Visualisation of subchondral erosion in rat monoarticular arthritis by magnetic resonance imaging.
High-resolution magnetic resonance imaging (MRI) was used to investigate antigen-induced monoarticular arthritis (AIMA) in the rat. In sagittal, spin-echo images of the knee, characteristic parallel bands, in the order dark-light-dark, were consistently observed 5-8 days after arthritis induction; the bands ran concentric with, and just beneath, the femoral and tibial articular surfaces. Concurrent radiology, histology and MRI (chemical shift-selective imaging and contrast enhancement with magnetisation transfer and gadolinium) established that the phenomenon reflected subchondral erosion, not artefact. The outer hypointense band corresponded to calcified cartilage underlying the articular surface. The central hyperintense band reflected inflammatory matrix displacing normal haematopoietic tissue immediately subchondrally; here, trabecular bone had mostly disappeared, but adjacent articular cartilage, although under attack and lacking proteoglycan, appeared structurally normal. The inner hypointense band reflected deeper, truncated trabeculae within inflammatory matrix, layered with pallisading osteoblast-like cells. This study exemplifies the power of MRI for revealing localised joint pathology non-invasively, and shows that rat AIMA shares many pathological features with arthritis in human beings.
Carpenter
T A
TA
Herchel Smith Laboratory for Medicinal Chemistry, Cambridge University Forvie Site, UK.
Everett
J R
JR
Hall
L D
LD
Harper
G P
GP
Hodgson
R J
RJ
James
M F
MF
D000818:Animals; D001169:Arthritis, Experimental / Q000000981:diagnostic imaging / Q000473:pathology*; D002358:Cartilage, Articular / Q000473:pathology; D003287:Contrast Media; D005269:Femur / Q000473:pathology; D019786:Gadolinium DTPA; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009942:Organometallic Compounds; D004369:Pentetic Acid / Q000031:analogs & derivatives; D011859:Radiography; D051381:Rats; D017208:Rats, Wistar; D013977:Tibia / Q000473:pathology
D003287:Contrast Media; D009942:Organometallic Compounds; D004369:Pentetic Acid; D019786:Gadolinium DTPA