Premium
Multicomponent T 2 * mapping of knee cartilage: Technical feasibility ex vivo
Author(s) -
Qian Yongxian,
Williams Ashley A.,
Chu Constance R.,
Boada Fernando E.
Publication year - 2010
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.22450
Subject(s) - cartilage , knee cartilage , relaxation (psychology) , ex vivo , nuclear magnetic resonance , scanner , t2 relaxation , chemistry , osteoarthritis , transverse plane , biomedical engineering , materials science , physics , anatomy , articular cartilage , magnetic resonance imaging , optics , in vitro , pathology , biology , medicine , biochemistry , alternative medicine , radiology , neuroscience
Disorganization of collagen fibers is a sign of early‐stage cartilage degeneration in osteoarthritic knees. Water molecules trapped within well‐organized collagen fibrils would be sensitive to collagen alterations. Multicomponent effective transverse relaxation ( T 2 *) mapping with ultrashort echo time acquisitions is here proposed to probe short T 2 relaxations in those trapped water molecules. Six human tibial plateau explants were scanned on a 3T MRI scanner using a home‐developed ultrashort echo time sequence with echo times optimized via Monte Carlo simulations. Time constants and component intensities of T 2 * decays were calculated at individual pixels, using the nonnegative least squares algorithm. Four T 2 *‐decay types were found: 99% of cartilage pixels having mono‐, bi‐, or nonexponential decay, and 1% showing triexponential decay. Short T 2 * was mainly in 1‐6 ms, while long T 2 * was ∼22 ms. A map of decay types presented spatial distribution of these T 2 * decays. These results showed the technical feasibility of multicomponent T 2 * mapping on human knee cartilage explants. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.