two types
Hard X-rays
X-rays with photon energies above 5-10 keV (below 0.2-0.1 nm
wavelength).
Soft X-rays
X-rays with photon energies below 5-10 keV (below 0.2-0.1 nm
wavelength).
6. Medical uses
Computer tomography
Imaging alternatives for soft tissues are computed axial
tomography (CAT or CT scanning)
Fluoroscopy
Fluroscopy is another X-ray test methodology. Examples
include cardiac catheterization (to examine for coronary artery
blockages) and Barium swallow (to examine for esophageal
disorders).
Radiotherapy
The use of X-rays as a treatment is known as radiation therapy
and is largely used for the management (including palliation
of cancer); it requires higher radiation energies than for
imaging alone.
7. Principle of Working
X-rays are produced in: specially constructed glass tube,
which basically comprises.
A source for the production 0f electrons, Cathode
a energy source to accelerate the electrons,
a free electron path,
a means of focusing the electron beam and
a device to stop the electrons. Anode
Stationary mode tubes and rotating anode tubes are the two
main types of X-ray tubes:
9. Three major elements of an x-ray
machine:
1.Vacuum Tube
2. High Voltage Power Source
3.Operating Console
10. Three major elements of an x-ray
machine:
1.Vacuum tube:
made upof Pyrex glass.
tungsten anode is
enclosed along with
cathode.
cathode oremitter.
11. X-ray tube
Cathode accelerateselectrons
and leads them to
anode(electron beam).
Only a small portion of the
electron beam is convertedto
x rays.
Photons are discharged in all
directions.
By adjusting current and
voltage, we can direct the
beamon avisiblesubstance.
12. Rotating Anode
The anode of rotating anode
tube consist of a large disc of
tungsten, or an alloy of
tungsten, which theoretically
rotates at a speed of about
3600 rpm.
The purpose of rotating
anode is to spread the heat
produced during anexposure
overa largeareaof anode.
13. 2.High Voltage Power Source
A transformer isused
Alternates between the voltage of currents being
sent to theemitteror to the anode.
Emitterrequires small voltage supply forsmall
currents
Anode needs a large voltage supply
14. 3. Operating Console
Control unit..
Manages current, voltageand
timer.
Current control allows adjustment
of tube current to vary radiation
intensity.
Voltage control allows adjustments
in anode to change energy of
radiation.
Timerdetermines thedurationof
exposure.
16. Advantages:
- It is non-invasive.
- Itcan be madeavailableas a portablex-ray unit.
- It is lesscostly when compared to theother imaging modalities
like MRI orCT.
Limitations:
- X-ray uses radiation, which can causecancer if you areexposed
to itovera prolonged period of time.
- Do not provideas much informationas MRI and CT.
