F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA.
Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA.
Magn Reson Med. 2024 Oct;92(4):1456-1470. doi: 10.1002/mrm.30134. Epub 2024 May 15.
To develop a 3D, high-sensitivity CEST mapping technique based on the 3D stack-of-spirals (SOS) gradient echo readout, the proposed approach was compared with conventional acquisition techniques and evaluated for its efficacy in concurrently mapping of guanidino (Guan) and amide CEST in human brain at 3 T, leveraging the polynomial Lorentzian line-shape fitting (PLOF) method.
Saturation time and recovery delay were optimized to achieve maximum CEST time efficiency. The 3DSOS method was compared with segmented 3D EPI (3DEPI), turbo spin echo, and gradient- and spin-echo techniques. Image quality, temporal SNR (tSNR), and test-retest reliability were assessed. Maps of Guan and amide CEST derived from 3DSOS were demonstrated on a low-grade glioma patient.
The optimized recovery delay/saturation time was determined to be 1.4/2 s for Guan and amide CEST. In addition to nearly doubling the slice number, the gradient echo techniques also outperformed spin echo sequences in tSNR: 3DEPI (193.8 ± 6.6), 3DSOS (173.9 ± 5.6), and GRASE (141.0 ± 2.7). 3DSOS, compared with 3DEPI, demonstrated comparable GuanCEST signal in gray matter (GM) (3DSOS: [2.14%-2.59%] vs. 3DEPI: [2.15%-2.61%]), and white matter (WM) (3DSOS: [1.49%-2.11%] vs. 3DEPI: [1.64%-2.09%]). 3DSOS also achieves significantly higher amideCEST in both GM (3DSOS: [2.29%-3.00%] vs. 3DEPI: [2.06%-2.92%]) and WM (3DSOS: [2.23%-2.66%] vs. 3DEPI: [1.95%-2.57%]). 3DSOS outperforms 3DEPI in terms of scan-rescan reliability (correlation coefficient: 3DSOS: 0.58-0.96 vs. 3DEPI: -0.02 to 0.75) and robustness to motion as well.
The 3DSOS CEST technique shows promise for whole-cerebrum CEST imaging, offering uniform contrast and robustness against motion artifacts.
开发一种基于 3D 堆叠螺旋（SOS）梯度回波读出的高灵敏度 CEST 映射技术。通过多项式洛伦兹线拟合（PLOF）方法，将所提出的方法与传统采集技术进行比较，并评估其在 3T 下同时映射人脑中胍基（Guan）和酰胺 CEST 的功效。
优化饱和时间和恢复延迟以实现最大的 CEST 时间效率。将 3DSOS 方法与分段 3D EPI（3DEPI）、涡轮自旋回波和梯度和自旋回波技术进行比较。评估图像质量、时间 SNR（tSNR）和测试-重测可靠性。在一位低级别胶质瘤患者身上展示了源自 3DSOS 的 Guan 和酰胺 CEST 图谱。
确定 Guan 和酰胺 CEST 的优化恢复延迟/饱和时间分别为 1.4/2s。除了将切片数增加近一倍外，梯度回波技术还在 tSNR 方面优于自旋回波序列：3DEPI（193.8±6.6）、3DSOS（173.9±5.6）和 GRASE（141.0±2.7）。与 3DEPI 相比，3DSOS 在灰质（GM）中显示出可比的 GuanCEST 信号（3DSOS：[2.14%-2.59%]与 3DEPI：[2.15%-2.61%]）和白质（WM）（3DSOS：[1.49%-2.11%]与 3DEPI：[1.64%-2.09%]）。3DSOS 在 GM（3DSOS：[2.29%-3.00%]与 3DEPI：[2.06%-2.92%]）和 WM（3DSOS：[2.23%-2.66%]与 3DEPI：[1.95%-2.57%]）中也实现了显著更高的酰胺 CEST。3DSOS 在扫描重扫可靠性（相关系数：3DSOS：0.58-0.96 与 3DEPI：-0.02 至 0.75）和抗运动伪影方面也优于 3DEPI。
3DSOS CEST 技术有望用于全脑 CEST 成像，提供均匀的对比度和对运动伪影的鲁棒性。
