Ultrasound imaging for the rheumatologist XI. Ultrasound imaging in regional pain syndromes

Regional pain syndromes (RPS) are common complaints in clinical rheumatological practice. Ultrasound (US) allows a detailed assessment of soft tissue involvement and its use may have considerable impact on the management of RPS. The present review provides an update of the available data about US imaging in RPS together with research issues relating to periarticular soft tissue pathology. The research agenda covers: definition of standard scanning protocols for US examination of the most common RPS assessed by the rheumatologist and the clinical impact of US findings in the management of patients with RPS.

Pulmonary Pathology of the Rheumatic Diseases

Thoracic manifestations of the rheumatic diseases (RDs) are a significant cause of morbidity and mortality worldwide. The five RDs most frequently associated with pleuropulmonary disease are (1) rheumatoid arthritis (RA), (2) systemic lupus erythematosus (SLE), (3) progressive systemic sclerosis (PSS), (4) polymyositis/dermatomyositis (PM/DM), and (5) Sjögren syndrome (SS). The clinical presentation is highly variable, ranging from pleuritic pain alone to slowly progressive breathlessness accompanied by cough. On occasion RD may present acutely with overwhelming respiratory failure as the first pulmonary manifestation. In all of the RDs, the pathology is dominated by either or both inflammation and fibrosis, but the anatomical distribution in each varies somewhat. For example, airway-associated lymphoid hyperplasia is a common manifestation of SS, PM/DM preferentially involves the alveolar parenchyma, and pleural inflammation is most commonly seen in RA. Such changes may be detected radiologically as peribronchovascular disease in SS, ground-glass infiltrates in PM/DM, and pleural disease with effusion in RA. Some RDs are more commonly associated with distinctive histopathology, such as rheumatoid nodules in RA, or lymphoid hyperplasia in both RA and SS. Patients with PSS are at particular risk for pulmonary hypertension when the lung is involved. Also, statistically, acute lung injury occurs more commonly in some, such as SLE and PM/DM. The very common use of immunosuppressive agents in the treatment of RD creates additional diagnostic problems related to drug toxicity and infection. Finally, a major confounding factor occurs when preclinical RD presents first as pulmonary disease (particularly PM/DM), an occurrence that may invoke one of the so-called idiopathic interstitial pneumonias. The most common pleuropulmonary pathological manifestations of the five major RDs are presented and discussed with brief radiological correlations.

Diagnosis of gout by ultrasound

OBJECTIVES

To establish the usefulness of ultrasonography (US) for diagnosing gout and to determine whether there are sonographic features that are characteristic for gout but not for other arthropathies.

METHODS

We retrospectively compared joint images of gout patients with matching images from patients with other rheumatic conditions. Images of 37 joints of 23 patients with monosodium urate (MSU) crystal-proven gout were reviewed. MSU crystals were identified in at least one joint in each patient. Our control group had 23 randomly selected patients with 33 examined joints with rheumatic conditions other than gout.

RESULTS

Specific diagnostic features included a hyperechoic, irregular band over the superficial margin of the articular cartilage described as a double contour sign in 92% of gouty joints and in none of the controls (P < 0.001); hypoechoic to hyperechoic, inhomogeneous material surrounded by a small anechoic rim, representing tophaceous material, was seen in all gouty metatarsophalangeal (MTP) joints, in all metacarpophalangeal (MCP) joints and in none of the controls (P < 0.001); erosions adjacent to tophaceous material were seen in 65% of MTP joints and in 25% of MCP joints. One erosion was seen in a MTP joint in a control patient with psoriatic arthritis.

CONCLUSIONS

US can detect deposition of MSU crystals on cartilaginous surfaces (P < 0.001) as well as tophaceous material and typical erosions. US may serve as a non-invasive means to diagnose gout.

Hand arthritis in systemic lupus erythematosus: an ultrasound pictorial essay

A small minority of systemic lupus erythematosus (SLE) patients may develop a deforming arthritis, typically with a non-erosive (Jaccoud's) pattern, although erosive features indistinguishable from rheumatoid arthritis may also occur. High-resolution ultrasonography (HRUS) allows detailed 'real time' imaging of joint and tendon morphostructural changes involving the hand in patients with several rheumatic diseases. The main aim of this pictorial essay is to provide the first descriptive HRUS and power Doppler (PD) findings of joint and tendon involvement of the hand and wrist in patients with SLE arthritis. Seventeen patients with SLE and hand involvement were examined. HRUS of the wrist, 2nd and 3rd MCP joints, 3rd PIP joint and 2nd, 3rd and 4th finger flexor tendons were studied in the dominant hand for each patient. Sixteen (94%) patients had joint effusion or synovial hypertrophy in the wrist. Twelve (71%) patients had joint effusion or synovial hypertrophy in 2nd or 3rd MCPJs. Eight (47%) patients had erosion at 2nd or 3rd MCPJs. In three cases erosions were not present radiologically. Eleven (65%) patients had evidence of tenosynovitis. In SLE, HRUS with PD detects a high prevalence of inflammatory pathology in the tendons and synovium of the hand and wrist, and a high prevalence of MCP joint erosions. HRUS offers a sensitive, real-time and readily repeatable assessment of soft-tissue, inflammatory and bony changes in SLE hands.

Radiological bone lesions in fibroblastic rheumatism; case report

INTRODUCTION

Fibroblastic rheumatism (FR) is a rare disease characterized by polyarthralgia associated with painless subcutaneous nodules, sclerodactyly and finger contractures.

CASE REPORT

A 45-year-old man presented with peripheral vascular disease, polyarthralgia and subcutaneous nodules. The diagnosis of FR was confirmed by histological examination of a biopsy sample of a nodule, which showed myofibroblast proliferation. Radiographs of both hands showed bilateral erosion of the distal and proximal interphalangeal joints, of the right trapezium bone and acro-osteolysis of the third phalanx of the right-hand second finger.

COMMENTS

Although the clinical features of FR have now been well described, the literature includes few radiological descriptions. In most reported cases, radiographs are normal at disease onset. Joint radiographs performed later usually show bone destruction of the hands and feet.

[Improvements in the management of rheumatic patients from vertebral image obtained through dual-energy X-ray absorptiometry]

The diagnosis of asymptomatic vertebral fracture is clinically useful and the identification of new fractures may influences the choice of appropriate therapeutic measures. In order to identify moderate and asymptomatic vertebral deformities in an objective and reproducible manner, vertebral morphometry is performed. This method measures the vertebral body's anterior, middle and posterior heights at the dorsal and lumbar level. Currently this technique is performed on lateral images of the spine obtained through the traditional X-ray method (radiological morphometry or morphometric X-ray radiography, MRX) and, more recently from images obtained through dual-energy X-ray absorptiometry (DXA) machines (visual assessment of X-ray absorptiometry scans or morphometric X-ray absorptiometry, MXA), commonly used to measure bone mineral density. The main advantage of MXA relative to MRX is the lower radiation dose to which the patient is exposed during the exam. In addition, MXA scans offers the advantage of acquiring a single image of thoracic and lumbar spine, without any distortion (e.g.: coning). The most obvious advantage of MXA is the opportunity of obtaining during the same session a bone mineral density evaluation, and digital images that are easily processable, manageable, recordable and comparable for the patient's follow up. A limitation of the MXA technique is the inferior quality of the images, that make often impossible the detection of the vertebral edges, and the impossibility to visualize the upper thoracic vertebral bodies. MXA, despite its intrinsic limitations, when carried out by trained personnel may provide substantial improvements in the management (diagnosis and follow-up) of rheumatic patients.

[Rheumatological symptoms masking neoplasm in children]

Fevers, arthritis, myalgia and skin changes are the most typical features of rheumatic diseases, although one should remember that the same symptoms could mask neoplasm. This study shows that some patients with rheumatological symptoms treated in the Department of Lung Diseases and Children Rheumatology, Medical University of Lublin were finally diagnosed with neoplasm. In focus is the initial phase of the patients' illnesses.

MATERIAL AND METHODS

We analyzed retrospectively the case histories of all patients admitted to the department between 1997 and 2005 (1560 hospitalizations). An oncological disease was diagnosed in 9 cases: leukemia in 4 children (acute lymphoblastic leukemia-ALL- in 3 cases, acute non-lymphoblastic leukemia-ANLL- in 1 case), Hodgkin's disease in 1 child, bone tumours in 2 children, liver tumour in 1 child and a tumour of the central nervous system in 1 child.

CONCLUSIONS

The cases described should draw the physicians' attention to the fact that in the initial phase an oncological disease may be masked by rheumatological symptoms.

Technology Insight: the role of color and power Doppler ultrasonography in rheumatology

An increasing number of rheumatologists have access to ultrasound equipment that provide both color and power Doppler modes, which can be used to investigate musculoskeletal and vascular pathologies. Musculoskeletal Doppler ultrasonography can be used to estimate levels of inflammation, to document the anti-inflammatory effect of agents such as corticosteroids and tumor necrosis factor inhibitors, to differentiate between inflammatory and degenerative disease, and to distinguish between normal and inflamed joints in cases of minor synovial swelling. Vascular Doppler ultrasonography can be used to determine organ involvement in small-vessel vasculitides, to delineate aneurysms in vasculitides of medium-sized arteries, and to assess the characteristic findings in large-vessel vasculitis. Numerous studies, including a meta-analysis, have been published on the use of temporal-artery ultrasonography for the diagnosis of giant cell arteritis. Duplex ultrasonography is a sensitive approach for detecting characteristic edematous wall swellings in active temporal arteritis and for assessing vasculitis of the axillary arteries (large-vessel giant cell arteritis) in patients with suspected temporal arteritis, polymyalgia rheumatica, or fever of unknown origin. Duplex ultrasonography can also be used to assess vasculitis of subclavian and carotid arteries in younger patients with Takayasu's arteritis and acute finger artery occlusions in patients with small-vessel vasculitides.

Role for positron emission tomography in skeletal diseases

Imaging plays a prominent role in the diagnosis and management of rheumatic diseases. Conventional imaging methods provide high-resolution structural information but usually fail to distinguish between active lesions and residual changes. Positron emission tomography (PET) with the tracer 18F-fluorodeoxyglucose (18F-FDG) was recently introduced into clinical practice as a means of obtaining information on both structure and metabolic activity. 18F-FDG-PET is widely used in oncology and may be valuable in patients with infections or inflammatory diseases, most notably vasculitis. Although encouraging results have been published, the number of studies remains small, as 18F-FDG-PET is an expensive investigation that is not available everywhere. Further work is needed to determine the cost-effectiveness ratio of 18F-FDG-PET in patients with infections or inflammatory diseases. Imaging plays a prominent role in the diagnosis and management of many musculoskeletal diseases. Although considerable progress has been made recently, the structural information supplied by conventional imaging methods is inadequate in some patients. Positron emission tomography (PET) after injection of 18fluorodeoxyglucose (18F-FDG) provides information on tissue metabolism. The usefulness of 18F-FDG-PET in oncology is now widely recognized. Other uses are emerging, in part thanks to the development of new cameras that combine dedicated detectors and an X-scanner in order to ensure accurate three-dimensional localization of metabolically active lesions. However, the exact role for 18F-FDG-PET needs to be studied in larger populations of patients.

Clinical, radiographic and MRI findings of the temporomandibular joint in patients with different rheumatic diseases

The aim of this study was to investigate the condition of the temporomandibular joint (TMJ) in patients with different rheumatic diseases, and report correlations between the clinical, radiographic and magnetic resonance imaging (MRI) findings. The 67 patients were divided into four groups: 16 with rheumatoid arthritis (RA), 15 with mixed connective tissue disease (MCTD), 18 with ankylosing spondylitis (AS) and 18 with spondyloarthropathy (SPA). They were clinically examined, and panoramic tomography, lateral panoramic radiography and MRI of the TMJ were performed. MRI showed reduced articular cartilage in 25% (4/16) of RA, 0% (0/15) of MCTD, 17% (3/18) of AS and 17% (3/18) of SPA patients. Condylar changes included erosion, osteophytes and abnormal shape. Disc alterations included perforation, abnormal anterior position and decreased movement. These abnormalities were most frequent in RA patients, and least frequent in MCTD and SPA patients. Crepitation and reduced maximum opening of the mouth correlated with abnormalities of the disc and articular cartilage as shown by MRI. Severe condylar erosion in panoramic tomograms significantly correlated with MRI findings of condylar erosion (P<0.01), diminished thickness of condylar cartilage, abnormal condylar shape, and abnormal shape of the temporal surface of the TMJ (P< or =0.001). The presence of crepitation, limited mandibular movement and/or pain on movement of the jaw often indicated structural damage to the TMJ. Panoramic radiographs provide an alternative method to MRI but, to obtain a more detailed anatomic picture, MRI is recommended for patients with acute unexplained pain or as part of preoperative work up. A panoramic recording is not indicated when MRI is planned.

Assessment of enthesitis in ankylosing spondylitis by power Doppler ultrasonography

OBJECTIVE

To evaluate the relationship between power Doppler ultrasonography (PDUS) assessment and clinical variables including enthesitis index, pain threshold and disease activity parameters, and to document grey-scale US findings of the 13 entheses examined.

DESIGN AND PATIENTS

A total of 390 entheses were examined in thirty patients with AS, and clinical variables of the Maastricht Ankylosing Spondylitis Enthesitis Index (MASES), anthropometric measurements, disease activity and functional parameters were documented. A total MASES score by palpation (t-PS) and algometric pressure pain threshold (t-PPT) was obtained. Grey scale and PDUS examination of 13 entheses were performed. Grey-scale changes such as altered tendon echogenity, calcification, cortical reactive changes and bursitis were noted, and flow on PDUS was graded semi-quantitatively.

RESULTS

Cumulative power Doppler (t-PDS) score significantly correlated with t-PS and t-PPT. Ultimate correlations were found between power Doppler scores and pain, disease activity and disability parameters. Changes in grey scale combined with PDUS were more prevalent in lower-extremity entheses. The intraobserver agreement of flow signal grading was excellent (kappa = 0.82). Clinical and sonographic results were concordant for three regions, but were discordant for four regions where tenderness was accepted as the sole clinical manifestation of enthesis.

CONCLUSION

Pain or tenderness is associated with increased vascularity of entheses. Power Doppler US examination of the entheses may be useful and complementary to the clinical evaluation, and further research is needed to assess its role in diagnosis and follow-up of disease course.

Ultrasound imaging for the rheumatologist III. Ultrasonography of the hip

Ultrasonography (US) is a reliable and useful diagnostic tool for the assessment of hip pathology. It depicts changes within the coxo-femoral joint (synovitis, erosions, osteophytes) and in the adjacent peri-articular tissues (calcifications, tendonitis, enthesitis, bursitis) in many rheumatic diseases (rheumatoid arthritis, spondyloarthritis, osteoarthritis, polymyalgia rheumatica ) and in some orthopaedic disorders (septic arthritis, trauma, abscess, painful hip after arthroplasty). It is commonly used both in adults and in children. In the assessment of hip joint pathology, US exerts considerable diagnostic supremacy over physical examination. In fact, by virtue of its size and position, reliable physical examination of the hip is often difficult thus making US particularly useful as a bedside tool for the evaluation of a painful hip. Hip US has also proven to be of great practical benefit when performing aspiration and injection within the joint and in the periarticular soft tissues. The relatively limited acoustic windows available to the US beam is the principal limitation to hip US thereby making detailed examination of some important structures impossible together with the interpretation of power Doppler signal sometimes unreliable. In addition, the deep location of the hip can confer further problems to US scanning in obese or particularly muscular subjects.

Ultrasound imaging for the rheumatologist II. Ultrasonography of the hand and wrist

The hand is one of the anatomical regions most frequently explored by ultrasonography (US) in rheumatology. The last generation US systems equipped with high frequency probes allow for a quick and accurate assessment of even minimal pathological changes in patients with rheumatic conditions affecting the small joints and the soft tissues of the hand and wrist. Several studies have demonstrated the great value of US imaging of the hand and wrist in rheumatology but there are still controversial issues which yet have to be adequately addressed, particularly with regard to US semi-quantitative evaluation of synovitis and bone erosions in patients with chronic arthritis. This paper provides the basic knowledge, reviews the available evidence and discusses the potential of US in the evaluation of the hand and wrist.

Ultrasound imaging for the rheumatologist

Over the last few years, technological advances have resulted in dramatic improvements in quality and resolution of ultrasonography (US), allowing it to become a very powerful tool in rheumatological clinical practice. Despite the fact that the impact of US on final diagnosis or therapeutic options for rheumatic patients has not yet been defined, there is now growing evidence that US improves clinical diagnosis and intervention skills. This review discusses the most important issues connected with the practice of US in rheumatology including: basic requirements, scanning technique, clinical applications, training and future developments. Moreover, it provides a general overview of both US anatomy and pathology relevant for the rheumatologist.

Ultrasound detection of entheseal insertions in the foot of patients with spondyloarthropathy

The aim of the study was to evaluate entheseal involvement in the foot of patients with spondyloarthropathy (SpA) by ultrasonographic (US) examination and compare the results with clinical and radiological findings. Forty-four patients (27 men, 17 women) with a diagnosis of SpA were recruited. Patient evaluation included physical examination (swelling and pain), Bath Ankylosing Spondylitis Radiological Index, Bath Ankylosing Spondylitis Disease Activity, Bath Ankylosing Spondylitis Metrological Index, and laboratory parameters (erythrocyte sedimentation rate, C-reactive protein). Foot x-rays of the patients were assessed and scored according to SpA Tarsal Radiographic Index (SpA-TRI). A high-resolution US was used to examine the tendon and ligament insertion sites in the foot, and the findings were scored according to Glasgow Ultrasound Enthesitis Scoring System (GUESS). The mean age and disease duration of the patients were 39.9+/-12.5 and 9+/-8.2 years, respectively. US revealed pathological findings in 25 of 44 (56.8%) patients, most of whom exhibited no clinical signs of foot involvement. Pain and swelling at entheseal insertions were detected in only 16 (37%) patients. The mean GUESS score and SpA-TRI score were 2.2+/-2.5 and 3.3+/-3.7, respectively. There was a correlation between the scores of GUESS and SpA-TRI, particularly at the Achilles and plantar fascia insertion sites. The mean score of SpA-TRI was higher in patients with enthesopathy, detected by US, than in patients without enthesopathy (4.6+/-4.4 vs 1.8+/-2.1). There was no significant correlation between the mean GUESS score and clinical and laboratory variables. In conclusion, involvement of tendon and entheses is not rare, and US is a valuable diagnostic method in detecting subclinical enthesopathic changes. The GUESS and SpA-TRI are suggested in quantifying US and radiological changes in the foot of patients with SpA.

Clinical utility of the anti-CCP assay: experiences with 700 patients

Our objective was to determine the frequency of antibodies to cyclic citrullinated peptides (CCPs) in a series of patients with a variety of rheumatic diseases. Seven hundred consecutive serum samples from patients at an outpatient clinic were tested for the presence of rheumatoid factor (RF) and anti-CCP. Clinical diagnosis, radiographic information, and other laboratory data were taken from patients' charts. The sensitivity and specificity of anti-CCP reactivity for the diagnosis of rheumatoid arthritis (RA) were 74.0% and 94.5%, respectively; the corresponding results for RF were 69.7% sensitivity and 81.0% specificity. Highest rates of false-positive RF tests were found in patients with SLE (18.3% vs. 12.7% CCP), Sjögren's syndrome (73.3% vs. 3.3% CCP), and a control group with chronic hepatitis (24.7% vs. 1.3% CCP). The detection of anti-CCP is useful for the diagnosis of RA because of its similar sensitivity but higher specificity compared with RF. Anti-CCP also helps to diagnose other inflammatory and noninflammatory diseases (especially connective tissue diseases) by reducing the rate of false-positive results in comparison with RF.

Evaluation of cartilage composition and degradation by high-resolution magic-angle spinning nuclear magnetic resonance

Rheumatic diseases are accompanied by a progressive destruction of the cartilage layers of the joints. Although the number of patients suffering from rheumatic diseases is steadily increasing, degradation mechanisms of cartilage are not yet understood, and methods for early diagnosis are not available. Although some information on pathogenesis could be obtained from the nuclear magnetic resonance (NMR) spectra of degradation products in the supernatants of cartilage specimens incubated with degradation-causing agents, the most direct information on degradation processes would come from the native cartilage as such. To obtain highly resolved NMR spectra of cartilage, application of the recently developed high-resolution magic-angle spinning (HR-MAS) NMR technique is advisable to obtain small line-widths of individual cartilage resonances. This technique is nowadays commercially available for most NMR spectrometers and has the considerable advantage that the same pulse sequences as in high-resolution NMR can be applied. Except for a MAS spinning equipment, no solid-state NMR hardware is required. Therefore, this method can be easily implemented. Here, we describe the most important requirements that are necessary to record HR-MAS NMR spectra. The capabilities of the HR-MAS technique are discussed for the 1H and 13C NMR spectra of cartilage.