BCF Technology news

Digital Radiography: The difference between CR and DR veterinary X-ray systems

16th April 2013

An explanation of the different types of Digital Radiography available today

Craig BCF Account Manager
 
By Craig Hoines – BCF Technology, Account Manager for the South of England  

What does digital X-ray mean for vets?

When hearing about digital radiography for vets you may have heard various terms such as CR, DR, DDR and CCD. Finding it a little confusing? We have attempted to explain the differences between all these different terms in this blog and help you understand each of them.

Definitions of Digital Radiography

Digital X-ray is the electronic capture of an X-ray exposure. The exposure is captured in a device that converts the X-rays to a digital signal, which is then represented on a viewing monitor for diagnosis. An image from an X-ray system that appears on a viewing monitor may have come from one of three technologies that we will introduce (CR, CCD and DR/ DDR).  So what’s the difference between these technologies and which one is right for you?

Computed Radiography (CR) 

This modality is widespread in the UK due to its lower entry level price. The technology requires your original X-ray head/ generator to be fired at a CR cassette, as is done with film cassettes. Instead CR cassettes contain a reusable phosphorus screen. Cassettes are available in a number of different sizes.

CR and DR Differences

The CR cassette is placed into a processor which in turn removes the screen from the cassette. The CR reader then energizes the screen with a laser. This causes light emissions corresponding to the energy imparted by the X-ray exposure. The time between taking the exposure and then see the image on the computer screen with CR is about a minute. The CR reader then applies ultraviolet light to the phosphorus screen to erase the latent image left of the phosphorus screen. The fastest systems produce 60 plates per hour and others go down to 20 plates per hour.

CR and DR Differences

The Vita CR veterinary X-ray system

Close Couple Device (CCD)

CCD technology is not so widespread, the cost is more than with CR, but the image quality is not as good. The technology also requires your original X-ray head/ generator to be fired, but this time at a receptor under the table which contains a CCD device which has a screen which emits light when hit by X-rays, this is then recorded by a receptor. Best explained as a digital camera at the base of an X-ray table. It takes only a few seconds from exposure to seeing an image. However, due to the nature of the CCD receptor, the radiation exposure is greater than that of the CR or DDR systems to achieve a reasonable image. The image quality is not normally as good as either film, CR or DR.

Direct Digital Radiography (DDR sometimes just called DR)

This technology is the most widely used technology in the US, and is on the increase within the UK. DDR is widespread in equine use in the UK and it had revolutionised ambulatory X-ray examinations.

Advantages of Direct Digital Radiography for equine vets

No longer do equine vets have to return to their practice to process X-rays only to find they need to re-do some. Now with portable DDR they can have an image in seconds right there in the stable and be able to talk through the image with the owner. Wireless plates are now the next stage in this revolution, removing the issue of horses standing on cables and making the whole process easier and safer.

CR and DR Differences

Cuattro Wireless equine DDR system 

Direct Digital Radiography for small animal practices

DR is acknowledged as the way forward for small animal practices. Pricing has been seen as a factor for moderate take up in small animal practices but the image quality is recognised as the best quality available. Prices of DDR have gone down over recent years from £70,000 to around £35,000. This makes DDR much more viable for a busy small animal practice.

Direct Digital Radiography further explained

DDR uses your original X-ray head/ generator to expose a panel that is situated under the X-ray table. The panel is made up of a scintillated material such as amorphous silicon, caesium or selenium which converts the X-rays to light which is subsequently turned into a digital signal and converted to an image. This process takes seconds even though the panel can be as large as your largest cassette i.e. 35 x 43cm. The image resolution and quality is unsurpassed due to the panel size and sensitivity. It is worth noting that the different scintillated materials offer different image qualities and the laws of economics prevails here- it’s impossible to pay a little and get a lot?

CR and DR Differences
 

Example of a small animal DDR system

The various ways of obtaining an X-ray image

Traditional wet processing

CR and DR Differences

Computed Radiography (CR)

CR and DR Differences

Direct Digital Radiography (DDR or DR)

CR and DR Differences

The Benefits of Digital Radiography (either CR or DR)

 

  • No wet processing required: better consistency of x-rays
  • No darkroom required: saves space 
  • No consumables: no more film or chemistry – reduces costs 
  • No chemical disposal: reduces costs and protects environment 
  • No film or chemistry store: saves space 
  • No rooms full of filing cabinets of X-ray images 
  • Reduction of artefacts: improves image quality 
  • Higher quality images: more accurate diagnosis (it should be noted that digital radiography will not improve image quality where bad radiographic technique is used)
  • Manipulation of image to highlight different detail (bone or soft tissue) or compensate for exposure: reduces the number of re-takes & exposures - saves time 
  • Share images via email or CD: quicker referral 
  • Multiple plates of varying sizes, similar to existing cassette/screen: maintains existing flexibility Image capture time substantially reduced from wet processing: saves time


Differences between CR and DR Technology


 

Capital Costs

CR

From £15,000

DR

From £35,000

Size

Portable, but generally practice based

Portable for field use or static for practice use

Processing Time

From 55 seconds

From 3 seconds

Image available on site

Only if reader located on site

Yes

Plate

Phosphor screen in cassette

Amorphous silicon connected to computer

Archiving of Images

To PC archive, external hard-drive or DVD

To PC archive, external hard-drive or DVD

Related Links:

 

 



For more information and advice visit www.bcftechnology.com or call +44 (0)1506 460 023.
Your local BCF Account Manager will also be happy to help you.