Laboratory of FMRI Technology (LOFT), Mark & Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, California.
Center for Neurorestoration, Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, California.
Magn Reson Med. 2019 Jul;82(1):449-459. doi: 10.1002/mrm.27712. Epub 2019 Mar 7.
Noncontrast enhanced dynamic magnetic resonance angiography delineates the pattern of dynamic blood flow of the cerebral vasculature. A model-free solution was proposed to quantify arterial blood flow (aBF) by using the monotonic property of the residual function.
Analytical simulations and in-vivo studies were performed to evaluate the performance of the proposed method by comparing the aBF values generated from the proposed and conventional singular value decomposition methods. The aBF values were compared with blood flow velocity measured by 2D phase contrast MRI, and compared between balanced steady-state free precession-based radial and spoiled GRE-based Cartesian acquisitions. Hemodynamic parametric maps were generated in 1 patient with arteriovenous malformation.
The proposed method generates reliable aBF measurement at different signal-to-noise ratio levels, whereas overestimation/underestimation of aBF was observed when a high/low threshold was applied in the singular value decomposition method. Average aBF in large vascular branches was 214.4 and 214.5 mL/mL/min with radial and Cartesian acquisitions, respectively. Significant correlations were found between aBF and blood flow velocity measured by phase contrast MRI (P = 0.0008), and between Cartesian and radial acquisitions (P < 0.0001). Altered hemodynamics were observed at the lesion site of the arteriovenous malformation patient.
A robust analytical solution was proposed for quantifying aBF. This model-free method is robust to noise, and its clinical value in the diagnosis of cerebrovascular disorders awaits further evaluation.
非对比增强动态磁共振血管造影描绘了脑血管血流的动态模式。提出了一种无模型解决方案，通过利用残差函数的单调特性来量化动脉血流量（aBF）。
进行了分析模拟和体内研究，通过比较从提出的和传统的奇异值分解方法生成的 aBF 值来评估所提出方法的性能。将 aBF 值与通过 2D 相位对比 MRI 测量的血流速度进行比较，并在基于平衡稳态自由进动的径向和基于扰动脉冲 GRE 的笛卡尔采集之间进行比较。在 1 例动静脉畸形患者中生成了血流动力学参数图。
所提出的方法在不同的信噪比水平下生成可靠的 aBF 测量值，而在奇异值分解方法中应用高/低阈值时会观察到 aBF 的高估/低估。在大血管分支中，平均 aBF 分别为 214.4 和 214.5 mL/mL/min，使用径向和笛卡尔采集。aBF 与相位对比 MRI 测量的血流速度之间存在显著相关性（P = 0.0008），以及笛卡尔和径向采集之间存在显著相关性（P < 0.0001）。在动静脉畸形患者的病变部位观察到血流动力学改变。
提出了一种用于量化 aBF 的稳健解析解。这种无模型方法对噪声具有鲁棒性，其在诊断脑血管疾病中的临床价值有待进一步评估。
