E2870. Multimodality Diagnostic and Interventional Imaging in Early Synovial Arthropathy: “Macropattern” vs. “Micropattern” Approach
  1. Amit Katyan; Vardhman Mahavir Medical College and Safdarjung Hospital
  2. Dharmender Singh; Vardhman Mahavir Medical College and Safdarjung Hospital
  3. Nishith Kumar; Vardhman Mahavir Medical College and Safdarjung Hospital
Current role of imaging is diagnosis of synovial arthropathy at an “early stage” i.e., when bone manifestations have not occurred. Diagnostic imaging in early arthritis involves understanding the pattern of joint involvement, assessment of synovitis and quantification of mono sodium urate crystals in gout. Ultrasound (US) and CT-guided joint fluid aspiration, synovial biopsy, and guided bone biopsies are important interventional strategies in establishing a definitive diagnosis.

Educational Goals / Teaching Points
To propose a diagnostic algorithm for imaging assessment in early arthritis. To illustrate US, dual energy CT, power Doppler and MR appearances of synovial arthropathies. To describe appropriate clinical and ultrasound guided interventions for definitive diagnosis in early synovial arthropathy.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Imaging approach to synovial arthropathies (SA) can be classified as “macropattern” or “micropattern”. A macro-pattern approach is based on the number of joints involved (monoarticular or polyarticular) and serological factors (rheumatoid factor and HLA-B27 status). Micro-pattern assessment includes assessment of earliest signs of SA, i.e., synovitis and periarticular hyperemia and late changes including cartilage and bone changes. US assessment of specific small joints as per ACR/EULAR criteria is the current standardized imaging protocol for RA. Assessment of Spondylarthritis International Society (ASAS) criteria classifies seronegative spondyloarthropathy into axial and peripheral arthropathy based on specific imaging criteria. US of the small joints is performed using a 12-18 MHZ transducer in a position which enables maximum exposure of the joint under assessment. Dynamic US provides a unique opportunity for directly evaluating mobility of tendons, ligaments in relation to the synovium and joint. US and power Doppler allows excellent visualization of joint effusion, synovial thickening, and hyperemia. MRI is reserved for assessment of US-indeterminate cases and spondylarthritis. Dual-energy CT is the gold standard for diagnosis of gout. US and CT guided aspirations and synovial biopsies are minimally invasive methods for obtaining samples for pathological diagnosis.

A “Micropattern” versus “Macropattern” approach and precise US and CT guided interventions are state-of-the-art imaging strategies for diagnosis of SA at an early stage and prevent disability.