0:00

So let's say first one is this computed radiography.

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As I say, computed radiography comes under indirect

0:08

digital.

0:09

So the way it works is like, this is the generic term applied to an

0:13

imaging system which has photostimulable

0:17

storage phosphor. This is like a film screen cassette, but it

0:21

has a storage phosphor plate to acquire the X-ray projection

0:25

image.

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It absorbs the information, then the cassette or this phosphor

0:30

has to be read out by what is called as a computed radiography

0:34

reader that will extract the electronic latent image,

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and that image is then transferred into digital electronics to

0:42

convert the signal into digital form and so forth.

0:46

So in this picture shown here is like you have the image acquisition

0:50

part where you have an X-ray tube, the existing room.

0:54

Instead of inserting a film cassette here, you can now

0:57

insert a CR plate.

1:00

The CR plate can be reused continuously.

1:04

When the radiographer starts, he or she will take the CR plate

1:08

and connects it with the CR reader to the particular image

1:12

or a particular patient by the barcode.

1:15

Then once they insert it and take a picture, then

1:19

the CR plate is inserted in this type of a reader.

1:23

Instead of processing in a dark room, now you have a CR reader

1:27

where you insert the phosphor plate.

1:29

The CR plate, once it's inserted here, it removes the phosphor

1:33

plate, and they have a reader inside, basically

1:37

allowing a high-intensity laser going through the

1:40

plate and releasing the captured energy.

1:44

And the captured photons is what creates the latent image.

1:48

And that converts into electrical signal, and then you have an

1:51

image coming here. So it's a two-step process, almost

1:55

like the analogy is film screen system, you take a film, you go to

1:59

the dark room, process the dark film, and you get an image.

2:03

With the CR plate, you have a CR plate, you use a CR

2:07

reader, and it reads through the plate, get the information,

2:11

and then the CR plate can be reused.

2:14

So the way it works is like, this is the principle.

2:17

X-ray system with a photostimulable phosphor, that's the

2:20

CR plate, has a phosphor detector.

2:23

It will capture the information, basically traps the

2:27

X-rays coming in into this phosphor plate, and that

2:31

captured photons are then exposed in an image

2:34

reader.

2:36

And the reader then it is doing some computational and

2:40

processing for image scaling and then convert it into a digital

2:44

image, and you get a CR image.

2:47

And this plate can be reusable once it is exposed to a

2:51

bright light and removing all the storage phosphor back to the ground

2:55

state. And that's the principle behind it.

2:58

And this became as a very first step when hospital

3:02

started converting from analog system to digital,

3:06

because this was less expensive than going directly into

3:09

digital radiography. Because with this system, they could use

3:13

the existing X-ray room, and all they had to buy is

3:17

the CR plates, which go into the same slot as the film

3:21

screen cassette, and thereby, immediately the system becomes digital.