GE Healthcare, Global Applied Science Laboratory, Bethesda, Maryland, USA.
Magn Reson Med. 2012 Mar;67(3):622-7. doi: 10.1002/mrm.24137. Epub 2012 Jan 3.
A modified Look-Locker acquisition using saturation recovery (MLLSR) for breath-held myocardial T(1) mapping is presented. Despite its reduced dynamic range, saturation recovery enables substantially higher imaging efficiency than conventional inversion recovery T(1) mapping because it does not require time for magnetization to relax to equilibrium. Therefore, MLLSR enables segmented readouts, shorter data acquisition windows, and shorter breath holds compared with inversion recovery. T(1) measurements in phantoms using MLLSR showed a high correlation with conventional single-point inversion recovery spin echo. In vivo T(1) measurements from normal and infarcted myocardium in 41 volunteers and patients were consistent with previously reported values. Twenty subjects were also scanned with MLLSR using an accelerated sampling scheme that required half the scan time (eight vs. 16 heartbeats) but yielded equivalent results. The flexibility afforded by the improved imaging efficiency of MLLSR allows the acquisition to be tailored to particular clinical needs and to individual patient's breath-holding abilities.
介绍了一种使用饱和恢复（MLLSR）的改良 Look-Locker 采集方法，用于屏气心肌 T(1) mapping。尽管其动态范围减小，但由于饱和恢复不需要时间让磁化弛豫到平衡，因此与传统的反转恢复 T(1) 映射相比，它可以实现更高的成像效率。因此，与反转恢复相比，MLLSR 可以实现分段读取、更短的数据采集窗口和更短的屏气时间。使用 MLLSR 在体模中进行的 T(1) 测量与传统的单点反转恢复自旋回波具有高度相关性。在 41 名志愿者和患者的正常和梗死心肌中进行的体内 T(1) 测量与以前报道的值一致。20 名受试者还使用加速采样方案进行了 MLLSR 扫描，该方案需要一半的扫描时间（8 次心跳与 16 次心跳），但结果等效。MLLSR 成像效率的提高所带来的灵活性允许根据特定的临床需求和个体患者的屏气能力来调整采集。
