Clinical Application of Musculoskeletal Ultrasound in Rheumatology in Taiwan

Yu-Fen Hsiao

Department of Internal Medicine, Chu Shang Show Chwan Memorial Hospital, Nantou, Taiwan

Ko-Jen Li

Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan

Diagnosis of rheumatic diseases is difficult due to diverse symptoms that can involve the bone, joints, muscles, tendons, blood vessels, or nerves. In the past, physicians made diagnoses based on history-taking, physical examinations, serological tests, and X-rays. However, difficulties in diagnosing rheumatic diseases arose from limitations in the sensitivity and specificity of serological tests and X-rays.

Magnetic resonance imaging (MRI) has a high sensitivity for detecting tiny inflammatory or destructive changes, which can help physicians in early diagnosis or in the monitoring of disease progression. However, MRI has a number of disadvantages, including its expense, time required, and its limited use in evaluating renal function, which hinder the use of MRI in routine practice. In contrast to MRI, musculoskeletal ultrasound (MSUS) has the advantage of being able to provide convenient, fast and real-time images for early diagnosis and routine follow-up [1]. In evaluations of soft-tissue lesions, MSUS and MRI are more sensitive than plain radiography and computed tomography. MSUS has the advantages of being non-radioactive, inexpensive, portable, and repeatable. It can provide high-resolution, power Doppler, real-time imaging of articular, periarticular and soft-tissue structures in the evaluation of rheumatologic disease. Furthermore, ultrasound-guided procedures allow for better assessment of target lesions with minimal injury to adjacent tissues such as nerves or blood vessels [2]. There is growing evidence to show that MSUS can play a more important role in the diagnosis and treatment of rheumatic diseases.

Spondyloarthropathies are composed of five diseases with similar rheumatic presentations, including ankylosing spondylitis, psoriatic arthritis, reactive arthritis, spondylitis associated with inflammatory bowel disease (IBD) and undifferentiated spondyloarthropathy. Enthesitis is one of the most common features of spondyloarthropathies. However, the diagnosis is difficult to make due to lack of clinical awareness and there being no standard method for evaluation in the past. MSUS is considered a good tool for evaluating enthesitis, with a high sensitivity and specificity. There are many sonographic quantitative scoring systems for enthesitis evaluation, including the Glasgow Ultrasound Enthesitis Scoring System (GUESS), Mander Enthesitis Index (MEI), and the Madrid Sonographic Enthesitis Index (MASEI) [[3], [4], [5]]. In this issue of the Journal of Medical Ultrasound, Hsiao et al report a pilot study using GUESS to evaluate enthesitis in patients with and without IBD [6]. Subclinical enthesopathy with higher GUESS scores were found in patients with IBD. Thus, musculoskeletal involvement in IBD should not be overlooked by simple history-taking or clinical examinations. Further long-term MSUS follow-up is needed in IBD patients.

MSUS is more sensitive than plain radiography in the detection of synovial hyperplasia, effusion, bony erosions, and inflammation with emerging power Doppler signals, allowing earlier diagnosis of progressive rheumatoid arthritis. This is important as it is now possible to aim for low disease activity in rheumatoid arthritis in this era of biological agents. MSUS can be another tool to guide treatment other than clinical symptoms, laboratory examinations and radiography. Ultrasound is becoming a useful tool that is integrated into clinical practice and linked to decision-making [7].

According to Raftery et al, MSUS performed by a rheumatologist aided diagnosis of synovial and tendon inflammation and guided injections, while MSUS performed by a radiologist aided diagnosis of structural pathology [8]. It is essential for rheumatologists to acquire ultrasonography skills in order to improve patient care [9]. The accuracy of ultrasound examinations is operator-dependent and the technical capabilities of MSUS are a critical issue in the extensive application of MSUS in rheumatology practice. In this issue of the Journal of Medical Ultrasound, Chen et al present a study of MSUS and MRI in detecting full-thickness rotator cuff tears [10]. With arthroscopic findings as the gold standard, MSUS performed by a qualified rheumatologist has good sensitivity and accuracy in detecting full-thickness rotator cuff tears, with good agreement with MRI.

In Taiwan, MSUS was introduced to rheumatology 20 years ago. However, there remain barriers to the more widespread use of MSUS in daily practice because of equipment costs, heavy clinical load, long learning curve and certification requirements. The training programs on the use of MSUS in rheumatology were developed by the Taiwan Rheumatology Association (TRA) only in the last 7 years. In 2013, the director of the TRA, Professor Der-Yuan Chen, focused on integrating the training and certifications in the TRA and the Chinese Taipei Society of Ultrasound in Medicine (SUMROC). Due to his efforts, the MSUS certification program for rheumatologists was organized this year. We believe that more and more Taiwan rheumatologists will join the training programs and MSUS will become a useful tool in the daily practice of every rheumatologist.

© 2014 Published by Elsevier Inc.