Ultrasound Quick-Tip: DIY Image Optimization Tip
Calibrating your monitor is the most overlooked, simple way to optimize an image. It's easy. Here's how.
I've travelled sea-to-shining sea here performing ultrasound applications training and various service calls. It seems that on nearly every visit, I find that the customer's monitor has not been calibrated to their room.
If you don't have a properly calibrabrated ultrasound monitor, you are not seeing the whole picture. Literally. And the problem is that most people don't know it's needed nor how to do it. In this article, I'll show you how.
But Brian, shouldn't it already be calibrated by company who sold it to me?
No. A monitor can only be calibrated properly when it's set in the room in which the scanning will be performed. A bright room will have different calibration results than a dark room.The shop from which it came was probably tested in a bright room, which is typically not the type of environment it will ultimately be used. It's important to note that the last step in the testing process at a factory, distributor, or refurbishing shop may be to turn up the brightness and contrast for various system diagnostics. They don't always turn it down. Regardless, systems aren't tested in dark rooms typically. The brightness is almost always too high.
Why is it important? My images are fine.
Because you may be missing data or seeing too much data. When it's not calibrated bright enough... you lose the low-end spectrum in the greyscale, which means small details are missing from your image. And if it's too bright, strong echos will appear very bright and may over-represent what you're really seeing.
How much does it cost? I'm not technical
It shouldn't cost you a cent. I've outlined the instructions below and isn't terribly complicated.
How to calibrate your ultrasound monitor
It's not too hard. I have some questions for you to answer along the way, but the final steps aren't too difficult.
1. Is it CRT or LCD?
There are different processes for LCD and CRT monitors. When I use the term LCD, I am referring to the modern-looking Flat-Panel monitors. CRT's are the old-style monitors that looks like a traditional TV. Take note of which one you have.
2. Set the lighting in the room
Adjust the lighting in the scan room to how it will be during typical ultrasound procedures.
3. Keep the monitor on for at least 30 minutes (CRT and LCD)
You're looking to replicate the environment in which it's most typically used.
4. Set a basic default imaging mode
Any of the basic defaults such as general abdominal, OB, Carotid, or adult cardiac should be fine.
5. Check for on-board ultrasound monitor calibration tools
Your ultrasound may have tools to guide you through the process. To find out, check your user manual. If you don't have a manual available, user manuals can be found on your system by pressing F1 on the keyboard or look on the keyboard for a question mark or Help button. If you have neither, most ultrasound systems have a Utility, Setup, Config, System, or Options button/menu. Press the button and look for a System Tools, Service, or similar button. Within this, you can often find a monitor calibration menu. If you can't find it, or your machine is from before the early 2000s, you may not have it. Check your user manual. I have an extensive library of ultrasound user manuals, so you could also contact me and I can let you know if there are on-board calibration tools on your ultrasound system. email@example.com
Often the tools are awful. If you can, get the gray levels correct and don't worry too much about the color.
6. No calibration tools or the tool was confusing
If you found the calibration tool to be complex, you're not alone. I find them cumbersome on some systems. Time to move on to the next step.
7. Find the contrast/brightness settings on your monitor
These are found in many places. Some LCD ultrasound monitors don't have a contrast adjustment on them. Regardless, on most CRT and LCD monitors, the contrast/brightness adjustments are on the front of the monitor, below the main screen. They can also be found on the right-or-left side of the monitor. For some portable/laptop systems, they may be hidden in some menu within the software. Check the user manual if they're not visible.
8. Adjust the contrast
Turn the contrast adjustment to 100%. If distortion occurs, scale it back to the point where the image does not appear distorted.This will vary from machine-to-machine. Some LCD monitors may have contrast settings at 30%-50%, but most CRT's are 90%-100%. SOME LCD ULTRASOUND MONITORS DO NOT HAVE A CONTRAST SETTING.
9. Find the greyscale bar on the monitor
It looks like this:
10. Adjust the Brightness
Brightness is a misnomer, you're actually adjusting black levels, not the white levels. Sorry, I'm a nerd and for some reason I think it's important for people to know this. Regardless:
- Crank up the brightness to 100% (or its highest setting)
- Note the position of the bottom of the grayscale bar.
- Turn the brightness down to 0 (or its lowest setting).
- With the grayscale at its lowest setting, look to the spot where the bottom grayscale bar previously appeared.
- Slowly increase the brightness... you'll the white bars will slowly creep down as you make adjustments.
- When you see the last portion of that gray bar appear, turn it back down until it's no longer visible.
- Make minor adjustments so that the lowest bar is Not Visible, while the bar above it is Barely Visible.
11. Congratulations, you're done. Now, write down the settings!
Write down the location of the system, the date, and the final settings you created. Tape it to the side or back of the monitor. I've seen situations where people make pen marks on it or tape them down so people don't accidentally mess them up. If you're going to draw on your monitor, I recommend using scotch tape to make the marks. You'll stay out of trouble that way.
That's it, a few simple steps to make sure you're seeing the Whole Picture. You'll be able to see new things, and make better diagnosis with these simple steps.
As always, feel free to drop a comment or email me with your questions! If you seek other ultrasound quick tips, please let me know and I'll post them here. firstname.lastname@example.org
Til next time,
President, GPS Medical Inc.