Herausforderungen der magnetresonanztomografischen Diagnose der axialen Spondylarthritis

Zusammenfassung

In der Bildgebung der axialen Spondylarthritiden einschliesslich der ankylosierenden Spondylitis steht das konventionelle Röntgenbild der Sakroiliakalgelenke (SIG) an erster Stelle. Da sich pathologische Veränderungen hier jedoch erst spät nachweisen lassen, verzögert sich die Diagnosestellung im Schnitt um 5–9 Jahre. Die fehlende Sensitivität des Röntgenbildes für frühe Krankheitsstadien lässt also eine diagnostische Lücke entstehen, welche auch den Therapiebeginn erheblich verzögern kann. Mit der Magnetresonanztomografie (MRT) der SIG steht uns eine moderne, sehr sensitive Modalität zur Erkennung der frühen Spondylarthritis (SpA) zur Verfügung, welche diese Lücke schließen kann. Die heute flächendeckende Verfügbarkeit geeigneter MRT-Geräte und die immer genauere Klassifikation der SIG-Veränderungen machen sie zu einer Untersuchungsmethode, welche nicht mehr den großen Krankenhäusern vorbehalten ist, sondern überall im klinischen Alltag eingesetzt werden kann und sollte. Essenziell für die Bildinterpretation ist die Kenntnis der in der MRT sichtbaren Pathologien, welche in aktive und strukturelle Veränderungen eingeteilt werden. Zu den aktiven Veränderungen zählen paraartikuläre Osteitiden, Synovitiden, Kapsulitiden und Enthesitiden; zu den chronischen Veränderungen Erosionen, subchondrale Sklerosierungen, transartikuläre Knochenbrücken und periartikuläre Verfettungen. Sie lassen sich durch ihr jeweils typisches Signalverhalten und ihre Lage gut charakterisieren. Zusätzlich ist das Wissen über mögliche anatomischen Varianten und Differenzialdiagnosen relevant – in unklaren Fällen kann eine ergänzende computertomoprafische Bildgebung hilfreich sein. Die aktuelle Diskussion neuer Konzepte (wie bspw. das „Backfill“ in den SIG) zeigt, dass die diagnostischen Möglichkeiten auch hier in Zukunft noch vielfältiger werden. Eine interdisziplinäre Zusammenarbeit von Rheumatologen und Radiologen mit optimaler Ausschöpfung dieser „frühen“ diagnostischen und therapeutischen Möglichkeiten trägt zu einer Verbesserung der Patientenversorgung bei.

Abstract

Conventional radiography of the sacroiliac joints (SIJs) remains the first-line modality in the imaging diagnosis of axial spondyloarthritides including ankylosing spondylitis. However, radiographic SIJ changes occur late in the evolution of disease, delaying the radiographic diagnosis by an average of 5–9 years. Therefore, the lack of sensitivity of radiographs to early disease is a diagnostic gap that can considerably delay the initiation of appropriate treatment. This gap may be closed by magnetic resonance imaging (MRI) of the SIJs – a highly sensitive, state-of-the-art imaging modality for the detection of early spondyloarthritis (SpA). Suitable MRI systems are now widely available, and the classification of SIJ changes is becoming more and more accurate. Therefore, MRI can and should be used routinely everywhere today and is no longer confined to large hospitals. It is essential for radiologists interpreting the MRI findings to be familiar with the spectrum of abnormalities, which are subdivided into active disease processes and structural lesions. Active disease changes include para-articular osteitis, synovitis, capsulitis, and enthesitis; chronic abnormalities include erosions, subchondral sclerosis, transarticular bone bridging, and periarticular fatty lesions. Structural lesions have typical signal intensities and are found in typical locations, allowing good characterisation of these lesions. Moreover, knowledge of possible anatomic variants and differential diagnoses is relevant. If MRI is inconclusive, supplementary computed tomography may be helpful. The current discussion of new concepts (e. g. backfill of erosions) indicates that the spectrum of diagnostic options will expand further in the future. Interdisciplinary cooperation of rheumatologists and radiologists with optimal use of early diagnostic and therapeutic options will improve patient management.

Schlüsselwörter

MRT - Sakroiliitis - Spondyloarthritis - Osteitis condensans

Key words

MRI - sacroiliitis - spondyloarthritis - osteitis condensans

• Literatur

• 1 Kiltz U, Sieper J, Rudwaleit M. et al. German Society for Rheumatology S3 guidelines on axial spondyloarthritis including Bechterew‘s disease and early forms: 1 Introduction/preliminary comments. Z Rheumatol 2014; 73 (Suppl. 02) 23-25
• 2 Rudwaleit M, van der Heijde D, Landewe R. et al. The development of Assessment of SpondyloArthritis international Society classification criteria for axial spondyloarthritis (part II): validation and final selection. Ann Rheum Dis 2009; 68: 777-783
• 3 Rudwaleit M, van der Heijde D, Landewe R. et al. The Assessment of SpondyloArthritis International Society classification criteria for peripheral spondyloarthritis and for spondyloarthritis in general. Ann Rheum Dis 2010; 70: 25-31
• 4 Feldtkeller E, Khan MA, van der Heijde D. et al. Age at disease onset and diagnosis delay in HLA-B27 negative vs. positive patients with ankylosing spondylitis. Rheumatol Int 2003; 23: 61-66
• 5 Rudwaleit M, Haibel H, Baraliakos X. et al. The early disease stage in axial spondylarthritis: results from the German Spondyloarthritis Inception Cohort. Arthritis Rheum 2009; 60: 717-727
• 6 Ciurea A, Scherer A, Exer P. et al. Tumor necrosis factor alpha inhibition in radiographic and nonradiographic axial spondyloarthritis: results from a large observational cohort. Arthritis Rheum 2013; 65: 3096-3106
• 7 van der Linden S, Valkenburg HA, Cats A. Evaluation of diagnostic criteria for ankylosing spondylitis. A proposal for modification of the New York criteria. Arthritis Rheum 1984; 27: 361-368
• 8 Kiltz U, Rudwaleit M, Sieper J. et al. German Society for Rheumatology S3 guidelines on axial spondyloarthritis including Bechterew‘s disease and early forms: 6 Diagnostics. Z Rheumatol 2014; 73 (Suppl. 02) 49-65
• 9 Mandl P, Navarro-Compan V, Terslev L. et al. EULAR recommendations for the use of imaging in the diagnosis and management of spondyloarthritis in clinical practice. Ann Rheum Dis 2015; 74: 1327-1339
• 10 Braun J, Baraliakos X, Hermann KG. et al. Golimumab reduces spinal inflammation in ankylosing spondylitis: MRI results of the randomised, placebo-controlled GO-RAISE study. Ann Rheum Dis 2012; 71: 878-884
• 11 Song IH, Hermann KG, Haibel H. et al. Prevention of new osteitis on magnetic resonance imaging in patients with early axial spondyloarthritis during 3 years of continuous treatment with etanercept: data of the ESTHER trial. Rheumatology (Oxford) 2015; 54: 257-261
• 12 Song IH, Hermann KG, Haibel H. et al. Inflammatory and fatty lesions in the spine and sacroiliac joints on whole-body MRI in early axial spondyloarthritis-3-Year data of the ESTHER trial. Semin Arthritis Rheum 2016; 45: 404-410
• 13 Rudwaleit M, Jurik AG, Hermann KG. et al. Defining active sacroiliitis on Magnetic Resonance Imaging (MRI) for classification of axial spondyloarthritis – a consensual approach by the ASAS/OMERACT MRI Group. Ann Rheum Dis 2009; 68: 1520-1527
• 14 Lambert RG, Bakker PA, van der Heijde D. et al. Defining active sacroiliitis on MRI for classification of axial spondyloarthritis: update by the ASAS MRI working group. Ann Rheum Dis 2016;
• 15 Leone A, Marino M, Dell'Atti C. et al. Spinal fractures in patients with ankylosing spondylitis. Rheumatol Int 2016;
• 16 Liu CC, Lin YC, Lo CP. et al. Cauda equina syndrome and dural ectasia: rare manifestations in chronic ankylosing spondylitis. Br J Radiol 2011; 84: e123-e125
• 17 Weber U, Pfirrmann C, Kissling R. et al. Whole body MR imaging in ankylosing spondylitis: a descriptive pilot study in patients with suspected early and active confirmed ankylosing spondylitis. BMC Musculoskelet Disord 2007; 8: 20
• 18 Weckbach S, Schewe S, Michaely HJ. et al. Whole-body MR imaging in psoriatic arthritis: Additional value for therapeutic decision making. Eur J Radiol 2009; [pii] 10.1016/j.ejrad.2009.06.020
• 19 Song IH, Hermann K, Haibel H. et al. Effects of etanercept versus sulfasalazine in early axial spondyloarthritis on active inflammatory lesions as detected by whole-body MRI (ESTHER): a 48-week randomised controlled trial. Ann Rheum Dis 2011; 70: 590-596
• 20 Mager AK, Althoff CE, Sieper J. et al. Role of whole-body magnetic resonance imaging in diagnosing early spondyloarthritis. Eur J Radiol 2009; 71: 182-188
• 21 Althoff CE, Sieper J, Song IH. et al. Active inflammation and structural change in early active axial spondyloarthritis as detected by whole-body MRI. Ann Rheum Dis 2013; 72: 967-973
• 22 Olivieri I, Gemignani G, Camerini E. et al. Differential diagnosis between osteitis condensans ilii and sacroiliitis. The Journal of rheumatology 1990; 17: 1504-1512
• 23 Althoff CE, Bollow M, Feist E. et al. CT-guided corticosteroid injection of the sacroiliac joints: quality assurance and standardized prospective evaluation of long-term effectiveness over six months. Clin Rheumatol 2015; 34: 1079-1084
• 24 Althoff CE, Feist E, Burova E. et al. Magnetic resonance imaging of active sacroiliitis: Do we really need gadolinium?. Eur J Radiol 2009; 71: 232-236
• 25 Klang E, Aharoni D, Hermann KG. et al. Magnetic resonance imaging of pelvic entheses – a systematic comparison between short tau inversion recovery (STIR) and T1-weighted, contrast-enhanced, fat-saturated sequences. Skeletal Radiol 2014; 43: 499-505
• 26 Bollow M, Braun J, Kannenberg J. et al. Normal morphology of sacroiliac joints in children: magnetic resonance studies related to age and sex. Skeletal Radiol 1997; 26: 697-704
• 27 Wittram C, Whitehouse GH. Normal variation in the magnetic resonance imaging appearances of the sacroiliac joints: pitfalls in the diagnosis of sacroiliitis. Clin Radiol 1995; 50: 371-376
• 28 Cidem M, Capkin E, Karkucak M. et al. Osteitis condensans ilii in differential diagnosis of patients with chronic low back pain: a review of the literature. Mod Rheumatol 2012; 22: 467-469
• 29 Maksymowych WP, Wichuk S, Chiowchanwisawakit P. et al. Fat metaplasia and backfill are key intermediaries in the development of sacroiliac joint ankylosis in patients with ankylosing spondylitis. Arthritis Rheumatol 2014; 66: 2958-2967
• 30 Hu Z, Wang X, Qi J. et al. Backfill is a specific sign of axial spondyloarthritis seen on MRI. Joint Bone Spine 2016; 83: 179-183
• 31 Weber U, Pedersen SJ, Ostergaard M. et al. Can erosions on MRI of the sacroiliac joints be reliably detected in patients with ankylosing spondylitis? – A cross-sectional study. Arthritis Res Ther 2012; 14: R124