Ultrasound and Doppler micro-imaging in a model of rheumatoid arthritis in mice.
OBJECTIVE
The evaluation of joints in arthritis using conventional ultrasonography is not really feasible in mice because of the small size of the animal. However, compared with classical analysis (clinical and histological examination) it is a non-invasive method that allows follow-up of the same animal throughout the whole experiment. Moreover, power Doppler allows the study of blood flow that reflects inflammatory activity within the synovium of arthritic joints. Our aim was to determine whether ultrasonography analysis could accurately detect arthritis lesions in a mouse model of rheumatoid arthritis, namely collagen-induced arthritis.


METHODS
Collagen-induced arthritis was induced in 28 mice by immunising with collagen type II. Every week for 8 weeks, ultrasonography and Doppler analysis were performed on knees and ankles of all mice using the ultrasound biomicroscope (UBM), which is particularly dedicated to studying the mouse. Clinical and histological evaluations were performed as usual.


RESULTS
We established a semiquantitative analysis by setting an UBM scoring. UBM grades were correlated to clinical and histological scores of arthritis. Vascularisation within the synovium could be estimated by power Doppler analysis and a semiquantitative vascularisation scale was established, which allowed us to show a good correlation between vascularisation scores and histological or clinical scores of arthritis.


CONCLUSIONS
This is one of the first studies that shows it is possible to visualise a selected set of joints in a small animal using UBM analysis. It provides new perspectives in evaluating experimental models of rheumatoid arthritis and other joint diseases.
Clavel
G
G
INSERM ERI-18, Université Paris 13, France.
Marchiol-Fournigault
C
C
Renault
G
G
Boissier
M-C
MC
Fradelizi
D
D
Bessis
N
N
D000818:Animals; D001169:Arthritis, Experimental / Q000000981:diagnostic imaging* / Q000473:pathology; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging* / Q000473:pathology; D004195:Disease Models, Animal; D007596:Joints / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D033401:Microscopy, Acoustic; D012039:Regional Blood Flow; D012720:Severity of Illness Index; D013583:Synovial Membrane / Q000098:blood supply / Q000000981:diagnostic imaging; D018608:Ultrasonography, Doppler / Q000379:methods