Magnetic resonance imaging systems: optimization in clinical use.
Magnetic resonance imaging systems: optimization in clinical use.
复制标题
磁共振成像系统：临床使用的优化。
作者：
J. Kneeland;R. Knowles;P. Cahill
磁共振（MR）成像给用户带来了大量可能严重影响图像质量的选项。用户可以控制的最重要的参数是接收器频率、尖端角度、成像和补偿梯度强度、平均信号的数量、相位编码梯度步骤的数量和重复时间。所有这些参数都是系统变化的，并确定了0.5T Teslacon系统的最佳值，该系统采用了幻影和正常志愿者。在正常的调谐条件下，z补偿梯度呈现最关键的调节。还仔细检查了图像质量和研究时间之间的折衷，确定以下为最佳：头部线圈的192个梯度步长加两个信号平均值，或体线圈的192个梯度步长加四个信号平均值。
Magnetic resonance (MR) imaging confronts the user with a large number of options that can critically affect image quality. Among the most important parameters over which the user may exercise control are receiver frequency, tip angles, imaging and compensatory gradient strengths, the number of signals averaged, the number of phase encoding gradient steps, and the repetition times. All of these parameters were systematically varied and optimal values determined for a 0.5T Teslacon system, a task which employed both phantoms and normal volunteers. Under the normal conditions of tuning, the z-compensatory gradient presents the most critical adjustment. The compromise between image quality and time of study was also carefully examined, with the following determined as best: 192 gradient steps plus two signal averages for the head coil, or 192 gradient steps plus four signal averages for the body coil.