In vivo sodium multiple quantum spectroscopy of human articular cartilage

The authors report, for the first time, sodium properties of human articular cartilage in vivo using sodium multiple-quantum-filtered methods with a surface coil, A flip angle-independent, phase-cycled pulse sequence was used to obtain triple-quantum-filtered spectra as a function of preparation time, Biexponential relaxation rates were calculated by fitting the triple-quantum-filtered spectral amplitudes to a theoretical expression, Theoretical analysis of the flip angle dependence of even rank two-quantum coherence (T-2(2)), Odd rank two-quantum coherence (T-2(3)), and triple-quantum coherence are presented and verified against experimental results on a cartilage specimen, Sodium multiple-quantum-filtered spectral lineshapes obtained in vivo correlate well with those observed on in vitro specimens, Relaxation rates obtained from asymptomatic volunteers were found to be: T-2rise = 1.0 +/- 0.12 ms, T-2decay = 12.0 +/- 0.75 ms (mean +/- SD), The diagnostic potential of this method in detecting early changes in articular cartilage is described.