Table I.

Comparisons between high-frequency US- and MRI-detected abnormalities in joints (n=858) in rheumatoid arthritis.

Item	No. joints	US (% total joints)	MRI (% total joints)	P-value	χ2
Bone erosion	858	44 (5.1%)	35 (4.1%)	0.300	1.075
Bone marrow edema	858	0 (0.0%)	47 (5.5%)	<0.001	48.324
Synovial proliferation	858	132 (15.4%)	66 (7.7%)	<0.001	24.870
Joint effusion	858	89 (10.4%)	52 (6.1%)	0.001	10.578
Tendinitis	390	18 (4.6%)	14 (1.5%)	0.470	0.521
Tendon sheath edema	390	37 (9.5%)	30 (7.7%)	0.371	0.800

US, ultrasound; MRI, magnetic resonance imaging.