PRESENTATION OF IMAGES PERFORMED

When I undertake a shoulder ultrasound I have the patient seated in an office chair without the side arms. I find this useful as the mobile chair makes it much easier to move the patient into position. It is especially helpful when I only want to make small movements.

I have also adapted the position of having the patient away from me in the chair. I find this gives me better posture for the scan, whilst at the same time I can keep the patient in the position I want by pushing with my arm and body. I did try scanning from directly in front of the patient, but I found I was almost reaching towards the patient and couldn’t get the power and strength I needed for the scan.

1. Bicep Tendon

How to image the bicep tendon:

The arm should have the forearm flexed to 90 degrees with the palm facing up. The forearm should rest on the patient’s thigh. The bicep tendon can be identified between the greater and lesser tuberosities. Imaging should be performed in both axial and longitudinal planes.

Slide the probe superiorly to its position between the supraspinatus and subscapularis tendons. It should be examined from this point down to the myotendinous junction (Beggs et al, 2012).

The two examples above show the bicep tendon with a fibril seen. Not a lot of detail can be gained from the images due to the depth setting. The setting should be altered to make sure the region of interest, being the bicep tendon, is brought closer to the surface. Probe pressure and heel/toe of the probe could also be used to ensure the best visualisation of the tendon that can be achieved. Both images have adequate gain settings.

The two images above are a better representation of the bicep tendon. The tendon is zoomed up and makes visualisation of the tendon fibrils better. In both images the fibrils are well visualised and allow a more accurate assessment. The depth and the gain are both well set for the tendon. The positioning of the probe has ensured that anisotropy is not present – the tendon is well visualised.

The set of four images above show the bicep in its entirety in the longitudinal plane. Whilst they are scanned in the correct regions, it is important to note that in order to see the tendons adequately the probe needs to be parallel to the tendon fibrils. Probe pressure is needed to alter this phenomenon and ensure the tendon is better visualised. It is also important to note that the bicep needs to be visualised over the top of the humeral head as far as possible to assess for tendinopathy. This is an area of compression so it is important to show.

These images above show a better visualisation of the tendon fibrils. The second image shows the tendon as it passes over the humeral head, which is further than the first group of images assessed. The third and fourth images show the distal bicep tendon with the probe parallel to the tendon fibrils. The images below really show a better positioning of the probe in relation to the tendon and a better coverage of the superior portion.

Of all of the tendons I found the bicep the easiest to be comfortable in scanning. In most patient’s it is a superficial tendon and it easily identified running down the middle of the humerus bone. Knowing the normal anatomy of the bicep and the position it should be found in makes scanning the bicep much easier than other tendons of the rotator cuff. The main aspect I had to practice when I first started scanning shoulders was to ensure good probe pressure and angling the probe to show the tendon fibrils well. It was surprising to see how much probe pressure and heel/toeing of the probe was required to produce a good quality image.

2. Subscapularis

How to image the subscapularis tendon:

The forearm should be rotated externally as far as possible with the elbow sitting in by the patient’s side. The tendon should be imaged in both the longitudinal and transverse planes (Zelesco et al, 2014). It is often also useful to image the tendon during dynamic internal and external movement (Beggs et al, 2012).

The two images above were my first attempt at scanning a shoulder. Whilst both images show tendon fibrils, the second image is not a true representation of the subscapularis tendon. It appears to be taken to superior. Both images have adequate depth and gain settings. The main issues would appear to be that the subscapularis tendon has not be shown in full.

The three images below show a much better representation of the subscapularis tendon. You can identify that the probe has been moved to adequately show the entire tendon has been shown. The probe pressure is adequate to show as much of the tendon as possible in one go.

The two images above are of the subscapularis tendon in transverse. The image on the left shows a slightly better attempt at the subscapularis tendon. The image on the right does not appear to be a true transverse of the subscapularis tendon. Due to the rotation of the tendon and the position versus the humerus it is difficult to determine if the tendon imaged is actually the subscapularis.

These three images are a better representation of the subscapularis tendon. All of the images show a nice rounded humeral head. The middle image even shows the bicep tendon, this is good as the subscapularis tendon sits medially to the bicep tendon.

When scanning the subscapularis tendon positioning of the shoulder is very important. The arm needs to be fully externally rotated to ensure the tendon is visualised sufficiently. With the arm in a neutral position only about 10% of the subscapularis tendon can be visualised, meaning the tendon has not been fully assessed (Zelesco et al, 2014). Practicing on work colleagues made locating this tendon and probe position easier over time. I found that locating the bicep tendon and then sliding the probe medially showed the subscapularis tendon nicely. Again probe pressure is important to ensure the probe is parallel to the tendon fibrils.

3. Infraspinatus

How to image the infraspinatus tendon:

The tendon is placed over the posterior shoulder compartment of the glenohumeral joint. The hand should be placed on the shoulder of the opposite side. The infraspinatus muscle can often be followed to find the tendon insertion onto the humerus (Zelesco et al, 2014; Beggs et al, 2012).

The two images above are my first attempt at scanning infraspinatus tendon. The two images do not demonstrate the tendon well. The first image does not show any tendon insertion and appears to be too inferior. The second image appears to be too high and appears more like the supraspinatus tendon inserting onto the top of the humerus. The first image does not demonstrate the tendon fibrils well and it would be difficult to determine if there was a partial tear present. The first image is actually difficult to assess if a tendon has in fact been imaged.

The four images above are a much better demonstration of the infraspinatus tendon. It shows the thin tendon from its insertion as it passes over the humerus. Technically the images have a nice fibrillar pattern for the tendon and the contrast is gain is set

well enough to see if there is any hypoechoic regions within the tendon which would indicate a tear.

I definitely found imaging of the infraspinatus tendon very difficult to begin with. As the tendon is generally much smaller than other rotator cuff tendons it took my eye and positioning of the probe longer to adapt. In larger patient’s this is still a tendon which can be more difficult to visualise well due to detail of a smaller tendon. Imaging of the infraspinatus tendon took a lot more practice. At least now, even with the larger patient, I am more confident in my probe positioning to detect the infraspinatus tendon.

4. Posterior Shoulder – including joint, labrum and glenoid notch

How to image the posterior shoulder:

With the hand on the opposite shoulder the transducer is placed over the glenohumeral region of the posterior shoulder. The labrum should be assessed if the patient’s body habitus allows. Effusions and cysts should be assessed in this region (Beggs et al, 2012).

The two images above were performed to image the glenoid labrum. The two images have highlighted the area where the labrum is seen. Both images show this structure well. Penetration and technical settings are adequate to see the labrum and assess if there are any cysts or if there is a joint effusion present. Neither of those pathologies were seen on these two patients. Both of the above images show a smooth labral out line with no protruding labral cysts or bulging synovial fluid.

This image above is a more complex patient. The glenoid region is seen a lot deeper than two patients previously. Because of this a curved linear transducer had to be used to produce adequate penetration. The image is able to demonstrate the bulging of the synovial fluid above both the humerus and glenoid regions. Due to the lower frequency transducer used the labrum cannot be seen as well due to the lack of detail.

It is important to note that due to the increase in depth of the posterior labrum and shoulder joint a lower transducer probe may be used. If this is done it must be remembered that in order to penetrate the depth detail is lost and more subtle structures may not be seen well if at all. This a trade-off that the sonographer needs to make a decision on in order to aid the diagnosis.

I found imaging of the posterior joint compartment and the glenoid labrum not too difficult to grasp. The main issue I found when starting out was locating the joint. Initially I found I would always start too medial and would have to slowly scan laterally to find the joint. My main issue with imaging of the posterior compartment of the shoulder is due to its depth. The deep structure can often make visualisation poor meaning that subtle lesions may not always be seen. If this is the case I will tell the Radiologist that posterior visualisation is poor and why. I will also tell them what factors I have tried to improve the image.

5. Supraspinatus

How to image the supraspinatus tendon:

The biceps should be used as a landmark. Both tendons run parallel to each other with the bicep having a more defined fibrillar pattern. The supraspinatus tendon will be found posterior to the bicep tendon. Imaging should be performed in both transverse and longitudinal planes (Beggs et al, 2012)

The hypoechoic region, circled, is a posterior joint

effusion.

The set of three images above were from my first (unofficial, out of hours) attempt at scanning a shoulder. The images are of the correct shoulder region but they are not adequately rotated over the tendon to show it appropriately. Whilst tendon fibril could be visualised it is the fact that the tendons weren’t shown in a better, longer, longitudinal view that makes them of poor quality.

These four images are a much better representation of the supraspinatus tendon. The tendon fibrils are shown clearly in the anterior, middle and posterior sections. These images are true longitudinal view of the tendon so would be able to adequately identify any tendinopathy or tears.

The biggest improvement is that the probe is now in the true longitudinal plane to the tendon. This means that a greater portion of the tendon can be seen to assist in assessing for tendinopathy or tears. The tendon is seen in its entire insertion onto the humerus. This is especially important to assess for tears at the region of the origin of the supraspinatus tendon.

The three images above are not adequate representations of the supraspinatus tendon in transverse. The plane is not transverse to the supraspinatus tendon. It has a more obliqued appearance. There is also inadequate probe pressure meaning the tendons are not visualised well to their anterior and posterior portions. The depth used in the image could be decreased. The current depth takes into account too much humerus, which is of no clinical significance for the image.

These three images are a much better representation of the supraspinatus tendon. The tendon fibrils are shown clearly in the anterior, middle and posterior sections. These images are true transverse to the tendon so would be able to adequately identify any tendinopathy or tears. The depth is set to adequately cover the region of interest, which is the tendon rather than the humerus. There is adequate probe pressure used to ensure the tendon is fully visualised.

Whilst the seven improved images below of the supraspinatus look really clear and show a lovely tendon, I found imaging of this tendon difficult to get to such a high quality. We often see patients with poor rotator cuff tendons, so mastering the ideal images took time. Similar to the subscapularis tendon I use the bicep tendon as my guide to positioning. When I find the bicep tendon I move laterally to ensure I am over the supraspinatus tendon. From this point I turn the tendon out in longitudinal and image across the tendons width.

6. Acromioclavicular Joint

How to image the acromioclavicular joint:

The probe should be placed in the coronal plane on top of the patient shoulder. Sweeping through the joint from anterior to posterior is important to assess the entire joint (Beggs, 2012).

The AC joint is a very superficial structure so gentle probe pressure is important. If pressure is too great effusions or cysts may be missed. Both images above had adequate depth settings to not only see the top of the AC joint, but also into the joint to ensure there is no cyst or separation.

The image above is shown to demonstrate when pathology is seen that an extension from protocol is performed. The image on the left was of the right AC joint, which was the side requested to be imaged. The ultrasound was highly suggestive of a subluxation of the joint. To aid in this diagnosis a comparison view of the left side was also performed to show a normal AC joint for this patient.

Similar to the bicep tendon I found imaging of the AC joint easier than some of the other tendons. It is superficial and is seen or palpated easily. What I needed to practice was to ensure I stayed straight over the joint and didn’t oblique through it. I also had to ensure I kept soft probe pressure to make sure I didn’t miss any fluid collections or cysts that could be decreased with pressure.

7. Subacromial/subdeltoid bursa and

This was something that my eye took a little bit of time adjusting to. I found the bursa was easier to identify if there was an increase in bursal fluid. If there wasn’t an increase in fluid, but rather just thickening of the bursal walls I initially struggled to differentiate this with the tendon and muscles around them. As I performed more

scans and became more confident with my anatomy, both normal and abnormal, I was happier in identifying the thickened bursa.

The images below are those of the subacromial-subdeltoid bursa. When I first started I would assess the bursa for thickening or fluid and a senior would perform the dynamic assessment for impingement. As I became more confident I was able to also assess for impingement.

The spilt image on the top right was one I performed while supervised by a senior sonographer. It shows the extent of the bursal thickening and impingement on abduction. The third image on the bottom was one I performed myself. I have been told to always label the degree of abduction to allow the Radiologist to correctly assess impingement. Ensuring I could initially position the probe correctly and then stay in that position during dynamic assessment was something that I had to work on. When I first started dynamically assessing for impingement of the bursa I would find my probe sliding slightly off the region of interest. This took a lot of practice, but probe pressure and concentration makes it easier.

The two images above are of non-dynamic assessment of the SASD bursa. Both of the images have been taken as the supraspinatus tendon inserts into the humerus. I was also told to ensure that the measurement of the bursa included the bursal walls, not just the fluid contained within it.

Overall my imaging of the shoulder has improved over time. It took me lots of practicing on friends and work colleagues to practice techniques and probe pressure and positioning. Whilst I found some of the imaging easier than others (such as the bicep and AC joint) some tendons took me time to master to ensure I could assess a tendon in its entirety (e.g. supraspinatus and infraspinatus).

My images have developed with help from senior sonographers who taught me techniques and made sure I could optimise my images. The Radiologists have also assisted me immensely by educating me on pathologies. I found that the more time I put into understanding the anatomy it made the comprehension of locating the tendons easier. When I became more confident in my anatomy it made it easier to place the probe in the correct position. It also made understanding of the shoulder movements to better visualise the tendons – I was able to image the tendons in my head and determine how they would change with certain shoulder movements.

I look back on my earlier images and wonder how I could have produced them. I was glad they were only practice images on friends and colleagues, as they needed so many changes to make them acceptable. I am glad I have the chance to look back on them to see how far I have come. Even though I regularly undertake other types of ultrasounds, the transition to performing a shoulder ultrasound took a lot of time and practice. I now have a greater appreciation of MSK sonographers and I can understand the theory and practical training that they have to undertake to become so good at what they do.

Over the past 4 months I have seen my own improvement in shoulder ultrasounds. I know my senior sonographers have also seen progression from basically needing 1 on 1 supervision to start off with, to being able to perform shoulder ultrasounds with myself and a consultant MSK Radiologist. I am confident in understanding the clinical assessment prior to starting the ultrasound scan. I always explain this to the patient and role it plays in providing adequate images for the Radiologist. I am confident in talking to the patient throughout the examination and I feel I am able to make the patient feel at ease and comfortable both for the examination and in my presence. I always try and make the examination as comfortable for the patient as I possibly can, always trying to put myself in their position and performing the scan how I would feel comfortable.

I always follow the examination protocol. I understand that the protocol we have in place is the minimum number of images required to complete an examination. I am now quite comfortable and confident in expanding an examination where pathology is suspected or seen. I will scan the opposite side to allow comparisons to be made to normal anatomy (in most cases anyway). I will use colour Doppler for suspicions of tendinopathy and tears and I am aware of my compression in these situations.

Just recently I expanded my examination on a patient who came in for a shoulder ultrasound following trauma 2 weeks prior. I expanded my scan given that the patient had very specific pain. It turned out that this patient had a resolving hematoma in the deltoid muscle that I would have missed had I just stuck to the department imaging protocol.

I still recognise that I have limitations such as taking a little bit more time than others (our senior sonographers can complete a shoulder ultrasound in around 15 minutes). I also acknowledge that assessing and differentiating between tears takes me longer. When I have completed my scan I am always happy to present my findings to the Radiologist. I am also happy to speak to the Radiologist if I have an issue differentiating pathology or tears. I am happy with how far I have come since starting shoulder ultrasounds. I understand that I still have a long way to go, but the more practice I get the more confident I get and the better my images I produce.

References

Beggs, Bianchi, Bueno, et al. Musculoskeletal Ultrasound Technical Guidelines – Shoulder. European Society of Musculoskeletal Ultrasound. Accessed online August 3rd 2015. http://www.essr.org/html/img/pool/shoulder.pdf

Ultrasoundpaedia. Accessed online 21st May 2015. http://www.ultrasoundpaedia.com/normal-shoulder/

Zelesco, M, Halaveskevich, E and Abbott S. Royal Perth Hospital Ultrasound Department Protocols. 2014.

All ultrasound images used above have been produced by myself. I have deidentified all of the images for the purpose of the assessment.

The model images depicting probe position have all been taken from Ultrasoundpaedia.