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 (T2[2]), odd rank two-quantum coherence (T2[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.
Reddy
R
R
School of Medicine, Department of Radiology, University of Pennsylvania, Philadelphia 19104-6100, USA.
Li
S
S
Noyszewski
E A
EA
Kneeland
J B
JB
Leigh
J S
JS
D000818:Animals; D002358:Cartilage, Articular / Q000737:chemistry*; D002417:Cattle; D006801:Humans; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D012964:Sodium / Q000032:analysis*
D012964:Sodium