Macromolecule and water magnetization exchange modeling in articular cartilage.
Magnetization exchange effects between the matrix macromolecules (e. g., collagen and proteoglycan) and water were examined in normal, deuterated, and proteoglycan-depleted articular cartilage. Relaxation results (T(2), T(1rho), and T(1)) suggested that a four-site exchange scheme provided an accurate model for articular cartilage relaxation and interspin group coupling details. Magnetization exchange within the collagen-bulk-water, proteoglycan-collagen, and collagen fibrillar water-collagen cartilage subsystems were quantified. Although collagen-bulk-water was the largest of the cartilage coupling subsystems ( approximately 90% signal) and is exploited in MRI, the rates of magnetization transfer (MT) within the latter subsystems were appreciably larger. Magnetization exchange rates for proteoglycan-collagen and collagen fibrillar water-collagen were 120 s(-1) and 4.4 s(-1), respectively. The observation of these latter two exchange subsystems suggested potential clinical MRI-MT applications in detecting molecular abnormalities associated with osteoarthritis.
Lattanzio
P J
PJ
Institute of Medical Science, University of Toronto, Toronto, Canada.
Marshall
K W
KW
Damyanovich
A Z
AZ
Peemoeller
H
H
D000818:Animals; D001834:Body Water / Q000737:chemistry*; D002358:Cartilage, Articular / Q000737:chemistry*; D002417:Cattle; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D008954:Models, Biological; D016011:Normal Distribution; D012016:Reference Values; D013997:Time Factors
D046911:Macromolecular Substances