What Is Contrast In Radiography.
The radiographic contrast viewed on an illuminator is called radiographic contrast The contrast means the difference in density between two area of film. The contrast may be
a) Subject contrast.
b) Radiographic contrast.
c) Subjective contrast.
a) Subject contrast:- The subject Contrast refers, the difference in x-ray intensity of transmitted through different parts of body is called subject contrast. The thinner and the thicker body parts attention radiation capacity is different. The subject Contrast is proportional to the relative number of transmitted. The subject contrast depends on the following components.
– Patient thickness.
– Tissue density.
– Effective atomic number of tissue.
– Kilovoltage (Kvp).
– Contrast media.
– Scattered radiation.
b) Radiographic contrast:- The various degree of brightness when light is transmitted through film is called radiographic film, which provides anatomical details in film. The radiographic contrast depends on the following parameters.
– Subject contrast
– Scattered radiation
– Intensifying screens.
– Film fog.
– Development.
– Film density.
– Types of film.
c) Subjective contrast:- The subjunctive contrast depends upon following parameters.
– Subject contrast.
– Radiographic contrast.
– The observer.
– Viewing boxes.
– Ambient light.