Univ Rennes, CRLCC Eugene Marquis, Inserm, LTSI-UMR1099, Rennes, France.
The Australian e-Health Research Centre, CSIRO, Brisbane, Australia.
Magn Reson Med. 2021 Mar;85(3):1364-1378. doi: 10.1002/mrm.28517. Epub 2020 Sep 29.
To demonstrate that fluid and white matter suppression (FLAWS) imaging can be used for high-resolution T mapping with low transmitted bias field ( ) sensitivity at 7T.
The FLAWS sequence was optimized for 0.8-mm isotropic resolution imaging. The theoretical accuracy and precision of the FLAWS T mapping was compared with the one of the magnetization-prepared two rapid gradient echoes (MP2RAGE) sequence optimized for low sensitivity. FLAWS images were acquired at 7T on six healthy volunteers (21 to 48 years old; two women). MP2RAGE and saturation-prepared with two rapid gradient echoes (SA2RAGE) datasets were also acquired to obtain T mapping references and maps. The contrast-to-noise ratio (CNR) between brain tissues was measured in the FLAWS-hco and MP2RAGE-uni images. The Pearson correlation was measured between the MP2RAGE and FLAWS T maps. The effect of on FLAWS T mapping was assessed using the Pearson correlation.
The FLAWS-hco images were characterized by a higher brain tissue CNR ( , , ) than the MP2RAGE-uni images ( , , ). The theoretical accuracy and precision of the FLAWS T mapping ( ) were in agreement with those provided by the MP2RAGE T mapping ( ). A good agreement was found between in vivo T values measured with the MP2RAGE and FLAWS sequences (r = 0.91). A weak correlation was found between the FLAWS T map and the map within cortical gray matter and white matter segmentations ( ; ).
The results from this study suggest that FLAWS is a good candidate for high-resolution T -weighted imaging and T mapping at the field strength of 7T.
证明在 7T 场强下，FLAWS 成像可用于具有低传输偏场（ ）灵敏度的高分辨率 T 映射。
优化了 FLAWS 序列以实现 0.8 毫米各向同性分辨率成像。比较了 FLAWS 序列和针对低灵敏度优化的磁化准备双快速梯度回波（MP2RAGE）序列的 T 映射的理论精度和精度。在 7T 上对六名健康志愿者（21 至 48 岁；两名女性）进行了 FLAWS 图像采集。还采集了 MP2RAGE 和饱和准备的两个快速梯度回波（SA2RAGE）数据集，以获得 T 映射参考和 图。在 FLAWS-hco 和 MP2RAGE-uni 图像中测量脑组织结构的对比噪声比（CNR）。测量了 MP2RAGE 和 FLAWS T 图之间的 Pearson 相关性。使用 Pearson 相关性评估了对 FLAWS T 映射的影响。
FLAWS-hco 图像的脑组织结构 CNR（ ， ， ）高于 MP2RAGE-uni 图像（ ， ， ）。FLAWS T 映射的理论精度和精度（ ）与 MP2RAGE T 映射提供的精度（ ）一致。在体内，用 MP2RAGE 和 FLAWS 序列测量的 T 值之间存在良好的一致性（r = 0.91）。在皮质灰质和白质分割内，FLAWS T 图与 图之间存在弱相关性（ ； ）。
这项研究的结果表明，FLAWS 是在 7T 场强下进行高分辨率 T 加权成像和 T 映射的良好候选者。
