title: High-resolution magnetic resonance imaging of ankle joints in murine arthritis discriminates inflammation and bone destruction in a quantifiable manner.
abstract: OBJECTIVE
  The ability to noninvasively monitor the development of inflammatory arthritis longitudinally has become increasingly important in experimental rheumatology. Magnetic resonance imaging (MRI) allows for detailed examination of anatomic structures, as well as the assessment of joint and soft tissue inflammation. The aim of this study was to extend the use of MRI to include quantitative measurements of bone destruction in murine ankle joints.
  
  
  METHODS
  Joint disease was measured serially using clinical, histologic, in vivo imaging system (IVIS), micro-computed tomography (micro-CT), and MRI techniques in mouse ankle joints, using the K/BxN serum transfer-induced acute arthritis and K/BxA(g7) chronic arthritis models. Ankle joint MRI was performed using a gradient-echo pulse sequence to evaluate bone destruction and a spin-echo sequence to evaluate inflammation (long T2 signal).
  
  
  RESULTS
  Arthritic mice, as compared to control mice, demonstrated increased disease severity according to clinical, histologic, IVIS, and MRI measures. Following induction of arthritis, the majority of volume expansion of the long T2 signal occurred in a juxtaarticular, rather than intrarticular, manner within the ankle joints. Bone destruction in K/BxA(g7) mouse ankle joints was readily detectible by MRI. Linear regression analyses demonstrated significant correlations between the clinical score and joint radiance intensity assessed by IVIS, between the ankle joint width and increased long T2 signal on MRI, and between the bone volume obtained by micro-CT and bone volume obtained by MRI.
  
  
  CONCLUSIONS
  MRI is an optimal technology for anatomic localization of articular and soft tissue changes during the development and progression of inflammatory arthritis. Future studies may combine MRI with in vivo labeling agents to investigate joint disease in a cell type-specific manner.
authors.affiliation: Northwestern University Feinberg School of Medicine, Chicago, Illinois.
authors.forename: Shawn
authors.initials: S
authors.lastname: Rose
authors.forename: Emily A
authors.initials: EA
authors.lastname: Waters
authors.forename: Chad R
authors.initials: CR
authors.lastname: Haney
authors.forename: C Thomas J
authors.initials: CT
authors.lastname: Meade
authors.forename: Harris
authors.initials: H
authors.lastname: Perlman
mesh_terms: D000818:Animals; D000843:Ankle Joint / Q000000981:diagnostic imaging / Q000473:pathology*; D001169:Arthritis, Experimental / Q000000981:diagnostic imaging / Q000473:pathology*; D001862:Bone Resorption / Q000000981:diagnostic imaging / Q000473:pathology*; D018450:Disease Progression; D007249:Inflammation / Q000000981:diagnostic imaging / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D051379:Mice; D011859:Radiography