Introduction – What is an image Quality Problem? o What is an image quality problem? o Image quality problems are just that, a problem with the actual ultrasound image. This is an issue where in one way or another the ultrasound image itself is compromised and is not at the level expected for a particular unit. o What an image quality issue is not? o Image quality issues are not lockup issues or a non-booting issue. o They have no impact of the functionality of the rest of the unit. o Sometimes a lockup or other issue will have an image quality component, in most of those cases it is best to focus on the lockup (or other) issue and use the image quality information as just extra information to help steer you to a resolution.
Defining the Problem o Image quality issues are difficult, some of the most difficult things we resolve. o Defining exactly what is wrong with the image is a big part of the process. o This will often take the help of the Sonographer and scanning of yourself to duplicate the issue. o We will talk about Ultrasound Phantoms in a few minutes. o Once you have defined and can duplicate the problem, you can begin the process of trying to solve the issue. o If the issue is intermittent, and they often are, work with your Sonographers to gather as much data as possible. Capturing pictures, trying different probes while the issue is happening. Location of the machine, in the ultrasound lab or out on a portable. If portable, where?
Defining the Problem o Breaking down what is happening on the screen will help you troubleshot down to a subsection of the unit. o Image area versus the whole screen. o Image quality problems occur in the ultrasound image area only. They do not occur in the “data” areas of the screen. o Horizontal versus Vertical Problems o Vertical problems are generally in the front end (or scanner sub-section) of a unit. o Horizontal problems are generally in the back end (or scan converter sub-section) of a unit. o Is the problem in 2D, Color or both? o Image quality issues that show up in Color Doppler, often are sometimes just Color issues alone. o Sometimes issues are the result of a 2D image issue that has movement and is more visible in color. o Try to visualize the artifact in 2D, with color turned off. If so your problem is actually a 2D problem not a color problem.
Ultrasound Image compared to Ultrasound Screen Ultrasound Screen Area Ultrasound Image Area (the entire pictured area) (Inside the RED area only) Image Area
2D image with noise that show up in Color Doppler o Here you can see there are noise lines running vertically through the image. o The noise is outside the color box, telling us that the problem is not in color but actually 2D. Noise
2D image with noise that show up in Color Doppler o This image shows the noise that we saw in 2D being highlighted by color. o It would be easy to think this is just a color issue. o Good troubleshooting revealed the truth, the noise is in 2D, therefore the color sub-system is not at fault. Noise
First the Transducer then move Beyond o Ultrasound Transducers are the number one cause of image quality issues! o It is always wise to eliminate the transducer first. o Do this by moving the transducer to another unit or trying another transducer on the current unit. o Remember that some artifacts can be frequency related, therefore it is always best to use the exact same type of transducer to swap with. If one is not available, get as close to the same frequency as possible. o For the rest of our discussion today we will assume the transducer is good. o Now we must use our knowledge of what we know and what we have discovered based on looking at the ultrasound image.
The Quick Fixes o Sometimes we can try one of the following techniques without getting to deep into the problem and achieve a quick fix to an image quality problem. o NOTE: You must first have a solid idea on what the image quality problem looks like before you start down this path. Otherwise you could make your system actually look worse! o The fast things to check or try: o Monitor adjustment and cleaning o Restoring Presets o Reseating Boards (resolves oxidization issues) o Running DC offset on units that have this calibration o RFI interference
Quick Fixes: Monitor Adjustment and Cleaning o Ultrasound Monitors will often need adjusting over their lifespan. o Not as needed with LCD as it is with CRT monitors. o Most CRT units are now old and should have been adjusted a few times by now. o Adjusting the Monitor o I advise adjusting the monitor in the presence of the sonographer. o Sonographers are very attached to the “look” of the image, adjusting the monitor will change that and the sonographer needs to be okay with what you are doing.
Quick Fixes: Monitor Adjustment and Cleaning o Remember when adjusting a monitor o Record starting point o If it is an analog monitor, mark the knob position with a marker. o Set room lighting correctly to how the Sonographer would have it when scanning. o Adjusting the brightness first for setting the background level. o Adjust the Contrast for setting the gray level of the image. o If the adjustment does not go well, start over back to your recorded settings and try again. It is easier then trying to force it to work. o Clean the monitor o I have found a monitor or two over the years that has developed such a film on it that a simple wiping down did nothing, it needed to be scrubbed, after which the image was much brighter!
Quick Fixes: Restoring Presets o An accidental change to a preset or a unit failure that results in a change to a preset can cause the image quality to be poor. o This can also come from a new sonographer making a change to a unit and accidentally changing setting they were unaware of. o I have also found some students will make changes while learning equipment. o This can often be verified by looking at images on PACS from a month or two ago to see if the presets have changed. o If the unit was recently upgraded it would not be wise to install older presets into the unit. o Make a backup of the Presets before you restore older ones, that way you can always get back to where you started.
Quick Fixes: Reseating Boards o All boards have the potential to oxidize, when they do they can cause an image quality issue. o These issues tend to be the type that we have a hard time pinpointing exactly what is wrong with the image. o These issues can look like any image quality problem. o It is almost always worth a try to reseat boards to resolve and issue. However, the success rate of repair is low. I would say around 10%. o Again, understand your problem first so you can tell if you resolve anything after the reseating is completed.
Quick Fixes: Running DC offset o If a unit has a DC offset utility, loosing that data can cause an image quality issue. o This applies mostly to the GE Vivid ultrasound unit series, plus the GE Logiq E9. o Also some units store their DC offset on the Preset disk, so you may accidentally restore an old (not accurate) offset back into a unit. o Running DC offset can restore an image to it’s proper diagnostic image. o Run anytime you replace a front end board.
Quick Fixes: RFI o Radio Frequency Interference, can create 2D, Color, PW, or CW artifacts. o RFI can invade the system via few different methods and honestly some are not even RFI, some are ground loop noise or even magnetic interference. o Generally RFI displayed in an image will have a moving component to it. I have often had people describe it as raining. It is often seen in color first, because the unit picks up the movement and colorizes it like blood flow. o If the unit does not display any noise until the transducer is picked up or placed onto a patient this is often ground loop noise and nearly always from an external source. o This is listed under quick fixes, and sometimes they are quick, but many times it is not. o The most important thing is to identify and duplicate the problem! o These problems can be frequency specific. o Remember that the unit itself can create RFI.
Quick Fixes: RFI o Here is a picture of RFI. What you can not see here that the curved lines in the far field are moving. o When color is applied that motion turns into rows of color artifact. o This is a situation where knowing this occurs in 2D helps us determine that this was in fact RFI. o Notice also how the lines are curved, this is because they where using a curved probe. o Video of RFI, notice how it moves.
Quick Fixes: Finding RFI o If you believe the problem is RFI you need to troubleshoot the environment. o Take the unit to a different location and see if you can duplicate the problem. o Make sure the new location is very far away and no chance it is on the same electrical circuit. o Often a closed up XRAY room is great, the lead walls help isolate the unit from RFI. o If this resolves the problem you can begin the task of finding the cause. o Many, many things can cause RFI, here are a few I have found: o Light switches (particularly dimmers), Gel Warmers, Halogen lamps, Ethernet jacks, Ethernet patch cables, oscillating fans, any florescent bulb, TV’s, video cables to external monitors, motorized beds, coils of wire in a drop ceiling, or anything else that is electronic / motorized can be a potential cause! o If isolating the unit does not work then you must assume the noise if from the unit itself and continue to troubleshoot.
Isolating to the Front End or Back End o When trouble shooting image issues and the transducer has been eliminated as the fix the first thing we want to do is figure out if it is a Scanner issue or Scan Converter issue. o The Scanner is also called the Front End o Scan Converter is also called the Back End o Generally in ultrasound image formation problems can be attributed to either the front end or the back end. Once we eliminate one it reduces the number of pieces that we need to think about. o There are a few things that we can look at in the image / artifact to help us determine where the problem is occurring. o First we will focus on Horizontal vs. Vertical problems o Second, partial image compared to whole image issues.
Vertical Image Issues o When you have vertical lines in the image area, not whole screen it is most often an issue with the Front End of the unit. o These lines are generally black, however it is possible for them to be white o Most ultrasound system front ends compose the ultrasound image line by line. o Zonare would be the one not like this, they use a different technique. o Due to this type of image formation, each line (or sometimes small groups of lines together) are formed separately. o Each board in the Front End works on each line individually (or in small groups) until they are all added together. o They are added together as the data moves through the system, it is too much discussion for today but is a process called Summing Delay Line processing o The ultrasound information remains as a single line or block of lines up to usually the last board in the front end, generally at the last board the image is now whole.
Troubleshooting Vertical Image Issues o Therefore when a unit has a vertical image issue problem we will look at the front end of the unit. o Troubleshooting is easiest with a linear or curved linear transducer. o Try the transducer in each port, it is possible to have a bad port. o Most units have multiple transmit / receiver boards or channel boards. o These boards can often be rotated which will may result in the vertical line moving in the image. Here is an example of the vertical line shift from moving channel boards.
Horizontal Lines o Based on how the ultrasound image is formed it is very difficult for a horizontal line to be caused by the Front End, they are generally Back End problems. o There are two types of horizontal lines. o Lines that remain in the image area. o Lines that travel out of the image area. o Horizontal lines in general are rare. o Horizontal lines inside the image area, based on experience, are related to ram storage. It is best to look at the boards that have large amounts of ram. o Horizontal lines that exceed the image area can also be attributed to the display processing of the unit. o Look at anything that is developing the video signal of the unit.
Partial Image Issue Compared to Whole Image Issues o The hardest image quality problems are those where the image just does not look right. o Often described as “grainy,” “too black/white”, “too gray”, “too bright”, “too dark” or the classic – “seems like there is a film over the image.” o These problems don’t have lines associated with them. o Often these problems look different on different people. o These can be daunting issues and will require a fair bit of comparative scanning. o These problems usually fall into two categories, the entire image area or partial image area. o This area of troubleshooting will take more than a cursory knowledge of the unit. You will need a solid understanding of how the image is processed in order to help eliminate boards or sub-systems from the list of possible prospects.
Partial Image Issue Compared to Whole Image Issues o In order to help eliminate boards or sub-systems from the cause it will help if we can tell if the image problem is the entire image area or just part of it. o If it is part of the image area then you can exclude boards that operate on the whole image. o If a board effects the entire image it is not likely that it would cause a problem in just one area. o The focus should be placed on boards the effect parts of the image area. o Often these will be channel boards or beamformer boards but can include transmitters, receivers as long as they are not handling them in single line mode. o If it is the entire image that has the problem then look at boards that effect the whole image. o Focus on boards that work on the entire image at once. o Also boards that handle each line coming back can make every line look bad and therefore make the image look bad. o Don’t forget to think about the system power supplies. o Let’s work through an example, watch this video.
Tools that Can (or Can’t) Help o Diagnostics and Logs o Ultrasound units don’t generally see image quality problems in their diagnostics. o Most diagnostics are really good at saying something works or it does not. With image quality it “works” but just looks bad. o They can work some with problems like lines being out, but not just bad image quality. o The same goes for Logs, there is nothing in a Log because the unit does not know it has an issue. o Phantom o Can be somewhat helpful, certainly with dropout problems. o With partial or whole image area, image quality problems, a Phantom is just to easy to scan modern ultrasound units. o In these situations you will need to scan yourself.
Wrap it up with a Backup! o When you are done, you should always back up your presets again. o This is a practice of mine nearly every time a touch an ultrasound unit. o I often do this even when I change nothing! o It is a great practice and you can never have to many preset disks. o CD’s or DVD’s are just one scratch from being useless. o Another great idea is to write the unit’s IP address information onto the CD or DVD.
Summing it UP o Define and Identify the problem. o Confirm or eliminate the transducer. o Try the Quick Fixes. o Isolate to the front end or back end of the ultrasound unit. o Horizontal vs Vertical Issues o Partial vs Whole Image Issues o Remember nothing replaces scanning yourself. o Create another backup.
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