CASSETTE

cassette

The caste is the rigid holder that contains the screens and film. the front surface, the side facing the tube , should be made of material with low atomic number, such ads plastic or cardboard or aluminum and should be thin yet sturdy. Attached to the inside of front cover is the front screen and attached to the back cover is the back screen. The radiographic film is loaded between these two screens. These days most cassettes are loaded with identical screen for front and back. Between each screen and the cassette cover will be compression device such as felt or rubber that maintains close screen film contact when the cassette is closed and latched. The back cover is usually made up of heavy metal such as lead to minimize backscatter. The x-rays pass through the film screen combination to back cover will be absorbed photoelectrically more readily in high z material then in low z material.this called cassette.