Murphy-Boesch J, Jiang H, Stoyanova R, Brown T R
Department of NMR and Medical Spectroscopy, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA.
Magn Reson Med. 1998 Mar;39(3):429-38. doi: 10.1002/mrm.1910390313.
A method is described for quantifying phosphorus metabolites in tissue using spectra localized with surface coils and chemical shift imaging (CSI) and assuming that metabolites are uniformly distributed within a well-defined volume. An analytical expression is developed that yields a single numerical correction factor that takes into account the excitation and receiver profiles of the coil, T1 saturation, and point spread effects associated with Fourier transformation of CSI data. An external phosphorus standard is used to calibrate instrument gain and the B1 profile of the coil. For spherical samples, point spread effects can modulate the signal intensities of three-dimensional CSI spectra from -32% to +54%, depending on the voxel size. Measurements of phantoms of known concentrations showed systematic variations of +/- 10% and random errors of +/- 5%. We have used this method to measure the concentration of phosphocreatine in the thigh muscle of normal volunteers.
本文描述了一种使用表面线圈定位光谱和化学位移成像（CSI）来定量组织中磷代谢物的方法，并假设代谢物在定义明确的体积内均匀分布。推导出一个解析表达式，该表达式产生一个单一的数值校正因子，该因子考虑了线圈的激发和接收轮廓、T1饱和以及与CSI数据傅里叶变换相关的点扩散效应。使用外部磷标准来校准仪器增益和线圈的B1轮廓。对于球形样品，点扩散效应可将三维CSI光谱的信号强度调制-32%至+54%，具体取决于体素大小。已知浓度模型的测量显示系统变化为+/-10%，随机误差为+/-5%。我们已使用此方法测量正常志愿者大腿肌肉中磷酸肌酸的浓度。
