Which layer holds the photostimulable phosphor or latent image?

X-ray beam produces a latent image in the photostimulable fluorohalides that are in the active layer of the IP. Xray photon strikes the IP phosphors and is absorbed by photoelectric absorption.

What is photostimulable phosphor made of?

Mammography and Digital Equipment These detectors employ a plastic sheet coated with a photostimulable phosphor material as the x-ray absorber. These are typically made from BaFBR:Eu2+. The phosphor plates are exposed to x-rays and an electronic charge is stored at the location of the absorbed x-ray.

What is radiographic plate?

The “radiographic imaging plate” (IP) or “photo-stimulable phosphor” is a film-like radiographic detector comprised of specifically designed phosphors that trap and store the radiation energy. The imaging plate is housed in a special cassette and placed under the object to be examined and the X-ray exposure is made.

What is photostimulable storage phosphor imaging plate?

Photostimulated luminescence (PSL) is the release of stored energy within a phosphor by stimulation with visible light, to produce a luminescent signal. A plate based on this mechanism is called a photostimulable phosphor (PSP) plate and is one type of X-ray detector used in projectional radiography.

Why are imaging plates sensitive to radiation?

Why are imaging plates more sensitive to radiation than radiographic film? They absorb more low energy scatter. This means that areas that receive very little radiation can be enhanced by the computer instead of all the densities clumping around the toe of the D log E curve as they do when using a film receptor.

What is the function of the phosphor layer of a PSP receptor?

This is a layer that sends light in a forward direction when released in the cassette reader. This layer may be black to reduce the spread of stimulating light and the escape of emitted light.

Which of the following digital imaging systems uses a photostimulable phosphor?

computed radiography
There are two types of digital imaging systems used in intraoral radiography – computed radiography (CR) and direct radiography (DR). CR uses a photostimulable phosphor (PSP) plate to capture the image.

What is the purpose of europium in a photostimulable phosphor?

What is the purpose of europium in a photostimulable phosphor? The europium is called an activator. It is responsible for electrons being trapped in metastable states.

What is CR and CT?

Both DR and CR modalities produce a 2D image of the object. In contrast, CT systems produce a 3D image that is created by taking multiple image ‘slices’ (usually many thousands) at different angles around a single axis of object rotation.

Is computed radiography digital?

Digital Radiography (DR) is the latest advancement in Radiography. Computed Radiology (CR) is the digital replacement of X-ray film radiography. CR radiography uses phosphor image plates to create a digital image. Although it is an older technology, it is still digital technology and is more cost effective.

What is the purpose of a photostimulable phosphor?

Photostimulable phosphors (PSP) are materials that store absorbed energy within excited electrons and release it in the form of light on exposure to laser energy.

What are the advantages and disadvantages of computed radiography?

Disadvantages for DR

CR	DR
Can be retrofitted to existing installations	All-new setup necessary
Lower image quality	Better image quality
More time to final image viewing (5-7 minutes)	Rapid image viewing (within 1 minute)
Labor-intensive due to the need for cassette transfer to the plate reader	Completely digitized setup

How does a photostimulable plate work?

The imaging plate is coated with photostimulable phosphors. The phosphor layer is doped with special substances to alter the crystalline structure and physical properties. After radiation, the enhanced phosphor material absorbs and stores x-ray energy in gaps of the crystal structure, building a latent image.

What are imaging plates used for in radiography?

Imaging Plate An imaging plate is used in computed radiography (CR) instead of a conventional film cassette. The imaging plate is coated with photostimulable phosphors. The phosphor layer is doped with special substances to alter the crystalline structure and physical properties.

What is the imaging plate in PSP systems?

In PSP systems, the radiographic image is recorded on a thin sheet of plastic known as the imaging plate. The imaging plate consists of several layers ( Figure 4-4 ): • A protective layer. This is a very thin, tough, clear plastic that protects the phosphor layer. • A phosphor layer (or active layer).

What is a photostimulable phosphorus plate?

X-rays may induce such an energy storage. A plate based on this mechanism is called a photostimulable phosphor (PSP) plate and is one type of X-ray detector used in projectional radiography. Creating an image requires illuminating the plate twice: the first exposure, to the radiation of interest, “writes” the image,…