Schnell Susanne, Wu Can, Ansari Sameer A
aDepartment of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois bDepartment of Biomedical Engineering, Northwestern University, Evanston, Illinois cDepartment of Neurology, Northwestern University dDepartment of Neurological Surgery, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA.
Curr Opin Neurol. 2016 Aug;29(4):419-28. doi: 10.1097/WCO.0000000000000341.
To evaluate the feasibility of 4-dimensional (4D) flow MRI for the clinical assessment of cerebral and extracerebral vascular hemodynamics in patients with neurovascular disease.
4D flow MRI has been applied in multiple studies to qualitatively and quantitatively study intracranial aneurysm blood flow for potential risk stratification and to assess treatment efficacy of various neurovascular lesions, including intraaneurysmal and parent artery blood flow after flow diverter stent placement and staged embolizations of arteriovenous malformations and vein of Galen aneurysmal malformations. Recently, the technique has been utilized to characterize age-related changes of normal cerebral hemodynamics in healthy individuals over a broad age range.
4D flow MRI is a useful tool for the noninvasive, volumetric and quantitative hemodynamic assessment of neurovascular disease without the need for gadolinium contrast agents. Further improvements are warranted to overcome technical limitations before broader clinical implementation. Current developments, such as advanced acceleration techniques (parallel imaging and compressed sensing) for faster data acquisition, dual or multiple velocity encoding strategies for more accurate arterial and venous flow quantification, ultrahigh-field strengths to achieve higher spatial resolution and streamlined postprocessing workflow for more efficient and standardized flow analysis, are promising advancements in 4D flow MRI.
评估四维（4D）流动磁共振成像（MRI）用于临床评估神经血管疾病患者脑内和脑外血管血流动力学的可行性。
4D流动MRI已应用于多项研究，以定性和定量研究颅内动脉瘤血流，用于潜在风险分层，并评估各种神经血管病变的治疗效果，包括血流导向支架置入术后动脉瘤内和载瘤动脉血流，以及动静脉畸形和大脑大静脉动脉瘤样畸形的分期栓塞治疗效果。最近，该技术已被用于描述广泛年龄范围内健康个体正常脑血流动力学的年龄相关变化。
4D流动MRI是一种有用的工具，可用于对神经血管疾病进行无创、容积性和定量血流动力学评估，无需使用钆对比剂。在更广泛的临床应用之前，有必要进一步改进以克服技术限制。当前的发展，如用于更快数据采集的先进加速技术（并行成像和压缩感知）、用于更准确动脉和静脉血流定量的双或多速度编码策略、用于实现更高空间分辨率的超高场强以及用于更高效和标准化血流分析的简化后处理工作流程，都是4D流动MRI中有前景的进展。
