Ultrasound in inflammatory arthritis –

can it help me?

Spring 2010: Trish Cornell, Senior Rheumatology Practitioner

Taken from NRAS magazine, Spring 2010

Introduction

Some of you may be aware of a new method of looking at your joints for inflammation when you attend your rheumatology department. Over the past few years there has been some very good evidence to suggest that looking at joints using an ultrasound picks up more inflammation in the joint than can be felt on examination  and also damage to the bone at an earlier stage than an x-ray can. Several rheumatology units around the UK are either providing this service or are fundraising in order to purchase a machine for their department.  

What is ultrasound?

Ultrasound is a machine that uses sound waves that you can’t hear to bounce off tissues in the body. It travels freely through fluid and soft tissues but is reflected back (echoes) when it ‘hits’ a more solid surface. It doesn’t hurt and uses ‘jelly’ to cushion the probe from the skin and allow transfer of the picture to the computer screen.

What does an ultrasound scan involve?

To ultrasound your hands you would normally sit with a cushion in your lap or on a couch. The operator places a probe on your skin over the part of your body to be examined. The probe is a bit like a very thick blunt pen. Lubricating jelly is put on your skin so the probe makes good contact with your body. The probe is connected by a wire to the ultrasound machine and monitor. Pulses of ultrasound are sent from the probe through the skin into your body. The ultrasound waves then echo ('bounce back') from the various structures in the body.

The echoes are detected by the probe and are sent down the wire to the ultrasound machine. They are displayed as a picture on the monitor. The picture is constantly updated so the scan can show movement as well as structure. A record of the results of the test can be made as still pictures or as a video recording.

Are there any side-effects or complications from ultrasound?
Ultrasound scans are painless and safe. Unlike x-rays and other imaging tests, ultrasound does not use radiation. It has not been found to cause any problems or complications.

How Is Doing An Ultrasound Helpful?

Here are some examples:

To start methotrexate or not in early disease? If you present very early with rheumatoid arthritis it can be difficult for us to be confident that that is the problem.  A scan by an experienced person can reveal signs of rheumatoid before they can be picked up on examination. This means we can treat the right people early with Methotrexate and similar drugs and be more confident about not treating the people who do not need it.

Should the dose of methotrexate be increased? Sometimes it’s difficult to decide whether the arthritis is active or not even with examination, particularly if the blood tests don’t show inflammation. Ultrasound can show us if the disease is active or whether the pain and tenderness is coming from damage in the joint. Sometimes people are reluctant to increase their medication even if they have active disease, the ultrasound machine can help to show you what is happening in your joints. Using the doppler shows inflammation in your joints on the screen as red ‘fire’, this is really useful to show you and your partner or carer if they accompany you to the clinic appointment how active the arthritis is.  

Conclusion

Ultrasound is a really useful tool for rheumatologists and specialist nurses to use when monitoring the effectiveness of treatment and disease activity. It’s very safe and does not cause pain to the patient. Unfortunately the machines are quite expensive and range in price from £18,000 to £125,000 and although most rheumatology departments would like to use ultrasound in their daily practice it is not always possible due to the cost.