What to expect from a diagnostic ultrasound and ultrasound guided procedure

For more detailed information on musculoskeletal ultrasound and its benefits please see this blog post.

Diagnostic ultrasound

When being examined, the doctor will be scanning the desired area by placing gel on the skin and applying the probe. The doctor will then proceed to look at the different structures in a systematic manner using established protocols. To make sure they don't miss important structures, they may not start with the area that bothers you first, but don't worry- they will indeed scan your most painful area.

When the physicians are scanning your body, they will often find structural changes to different body parts that are not painful, and may be incidental findings.  This would the equivalent to taking a high resolution photo of an older home- there may be many small signs of wear and tear that do not actually affect the function of the house.  This is especially true when scanning the body with ultrasound- since ultrasound is extremely high resolution (over three times higher than MRI), incidental structural changes are extremely common.

To help distinguish between incidental structural changes and those that are symptomatic, an important part of the examination is sonopalpation, which is applying pressure using the ultrasound probe.  This is one of the greatest strengths of diagnostic ultrasound- we can identify those structures that both have architectural changes and are also painful.  We refer to this as concordantly painful.  Throughout the exam the doctor will often ask if you are experiencing any pain. While the positioning of the body part itself may be uncomfortable, when asking this question, they are referring specifically to where the probe currently is being placed.

Some clinics will use an ultrasound tech to perform their ultrasound imaging.  At Lake Washington Sports & Spine, all of our studies are personally performed by the physicians, Dr. Chimes and Dr. Hyman.  One of the reasons we do it this way is that our physicians primarily view the ultrasound as an opportunity to educate their patients, helping patients become more aware of their bodies and how their structures influence their function and discomfort.  We encourage patients to ask questions, and they are welcome to bring friends, family members, and members of their treatment team with them.  We've had patients bring their physical therapist, personal trainer, or chiropractors to join them at the visit, which is a fun and educational way to make sure everyone on the team is on the same page.

Ultrasound Guided Procedures

While there are a number of different procedures performed in the office at Lake Washington Sports and Spine, the most common is a cortisosteroid injection, the so-called "cortisone shot". We encourage patients not to refer to these as cortisone shots though, because almost all injections are corticosteroid injections, and this does not help distinguish different injections from one another.  It would be analogous to referring to a surgery as a "scalpel surgery"- while this is technically true, it would not distinguish a small bowel resection from a breast reconstruction.

The most relevant information for any injection is two factors:
1. Where the medication was placed
2. How it got there

For example, we may refer to an injection as an "ultrasound-guided subacromial bursa injection."  This means that the injection was targeted to a very specific location within the shoulder (the sub-acromial bursa), and how we know how we targeted the injection (using ultrasound-guidance).   We specifically like to know if imaging was used to guide the injection, which dramatically increases the likelihood that the needle was actually where we thought it was.   For injections that don't use guidance, some use the term "blind" injections, since you are not directly visualizing the needle tip.  We usually refer to blind injections as "landmark-guided", meaning that the clinician used touch sensation to feel for the intended location.

The exact procedure will differ depending on what the body part is and what structure is being targeted, but the next paragraph will give a general idea for what to expect when having one of these done in our office.

The doctor will apply some gel to the skin and place the ultrasound probe over the area and scan it to localize the target. After this is done, the gel will be cleaned off and the skin will be cleaned with cleaning solution. At this point, the doctor will then inject numbing medication into the skin using a very thin needle.  To the extent that there is much pain during a procedure, the numbing is usually the worst part, although it is not particularly painful.  It causes a burning that lasts on average 8 seconds, and is usually significantly less painful than a blood draw or flu shot.

After numbing the skin, more gel is then applied and the probe is used to visualize the target. Once the target is adequately visualized, another needle is inserted and directed towards the target. Once the needle has reached the target, the medication is then injected. Often patients will feel some pressure in the area, but it should not be especially painful. Once the medication is administered, the needle is removed, the skin is cleaned off, and a Band-Aid is applied.

Patients will often ask what they are supposed to expect after the injection. Most patients will come off the table feeling at least some level of relief. Typically this is due to the numbing medication that was injected along with the steroid, which takes about 8 seconds to take effect. How long the numbing lasts for is variable depending on the patient, but can last anywhere from 2 hours to forever. The steroid medication works more gradually and often can take about 2 weeks before its peak effectiveness. 

It is not unusual for patients to feel relief for 2 hours or so before having the pain return. This is completely normal, and we advise patients to ice regularly and monitor how they are feeling until we see them for a follow up, normally about 2 weeks post injection.

The post-injection follow-up is important.  The injection is part of the overall treatment plan, but is not a substitute for other parts of the treatment, which will nearly always involve an exercise prescription, and may also include physical therapy or chiropractic care.  At Lake Washington Sports & Spine, we strongly believe in the need to "Rehabilitate beyond the Resolution of Symptoms," and a major focus of our aftercare is to make sure patients not only feel better, but also know how to prevent recurrences, and know tactics to bring their symptoms under control if they have a recurrence.