CR Quality Control #10 – Residual Image Testing

This test evaluates the CR reader’s erasure function and should be performed semi-annually.  Each exposed image plate should be adequately erased during the processing cycle to prevent a residual image on the next image.

Procedure:

1. Erase your dedicated test IP
2. Place a lead apron on the floor of your x-ray room (use same room that baseline image was performed in)
3. Place test IP on lead apron
4. Place phantom on cassette (same orientation as baseline image)
5. Raise the x-ray tube to maximum height, center, and open collimation about 1" past edges of test IP
6. Expose the phantom at using twice the mAs value of the baseline image and process the image (or perform immediately following the system linearity test after the cassette has been erased on the exposure that was made at double the baseline).
7. Turn the phantom 180 degrees and place a radiopaque object in the center of the phantom
8. Expose at the normal baseline technique
9. Process the IP under “Contrast” menu selection

Results:

The processed image should appear normal compared to the baseline image, except that the phantom will be displayed upside down with the radiopaque object.  There should be no evidence of an additional phantom pattern.  If a residual image is present, re-test and call a service professional if the re-test does not eliminate the residual image.

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