Wellcome Centre for Integrative Neuroimaging, FMRIB Division, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
Division of Diagnostic and Interventional Neuroradiology, Department of Radiology, Clinic for Radiology and Nuclear Medicine, University of Basel, Basel, Switzerland.
Magn Reson Med. 2019 Mar;81(3):1595-1604. doi: 10.1002/mrm.27507. Epub 2018 Oct 25.
To establish the feasibility of using vessel-encoded pseudocontinuous arterial spin labeling (VEPCASL) for noninvasive vascular territory imaging (VTI) and artery-specific dynamic angiography of a large number of arterial branches above the circle of Willis within a clinically feasible scan time.
3D time-of-flight angiography was used to select a labeling plane and establish 7 pairs of encoding cycles. These were used for VEPCASL VTI and dynamic 2D angiography (8 min and 3 min acquisition times, respectively) in healthy volunteers, allowing the separation of signals arising from 13 arterial branches (including extracranial arteries) in postprocessing. To demonstrate the clinical potential of this approach, VEPCASL angiography was also applied in 5 patients with brain arteriovenous malformation (AVM).
In healthy volunteers, the artery-specific filling of the vascular tree and resulting perfusion territories were well depicted. SNRs were approximately 5 times higher than those achievable with single-artery selective methods. Blood supply to the AVMs was well visualized in all cases, showing the main feeding arteries and venous drainage.
VEPCASL is a highly efficient method for both VTI and dynamic angiography of a large number of arterial branches, providing a comprehensive picture of vascular flow patterns and the effect on downstream tissue perfusion within an acceptable scan time. Automation of labeling plane and vessel-encoding selection would improve robustness and efficiency, and further refinement could allow quantitative blood flow measurements to be obtained. This technique shows promise for visualizing the blood supply to lesions and collateral flow patterns.
在临床可行的扫描时间内，验证使用血管内编码伪连续动脉自旋标记（VEPCASL）进行无创性血管区域成像（VTI）和 Willis 环以上大量动脉分支的动脉特异性动态血管造影的可行性。
使用 3D 时间飞跃血管造影术选择标记平面并建立 7 对编码循环。这些循环用于 VEPCASL VTI 和动态 2D 血管造影（分别为 8 分钟和 3 分钟采集时间），在健康志愿者中，允许在后处理中分离来自 13 条动脉分支（包括颅外动脉）的信号。为了证明这种方法的临床潜力，还在 5 例脑动静脉畸形（AVM）患者中应用了 VEPCASL 血管造影。
在健康志愿者中，血管树的动脉特异性充盈和由此产生的灌注区域得到了很好的描绘。SNR 比单动脉选择性方法高约 5 倍。所有病例均能很好地显示 AVM 的供血动脉，显示主要供血动脉和静脉引流。
VEPCASL 是一种高效的方法，用于大量动脉分支的 VTI 和动态血管造影，在可接受的扫描时间内提供血管流动模式及其对下游组织灌注的影响的全面图像。标记平面和血管编码选择的自动化将提高稳健性和效率，进一步的改进可以允许获得定量的血流测量。该技术有望用于可视化病变的供血和侧支血流模式。
