论文标题
使用3D-QALAS的时间效率高分辨率3T全脑定量宽松指定和波 - 喀米岛读数
Time-efficient, High Resolution 3T Whole Brain Quantitative Relaxometry using 3D-QALAS with Wave-CAIPI Readouts
论文作者
论文摘要
目的:长期获取时间和信噪比(SNR)挑战阻碍了体积,高分辨率,脑组织松弛特性的定量映射。这项研究首次使用交错的外观锁定器采集序列与T2制备脉冲(3D-QALAS)采集方案结合了时间效率波 - 核Caipi读数,并在1.15 mmm3 isosososopic infox infox ins of t2制备脉冲(3D-QALAS)采集方案中结合了洛克锁定序列。方法:将波 - 卡皮读数嵌入到标准的3D-QALAS编码方案中,以r = 3x2的加速因子启用全脑定量参数图(T1,T2和PD),其由于G-Factor惩罚而导致最小的SNR损失。使用基于词典的映射算法估算了定量参数图,该算法结合了反转效率和B1场不均匀性。使用加速方案的定量图与ISMRM NIST Phantom中R = 2的Grappa加速度和10位健康志愿者中的Grappa加速度进行了定量比较。结果:当在ISMRM/NIST幻影和十位健康志愿者中进行测试时,使用加速协议的定量图显示了与从Rgrappa = 2处的常规3D-QALAS获得的良好一致性。结论:3D-QALAS随波谷读数的增强增强,可以在3分钟的3x2加速度以3分钟的时间在3分钟内以1.15 mm3的时间效率,全脑定量T1,T2和PD映射。当对NIST幻影和十名健康志愿者进行测试时,从加速波-Caipi 3D-Qalas方案获得的定量图显示出与从标准3D-QALAS(r = 2)方案获得的值非常相似的值,这暗示了提出拟议方法的鲁棒性和可靠性。
Purpose: Volumetric, high-resolution, quantitative mapping of brain tissue relaxation properties is hindered by long acquisition times and signal-to-noise (SNR) challenges. This study, for the first time, combines the time-efficient wave-CAIPI readouts into the 3D-quantification using an interleaved Look-Locker acquisition sequence with a T2 preparation pulse (3D-QALAS) acquisition scheme, enabling full brain quantitative T1, T2 and proton density (PD) maps at 1.15 mm3 isotropic voxels in only 3 minutes. Methods: Wave-CAIPI readouts were embedded in the standard 3D-QALAS encoding scheme, enabling full brain quantitative parameter maps (T1, T2, and PD) at acceleration factors of R=3x2 with minimum SNR loss due to g-factor penalties. The quantitative parameter maps were estimated using a dictionary-based mapping algorithm incorporating inversion efficiency and B1 field inhomogeneity. The quantitative maps using the accelerated protocol were quantitatively compared against those obtained from conventional 3D-QALAS sequence using GRAPPA acceleration of R=2 in the ISMRM NIST phantom, and ten healthy volunteers. Results: When tested in both the ISMRM/NIST phantom and ten healthy volunteers, the quantitative maps using the accelerated protocol showed excellent agreement against those obtained from conventional 3D-QALAS at RGRAPPA=2. Conclusion: 3D-QALAS enhanced with wave-CAIPI readouts enables time-efficient, full brain quantitative T1, T2, and PD mapping at 1.15 mm3 in 3 minutes at R=3x2 acceleration. When tested on the NIST phantom and ten healthy volunteers, the quantitative maps obtained from the accelerated wave-CAIPI 3D-QALAS protocol showed very similar values to those obtained from the standard 3D-QALAS (R=2) protocol, alluding to the robustness and reliability of the proposed methods.