DR versus CR Digital Radiography

Here are some general details about DR versus CR imaging systems. We are not even going into the Digital Radiography versus film based radiography argument as the point is mute. Digital radiography is here to stay and film based systems are on their way out! Two days before writing this I received an e-mail from my Fuji film distributor listing certain types and sizes of x-ray film that will no longer be in production, so if you haven’t gone digital yet, it will only be a matter of time before your forced to bite the bullet or stop taking x-rays altogether. So, with that in mind, here we go!

First off, both CR and DR are forms of digital radiography. CR stands for computerized radiography while DR stands for direct radiography. In other worlds DR also stands for digital radiography but for this article we are referring to DR as “Direct Radiography” and CR as “Computerized Radiography”. 

So let’s start with the ugly cousin…..CR.

CR gets a bad rap for a couple of reasons:

1. The amount of time it takes from exposure of the patient to actually seeing an image takes minutes versus a few seconds with DR systems.

2. The additional steps in the process of obtaining an image.

3. Image quality is not as good as most DR systems.

4. Labor intensive maintenance if the system goes down. (Note: Fuji CR systems are basically built like tanks and I  have had few problems with well maintained Fuji CR systems)

The most common complaint I have received about CR out in the field is the process involved from start to finish in acquiring an image to enhance. This seems to be more of a concern with busy imaging centers and radiology departments especially those with more than one x-ray room that utilizes only one CR reader.

The steps required to obtain a CR image go like this:

1. You place the needed cassette size/required image size, just like film imaging, into the cassette holder.

2. Line up and position the patient.

3. Dial in your techniques and make an exposure.

4. Remove the imaging cassette from cassette holder (wall bucky or table bucky).

5. Enter in patient info into the system, if you haven’t previously done this, and insert the imaging cassette into the CR reader.

6. Either wait for the image to be scanned and pop up on the screen for review and digital enhancements or repeat steps 1-5 with another image you must take.

7. Digitally  enhance, place markers or perform other software image protocols and send the image through to pacs or view the image at the reader workstation.

This is very similar to the steps required for film processing.

The biggest differences between film and digital CR images are you now have a high quality digital image that can be enhanced and marked up by a large number of software utilities, can be stored on a pacs system, local hard drive or cd rom and can be sent anywhere in the world with a few clicks of a mouse. You no longer have to purchase film, x-ray chemistry, monthly cleanings and you have no need for a dedicated darkroom or film storage area. Digital imaging also reduces the need for many retakes due to poorly selected x-ray techniques as the images have a wide latitude of adjustment by the computer aided software.

Now let’s review Prince Charming……DR

DR gets a bad rap for two main reasons:

1. It’s much more expensive than CR.

2. The imaging plates are very fragile and for non fixed systems, if they are ever dropped and damaged, your in for a bill that will be about 2/3rd’s of the entire systems original new price. And it does happen, quite often!

DR utilizes a direct imaging plate that is either fixed, tethered with a wire harness or wireless imaging plate. With a DR system there are basically only a couple of steps:

1. Position the patient.

2. Select your exam technique and make an exposure.

The image will pull up on your computer screen in 3 to 10 seconds depending on the system you purchased. Now all you have to do is enhance the image if necessary and add any markers or perform any other software protocols you choose that are available and then save it or send the image to pacs. DR systems also have the other benefits of CR systems such as no more dark room, no need to purchase film or chemistry and you store images in the same manner as CR so no need for expensive storage space. 

This is just a basic over view of C vs. DR and there are plenty of other online resources to choose from….some good and some bad…..if you have any further questions feel free to contact us!

Chris Salberg - CEO of Rapid X-Ray

www.rapidxray.biz

chris@rapidxray.biz