This study assessed T1? relaxation dispersion, measured by magnetic resonance imaging (MRI), as a tool to noninvasively evaluate cartilage material and biochemical properties. The specific objective was to answer two questions: (1) does cartilage initial elastic modulus (E 0) correlate with T1? dispersion effects and (2) does collagen or proteoglycan content correlate with T1? dispersion effects?Cadaveric patellae with and without visible cartilage damage on conventional MR were included. T2 and T1? relaxation times at 500 and 1000 Hz spin-lock field amplitudes were measured. We estimated T1? dispersion effects by measuring T1? relaxation time at 500 and 1000 Hz and T2 relaxation time and using a new tool, the ratio T1?/T2. Cartilage initial elastic modulus, E 0, was measured from initial response of mechanical indentation creep tests. Collagen and proteoglycan contents were measured at the indentation test sites; proteoglycan content was measured by their covalently linked sulfated glycosaminoglycans (sGAG). Pearson correlation coefficients were determined, taking into account the clustering of multiple samples within a single patella specimen.Cartilage initial elastic modulus, E 0, increased with decreasing values of T1?/T2 measurements at both 500 Hz (P = 0.034) and 1000 Hz (P = 0.022). 1/T1? relaxation time (500 Hz) increased with increasing sGAG content (P = 0.041).T1?/T2 ratio, a new tool, and cartilage initial elastic modulus are both measures of water-protein interactions, are dependent on the cartilage structure, and were correlated in this study.
View details for DOI 10.1177/1947603515569529
View details for Web of Science ID 000356631400006
View details for PubMedID 26069714
View details for PubMedCentralID PMC4462251