Quantification of cartilage biomechanical and biochemical properties via T1ρ magnetic resonance imaging

✍ Scribed by Andrew J. Wheaton; George R. Dodge; Dawn M. Elliott; Steven B. Nicoll; Ravinder Reddy

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 202 KB
• Volume: 54
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.20678

✦ Synopsis

Abstract

The aim of this study is to develop T~1ρ~ as an MR marker of the compositional and functional condition of cartilage. Specifically, we investigate the correlation of changes in cartilage biomechanical and biochemical properties with T~1ρ~ relaxation rate in a cytokine‐induced model of degeneration. Bovine cartilage explants were cultured with 30 ng/mL of interleukin‐1β to mimic the cartilage degradation of early osteoarthritis. The average rate of T~1ρ~ relaxation was calculated from T~1ρ~ maps acquired on a 4.7 T research scanner. Stress‐relaxation biomechanical tests were conducted with a confined compression apparatus to measure uniaxial aggregate modulus (H~A~) and hydraulic permeability (k~0~) using linear biphasic theory. Proteoglycan, collagen, and water content were measured via biochemical assays. Average T~1ρ~ relaxation rate was strongly correlated with proteoglycan content (R^2^ = 0.926), H~A~ (R^2^ = 0.828), and log~10~ k~0~ (R^2^ = 0.862). Results of this study demonstrate that T~1ρ~ MRI can detect changes in proteoglycan content and biomechanical properties of cartilage in a physiologically relevant model of cartilage degeneration. The T~1ρ~ technique can potentially be used to noninvasively and quantitatively assess the biochemical and biomechanical characteristics of articular cartilage in humans during the progression of osteoarthritis. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.