Question

how does an intensifying screen work and what does it do? The goal is to be able to understand what the question is asking, be able to understand the answer, and also use your own words as much as possible

Answer 1

How does an intensifying screen work and what does it do?

Intensifying screens are used in the x-ray cassette to intensify the effect of x-ray photon by producing a larger number of light photons. It decreases the mAs required to produce a particular density and hence decreases the patient dose significantly.

The thickness of an intensifying screen is about 0.4 mm.

They are thin sheets or layers of fluorescent materials. The screen-film combination is housed in either a cassette or a film changer. The x-ray energy is absorbed by an intensifying screen material and a portion of it is converted into light. Intensifying screens are used because film is much more sensitive to light than to x-radiation.

Direct imaging of X-rays on photographic film is inefficient because silver is only moderately electron-dense. Some compounds containing heavier elements (which are more electron dense and more efficient X-ray absorber) fluoresce when hit by X-rays. The visible photons emitted by the absorber are then detected by photographic film.

In the intensifying screen, there is an emulsion layer and a phosphor layer. The phosphor layer which flouresces the x rays converts them into light photons.

An advantage of x-ray intensifying screens is : decrease heat damage to x-ray tube.

A disadvantage of x-ray intensifying screens is : decrease image sharpness and resolution.