A MODIFICATION OF THE EULAR-OMERACT RA MRI SCORE FOR USE WITH AN EXTREMITY MRI SYSTEM WITH REDUCED FIELD OF VIEW: RAMRIS-RV
[2007] [SAT0445] A MODIFICATION OF
THE EULAR-OMERACT RA MRI SCORE FOR USE WITH AN EXTREMITY MRI SYSTEM WITH
REDUCED FIELD OF VIEW: RAMRIS-RV
J.E. Freeston 1,
D. Yocum 2, E. Olech 2, E.M.A. Hensor 1, P.
Emery 1, P.G. Conaghan 1 1Academic Unit of
Musculoskeletal Disease, University of Leeds, Leeds, United Kingdom, 2Department
of Rheumatology, University of Arizona, Tucson, United States
Background: The RA MRI score (RAMRIS) [1] presented in the EULAR-OMERACT
atlas is used to assess MRI images for synovitis, erosions and bone oedema in
the setting of clinical trials. With the development of a range of extremity
MRI (eMRI) machines which differ in magnet strength and field of view, the
RAMRIS may require modification.
Objectives: The main aim was to develop and test the reliability of a
modified version of the RAMRIS for eMRI with a reduced field of view
(RAMRIS-RV).
Methods: T1 weighted images from a mixed cohort of patients including
normal controls, early RA patients through to established severe RA were used.
All images were obtained using a MagneVu MV1000 0.2 Tesla machine. In a
preliminary study, in excess of 500 MCP and wrist bones were evaluated to
assess which joints were frequently visualised. Following this, the base of
metacarpal 1, pisiform and trapezium bones were excluded from the RAMRIS
template.
Inter-reader reliability study assessing erosions: 300 wrist bones (including
carpal bones, distal radius, distal ulna, and metacarpal (MC) bases) and 160
MCP joints (metacarpal heads and phalangeal bases) were scored 0-10 based on
the proportion of eroded bone compared to the `assessed bone volume' judged on
all available images, where 0: no erosion; 1: 1-10% of bone eroded; 2: 11-20%
etc. The OMERACT definition of a MRI erosion was used. For long bones, the
`assessed bone volume' is from the articular surface (or its best estimated
position if absent) to a depth of 1cm, while in carpal bones it is the whole
bone. A fused bone scored 10. A `not scorable' image was defined as either due
to motion artefact or the joint area having not been imaged (either partially
or completely). The images were scored by 2 experienced readers (EO, PGC).
Results: 260/300 wrist bone sites and 158/160 MCP sites were agreed to
be scorable by both readers. The results are shown in the Table.
|
Inter-reader Agreement Data |
||||
|
Joint Imaged |
Area Scored |
% Exact |
% Close |
Agreement |
|
|
(where applicable) |
Agreement |
Agreement |
on Damage (%) |
|
MCP2 |
Proximal |
76.9 |
92.3 |
76.9 |
|
MCP2 |
Distal |
51.3 |
76.9 |
69.2 |
|
MCP3 |
Proximal |
90.0 |
100.0 |
90.0 |
|
MCP3 |
Distal |
57.5 |
77.5 |
77.5 |
|
Base Metacarpal2 |
|
88.8 |
94.1 |
100.0 |
|
Base Metacarpal3 |
|
80.0 |
96.0 |
88.2 |
|
Base Metacarpal4 |
|
87.5 |
100.0 |
80.0 |
|
Base Metacarpal5 |
|
100.0 |
100.0 |
87.5 |
|
Capitate |
|
72.0 |
88.0 |
80.0 |
|
Hamate |
|
88.0 |
96.0 |
92.0 |
|
Lunate |
|
60.0 |
92.0 |
72.0 |
|
Scaphoid |
|
85.0 |
95.0 |
90.0 |
|
Trapezoid |
|
90.0 |
90.0 |
95.0 |
|
Triquetrum |
|
79.2 |
91.7 |
87.5 |
|
Distal Radius |
|
69.6 |
91.3 |
82.6 |
|
Distal Ulna |
|
63.2 |
84.2 |
89.5 |
The base of metacarpal 5 was visualised in less then 50% cases (13/25) and was
therefore removed from the final version of the RAMRIS-RV.
Conclusion: The RAMRIS-RV is a practical version of the RAMRIS that can
be used in clinical trials when eMRI with a reduced field of view is used. This
study shows excellent inter-reader reliability, albeit in a reduced number of
bony sites.
References: 1. Ostergaard M, Peterfy C, Conaghan P, McQueen F, Bird P,
Ejbjerg B, et al. OMERACT Rheumatoid Arthritis Magnetic Resonance Imaging
Studies. Core set of MRI acquisitions, joint pathology definitions, and the
OMERACT RA-MRI scoring system. J Rheumatol 2003;30(6):1385-6.
Diagnostics and imaging
procedures
Citation: Ann Rheum Dis 2007;66(Suppl II):564