Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
McCormick School of Engineering, Biomedical Engineering, Northwestern University, Evanston, USA.
J Magn Reson Imaging. 2019 Dec;50(6):1718-1730. doi: 10.1002/jmri.26784. Epub 2019 May 9.
Cerebral arteriovenous malformations (AVMs) are pathological connections between arteries and veins. Dual-venc 4D flow MRI, an extended 4D flow MRI method with improved velocity dynamic range, provides time-resolved 3D cerebral hemodynamics.
To optimize dual-venc 4D flow imaging parameters for AVM; to assess the relationship between spatial resolution, acceleration, and flow quantification accuracy; and to introduce and apply the flow distribution network graph (FDNG) paradigm for storing and analyzing complex neurovascular 4D flow data.
Retrospective cohort study.
SUBJECTS/PHANTOM: Scans were performed in a specialized flow phantom: 26 healthy subjects (age 41 ± 17 years) and five AVM patients (age 27-68 years).
FIELD STRENGTH/SEQUENCE: Dual-venc 4D flow with varying spatial resolution and acceleration factors were performed at 3T field strength.
Quantification accuracy was assessed in vitro by direct comparison to measured flow. FDNGs were used to quantify and compare flow, peak velocity (PV), and pulsatility index (PI) between healthy controls with various Circle of Willis (CoW) anatomy and AVM patients.
In vitro measurements were compared to ground truth with Student's t-test. In vivo groups were compared with Wilcoxon rank-sum test and Kruskal-Wallis test.
Flow was overestimated in all in vitro experiments, by an average 7.1 ± 1.4% for all measurement conditions. Error in flow measurement was significantly correlated with number of voxels across the channel (P = 3.11 × 10 ) but not with acceleration factor (P = 0.74). For the venous-arterial PV and PI ratios, a significant difference was found between AVM nidal and extranidal circulation (P = 0.008 and 0.05, respectively), and between AVM nidal and healthy control circulation (P = 0.005 and 0.003, respectively).
Dual-venc 4D flow MRI and standardized FDNG analysis might be feasible in clinical applications. Venous-arterial ratios of PV and PI are proposed as network-based biomarkers characterizing AVM nidal hemodynamics.
3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;50:1718-1730.
脑动静脉畸形（AVM）是动脉和静脉之间的病理性连接。双编码 4D 流 MRI 是一种扩展的 4D 流 MRI 方法，具有改进的速度动态范围，可提供时间分辨的 3D 脑血流动力学。
优化用于 AVM 的双编码 4D 流成像参数；评估空间分辨率、加速度和流量定量准确性之间的关系；并引入和应用血流分布网络图（FDNG）范式来存储和分析复杂的神经血管 4D 流数据。
回顾性队列研究。
受试者/体模：在专门的流动体模中进行扫描：26 名健康受试者（年龄 41±17 岁）和 5 名 AVM 患者（年龄 27-68 岁）。
磁场强度/序列：在 3T 场强下进行具有不同空间分辨率和加速度因子的双编码 4D 流。
通过与测量流量的直接比较，在体外评估定量准确性。使用 FDNG 来量化和比较具有各种 Willis 环（CoW）解剖结构的健康对照者和 AVM 患者之间的流量、峰值速度（PV）和脉动指数（PI）。
体外测量值与地面真实值进行学生 t 检验比较。体内组与 Wilcoxon 秩和检验和 Kruskal-Wallis 检验进行比较。
在所有体外实验中，流量均被高估，所有测量条件下的平均高估率为 7.1±1.4%。流量测量误差与通道内的体素数量显著相关（P=3.11×10-4），但与加速度因子无关（P=0.74）。对于静脉-动脉 PV 和 PI 比值，AVM 病灶内和病灶外循环之间存在显著差异（P=0.008 和 0.05），AVM 病灶内和健康对照循环之间也存在显著差异（P=0.005 和 0.003）。
双编码 4D 流 MRI 和标准化 FDNG 分析可能在临床应用中可行。PV 和 PI 的静脉-动脉比值被提出作为基于网络的生物标志物，用于表征 AVM 病灶内的血流动力学。
3 级技术功效：阶段 1 J. Magn. Reson. Imaging 2019;50:1718-1730.
