IN-VIVO SODIUM MULTIPLE-QUANTUM SPECTROSCOPY OF HUMAN ARTICULAR-CARTILAGE

The authors report, for the first time, sodium properties of human art icular cartilage in vivo using sodium multiple-quantum-filtered method s with a surface coil, A flip angle-independent, phase-cycled pulse se quence was used to obtain triple-quantum-filtered spectra as a functio n of preparation time, Biexponential relaxation rates were calculated by fitting the triple-quantum-filtered spectral amplitudes to a theore tical expression, Theoretical analysis of the flip angle dependence of even rank two-quantum coherence (T-2(2)), Odd rank two-quantum cohere nce (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 w ith those observed on in vitro specimens, Relaxation rates obtained fr om 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 de scribed.