Sonographic assessment of adult and juvenile rheumatoid arthritis

Transcription

1 Sonographic assessment of adult and juvenile rheumatoid arthritis Poster No.: C-1485 Congress: ECR 2013 Type: Educational Exhibit Authors: C. A. S. Ruano, P. L. Pegado, J. M. G. Lourenco, P. Alves, L. Vieira; Lisbon/PT Keywords: Musculoskeletal joint, Musculoskeletal soft tissue, Paediatric, Ultrasound, Ultrasound-Power Doppler, Education, Comparative studies, Arthritides, Inflammation DOI: /ecr2013/C-1485 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 17

2 Learning objectives In this poster we will illustrate the sonographic spectrum of both adult and juvenile forms of Rheumatoid Arthritis, focusing on the value of ultrasonography in early diagnosis and therapeutic monitoring. Furthermore we will emphasize particularities exclusive to arthritides in children and to their sonographic joint evaluation. Page 2 of 17

3 Background Rheumatoid Arthritis (RA) is a chronic progressive systemic inflammatory disease characterized by persistent symmetric polyarthritis. The hallmark feature of this condition is synovial inflammation, affecting any of the synovial joints as well as tendon sheaths. In the course of the disease, adjacent structures such as bones, tendons and ligaments will be involved. RA affects approximately 1% of the adult population, increasing with age and peaking at years. It is two to three times more common in women. [1] The hands are the major site of involvement, with characteristic distribution in the metacarpophalangeal (MCP) joints, proximal interphalangeal (PIP) joints, and wrist. The metatarsophalangeal (MTP) joints are also frequently implicated. Involvement of large joints (knees, ankles, elbows, hips, and shoulders) is common but generally occurs later than small joint involvement. The juvenile variant of RA, Juvenile Idiopathic Arthritis (JIA), is the most common chronic arthropathy in childhood, with a yearly incidence rate of 2-20 cases per 100,000. It comprises a heterogeneous group of arthritides with onset in children younger than 16, whose symptoms persist for at least 6 weeks. [2] JIA can be divided into 7 subtypes, which are Systemic-onset JIA, Oligoarthritis, Polyarthritis (with negative/positive Rheumatoid Factor), Enthesis-Related Arthritis, Psoriatic JIA and Undifferentiated Arthritis. [2] The most common type of JIA is the oligoarticular form, affecting typically one to four large joints, with the knee being the most commonly affected joint. The seropositive polyarticular form occurs in a minority of children (5-15%) and is characterized by polyarticular distribution (5 or more joints) and strong female preponderance, resembling adult RA. [3] In the absence of timely therapeutic care, both RA and JIA tend to evolve into debilitating and destructive arthropathy (Fig.1). Additionally, children may also suffer from growth abnormalities. Early diagnosis and aggressive treatment are therefore paramount to RA and JIA patients, as they increase the probability of a better prognosis. Traditionally, diagnosis and follow-up of RA are based on clinical and laboratorial data, and complemented by radiogram analysis. The latter not only lacks sensitivity in detecting joint structural abnormalities, particularly in early disease stages, but also is hazardous, especially for children. [3,4] Page 3 of 17

4 These limitations can be effectively overcome through sonographic joint examination. Ultrasonography (US) is a quick, inexpensive, non-ionizing, child-friendly method that can accurately identify synovitis. Page 4 of 17

5 Images for this section: Fig. 1: Hand radiograph of a female patient with long-standing RA, showing joint space narrowing, erosions, periarticular osteopenia, subluxation and carpal bone ankylosis.. Page 5 of 17

6 Imaging findings OR Procedure details Technical aspects of sonographic joint evaluation in Rheumatoid Arthritis In order to obtain uniform results in sonographic joint evaluation of RA patients certain requisites need to be fulfilled: The examination should be performed in a room with sustained mild temperature (20ºC). On arrival, patients should wait approximately 20 minutes to acclimatize to the ambient temperature. The examination should be performed with high resolution probes (>10 MHz), with gray scale (GS) US and Power Doppler (PD) US, to image both synovial proliferation and synovial vascularisation. As synovial vascularisation can be profoundly influenced by small changes in temperature and by light pressure, care should be taken to scan the joints with a thick layer of warm coupling media, avoiding excessive pressure with the probe. Imaging adult Rheumatoid Arthritis US is a valuable and reliable tool for accessing joint and tendon synovial inflammation, key features of RA. Small joints of the hand and wrist Although there is still no consensus on which joints should be scanned to assess the inflammatory burden of RA, most authors recommend the evaluation of the wrist joints, MCP joint and PIP joints, as they are the most frequently affected joints. [5,6] Joints must be scanned on both a longitudinal axis and a transverse view, preferably over the dorsal surface, as synovitis and effusions are more frequently visualized on this aspect of the joint. The volar surface may also be scanned for additional information. (Fig.2) Ultrasonographic findings of RA Page 6 of 17

7 US features of RA are synovial hypertrophy, tenosynovitis, joint effusion and erosions. Synovial hypertrophy is defined as an abnormal hypoechoic intra-articular tissue that is non-displaceable and poorly compressible. It may sometimes be isoechoic or hyperechoic relative to subdermal fat. (Fig. 3) Tenosynovitis is defined as hypoechoic (or anechoic) thickened tissue within the tendon sheath, with or without fluid, which is seen in 2 perpendicular planes. (Fig. 4,5) Both synovial hypertrophy and tenosynovitis may exhibit PD signal. Positive PD signal is indicative of active inflammation. (Fig. 6,7,8) Joint effusion is defined as abnormal hypoechoic (or anechoic) intra-articular material that is displaceable and compressible, and does not exhibit Doppler signal. (Fig. 9) Erosions are defined as intra-articular discontinuities of the bone surface, visible in 2 perpendicular planes. (Fig. 10) Although US examination has proven to be more sensitive than plain radiography in identifying small bone erosions, some areas may be difficult to assess, namely the ulnar aspect of the second MCP and the radial aspect of the fifth MCP. Large joints Although small joint involvement is more characteristic of RA, large joints are also frequently involved and are responsible for great disability. As in small joints, US evaluation has proven to be more sensitive than clinical examination in the identification of joint inflammation. [7] Symptomatic joints should be evaluated with at least two standardized scanning planes (four for the knee), in search for synovitis, tenosynovitis and bone erosions. (Fig.11) Imaging Juvenile Idiopathic Arthritis Numerous studies have validated US as a sensitive tool in the assessment of synovitis in adult RA. In JIA, despite the increasing application of US in routine care and its clear superiority compared to clinical evaluation in detecting synovitis, the validity of this technique has not yet been accurately established. Apart from the urgent need for universally accepted definition of the components of synovitis in JIA, joint evaluation in children is impaired by the lack of description of Page 7 of 17

8 the normal US anatomy in different age groups. Additionally there is an imperative requirement for standardized US protocols for joint evaluation.[8] Particularities of arthritides in children [9] In the immature skeleton, the epiphyses are vascularised and metaphyseal and epiphyseal vessels anastomose through the growth plate. Inflammation affecting the epiphyseal cartilage can extend to the ossification center, causing growth disturbances. For this reason both sides must be imaged to allow for comparison. The inflammatory process begins at the cartilage surface and spreads to the ossified tissues. Joint narrowing develops early and may progress rapidly to ankylosis. In contrast to adult RA, bone erosions are late abnormalities and usually localized in the epiphysis. Particularities of US joint evaluation in children US joint evaluation in growing children is challenging, as joint anatomy is constantly changing. According to the age of the paediatric patient, US images will range from completely anechoic joints (in an unossified immature skeleton) to hyperechoic mature bones. The cartilage of an unossified epiphysis should not be mistaken by fluid, since, unlike fluid, it is not displaced when pressure is applied. (Fig.12) Minimal amounts of fluid (particularly in the supra-patellar and para-patellar recesses) may be seen in healthy children s joints and should not be assumed as pathological. As in adult RA, PD US is a promising technique for detecting child joint inflammation. However, in children, small vessels that supply the growing skeleton may result in positive PD signal in the epiphysis. Sonographers must be trained to distinguish normal cartilage vascularisation from synovitis. [8] Ultrasonographic findings of JIA US characteristics of JIA are synovial thickening, synovial hyperaemia, joint effusion, cartilage thinning and bone erosions. (Fig. 13,14,15) Page 8 of 17

9 Unlike RA, there are no accepted definitions for synovitis in JIA. Most authors suggest applying the criteria developed for adults. The oligoarticular subtype is the most frequent form of JIA, the knee being the most commonly involved joint, followed by the ankle, wrist, hand, elbow, hip and shoulder. Synovial hypertrophy and joint effusion in the knee are commonly evaluated by measuring the anteroposterior diameter of the supra-patellar bursa on longitudinal axis. An anterior approach will hold better results when assessing synovial inflammation in the ankle, while a posterior approach suits the elbow more appropriately. Unlike in adult RA, erosions are a late finding in children, detected in patients with disease durations longer than 5 years. While normal cartilage is hypoechoic and has smooth margins, joint inflammation may lead to cartilage thickening, followed by irregularity of its outline. With persistent inflammation, cartilage thinning and erosions may prevail, resulting in joint dysfunction. (Fig. 16) Assessment of treatment response Although clinical scores remain the mainstay in assessing disease activity and treatment response, several studies have proven their limited reliability, especially in children. Serial US evaluations may complement clinical monitoring, in both RA and JIA patients, as they provide a more accurate analysis of synovial inflammation. An increase in synovial volume and vascularisation suggests active disease, while the decrease of synovium thickness, fluid volume or PD signal translates into positive treatment response. [5,10] Clinical remission is nowadays a realistic therapeutic goal in RA patients. However studies demonstrate progression of joint destruction despite the clinical labelling of remission. As US evaluation is able to detect latent synovitis, it may signal patients that would benefit from a more aggressive treatment. [6,10] Page 9 of 17

10 Images for this section: Fig. 2: Longitudinal (a, c) and transverse (b,d) US PD scans of normal MCP joints, scanned over the dorsal (a,b) and volar (c,d) surfaces. Note the hypoechoic hyaline cartilage covering the metacarpal head (arrows) and the triangle-shaped area of connective tissue (star). MC = metacarpal bone; PP = proximal phalanx; FDS = flexor digitorum superficialis tendon; FDP = flexor digitorum profundus tendon; EXT = extensor digitorum tendon. Fig. 3: Longitudinal (a) and transverse (b) US scans of the forth MCP joint of a female patient with early RA, showing synovial hypertrophy extending over the metacarpal head (arrows). Page 10 of 17

11 Fig. 4: Longitudinal (a) and transverse (b) US scans of the dorsal wrist of a female patient with long-standing RA, showing hypoechoic tenosynovitis (arrows) surrounding the extensor tendons (stars). Fig. 5: Longitudinal (a) and transverse (b) US scans of the ventral wrist of a female patient with early RA showing anechoic tenosynovitis (arrows) of the flexor carpi radialis tendon (stars). Fig. 6: Longitudinal GS US (a) and PD US (b) scans of the ulnar styloid of a male patient with early RA, showing hypertrophy (arrows)and hyperaemia (PD signal) of the synovium. Page 11 of 17

12 Fig. 7: Transverse PD US scan of the ventral wrist (a) and longitudinal US PD scan of the dorsal wrist (b) of a male patient with early RA. a) shows hypertrophy (arrows) and hyperaemia (PD signal) of the carpal joints synovium. b) shows active tenosynovitis (PD signal) of the extensor tendons (stars). Escaf = Scaphoid; SL= Lunate; Piram= Triquetrum. Fig. 8: Longitudinal (a) and transverse (b) PD US scans of the dorsal wrist of a male patient with early RA showing tenosynovitis (arrows) with hyperaemia (PD signal) of the extensor tendons (stars). Fig. 9: Longitudinal (a) and transverse (b) GS US scans of the second MCP joint of a female patient with early RA, showing anechoic joint effusion (arrow) and, in b) a small bone erosion (open arrow). Page 12 of 17

13 Fig. 10: Longitudinal (a) and transverse (b) GS US scans of the second MCP joint of a female patient with early RA showing bone erosions (open arrow) which were not visible in the corresponding radiograph (c). Fig. 11: Longitudinal PD US scan of the anterior recess of the elbow (a), showing synovial proliferation with positive PD signal. In a lateral approach to the same joint, GS US scan (b) detected bone erosion. Fig. 12: Longitudinal GS US scans of the supra-patellar recess of a) a healthy two-yearold girl, showing the anechoic unossified cartilage (star); b) a two-year-old boy with JIA, showing the unossified cartilage (star) and fluid in the supra-patellar recess (arrows). Unlike fluid, the normal cartilage is non compressible and non displaceable. Page 13 of 17

14 Fig. 13: Longitudinal GS US scans of the anterior recess of the hip (a) and the suprapatellar recess (b) of two two-year-olds with JIA, showing anechoic (a) and echoic (b) joint effusions (arrows), both compressible and displaceable.. Fig. 14: Longitudinal GS US scans of the supra-patellar (a) and lateral (b) recesses of the knee of a two-year-old boy with JIA, showing anechoic joint effusion (stars) and nodular thickening of the synovium (arrows). Page 14 of 17

15 Fig. 15: Longitudinal GS US scans of the supra-patellar (a) and lateral (b) recesses of the knee of a nine-year-old girl with JIA, showing anechoic joint effusion (stars) and nodular thickening of the synovium (arrows). Fig. 16: Longitudinal GS (a) and PD (b) US scans of the second MCP joint of an eightyear-old girl with seropositive polyarticular JIA, showing synovial proliferation (arrows) and hyperaemia (PD signal), and a subtle bone erosion (open arrow). Page 15 of 17

16 Conclusion RA and JIA are debilitating disorders that evolve to mutilating joint destruction in the absence of timely therapeutic care. Nowadays US may support the diagnosing of an early inflammatory arthritis, allowing for therapy implementation before irreversible joint destruction has occurred. Furthermore by discriminating between active and inactive synovial proliferation US may aid therapeutic monitoring and improve patient management. Page 16 of 17

17 References 1. Sommer O, Kladosek A, Weiler V, Czembirek H, Boeck M, Stiskal M. Rheumatoid arthritis: A practical guide to state-of-art imaging, image interpretation and clinical implications. Radiographics 2005; 25: Restrepo R, Lee E. Epidemiology, pathogenisis, and imaging of arthritis in children. Orthop Clin North Am. 2012; 43(2): Buchmann R, Jaramillo D. Imaging of articular disorders in children. Radiol Clin N Am 2004; 42: Tan YK, Conaghan PG. Imaging in rheumatoid arthritis. Best Pract Res Clin Rheumatol 2011; 25: Spencer SP, Ganeshalingam S, Kelly S, Ahmad M. The role of ultrasound in the diagnosis and follow-up of early inflammatory arthritis. Clin Radiol 2012; 67: Hammer HB, Terslev L. Role of Ultrasound in Managing Rheumathoid Arthritis. Curr Rheumat Rep 2012; 14(5): Hartung W, Kellner H, Strunk J, et al. Development and evaluation of a novel ultrasound score for large joints: one year experience in daily clinical practice. Arthritis Care Res. 2012; 64(5): Collado P, Jousse-Joulin S, Alcalde M, Naredo E, D Agostino M. Is ultrasound a validated imaging tool for the diagnosis and management of synovitis in Juvenile Idiopathic Arthritis? A systematic literature review. Arthritis Care Res. 2012; 64(7): Breton S, Jousse-Joulin S, Finel E, et al. Imaging approaches for evaluating peripheral joint abnormalities in Juvenile Idiopathis Arthritis. Semin Arthritis Rheum. 2012; 41(5): Rebollo-Polo M, Koujok K, Weisser C, Jurencak R, Bruns A, Roth J. Ultrasound findings on patients with Juvenile Idiopathic Arthritis in clinical remission. Arthritis Care Res. 2011; 63(7): Page 17 of 17