Ultrasound in Rheumatology

Consultant Musculoskeletal Sonographer, Alison Hall shares her Top Tips on Ultrasound in Rheumatology

1) Ensure that the request is justified?

Nice guidelines suggest that patients seen by their general practitioner with symptoms of inflammatory arthritis (IA) in the hands or feet where more than one joint is affectedshould be referred urgently to rheumatologists (1). In this group of patients, ultrasound scanning before referral is not indicated as delays and mis interpretation may lead to reduced outcomes for patients.

The diagnosis of Inflammatory conditions can be complex and relies on a combination of clinical and family history as well as a range of tests.These may or may not include ultrasound imaging as it may not be required in unequivocal cases and even where there is diagnostic doubt, a negative ultrasound scan does not exclude inflammatory arthritis.

It is useful for MSK sonographers and Radiologists to be able to recognise the common features of inflammatory arthritis in case they encounter them on routine MSK lists or if patients are referred for a scan from Rheumatology however they must understand the basics of inflammatory disease and the clinical significance of the appearances they may see.

2) Take a clinical history from the patient/referrer

Available clinical history is notoriously limited on ultrasound scan requests.In any area, this may result in misunderstanding/mis interpretation of ultrasound scan findings and the area of rheumatology scanning is no different.

As well as the importance of current disease status of the patient – is this a new patient for whom the scan is being used to aid diagnosis or is this a patient with known RA for the assessment of disease activity – it is vital for correct image interpretation that the sonographer/radiologist is aware of any medication being used to treat their symptoms.

Of particular importance in IA is the effect that steroid – intramuscular, oral or intra articular – has on Doppler activity.As the presence or absence of Doppler activity within the synovium has been proven to correlate with disease activity (2), any drug which reduces that activity, may result in a missed diagnosis of IA or misinterpretation of disease remission.

It is therefore vital that the sonographer/Radiologist has access to a list of current medication of their patient and questions them specifically around the use of steroids – this includes the use of steroids in other diseases such as asthma.

If patients have had any steroid treatments in the preceding 6 weeks, any potential reduction in Doppler signal must be taken into account during the scan and interpretation of findings and should be mentioned on the report as a possible cause of reduction in disease activity.

3) Ensure your equipment is correctly set

The scanning of small joints to confirm or exclude appearances of inflammatory arthritis such as active synovitis, relies heavily on the correct set-up of the ultrasound system.Grey scale imaging must allow for subtle detection in soft tissue changes around joints and tendons but more importantly, as previously stated,increases in Colour/power Doppler activity have been proven to correlate with levels of disease activity (2).

It is vital that imaging systems used for rheumatology examinations are of appropriate quality to allow for high resolution imaging and that the Doppler settings – in particular PRF, wall filter and colour/power Doppler frequency are set to detect low vascular flow in the soft tissue structures of joints.It is also vital that these parameters are altered according to patient habitus and the relative depth of joints to ensure that subtle low flow within joints is not missed.

4) Ensure good ergonomics

Good ergonomics are key to a long and healthy career for ultrasound health care professional.It is also vital that ultrasound examinations, some of which may be lengthy, do not cause unnecessary pain and discomfort for patients.

Most ultrasound examinations are performed with the patient sitting or lying on an examination couch.However when scanning the hands, it is common to see the patient sitting on the far side of the couch, arms extended, resting their hands on the mattress.It is also common that patents are unable to put their knees under the couch due to the rise/fall mechanism.

This patient position often causes the patient considerable discomfort, especially when that have an inflammatory arthritis.It also necessitates the sonographer/Radiologist turning their head away from the patient in order to see the screen.This frequent, repetitive turning can cause long term biomechanical issues for the individual.

One alternative to this is for the patient to sit on the couch with the back of the bed raised, feet resting up on the mattress.A pillow is then placed on their knees and their hands then rest on the pillow.This enables improved patient comfort and a more ergonomically sound position for the sonographer.

5) Standardised, thorough technique

Imaging interpretation relies on a sound knowledge of normal appearances in order to recognise the sometimes subtle changes that occur in disease progression.One factor to consider has always been standardisation of imaging technique so that any alterationsin appearance are not due to positional or equipment changes.It is also important to appreciate the prevalence of the detection of significant inflammation in asymptomatic joints and also of age related changes that occur in symptomatic joints to reduce the chance of mis-interpretation and subsequent mis-diagnosis .

It is for these reasons that standardised protocols with systematic scanning (often including asymptomatic small joints of the hands)in patients with suspected inflammatory arthritis is vital and that training includes patients of all ages and those with obviously active disease.More general considerations include the use of copious gel, slow, methodical scanning, light probe pressure and the optimisation of colour/power doppler controls.

If you want to learn more , access the Guidelines for Professional Ultrasound Practice and look out for BMUS study days that include this subject.


  1. https://pathways.nice.org.uk/pathways/rheumatoid-arthritis#content=view-node%3Anodes-when-to-refer-for-specialist-opinion
  2.  Porta et all ‘The role of Doppler Ultrasound in Rheumatic diseases Rheumatology’ 51:6 2012 976-982