Introducing the Radiography Cafe!

I've been wanting to find a better way for students, radiographers and instructors to get together and discuss ideas for a long time.  In fact, it was the main goal behind the beginnings of this blog.  Unfortunately, the comment section of a blog has some limited capacity for discussion.  But now, technology has progressed to the point where someone with virtually no experience building a website can construct a user forum in minutes.

I am pleased to bring you the Radiography Cafe (RadiographyCafe.freeforums.org)!

Here you will find a ground-level forum that I wish to populate with lots of great discussion about anything and everything radiography.  Since I am currently alone as administrator and moderator, please forgive me if I do not immediately respond to private messages or some of the initial posts as I will be doing this in my free time.  I am, however, seeking people interested in assisting with forum moderation and maintenance, so if you're interested, please register on the forum and send me a private message.

I hope this can be a valuable resource... and even if it doesn't turn out that way, I hope it can be a fun environment to get to know your fellow radiographer/student/instructor.

CR Quality Control #2 - Creating a Baseline Phantom Image

Before you begin your routine monthly/semi-annual/annual radiographic equipment testing, you need to have a baseline image to compare it to.  The idea is that when you perform your actual tests in the future, you will not be able to tell whether or not your results are good or bad without having something to reference.  This method provides the measurable standard for calculations that will need to be performed later during testing.

We use one phantom with multiple test tools within it at the place I work now.  Select a medium-range kVp (I use 80 kVp).  You will also need an x-ray room with relatively low mA stations, a lead apron, and some kind of log to record your results in.  The vendor we purchased our phantom from provided us with a log.  We also took a brand new 14x17 cassette out of circulation and only use it for QC testing to reduce variability (and keep it with your phantom).

Procedure:

1. Erase your test CR cassette before any exposures are made.
2. Raise your x-ray tube to its maximum height and keep it above the floor (not directly over the table).
3. Place a lead apron on the floor directly under your central ray.
4. Place your CR cassette on top of the lead apron (without a grid cap).
5. Place your phantom on top of the cassette - make sure to orient the top of the phantom to the top of the cassette and keep this orientation for all future testing.
6. Center your x-ray beam to the phantom and cassette, leaving about one inch of light field outside the borders and onto the lead apron.
7. Select 80 kVp and 100 mA.  Try also setting 0.10 seconds and make an exposure.
8. Process the image and note the exposure indicator (S#, Exposure Index, or LgM)
9. If needed, adjust the time station so that you achieve an optimum exposure indicator number (*see note for proper levels of exposure indicator numbers)
10. Once you have the disired technical factors, annotate the date, exposure factors, and "baseline image" and send to PACS - your PACS administrator can create a folder for QC images 
11. Create an individual baseline image for each CR reader and log results.

*When attempting to expose your baseline image for optimum exposure indicator, you may need to consult the manufacturer guidelines or your physicist.  As a starting point, you can use the following:  

• S# = 200... if you double your time (or overall mAs), you will half your S#
• Exposure Index (EI) = 1800... if you double your time (or overall mAs), you will add 300 to your EI
• LgM = 2.1... if you double your time (or overall mAs), you will add 0.3 to your LgM

The Baseline exposure log should include the following information that will be referred to for later testing:

• Room number (that the test exposures are made in)
• SID
• Image plate identification number
• kVp
• mA
• time station
• Target exposure indicator number (this is your baseline S#, EI, or LgM)
• CR reader (number your readers if you have not already done so)

Keep your logs, test cassette and phantom/s in a safe place away from your other equipment to minimize risk of circulation with other supplies.  Next, we'll get into some of the monthly tests.

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

Employment Survey Results

Back in October of 2012, I posted a survey about the employment situation across the country and asked six questions relating to the job market aimed at new graduates from radiography school.  With any survey, the more responses received, the more accurate the results.  I received 30 responses to my questions, and here they are:

The results were anonymized, but it seems there are a range of responses across the board.  I know the job market is not as good as when I graduated from x-ray school in 2000, but if these responses are representative of the national average, I have seen worse. 

In my book, Becoming a Radiologic Technologist, I explained the criteria that a radiography program must have 75% of its graduates employed (in any tech job) within 6 months of graduation.  I would be interested in speaking to any of my readers who represent JRCERT to learn more about the re-accreditation process and statistics about radiography program probation due to low employment statistics. 

Until then, it seems that the market is competitive.  Like any field, that's not to say every graduate is guaranteed a job right out of school, or even a full-time day job.  There are positions available, but keep an open mind to the possibility that you may need to relocate, accept undesirable shifts, or have some delays in finding an ideal position.  I wouldn't discourage anyone from seeking an education in radiography, but you need to love what you're doing and be prepared for competition.

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