Attenuation is the reduction in intensity of an x-ray beam as it passes through matter due to absorption or deflection of photons. Attenuation depends on both the quantity and quality of photons in the beam, where quantity refers to the number of photons and quality refers to their energies. Four main factors determine the degree of attenuation: the energy of the radiation and the density, atomic number, and electrons per gram of the absorbing material. Higher radiation energy decreases attenuation while higher values of the material properties increase attenuation.

1. Attenuation
(Basic Physich)
MUHAMMAD NAEEMUDDIN
B.SC (Medical Imaging Technology /Radiology)
Subharti University Meerut

2. Attenuation
Definetion -
Attenuation is the reduction in the intensity of an x-ray beam, as it traverses
matter by either the absorption, or diflection of photons from the beam.
Because it is a measure of a change in x-ray intensity.
Attenuatin depends on the quantity and quality of the photons in a beam.

3. Quantity and quality are two terms used to expres the charecteristics of
an X-ray beam.
Quantity – Refer to the number of photons in the beam.
Quality – Refer to their eneries.
The inttensity of a beam is the product of the number and energy of
the photons.
So attenuation depends on both quantity and quality.

4. Factor affecting attenuation
Four factors determine the degree of attenuation of an x-ray
beam, as it passes through matter.
One involves the nature of the radiation, and
Three involves the composition of the matter.
Radiation
• Energy
Matter
• Density
• Atomic Number
• Electrons Per Gram

5. In creasing the radiation energy increases the
number of transmitted photons (and decreases of
attenuation),
While increasing the density, Atomic number, or
electrons Per Gram f the absorber decreases the
number of transmitted phton (and increases
attenuation).