Biomedical Research Imaging Center, Durham, NC 27599, USA; Department of Radiology, University of North Carolina at Chapel Hill, Durham, NC 27599, USA.
Biomedical Research Imaging Center, Durham, NC 27599, USA.
Magn Reson Imaging. 2023 Jul;100:84-92. doi: 10.1016/j.mri.2023.03.015. Epub 2023 Mar 24.
Cerebral small vessel disease (SVD) is responsible for primary intracerebral hemorrhages, lacunar infarcts and white matter hyperintensity in T weighted images. While the brain lesions attributed to small vessel disease can be characterized by conventional MRI, it remains challenging to noninvasively measure the early pathological changes of the small underlying vessels. We evaluated the feasibility of detecting alterations in white matter penetrating arterioles (PA) in patients with diabetes with ultra-high field 7 T MRI. 19 participants with diabetes mellitus (DM) and 19 age- and sex-matched healthy controls were scanned with whole brain T and susceptibility weighted MRI and a single slice phase contrast MRI 15 mm above the corpus callosum. The PC-MRI scans were repeated three times. PA masks were manually drawn on the first images after anonymization or automatically segmented on all three images. For each PA, lumen diameter, flow velocity and volume flow rate were derived by model-based analyses of complex difference images. Quasi-Poisson regression was performed for PA count using disease condition, age, and sex as independent variables. Linear mixed effect model analyses were performed for the other measurements using disease condition and age as fixed effect and participant pair specific disease condition as random effect. No severe radiological features of SVD were observed in T and susceptibility weighted images in any of the participants except for white matter hyperintensities with Fazekas score of 1 or 2 in 68% and 26% of patients and controls, respectively. The minimum diameter of visible PA was 78 μm and the majority had diameters <250 μm. Among the manually segmented PA with tilt angle less than 30 from the slice normal direction, flow velocities were lower in the DM group (1.9 ± 0.6 vs. 2.2 ± 0.6; p = 0.022), while no significant difference was observed in count, diameter, or volume flow rate. Similar results were observed in the automatically segmented PA. We also observed significantly increased diameter or decreased velocity with age in some of the scans. This study suggests that early PA alterations that are discriminative of disease state and age might be detectable in human cerebral white matter with 7 T MRI in vivo.
脑小血管病（SVD）是引起原发性脑出血、腔隙性梗死和 T 加权图像中的脑白质高信号的原因。虽然可以通过常规 MRI 来描述小血管疾病引起的脑损伤，但仍难以无创性地测量小血管基底的早期病理变化。我们使用超高场 7T MRI 评估了检测糖尿病患者脑白质穿通小动脉（PA）改变的可行性。19 名糖尿病患者（DM）和 19 名年龄和性别匹配的健康对照者接受了全脑 T 和磁化率加权 MRI 以及胼胝体上方 15mm 处的单次切片相位对比 MRI 扫描。PC-MRI 扫描重复了 3 次。在匿名化后的第一次图像上手动绘制 PA 掩模，或在所有 3 次图像上自动分割 PA 掩模。通过对复杂差分图像的基于模型的分析，为每个 PA 得出管腔直径、流速和体积流量。使用疾病状况、年龄和性别作为独立变量，对 PA 计数进行拟泊松回归。使用疾病状况和年龄作为固定效应，参与者特定疾病状况作为随机效应，对其他测量值进行线性混合效应模型分析。除了 68%和 26%的患者和对照组分别有 1 或 2 分的 Fazekas 脑白质高信号外，在任何参与者的 T 和磁化率加权图像中均未观察到 SVD 的严重放射学特征。可见 PA 的最小直径为 78μm，大多数直径<250μm。在倾斜角度小于切片法线方向 30°的手动分割 PA 中，DM 组的流速较低（1.9±0.6 比 2.2±0.6；p=0.022），但计数、直径或体积流量无显著差异。在自动分割的 PA 中也观察到了类似的结果。在一些扫描中，我们还观察到直径随年龄增大而增大或流速随年龄减小。本研究表明，在活体人类脑白质中，7T MRI 可能能够检测到具有疾病状态和年龄区分能力的早期 PA 改变。
