Ultrasound is a low-cost, non-invasive way of giving a diagnosis or more information. It can also be used to help with procedures, so your doctor might suggest doing an injection or procedure with ultrasound guidance.
Ultrasound can help evaluate pain around your body. Ultrasound and other imaging techniques like MRI give different information, so if you’ve had one the other may still be useful. If you think you tore a muscle or a tendon, we can evaluate the area with ultrasound to see. Additionally, for young pediatric patients, sometimes we can use the ultrasound to evaluate for broken bones and avoid doing X-rays.
Ultrasound is like a box of crayons but all of them are shades of gray. Based on the structure of the tissue, the structure will appear brighter or darker. A trained provider knows how to set the machine, where to look, and how to evaluate the images.
How an ultrasound works
Ultrasound is sound waves and the image is made by the waves going into your body, bouncing off your tissues and coming back to the probe. The ultrasound machine shows these waves as a live, moving picture on a screen.
To use an ultrasound, a gel is placed on your skin and the probe is moved over the gel.
There are different ultrasound probes, each with different frequencies and in different shapes. Depending on the probe used, the image will change. For example, the hockey stick probe is a high frequency probe which allows high resolution images of superficial tissues near the surface of your skin. It works well for images of hands, fingers, feet or toes. The curved probe or abdominal probe has lower resolution but allows you to see deeper structures in the body. It works well for visualizing hip joints. For joints that are medium or structures that are not quite as deep, the linear probe is in between the other two probes and is used for evaluating the structure of the knee, looking at ligaments, or looking for fluid inside the need.
When you’re having an ultrasound, the ultrasound machine can show the insides of your body moving. For example, if you’re getting an ultrasound of the inside of your wrist and you move your fingers, you can see the tendons move. An MRI or an X-ray is a single still image, but your doctor can see moving parts in an ultrasound. For instance, if you’re not sure if you have injured your finger, your doctor can move the ultrasound probe down the length of the tendons of your finger to make sure that they are still connected and that there are no tears, fluid around the tendons, or other abnormalities.
An X-ray may not show a foreign body such as a splinter in your body, and an MRI is overkill, but an ultrasound will show it easily and allow a doctor to remove it.
Frequently asked questions
Does ultrasound require a referral?
No, it does not. We can do the ultrasound at your appointment if you have a problem where I think ultrasound would be beneficial.
Is ultrasound covered by insurance?
Yes, it is. Typically, you do not need prior authorization for a diagnostic evaluation. However, if ultrasound is being used to guide a procedure that may require an authorization.
What do you mean by having the ultrasound guide a procedure?
Injections, such as steroid injections, platelet-rich plasma injections or other procedures, are common in orthopedics. If you need an injection, I can use ultrasound to guide the needle so as the needle is being inserted I can track its progress live in real time.
If a joint is painful but an X-ray doesn’t show anything concerning, would ultrasound be a good next step?
Absolutely. Ultrasound gives different information than an x-ray. An x-ray is great at looking at bones, while ultrasound struggles looking at bones because the sound waves do not pass through the bone.
Is there any hurt or discomfort from the ultrasound?
No, generally not. There may be some discomfort if, for instance, someone has a cut and I need to scan over it to see if a tendon is intact. I try to be as gentle as possible and for the most part it is relatively painless.
How much pressure do you have to use?
Very little pressure. If I need to scan a sensitive area, there are techniques to avoid even light pressure. For example, I can use extra gel and make a thicker layer of gel so that I’m not pressing on the surface. If I need to not touch the area at all, I can submerge the body part in a basin of water and use the water to transmit the sound waves instead of the gel.
Does the ultrasound treat an area or is it just diagnostic?
The type of ultrasound that I'm referring to and that I use is a diagnostic modality. It is not a therapeutic ultrasound. The only time it becomes therapeutic is when it's guiding a needle.
Can you get an ultrasound if you have metal in your body?
Absolutely. In fact, ultrasound may be more advantageous than some other imaging in that scenario. For instance, if you have hardware in some part of your body and we're trying to evaluate if that's causing pain or discomfort or irritating the surrounding tissues, ultrasound is a good way to look at that area.
Can you diagnose pain around knee and hip replacements with an ultrasound?
It depends. Ultrasound may be a test ordered if there is any concern about fluid collection or a muscle tear. If it's something to do with the hardware or inside the joints then often you will need additional tests.