Reddy R, Li S, Noyszewski E A, Kneeland J B, Leigh J S
School of Medicine, Department of Radiology, University of Pennsylvania, Philadelphia 19104-6100, USA.
Magn Reson Med. 1997 Aug;38(2):207-14. doi: 10.1002/mrm.1910380208.
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.
作者首次使用带有表面线圈的钠多量子滤波方法报告了体内人关节软骨的钠特性。采用一个与翻转角无关的相位循环脉冲序列来获取作为制备时间函数的三量子滤波光谱。通过将三量子滤波光谱幅度拟合到一个理论表达式来计算双指数弛豫率。给出了偶数阶双量子相干（T2[2]）、奇数阶双量子相干（T2[3]）和三量子相干的翻转角依赖性的理论分析，并与软骨标本上的实验结果进行了验证。体内获得的钠多量子滤波光谱线形与体外标本上观察到的光谱线形密切相关。发现从无症状志愿者获得的弛豫率为：T(2rise)=1.0+0.12毫秒，T(2decay)=12.0±0.75毫秒（平均值±标准差）。描述了该方法在检测关节软骨早期变化方面的诊断潜力。
