Sethi S K, Daugherty A M, Gadda G, Utriainen D T, Jiang J, Raz N, Haacke E M
From The MRI Institute for Biomedical Research (S.K.S., D.T.U., J.J., E.M.H.), Detroit, Michigan
Institute of Gerontology (A.M.D., N.R.).
AJNR Am J Neuroradiol. 2017 Aug;38(8):1617-1622. doi: 10.3174/ajnr.A5219. Epub 2017 May 25.
To date, research on extracranial venous collaterals has been focused on structure, with relatively little attention paid to hemodynamics. We addressed this limitation by quantitatively comparing collateral flow in patients with multiple sclerosis and healthy controls by using phase-contrast MR imaging. We hypothesize that patients with MS with structurally anomalous internal jugular veins will have elevated collateral venous flow compared with healthy controls.
The sample consisted of 276 patients with MS and 106 healthy controls. We used MRV to classify internal jugular veins as stenotic and nonstenotic based on an absolute cross-sectional area threshold in 276 patients with MS and 60 healthy controls; 46 healthy controls lacked this imaging. Individual and total vessel flows were quantified by using phase-contrast MR imaging on all patients. Veins were classified by extracranial drainage type: internal jugular veins (I), paraspinal (II), and superficial (III). Differences among healthy controls, patients with MS, nonstenotic patients, and stenotic subgroups in total venous flow by vessel type were evaluated in a general linear model for statistical analysis.
In the MS group, 153 patients (55%) evidenced stenosis, whereas 12 (20%) healthy controls were classified as stenotic ( < .001). Compared with healthy controls, the MS group showed lower type I flow and increased type II flow. Stenosis was associated with reduced flow in the type I vessels [(1272) = 68; < .001]. The stenotic MS group had increased flow in the type II vessels compared with the nonstenotic MS group [(1272) = 67; < .001].
Compared with healthy controls, patients with MS exhibit reduced venous flow in the main extracerebral drainage vein (internal jugular vein). In contrast, flow in the paraspinal venous collaterals is elevated in patients with MS and exacerbated by venous stenosis. Collateral drainage may be a compensatory response to internal jugular vein flow reduction.
迄今为止，关于颅外静脉侧支循环的研究主要集中在结构方面，而对血流动力学的关注相对较少。我们通过使用相位对比磁共振成像对多发性硬化症患者和健康对照者的侧支血流进行定量比较，解决了这一局限性。我们假设，与健康对照者相比，颈内静脉结构异常的多发性硬化症患者的侧支静脉血流会增加。
样本包括276例多发性硬化症患者和106例健康对照者。我们在276例多发性硬化症患者和60例健康对照者中，根据绝对横截面积阈值，使用磁共振静脉血管造影（MRV）将颈内静脉分为狭窄和非狭窄；46例健康对照者没有此项影像学检查。对所有患者使用相位对比磁共振成像对个体和总血管血流进行定量分析。静脉根据颅外引流类型分类：颈内静脉（I型）、椎旁静脉（II型）和浅表静脉（III型）。在一般线性模型中评估健康对照者、多发性硬化症患者、非狭窄患者和狭窄亚组之间不同血管类型的总静脉血流差异，以进行统计分析。
在多发性硬化症组中，153例患者（55%）存在狭窄，而12例（20%）健康对照者被分类为狭窄（P <.001）。与健康对照者相比，多发性硬化症组I型血流较低，II型血流增加。狭窄与I型血管血流减少相关（t(1272) = 68；P <.001）。与非狭窄的多发性硬化症组相比，狭窄的多发性硬化症组II型血管血流增加（t(1272) = 67；P <.001）。
与健康对照者相比，多发性硬化症患者脑外主要引流静脉（颈内静脉）的静脉血流减少。相反，多发性硬化症患者椎旁静脉侧支循环的血流增加，并且因静脉狭窄而加剧。侧支引流可能是对颈内静脉血流减少的一种代偿反应。
