Nuclear magnetic resonance: a gray scale model for head images.
Nuclear magnetic resonance: a gray scale model for head images.
复制标题
核磁共振：头部图像的灰度模型。
作者：
R. T. Droege;S. N. Wiener;M. Rzeszotarski;G. Holland;I. Young
从组织参数和机器参数两方面解释了核磁共振头部图像的灰度。这里考虑的组织参数包括自旋-晶格弛豫时间、自旋-自旋弛豫时间和质子密度。机器参数包括脉冲序列（饱和恢复、反转恢复或自旋回波）、重复时间和延迟时间。通过计算机模拟，检验了操作者可预测地改变核磁共振灰度的能力。模拟计算核磁共振像素值为组织和机器参数的选择组合。将计算值与从临床核磁共振图像中提取的值进行比较。模拟和临床像素值之间的一致意味着操作员可以使用机器参数来改变核磁共振灰度，从而控制对比度，适合诊断要求。核磁共振灰度可预测控制的程度通过图表、模拟对比度显示和代表性核磁共振图像来说明。
The gray scale of nuclear magnetic resonance (NMR) head images is explained in terms of tissue and machine parameters. Tissue parameters considered here include the spin-lattice relaxation time, the spin-spin relaxation time, and the proton density. Machine parameters include the pulse sequence (saturation recovery, inversion recovery, or spin echo), the repetition time, and the delay time. The ability of the operator to alter the NMR gray scale predictably is examined by computer simulation. The simulation computes NMR pixel values for a selected combination of tissue and machine parameters. The computed values are compared with those extracted from clinical NMR images. The agreement between simulation and clinical pixel values implies that the operator can use the machine parameters to alter the NMR gray scale, and thereby control contrast, appropriate to the diagnostic requirements. The extent to which the NMR gray scale can be predictably controlled is illustrated through graphs, simulated contrast displays, and representative NMR images.