X-Ray Definition Flashcards
Production of x-Ray
1- X-Rays are produced by bombarding metals with high speed electrons
2-When electrons strike a metal target, large deceleration occur and radiation is produced in the X-Ray region of the E.M spectrum
Features of an x-Ray
Electrons are emitted from heated cathode by thermionic emission
Electrons are accelerated through a large potential difference and bombardments of metal
X rays are produce by leaving the tube via window
Intensity
It is the wave power per unit area and it affects the degree of blackening of the image
Hardness
It is the penetration of the x-ray beam, which determines the fraction of the intensity of the incident beam that can penetrate part of the body being x-rayed
Summary
The shorted the wavelength the greater the penetration
Quality of picture
The quality of the shadow depends on it’s sharpness and contrast
Sharpness
A sharp image is one in which the edges of the organ is clearly defined
How to get a sharp image
The beam is made narrow by the geometry of the anode
The beam is limited by using apertures
A lead grid is placed in front of the film to absorb scattered x-ray photons
Contrast
It is the degree of blackening of the image between one organ and another
Half value thickness
It is the thickness of the medium required to reduce the transmitted intensity to on half of it’s value