Fully automated system for the quantification of human osteoarthritic knee joint effusion volume using magnetic resonance imaging.
BACKGROUND
Joint effusion is frequently associated with osteoarthritis (OA) flare-up and is an important marker of therapeutic response. This study aimed at developing and validating a fully automated system based on magnetic resonance imaging (MRI) for the quantification of joint effusion volume in knee OA patients.


METHODS
MRI examinations consisted of two axial sequences: a T2-weighted true fast imaging with steady-state precession and a T1-weighted gradient echo. An automated joint effusion volume quantification system using MRI was developed and validated (a) with calibrated phantoms (cylinder and sphere) and effusion from knee OA patients; (b) with assessment by manual quantification; and (c) by direct aspiration. Twenty-five knee OA patients with joint effusion were included in the study.


RESULTS
The automated joint effusion volume quantification was developed as a four stage sequencing process: bone segmentation, filtering of unrelated structures, segmentation of joint effusion, and subvoxel volume calculation. Validation experiments revealed excellent coefficients of variation with the calibrated cylinder (1.4%) and sphere (0.8%) phantoms. Comparison of the OA knee joint effusion volume assessed by the developed automated system and by manual quantification was also excellent (r = 0.98; P < 0.0001), as was the comparison with direct aspiration (r = 0.88; P = 0.0008).


CONCLUSIONS
The newly developed fully automated MRI-based system provided precise quantification of OA knee joint effusion volume with excellent correlation with data from phantoms, a manual system, and joint aspiration. Such an automated system will be instrumental in improving the reproducibility/reliability of the evaluation of this marker in clinical application.
Li
Wei
W
ArthroVision Inc, 1871 Sherbrooke Street East, Montreal, Quebec H2K 1B6, Canada. wei-li@arthrovision.biz
Abram
François
F
Pelletier
Jean-Pierre
JP
Raynauld
Jean-Pierre
JP
Dorais
Marc
M
d'Anjou
Marc-André
MA
Martel-Pelletier
Johanne
J
D000368:Aged; D000369:Aged, 80 and over; D001331:Automation; D005122:Exudates and Transudates; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000473:pathology*