这项工作的目的是将多回波自旋梯度回波 (SAGE) 回波平面成像 (EPI) 与基于导航器 (NAV) 的前瞻性运动补偿方法相结合，用于定量肝血氧水平依赖 (BOLD) ）使用屏气 (BH) 任务进行测量。开发了五回波 SAGE 序列来定量测量 T2 和 T2*，以足够的信噪比、空间分辨率和对 BH 引起的 BOLD 变化的敏感性来描述功能任务。为了解释呼吸运动，采用了单一梯度回波投影读数形式的导航器，沿着上下方向位于膈肌处。在基于自旋回波 EPI 的读数的每个横向成像切片之前，合并了导航器采集和脂肪抑制。从导航器获取运动数据并将其传输回序列，从而可以实时调整切片定位。这项研究包括六名健康志愿者和三名肝癌患者。在 BH 任务的每个时间点计算定量 T2 和 T2*。使用一般线性模型计算一级分析的 t 值参数以及 Echo1、T2 和 T2* 的肝血管反应性 (HVR)。使用导航信号成功补偿了呼吸活动引起的运动。屏气期间 T2 和 T2* 的平均变化分别约为 1% 和 0.7%。借助 NAV 前瞻性运动补偿，可以获得没有运动伪影的全肝 t 值。量化的肝脏 T2 (34.7±0.7ms) 和 T2* (29±1.2ms) 值与文献值一致。在健康志愿者中，统计 t 值和 HVR 在整个肝脏中的分布是均匀的。在肝癌患者中，由于转移或治疗，t值和HVR的分布不均匀。本研究证明了使用NAV前瞻性运动补偿技术结合五回波SAGE EPI定量测量肝脏BOLD的可行性BH 任务。© 2024 作者。约翰·威利 (John Wiley) 出版的《生物医学中的核磁共振》

The purpose of this work is to apply multi-echo spin- and gradient-echo (SAGE) echo-planar imaging (EPI) combined with a navigator-based (NAV) prospective motion compensation method for a quantitative liver blood oxygen level dependent (BOLD) measurement with a breath-hold (BH) task.A five-echo SAGE sequence was developed to quantitatively measure T2 and T2* to depict function with sufficient signal-to-noise ratio, spatial resolution and sensitivity to BOLD changes induced by the BH task. To account for respiratory motion, a navigator was employed in the form of a single gradient-echo projection readout, located at the diaphragm along the inferior-superior direction. Prior to each transverse imaging slice of the spin-echo EPI-based readouts, navigator acquisition and fat suppression were incorporated. Motion data was obtained from the navigator and transmitted back to the sequence, allowing real-time adjustments to slice positioning. Six healthy volunteers and three patients with liver carcinoma were included in this study. Quantitative T2 and T2* were calculated at each time point of the BH task. Parameters of t value from first-level analysis using a general linear model and hepatovascular reactivity (HVR) of Echo1, T2 and T2* were calculated.The motion caused by respiratory activity was successfully compensated using the navigator signal. The average changes of T2 and T2* during breath-hold were about 1% and 0.7%, respectively. With the help of NAV prospective motion compensation whole liver t values could be obtained without motion artifacts. The quantified liver T2 (34.7 ± 0.7 ms) and T2* (29 ± 1.2 ms) values agreed with values from literature. In healthy volunteers, the distribution of statistical t value and HVR was homogeneous throughout the whole liver. In patients with liver carcinoma, the distribution of t value and HVR was inhomogeneous due to metastases or therapy.This study demonstrates the feasibility of using a NAV prospective motion compensation technique in conjunction with five-echo SAGE EPI for the quantitative measurement of liver BOLD with a BH task.© 2024 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.