X-rays are high-energy electromagnetic waves with short wavelengths and high frequencies. They develop from the electrons of an atom and become photons when they are energised from a higher energy level to a lower level, releasing energy in the process. This happens when fast electrons decelerate suddenly, and their large amount of kinetic energy transforms them into photons of electromagnetic radiation.
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Jetzt kostenlos anmeldenX-rays are high-energy electromagnetic waves with short wavelengths and high frequencies. They develop from the electrons of an atom and become photons when they are energised from a higher energy level to a lower level, releasing energy in the process. This happens when fast electrons decelerate suddenly, and their large amount of kinetic energy transforms them into photons of electromagnetic radiation.
The electromagnetic spectrum is the entire range of electromagnetic waves, including light. It is composed of different types of waves with different wavelengths and energies.
X-rays are produced using an X-ray tube, which you can see in the image below. It is a vacuum tube that can convert an electrical input into X-rays. Its vacuum chamber contains a cathode or filament, which is a negatively charged electrode, and a rotating anode, which is a positively charged electrode.
Here’s a simplified explanation of the process of producing X-rays:
When an electron accelerates, it gains energy equal to one electronvolt (eV). We can calculate the maximum energy gained using the equation below. Note that e is the charge of one electron measured in coulombs (1.6 ⋅ 10-9C), V is the voltage across the anode in volts, h is Plank’s constant in joules per second (6.63 ⋅ 10-34J·s), fmax is the maximum frequency in Hertz (Hz), and c is the speed of light in metres per second (3 ⋅ 108m/s).
\[E_{max} = eV = h \cdot f_{max} = \frac{hc}{\lambda_{min}}\]
We can find the maximum frequency and minimum wavelength of an X-ray by rearranging the above equations:
\[f_{max} = \frac{eV}{h} \lambda_{min} = \frac{hc}{eV}\]
Digital image processing is the process in digital X-ray images to enhance or suppress specific parts of an image in order to provide a clear diagnosis.
As we mentioned above, X-rays are formed when highly energetic electrons are impacted on an anode and release energy in the form of photons. These photons are partially absorbed when they pass through materials. The amount of absorption depends on the type of material or substance.
A cassette, which holds a light-resistant film and an intensifying fluorescent screen, is placed behind the area of interest.
Nowadays, the cassette is replaced by a computer. Digital radiography (DR) is a modern approach that instantly produces a digital radiographic image on a computer by using X-ray sensitive plates to obtain data during the exam. The data collected is instantaneously transferred to a computer without using a cassette. DR increases image quality and saves time.
X-ray attenuation is when the net number of photons entering matter is reduced by absorption and scattering.
Attenuation of X-rays is defined as the reduction of energy due to the absorption of X-rays as they travel through a material.
Here is the equation for calculating the intensity of X-rays transmitted through a substance relative to the initial beam intensity:
\[I = I_0 \cdot e^{-\mu X}\]
The intensity of reflected beam I and incident beam I0 are measured in W/m2 (watt per square metre), the absorption coefficient μ is measured in m-1, and the distance travelled through a substance x is measured in m. The intensity decreases with the absorption distance. This is a problem as the quality of the image relies on reflected X-rays.
Check out our explanation on the Absorption of X-Rays for more in-depth information on this.
X-ray digital image processing is a process to obtain high-quality digital radiographic images in terms of maximising important details or suppressing unwanted details in the image as per the requirements needed for proper diagnosis. The most critical part of image processing is done when an X-ray machine is manufactured, but further processing is required. Some of these digital image processing factors are listed below.
Different algorithms are used to apply the image processing techniques mentioned above. It is an automatic procedure used to enhance the X-ray image quality. Some algorithms used to apply the digital image process techniques are listed below.
X-ray digital image processing is a process that is used to obtain high-quality digital radiographic images in terms of maximising important details or suppressing unwanted details in the image.
X-rays are formed when highly energetic electrons are impacted on an anode and release energy in the form of photons. These photons are partially absorbed when they pass through materials. The amount of absorption depends on the type of material or substance. A cassette, which holds a film that is light-resistant and an intensifying fluorescent screen, is placed behind the area of interest.
Digital image processing radiography is the process of enhancing digital radiography images so that the quality of the image is better.
You can process a digital X-ray by changing the contrast, spatial enhancement, and sharpness and by reducing sound.
How are X-rays transformed into photons?
When electrons impact the positive electrode, energy is released and the electron transforms into a highly energised photon or X-ray.
What are X-rays?
High energy electromagnetic waves that have a short wavelength and high frequency.
List some applications of X-ray imaging.
Medical (CT scan, angiogram), industrial (security or stress analysis imaging), or research (for material property research).
What is X-ray attenuation?
The reduction of energy due to the absorption of X-rays as they travel through a material.
List some image processing algorithms.
Low- and high-pass filters, directional or edge detection filters, and linear contrast stretch.
Which of the following is true?
A low-pass filter allows low spatial frequencies to pass while blocking high spatial frequencies.
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