Page 104 - Imaging of Osteoarthritis and Rheumatoid Arthritis in Hand Joints
P. 104

                                Chapter 6
High field MRI
Patients were placed in the prone position with the arm extended above the head and the hand placed in an 8-channel phased array wrist coil (Invivo Corp, Gainesville, Florida), within the centre of the magnet. The following sequences were obtained: a T2 weighted coronal Fast Recovery Fast Spin Echo (FRFSE) with fat suppression obtained (repetition time/echo time, automatic/68 ms; matrix 512x256; slice thickness/slice gap, 2.5/0.3 mm; Field of view 15x11.25 cm; 1 acquisitions, 19 slices), and T1 weighted coronal Spin Echo (SE) and Axial Fast Spin Echo (FSE) before and after contrast injection (repetition time/echo time, 500/15 ms; slice thickness/slice gap, 2.0/0.2 mm; 1 acquisitions; For coronal SE: matrix 512x512; Field of view 15x11.25 cm; for axial FSE: Echo train length 2; matrix 512x256; Field of view 12x6 cm).
MR Image evaluation
All images were evaluated by an experienced musculoskeletal radiologist (GSRM), after a training session. The reader was blinded to patient data, clinical data, and other imaging results. The anonymized images were read using the open source software ClearCanvas Workstation (ClearCanvas Inc., Toronto, Canada).
Images were scored according to the OMERACT RA MRI Score (RAMRIS) for synovitis, bone erosions and bone marrow oedema in MCP joints two through five and the wrist.20-22, Images from the RAMRIS atlas were used as a guideline for scoring.21, 22 Synovitis was scored in each MCP joint, the intercarpal- carpometacarpal area, the radiocarpal joint, and the distal radioulnar joint. Synovitis was scored according to RAMRIS as the presumed maximum volume of enhancing tissue in the synovial compartment (a score of 0: normal, 1: 0%– 33%, 2:34%–66%, and 3: 67%–100%), and a joint with a RAMRIS synovitis score ≥2 was defined as having synovitis, because grade 1 synovitis are often present in healthy controls.23, 24 BME and erosions were scored for all carpal bones, all metacarpal bases and the distal radius and distal ulna. For the long bones, only the area from the articular surface to a depth of 1 cm was assessed. BME was present with a RAMRIS score >0. Erosions were scored, according to the percentage of eroded bone (a score of 0: no erosion, 1: 1%–10%, 2: 11%– 20%, etc). Wrist bones were defined as having an erosion with a RAMRIS erosion score ≥2, because RAMRIS grade 1 wrist erosions are often present in healthy controls.23, 25

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