NEURO AIDS CONSORTIUM

高场NMR成像提供了改进的检测小 与生理功能相关的对比度变化（例如， 灌注）。 技术已经在4.1T上开发和实施 其已经显示出改善的对比度特性， 使用RF标记的心室功能成像。 射频标记矿床a 心动周期开始时视野中的线网格 然后随着心肌在心动周期中移动而变形。 该网格可用于心室运动的自动分析。 这种改善是由于在1000 ℃时磁弛豫速率降低所致。 4.1T与临床场强相比，改善的信噪比 固有的在更高的领域，并以射频激励 在UAB开发，它们本身可以提高标签线的持久性。 动物研究在心率为75至130 bpm的情况下进行 证明了标记线的持久性以结束标记。 心肌 已经使用动脉自旋反转技术对灌注成像 其通过以下步骤提供用于灌注估计的定量模型： 比较动脉血被磁性反转的图像与 控制图像。 1-3%的信号差异已经被可视化， 动物模型的高场成像。

High-field NMR imaging provides improved ability to detect small contrast changes associated with physiological function (e.g. perfusion). Techniques have been developed and implemented at 4.1T which have demonstrated improved contrast characteristics for ventricular function imaging using RF tagging. RF tagging deposits a grid of lines in the field of view at the start of the cardiac cycle which then distort as the myocardium moves across the cardiac cycle. This grid can be used in automated analysis of ventricular motion. This improvement resulted from the reduced magnetic relaxation rate at 4.1T vs clinical field strengths, the improved signal-to-noise ratio inherent at the higher field, and to radio frequency excitations developed at UAB which themselves improve tag line persistence. Animal studies have been carried out at heart rates from 75 to 130bpm demonstrating persistence of tag lines to end diastole. Myocardial perfusion has been imaged using an arterial spin-inversion technique which provides a quantitative model for perfusion estimation by comparing images in which arterial blood is magnetically inverted vs a control image. Signal differences of 1-3% have been visualized with high field imaging of animal models.