Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
The Intervention Center, Oslo University Hospital, Oslo, Norway.
MAGMA. 2019 Jun;32(3):359-368. doi: 10.1007/s10334-018-00731-1. Epub 2019 Jan 2.
To investigate the effects of a range of parameter settings on T measurement stability in the portal vein using the T1-mapping sequences Look-Locker (LL) and Modified Look-Locker inversion recovery (MOLLI).
Ten different versions of LL and MOLLI sequences were tested and compared to a reference sequence provided by the MR manufacturer. Ten healthy volunteers were imaged multiple times on two separate scan days at 3T. The mean T values and coefficient of variation (CoV) were calculated for each of the ten sequences and compared to the reference sequence.
Six of the tested sequences had T values close to the reference sequence; among those, three sequences achieved lower CoV than the reference sequence. Lowest CoV was achieved using a non-triggered LL sequence with 5 beat readout and a 45 flip angle (mean T 1733 ms ± 89 ms, CoV 1.3% ± 0.58%).
T-measurements in the hepatic portal vein can be performed with high precision using either MOLLI or LL sequences provided that LL sampling duration is sufficiently long and flip angle sufficiently high. The advantage of constant timing outweighed the advantage of ECG-triggering.
使用 T1 映射序列 Look-Locker（LL）和改良 Look-Locker 反转恢复（MOLLI）研究一系列参数设置对门静脉 T 测量稳定性的影响。
测试并比较了 10 种不同版本的 LL 和 MOLLI 序列与 MR 制造商提供的参考序列。10 名健康志愿者在 3T 上分别在两天进行了多次成像。为每个序列计算平均 T 值和变异系数（CoV），并与参考序列进行比较。
6 种测试序列的 T 值与参考序列接近；其中，有 3 种序列的 CoV 低于参考序列。使用非触发的 LL 序列，具有 5 次心跳读取和 45°翻转角时，CoV 最低（平均 T1733ms±89ms，CoV1.3%±0.58%）。
使用 MOLLI 或 LL 序列可以在肝门静脉中进行高精度的 T 测量，前提是 LL 采样时间足够长，翻转角足够高。定时恒定的优势超过了 ECG 触发的优势。
