CR Quality Control #1 – Screen Cleaning

One of the most important, yet sometimes underperformed activities we can do to keep our image quality high is routine cleaning of image plate phosphor screens.  Each CR system manufacturer will recommend a schedule for routine cleaning of IP’s, but I tend to think that a monthly schedule serves my department well.  This may vary depending on your department’s patient volume and usage. 

How to clean: Remove image plate from cassette holder.  Inspect in good lighting to identify any potential dust, scratches, or flaking off of the phosphor layer (see images below) that may produce artifacts.  Always replace the IP if needed – discuss the need for replacement with a radiologist and/or your department manager if you are uncertain whether or not the plate has enough damage.

Take a non-abrasive cloth or gauze and dampen it with screen cleaner (see manufacturer’s guidelines for type of recommended cleaner).  Wipe in small circular motions until the entire screen has been properly wiped down and inspect for dust.  Make sure that you use something that does not leave a lint residue.  Do not place cleaner directly on image plate. 

Let each screen dry, being careful not to rest the phosphor side of the screen down.  Most cleaners are alcohol-based and should dry rather quickly. Make sure each plate is completely dry before re-inserting into the cassette.

Each IP at my facility (we are using FUJI CR) has a barcode that can be catalogued and records can be kept logging which plates were cleaned, when they were cleaned, and by whom.  It should also be noted when any damage to an image plate is identified, as well as if a plate gets replaced.  I chose a rather worn cassette for the following image because you should also visually inspect the cassette.  Some times the hinges that hold the image plate inside the cassette become loose leaving the plate to fall to the floor and become scratched.  It’s much cheaper to replace hinges on a cassette than to replace the phosphor screen.

Any radiologist will tell you if artifacts are seen on your images, but monthly cleaning of the image plates should keep them to a minimum.  This is one of the easier activities any rad tech or student can perform that can be extremely valuable to image quality in your department.  Normal wear and tear will occur as the image plates are processed, but keeping a log over time should help you predict how often you will need to replace screens and how your department should budget for them.

Other posts in this series:

CR Quality Control #1 - Screen Cleaning
CR Quality Control #2 - Creating a Baseline Phantom Image
CR Quality Control #3 - Exposure Indicator Calibration
CR Quality Control #4 - Contrast Evaluation 
CR Quality Control #5 - Sharpness
CR Quality Control #6 - Shading Correction
CR Quality Control #7 - Laser Jitter
CR Quality Control #8 - Image Artifacts and Noise
CR Quality Control #9 - Exposure Linearity
CR Quality Control #10 - Residual Image Testing