RC 810 - Inflammatory arthritis: beyond the radiograph
1. To gain insight into the merits of various imaging modalities in the daily practice of radiology of rheumatology.
2. To appreciate the crucial radiological contribution we need to provide in order to support optimal clinical decision making.
Radiographs have been the cornerstone of rheumatology for a long time. Hand and foot radiographs are scored in rheumatoid arthritis patients to assess baseline bone destruction and are used in follow-up. In spondyloarthritis, pelvic radiographs are used to detect sacroiliitis. Radiographs and scoring methods are based on the identification of structural changes secondary to disease. Since new effective medication has become available, the focus in rheumatology has shifted towards early disease detection to treat early and prevent damage. Ultrasound and MRI might play a role in this since they detect active inflammation. With the use of colour Doppler in ultrasound, hypervascularisation can be appreciated and (teno)synovitis diagnosed. MRI has the additional value of the detection of bone marrow oedema and shows subclinical inflammation. The exact position of these imaging techniques in rheumatology is still under debate; however, they are increasingly used in research and daily practice. This refresher course aims to give an update on the diagnosis of inflammatory arthritis beyond the radiograph.
1. To become familiar with MRI techniques used in the assessment of rheumatoid arthritis.
2. To learn about the MRI findings in rheumatoid arthritis and their significance.
Magnetic resonance imaging is being increasingly used both in RA research and in clinical practice due to its capacity to provide insight into pathogenesis of RA, the ability to identify the key pathologic features of this entity at presentation, to follow up patients‘ treatment results, and to establish remission. This presentation will cover two issues: 1. MRI techniques used in the assessment of rheumatoid arthritis, including sequences and protocols most frequently applied in imaging of various peripheral joints and the spine; 2. MRI findings in rheumatoid arthritis within synovial joints, tendons’ sheaths, subchondral bone marrow, articular and extraarticular fat tissue. This part will make us aware that next to the synovium, which is a well-known source of inflammatory cells and a site for aggressive pannus formation, the same process may occur within the subchondral bone marrow or adipose tissue. In addition, the following issues will be addressed: 1. the importance of MRI in subclinical and early diagnosis of RA. 2. Monitoring the disease activity and progression, including the clinical relevance of synovitis and BME in terms of their role as an erosion precursor. 3. Assessing remission/residual synovitis, tenosynovitis, osteitis. 4. Identification of disease complications, especially within the spine.
1. To become familiar with imaging findings seen in the axial skeleton in spondyloarthritis.
2. To understand features on imaging which distinguish spondyloarthritis from other spinal diseases.
Inflammatory spondyloarthropathy (SpA) includes ankylosing spondylitis, psoriatic and reactive arthritis, enteropathic SpA, juvenile SpA and undifferentiated SpA. The assessment of spondyloarthritis (ASAS) International Society criteria for diagnosis of SpA includes MRI for disease staging. Imaging should include the sacro-iliac (SI) joints, and the dorsal and lumbar spine, utilising a combination of T1W and STIR or T2W fat-saturated sequences. In the SI joints, bone marrow oedema and sclerosis are present in areas of sub-chondral inflammation. Identification of bone erosion helps differentiate inflammatory disease from stress related or degenerative change. In the spine, inflammatory corner lesions of the vertebral bodies are one of the earliest signs of SpA, with bone marrow oedema on MRI. They may become sclerotic (previously termed Romanus lesions on radiographs), or fatty replacement may occur in inactive lesions. Inflammatory lesions also involve the facet joints, spinous processes, and costovertebral joints. Other features include disco-vertebral erosion, and syndesmophyte formation. Syndesmophytes may progress to profuse spinal ossification, with ankylosis across the intervertebral disc. Ankylosis of the facet joints, intervertebral ligaments and costovertebral joints also occurs in advanced disease. The proliferative bone formation in psoriasis and reactive arthritis tends to show more asymmetry than ankylosing spondylitis and enteropathic SpA, with more pronounced bony excrescences and paravertebral ossification. The radiologic patterns of inflammatory SpA must be differentiated from the bone formation associated with spondylosis deformans and DISH. Disco-vertebral erosion may mimic Modic changes associated with disc degeneration, cartilaginous Schmorl nodes an even infective discitis.
1. To become familiar with US techniques used in the assessment of inflammatory arthritis.
2. To learn about the US findings in inflammatory arthritis and their significance.
Ultrasound (US) is an established imaging modality for early detection, characterisation and follow-up of various forms of inflammatory arthritis, performed by radiologists and rheumatologists as well. It allows for the detection and characterisation of changes like synovial thickening, synovial proliferation, destructive pannus, effusion, erosions and enthesitis. Using PDUS a further assessment of synovitis and erosions can be obtained by classifying them in active versus nonactive, what has implication for the therapeutic management. Beside intraarticular inflammatory changes also periarticular and extraarticular inflammation in terms of tenosynovitis and enthesitis can be sensitively detected, not always easy to differentiate from articular inflammation by clinical investigation. However, as every imaging modality when assessing arthritis, the initial analysis has to start from the "joint-organ" concept, by dividing the imaging findings in synovial disease, cartilage disease or enthesis disease. This allows not only for basic differential diagnosis but is fundamental especially in more challenging cases, which will be also discussed in this lecture.