The evolution of ultrasound in rheumatology

Musculoskeletal ultrasound is a powerful tool not only for evaluating joint and related structures but also for assessing disease activity. Ultrasound in rheumatology has rapidly evolved and been incorporated into routine clinical practice over the past decade. Moreover, technological development of equipment has made it more accessible for rheumatologists. We present a review of advances in ultrasound in rheumatology, focusing on major chronological developments.

A comparison of ultrasound and clinical examination in the detection of flexor tenosynovitis in early arthritis

Background

Tenosynovitis is widely accepted to be common in rheumatoid arthritis (RA) and postulated to be the first manifestation of RA, but its true prevalence in early disease and in particular the hand has not been firmly established. The aims of this study were first to investigate the frequency and distribution of finger flexor tenosynovitis using ultrasound in early arthritis, second to compare clinical examination with ultrasound (US) using the latter as the gold standard.

Methods

33 consecutive patients who had who were initially diagnosed with polyarthritis and suspected of polyarthritis and clinical suspicion of inflammatory arthritis of the hands and wrists were assessed during consecutive, routine presentations to the rheumatology outpatient clinic. We scanned a total of 165 finger tendons and subsequent comparisons were made using clinical examination.

Results

Flexor tenosynovitis was found in 17 patients (51.5%) on ultrasound compared with 16 (48.4%) of all patients on clinical examination. Most commonly damaged joint involved on US was the second finger followed by the third, fifth, and fourth. Both modalities demonstrated more pathology on the second and third metacarpophalangeal (MCP) compared with the fourth and fifth MCP. A joint-by-joint comparison of US and clinical examination demonstrated that although the sensitivity, specificities and positive predictive values of clinical examination were relatively high, negative predictive value of clinical examination was low (0.23).

Conclusions

Our study suggest that clinical examination can be a valuable tool for detecting flexor disease in view of its high specificity and positive predictive values, but a negative clinical examination does not exclude inflammation and an US should be considered. Further work is recommended to standardize definitions and image acquisition for peritendinous inflammation for ultrasound.

Ultrasonography shows significant improvement in wrist and ankle tenosynovitis in rheumatoid arthritis patients treated with adalimumab

OBJECTIVE

Tenosynovitis is common in rheumatoid arthritis (RA) but knowledge is limited regarding its response to anti-inflammatory treatment. This study used ultrasonography (US) to examine the distribution and responsiveness of tenosynovitis to anti-tumour necrosis factor (anti-TNF) treatment in RA patients.

METHODS

Twenty patients with RA were examined at baseline and 1, 3, 6, and 12 months after starting adalimumab treatment, and grey-scale (GS) and power Doppler (PD) US scoring (semi-quantitative range 0-3) of wrist and ankle tendons was performed in addition to assessment of the 28-joint Disease Activity Score (DAS28), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR).

RESULTS

The extensor carpi ulnaris (ECU) tendon in the wrists and the closely related tendons tibialis posterior (TB) and flexor digitorum longus (FDL) in the ankles were most often inflamed. Median sum scores for this reduced number of tendons at baseline/12-month follow-up were 5/0.5 for GS (p < 0.001) and 4/0 for PD (p < 0.05), with reductions in the US scores during follow-up as large as those found for sum scores of all tendons. The standardized response means (SRMs) for sum GS or PD scores of the reduced number of tendons were higher (range -0.53 to -0.93) than for the sum scores of all tendons (-0.23 to -0.74), and showed larger responsiveness than CRP (-0.10 to -0.43) and ESR (-0.03 to -0.71).

CONCLUSION

Bilateral assessments of ECU, TB, and FDL tendons were as sensitive to change as the sum scores of all tendons, and scoring of this reduced number of tendons is suggested to be included in US scorings for follow-up of RA patients.

Finger tendon disease in untreated early rheumatoid arthritis: A comparison of ultrasound and magnetic resonance imaging

OBJECTIVE

To investigate the frequency and distribution of finger tenosynovitis in patients with early, untreated rheumatoid arthritis (RA) using gray-scale ultrasound (US) and magnetic resonance imaging (MRI).

METHODS

Fifty patients underwent US and MRI of metacarpophalangeal (MCP) joints 2-5. Twenty healthy controls underwent US only. Flexor and extensor involvement was documented for each joint. Intrareader reliability (IRR) was calculated by rereading static images.

RESULTS

Flexor tenosynovitis was found in 57 (28.5%) of 200 joints in 24 (48%) of 50 patients on US compared with 128 (64%) of 200 joints in 41 (82%) of 50 patients on MRI. Periextensor tenosynovitis was found in 14 (7%) joints in 9 (18%) patients on US compared with 80 (40%) joints in 36 (72%) patients on MRI. No controls had imaging tenosynovitis. Using MRI as the gold standard, the sensitivity, specificity, and negative and positive predictive values for US were 0.44, 0.99, 0.49, and 0.98, respectively, for flexor tenosynovitis and 0.15, 0.98, 0.63, and 0.86 for extensor tenosynovitis, respectively. The IRR was 0.85 and 0.8 for US and MRI, respectively. The most frequently involved joints on US and MRI were the second and third MCP joints.

CONCLUSION

This is the first study to compare US and MRI for the detection of tenosynovitis in the fingers of patients with early untreated RA. Tenosynovitis was found to be common using both modalities, with MRI being more sensitive. A negative US scan does not exclude inflammation and an MRI should be considered. Further work is recommended to standardize definitions and image acquisition for both US and MRI images.

Diagnostic value of high-resolution B-mode and doppler sonography for imaging of hand and finger joints in rheumatoid arthritis

OBJECTIVE

High-resolution sonography enables a detailed assessment of intraarticular and extraarticular soft tissue abnormalities of joints affected by rheumatoid arthritis (RA). This study was undertaken to evaluate the diagnostic value of B-mode sonography and power Doppler compared with that of clinical examinations and conventional radiography.

METHODS

The study group comprised 47 patients (14 men, 33 women) with different grades of RA; 31 patients were rheumatoid factor (RF) positive, and 16 were RF negative. The wrists, first through fifth metacarpophalangeal joints, and second through fifth proximal interphalangeal joints of these patients were scored with ultrasound in B-mode and power Doppler application, using a standardized technique. Involvement and severity of inflammation, as well as vascularization, were scored according to a new 3-point scale. The results were correlated with benchmarks of the clinical and radiologic investigations. Clinical status and conventional radiologic status were determined according to the Disease Activity Score and the Larsen score.

RESULTS

After preliminary studies in 15 patients, 39% of 704 joints were found to be abnormal by clinical investigation. Erosions were detected by radiography and sonography in 23% and 43% of joints, respectively. Hypervascularization was observed in 34% of 704 joints by power Doppler application. There was a significant correlation (P < 0.001) between the different methods for the detection of the severity of lesions. Use of a modern, state-of-the-art power Doppler program was necessary for semiquantification, and a standardized investigation technique and scoring system provided sufficient quality measures.

CONCLUSION

Sonography detects 20% more abnormalities than does radiography, and sonography has the potential to provide simple grading of disease activity. The rate of detection of abnormalities was slightly higher with clinical examination compared with sonography.

Imaging the joints in early rheumatoid arthritis

Radiography is the most widely utilized imaging modality for early rheumatoid arthritis, determination of radiographic progression remaining a crucial part of the evaluation of therapy. Conventional radiography is, however, insensitive for showing bone damage in early disease and is totally unsuitable for assessing synovial inflammation. The recognition of these limitations has led to intense interest in the multiplanar imaging capabilities of magnetic resonance imaging in rheumatoid arthritis and to an increasing use of ultrasonography for assessing synovitis and bone damage. This chapter discusses the role of radiography in early rheumatoid arthritis and the emerging use and role of magnetic resonance imaging and ultrasonography in evaluating synovitis and bone damage. The relationship between synovitis and bone damage is also addressed in the light of recent magnetic resonance imaging observations.

Evaluation of pannus and vascularization of the metacarpophalangeal and proximal interphalangeal joints in rheumatoid arthritis by high-resolution ultrasound (multidimensional linear array)

OBJECTIVE

To evaluate the extent of intraarticular vascularization and pannus formation in metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints of patients with rheumatoid arthritis (RA) by high-resolution ultrasound (US).

METHODS

A newly developed, high-resolution multidimensional linear array US was utilized to obtain longitudinal and transverse scans of joints with active RA (n = 21), moderately active RA (n = 39), or inactive RA (n = 93), and of joints from healthy controls (n = 120).

RESULTS

Healthy joints had no detectable pannus, whereas pannus could be detected in 52% of the joints with active RA, 82% of the joints with moderately active RA, and 67% of the joints with inactive RA. There was a significant difference in vascularization in the joints of all subgroups of RA patients and those of healthy subjects (P < 0.001). Moreover, vascularization differed significantly among the RA subgroups: inactive versus moderately active RA (P < 0.02) and inactive versus active RA (P < 0.05). Both pannus and vascularization appeared to be localized preferentially on the radial side of the joints.

CONCLUSION

Evaluation of pannus and the extent of vascularization within the joints of patients with RA by high-resolution US might be helpful in the assessment of disease activity, and thus influence therapeutic strategies.

Ultrasound guided synovial biopsy of the wrist

Seven patients (4 female and 3 male, mean age 46) with arthritis of the wrist (n = 7) without known etiology were evaluated. High-definition ultrasound equipment was used for localization of synovial hypertrophy, suitable for ultrasound guided biopsy without risk. A 18-gauge diameter Tru-cut biopsy needle was used in an automated gun. Two passes were performed with continuous guidance of the needle-tip. In all patients representative synovial tissue was obtained in adequate amount. No complications were encountered. Ultrasound guided biopsy is proposed as an effective technique which can be performed with low patient discomfort on an outpatient basis.

Finger tendon involvement in rheumatoid arthritis. Evaluation with high-frequency sonography

OBJECTIVE

To characterize finger tendon involvement in patients with rheumatoid arthritis (RA).

METHODS

The finger tendons of 20 RA patients were studied by ultrasonography using a high-frequency (13-MHz) transducer.

RESULTS

Eighteen patients (90%) showed finger tendon abnormalities: widening of the flexor tendon sheath (80%), loss of the normal fibrillar echotexture (60%), irregularity of the extensor (30%) and flexor (50%) tendon margins, tendon tear (10%), synovial cyst (20%).

CONCLUSION

High-frequency sonography is helpful in assessing even minimal finger tendon lesions in RA patients.

Effects of exercise and polysulfated glycosaminoglycan on the development of osteoarthritis in equine carpal joints with osteochondral defects

This study assessed the effects of postoperative exercise and intra-articular polysulfated glycosaminoglycan (PSGAG) on the repair of osteochondral defects in the carpal joints of ponies. Eighteen ponies with normal carpi had osteochondral defects (mean dimensions 2.4 cm x 0.9 cm) created arthroscopically on the dorsal aspect of the distal articular surface of the radial carpal bone. The ponies were randomized (while balancing for age [range, 2 to 15 years; median, 5.0 years]) to two groups--nine ponies were exercised and nine were stall confined. Beginning at surgery, six ponies in each group received five weekly intra-articular injections of PSGAG (250 mg) in one joint and lactated Ringer's solution in the contralateral joint; the remaining three ponies in each group received lactated Ringer's solution in both joints. The incremental exercise schedule on a circular, rotating walker was begun six days after surgery and occurred twice daily, reaching a maximum of 0.7 miles of walking and 2.7 miles of trotting by the third postoperative month. The effects of treatment on the joint tissues were determined by weekly lameness examinations and measurement of the range of carpal joint motion, carpal radiographs at six and 17 weeks after surgery, synovial fluid analysis, and cytologic evaluation of alcohol-fixed synovial fluid specimens at weeks 1 through 4 and week 17, and histology of the synovial membrane. Ultrasound images of the carpi were acquired before operation and at weeks 1, 2, 4, 8, 10, 13, and 17. Ponies were euthanatized 17 weeks after surgery. Exercise, without medication, caused more lameness throughout the study compared with no exercise. Exercised, nonmedicated ponies had the greatest limitation to carpal flexion (more painful joints), and nonexercised, nonmedicated (control) ponies had the least limitation to flexion. Radiographic scores indicated that the exercised, nonmedicated ponies had significantly (p < .05) more signs of osteoarthritis than exercised, medicated and control ponies. Ultrasonographic measurements indicated that exercise, without medication, caused the greatest increase in combined measurement of the joint capsule thickness and synovial fluid accumulation at all postoperative times. Synovial lining cell numbers in the synovial fluid from exercised ponies were significantly (p < .05) higher than in nonexercised ponies at week 1, and this trend continued at weeks 4 and 17 (p < .1). There were significantly (p < .05) more morphologic abnormalities in the synovial lining cells from exercised than from nonexercised ponies at week 17. Medication with PSGAG enabled exercised carpal joints to be flexed significantly further from weeks 2 through 6 compared with nonmedicated joints.(ABSTRACT TRUNCATED AT 400 WORDS)

Ultrasound examination of metacarpophalangeal joints in rheumatoid arthritis

To evaluate the ability of ultrasonography with high frequency transducer (13-MHz) in detecting metacarpophalangeal (MCP) joint abnormalities, 20 patients with rheumatoid arthritis (RA) and a symptomatic involvement of MCP joints were studied. Twenty healthy subjects served as controls. In all RA patients, ultrasonography clearly demonstrated one or more soft tissue and/or bone abnormalities. Sixteen patients (80%) had joint cavity widening because of effusion (1 case), synovial thickening (7 cases), and joint effusion with synovial thickening (8 cases). Loss of definition of the metacarpal articular cartilage was observed in 17 cases (85%). Sixteen (80%) had bone erosions and 9 (45%) showed a definite widening of the flexor tendons sheath. Margin irregularities of the extensor and flexor tendons were respectively visualized in 7 (35%) and in 8 (40%) cases. An extensor tendon rupture was observed in 2 cases (10%). Ultrasound examination by 13-MHz transducer appears to increase the accuracy of MCP joints evaluation in RA with respect to conventional radiography. It can be recommended as the first investigation in the assessment of soft tissue involvement in RA patients.

Intra-articular rheumatoid nodules and triggering of the knee joint

Rheumatoid nodules are a common extra-articular manifestation in rheumatoid arthritis. Intra-articular localisation of these nodules is rare and may produce clinical symptoms. Seven patients with walking problems due to an intra-articular rheumatoid nodule, which became entrapped on the ridge of the tibial plateau of the knee joint resulting in a phenomenon referred to as trigger knee, are described. After excision of the nodules all symptoms completely disappeared.

Ultrasonography in detection of effusion in the radiocarpal and midcarpal joints

Sixty radiocarpal and midcarpal joints in 30 healthy adults and 20 swollen wrists in 20 patients with chronic arthritis were examined by dorsal longitudinal ultrasonography (US). In five other patients intraarticular application of fluid into the radiocarpal joint could be seen as a change in the US scan. In 49 out of the 60 healthy wrists the unechogenic zone dorsally above the scaphoid bone was less than two millimetres, and the measurement did not change in dorsal or volar flexion. The side difference was less than one millimetre. In the healthy wrists the midcarpal area above bones was echogenic in US. In 15 radiocarpal and in 10 midcarpal joints out of the 20 swollen wrists, effusion could be depicted with US as an unechogenic zone. It was two millimetres or more in radiocarpal joint and it got bigger in dorsal and smaller in volar flexion.

Ultrasonography of the elbow joint

The nonechogenic space between the bone and the joint capsule was measured in ultrasonographic scans at six different sites in 60 elbow joints of 30 healthy adults as well as in 35 joints with clinical arthritis. The space could be demonstrated in all healthy joints on the volar side at the levels of the trochlea and the capitulum of the humerus. The space was more than 2 mm in three out of the 60 healthy joints at these levels, and the space did not increase in 30 degrees flexion of the joint. The means of the measurements were significantly higher at all six sites in the arthritic joints than in the healthy joints and on the volar site the space increased in 30 degrees flexion of the arthritic joint. The space was more than 2 mm in all arthritic joints at the levels of either the trochlea or the capitulum of the humerus. An ultrasonographic distance of more than 2 mm on the volar side of the elbow joint between the joint capsule and the bone is with high probability a sign of intraarticular effusion or synovitis. The effusion in the olecranon fossa can also be demonstrated in all cases.