CR Quality Control #7 - Laser Jitter

This test will determine whether the mechanical motion of the image plate, laser, and optics are consistent in the transport system of the CR reader.  It should be performed monthly, or after any service to the CR reader.

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. Use the same technical factors that produced the baseline image (check monthly log for exposure factors) and make an exposure
7. Annotate exposure indicator number and which CR reader was used
8. Print a hard-copy image on the laser printer
9. Inspect the edges of the "T" in the middle of the phantom for jagged edges

According to FUJI's FCR QA 1 Shot Phantom manual, a certain degree of jagged edges is expected, but under 2X magnification on the QC or reading stations, they should not be visible to the human eye.  Compare the new image to the baseline phantom image.

If the jagged edges appear at the QC station and the laser film, the reader should be serviced.  However, if the jagged edges only appear on the hard copy, but not the QC station, there may be a problem with the laser printer.  Call service and record results on the monthly log.

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