What Is a Density Of Film.
After the processing, The degree of blackening on the x-ray film is called density or optical density ( OD). The blackening is related to the number of x-ray or light photons that exposed the film. When the x-ray film exposed to x-ray, the metallic silver gives the blackness on the film. The degree of blackness is directly related to the intensity of radiation exposure. The optical density can be measured by using a densitometer. The range of optical density is approximately 0.25 – 2.5. The blackening or a radiograph or that a clear area of the radiograph represent low optical density and a black area represent high optical density.
The equation of optical density is:–
Optical Density (OD) = Log(I0 / It)
Where
I0 = Intensity of incidence light.
It = Intensity of transmitted light.
FAQs.
Q) What are the main factors that affect density of x-ray film?
The main factors that affect the density of x-ray films are KVp, mA, Time of exposure, distance, object thinness.
Q) What are the importance of density on the radiograph?
The importance of density on radiograph is the greater the difference in either density or thickness of two adjacent structure leads to greater contrast between those structure within the image.
Q) What are the basic radiographic densities?
The basic radiographic densities are
Metal( Bright white ).
Air( Black ).
Fat( Dark gray ).
Water or soft tissue ( Gray ).
Bone( white ).
Q) How is radiographic density measure?
The radiographic density measure by the densitometer.
Q) What is the controlling factor of density and does it affect it?
The product of mili ampere and the duration of exposure time controlling factor of density.