Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
Eur Radiol. 2014 Apr;24(4):850-6. doi: 10.1007/s00330-013-3081-x. Epub 2013 Dec 11.
To investigate the influence of atherosclerotic plaques on femoral haemodynamics assessed by two-dimensional (2D) phase-contrast (PC) magnetic resonance imaging (MRI) with three-directional velocity encoding.
During 1 year, patients with peripheral artery disease and an ankle brachial index <1.00 were enrolled. After institutional review board approval and written informed consent, 44 patients (age, 70 ± 12 years) underwent common femoral artery MRI. Patients with contra-indications for MRI were excluded. Sequences included 2D time-of-flight, proton-density, T1-weighted and T2-weighted MRI. Electrocardiogram (ECG)-gated 2D PC-MRI with 3D velocity encoding was acquired. A radiologist classified images in five categories. Blood flow, velocity and wall shear stress (WSS) along the vessel circumference were quantified from the PC-MRI data.
The acquired images were of good quality for interpretation. There were no image quality problems related to poor ECG-gating or slice positioning. Velocities, oscillatory shear stress and total flow were similar between patients with normal arteries and wall thickening/plaque. Patients with plaques demonstrated regionally increased peak systolic WSS and enhanced WSS eccentricity.
Combined multi-contrast morphological imaging of the peripheral arterial wall with PC-MRI with three-directional velocity encoding is a feasible technique. Further study is needed to determine whether flow is an appropriate marker for altered endothelial cell function, vascular remodelling and plaque progression.
• Femoral plaques are associated with altered dynamics of peripheral blood flow. • Multi-contrast MRI can investigate the presence and type of atherosclerotic plaques. • Three-dimensional velocity-encoding phase-contrast MRI can investigate flow and wall shear stress. • Atherosclerotic peripheral arteries demonstrate increased systolic velocities and wall shear stress.
利用三维方向速度编码二维（2D）相位对比（PC）磁共振成像（MRI）评估粥样斑块对股动脉血液动力学的影响。
在 1 年期间，纳入外周动脉疾病且踝肱指数<1.00 的患者。经机构审查委员会批准和书面知情同意后，对 44 例（年龄 70±12 岁）患者进行股总动脉 MRI 检查。排除 MRI 禁忌证的患者。序列包括二维时间飞越、质子密度、T1 加权和 T2 加权 MRI。采集心电图（ECG）门控二维 PC-MRI 及三维速度编码。一位放射科医生将图像分为五类。从 PC-MRI 数据中量化血流、速度和血管周向壁面切应力（WSS）。
采集的图像质量适合解读。不存在与 ECG 门控不良或层面定位不良相关的图像质量问题。正常动脉和壁增厚/斑块患者的速度、振荡切应力和总血流量相似。斑块患者表现为区域性收缩期峰值 WSS 增加和 WSS 偏心增强。
联合应用 PC-MRI 三维速度编码多对比形态学成像外周动脉壁是一种可行的技术。需要进一步研究以确定血流是否是改变内皮细胞功能、血管重塑和斑块进展的合适标志物。
•股动脉斑块与外周血流动力学改变有关。•多对比 MRI 可用于检查粥样斑块的存在和类型。•三维速度编码相位对比 MRI 可用于检查血流和壁面切应力。•粥样硬化外周动脉表现为收缩期速度和壁面切应力增加。
