1 Departments of Rheumatology and
2 Radiology, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ, UK
Musculoskeletal sonography is a tool that provides exciting opportunities to improve diagnostic capabilities and the quality of therapeutic interventions in many rheumatological conditions. The ever-increasing quality of resolution and the availability of dedicated, more affordable machines have made the use of ultrasound an increasingly attractive and feasible option for the rheumatologist [14]. The enthusiasm of rheumatologists for the technique is now well documented [14] and has been illustrated recently by a full attendance at the first British Society of Rheumatology course in musculoskeletal ultrasound, held over 1½ days in Cambridge, UK in November 2000.
The acquisition of imaging skills is not without its challenges. Access to equipment, regular training and supervision, the time commitment involved and possession of a sound knowledge of functional anatomy are all aspects that may, for some rheumatologists, inhibit the feasibility of the development of a service. These issues are illuminated by a survey performed at the first BSR course in Cambridge, reported in this issue [5]. The time commitment involved includes not only the time taken by trainee and trainer to learn the technique but also the impact that the use of ultrasound by rheumatologists may have on the workload within out-patient clinics. This will have an important implication for clinic workloads. Furthermore, although there has been a reduction in price over the past few years for a suitable machine for performing musculoskeletal ultrasound, the provision of new machines may still be considered an expensive proposition. The rationale is that the inclusion of ultrasonography within the clinic will ultimately improve the quality and efficiency of patient care, but this fact may sadly fall on the deaf ears of some service managers if the financial cost and the negative effect on patient throughout are too great.
Support for the use of ultrasound by rheumatologists would be likely to be stronger if the benefits of interventional ultrasound were demonstrated, in particular if it were shown that outcomes were improved with corticosteroid injections to soft tissue and joints performed under imaging guidance.
It is possible that only a minority of rheumatologists will be able to make the necessary commitment to developing adequate skills in diagnostic and/or therapeutic musculoskeletal ultrasound. The development of a clear, uniformly accepted approach to training in the technique is necessary, preferably with the input of our radiological colleagues. Backhaus et al. [4] have recently published guidelines for performing musculoskeletal ultrasound in rheumatology. These include recommendations for technical equipment, standardization of patient positions and scans for different regions. The importance of a sound knowledge of functional anatomy and continued hands-on supervised training is emphasized. However, no clear-cut guidelines are given as to the recommended number of cases and scanning hours before an examiner can claim to be competent. It is possible that such standards cannot be set, as there is likely to be wide variation in learning curves, but a required standard of competence must be developed, in keeping with the practice of other specialities. Although it is stated that there are European guidelines for training in rheumatology [4, 6], they are not readily accessible and we have not been able to obtain them. However, to address this deficiency, a working group within the British Society of Skeletal Radiologists is currently developing a structured curriculum for training and accreditation in musculoskeletal ultrasound for non-radiologists.
Minimum training requirements for ultrasonography have been proposed by professional bodies in the USA. The American College of Radiology recommends that, during a 4-month radiology residency programme, at least 3 months of sonographic training are completed, with involvement in a minimum of 500 sonographic examinations covering a spectrum of regions and systems [7]. The American Institute of Ultrasound in Medicine, a multi-disciplinary group comprising physicians from different specialities, basic scientists and sonographers, recommends involvement in 500 cases for those using sonography for multiple subspeciality applications or [multiple] anatomic areas. Those performing a single subspeciality application or imaging only a single anatomical area should be involved in a minimum of 300 cases during the training period [8].
Hertzberg (a radiologist) et al. [9] examined the effectiveness of such recommendations by evaluating the competence of radiology residents across a range of experience, against interpretation by an experienced attending radiologist. The case material was a mixture of abdominal, superficial parts, obstetrics, gynaecology and vascular pathology. Performance, rated on recognition of anatomical landmarks and reporting errors, improved progressively with increasing experience, but performance was still poor even after involvement in 200 cases.
The requirements described have been increasingly challenged by physician groups in the USA, on the basis that they are excessive. For example, the Society of Academic Emergency Medicine recommends 150 sonographic examinations, 50% on patients with clinical indications for scanning and 50% on healthy models [10]. Mandavia et al. [11] have demonstrated that emergency physicians can be taught focused ultrasonography with a high degree of accuracy on the basis of a 16-h introductory course. Similar or lower levels have been recommended for scanning of specific areas by other groups, such as primary care, obstetrics and surgery [1214]. In all of these cases, the trainee is being taught a very specific ultrasound technique for a single indication, and not a wide-ranging technique such as musculoskeletal ultrasound.
On the other hand, and of particular importance to musculoskeletal ultrasound, Miller et al. [15] performed a prospective assessment of the reproducibility and inter-observer agreement in the ultrasonic evaluation of the rotator cuff between three radiologists of whom two were experienced and one had 6 months of training in musculoskeletal ultrasound. Good agreement between the experienced radiologists was noted, but not with the less experienced examiner, for a basic skill such as the detection of full-thickness cuff tears.
The field of diagnostic ultrasonography is advancing rapidly and has much to offer the rheumatologist. It is clear that many issues must be addressed to allow further development of this field within our speciality, including the establishment of recognized training programmes.
Notes
Correspondence to: C. A. Speed, Rheumatology, Sports and Exercise Medicine, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ, UK.
References