The development of EERA: software for assessing rheumatic joint erosions.
OBJECTIVE
The principal aim of this study was to create a segmentation program, to be used by nonmusculoskeletal or junior fellows, that defines the bones in the metacarpophalangeal joint in a dynamic 3-dimensional image that will lead to higher inter-reader agreement of bone erosion scores.


METHODS
The second to fifth metacarpal head and phalangeal bases of 15 participants were rated according to the Rheumatoid Arthritis Magnetic Resonance Imaging Scoring system by one trained and one untrained reader. Two comparisons were made. The first comparison was between the 2 readers using only the traditional 2-dimensional magnetic resonance image set. The second comparison was between the 2 readers, with the untrained reader using a custom segmentation program with traditional 2-dimensional magnetic resonance image set.


RESULTS
The software marginally increased inter-reader reliability with the exception of the second metacarpal head, for which reliability was increased substantially. Future work will concentrate on improving image acquisition, better delineate erosions from surrounding bone oedema, and address methods to directly determine erosion volumes.


CONCLUSIONS
Software designed to display dynamic 3-dimensional images enables a relatively untrained user to score the metacarpophalangeal joints in the hand for erosions equivalent to that produced by an expert using the manual methods.
St Joseph's Hospital, McMaster University, Hamilton, Ontario, Canada. edmondpd@mcmaster.ca
Patrick D
PD
Emond
Abram
A
Choi
John
J
O'Neill
Jason
J
Xie
Rick
R
Adachi
Chris L
CL
Gordon
D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000473:pathology; D018450:Disease Progression; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008662:Metacarpophalangeal Joint / Q000473:pathology*; D015588:Observer Variation; D015203:Reproducibility of Results; D012984:Software