Patients with multiple sclerosis with structural venous abnormalities on MR imaging exhibit an abnormal flow distribution of the internal jugular veins.

PURPOSE: To evaluate extracranial venous structural and flow characteristics in patients with multiple sclerosis (MS). MATERIALS AND METHODS: Two hundred subjects with MS from two sites (n = 100 each) were evaluated with magnetic resonance (MR) imaging at 3 T. Contrast-enhanced time-resolved MR angiography and time-of-flight MR venography were used to assess vascular anatomy. Two-dimensional phase-contrast MR imaging was used to quantify blood flow. The MS population was divided into two groups: those with evident internal jugular vein (IJV) stenoses (stenotic group) and those without (nonstenotic group). RESULTS: Of the 200 patients, 136 (68%) showed IJV structural abnormalities, including unilateral or bilateral stenoses at different levels in the neck (n = 101; 50.5%) and atresia (n = 35; 17.5%). The total IJV flow normalized to the total arterial flow of the stenotic group (56% ± 22) was significantly lower than that of the nonstenotic group (77% ± 14; P < .001). The arterial/venous flow mismatch in the stenotic group (12% ± 15) was significantly greater than that in the nonstenotic group (6% ± 12; P < .001). The ratio of subdominant venous flow rate (Fsd) to dominant venous flow rate (Fd) for the stenotic group (0.38 ± 0.27) was significantly lower than for the nonstenotic group (0.59 ± 0.23; P < .001). The majority of the stenotic group (67%) also had an Fsd of less than 3 mL/s, a Fd/Fsd ratio greater than 3:1, and/or a total IJV flow rate of less than 8 mL/s. CONCLUSIONS: MR imaging provides a noninvasive means to separate stenotic from nonstenotic MS cases. The former group was more prevalent in the present MS population and carried significantly less flow in the IJVs than the latter.

Magnetic resonance imaging signatures of vascular pathology in multiple sclerosis.

Venous vascular contributing factors to multiple sclerosis (MS) have been known for some time. Only recently has the scope of their potential role become more apparent with the theory of chronic cerebrospinal venous insufficiency (CCSVI). As research expands to further explore the role of vascular pathology in the MS population, it is expedient to review the evidence from an imaging perspective. In this paper, we review the current state-of-the-art methods using magnetic resonance imaging (MRI) as applied to imaging MS patients and CCSVI. This includes evaluating imaging signatures of vascular structure and flow as well as brain iron content. Upon review of the literature, we find that extracranial venous anomalies including stenosis, venous malformations, and collateralization of flow in the major veins of the neck have been observed to be prevalent in the MS population. Abnormal flow has been reported in MS patients both in major vessels using phase-contrast flow quantification and in the brain using perfusion-weighted imaging. We discuss the role of quantitative flow imaging and its potential in assessing possible biomarkers for abnormal flow. Finally, it has been suggested that the presence of high iron content may indirectly indicate progression of existing vascular pathology. To that end, we review the use of susceptibility-weighted imaging in monitoring iron in the thalamus, basal ganglia, and MS lesions.

Characteristics of flow through the internal jugular veins at cervical C2/C3 and C5/C6 levels for multiple sclerosis patients using MR phase contrast imaging.

OBJECTIVES: To study blood flow characteristics through the internal jugular veins (IJVs) at the cervical levels C2/C3 and C5/C6 in the neck of multiple sclerosis (MS) patients. METHODS: Magnetic resonance imaging at 3T was performed on 323 MS patients. Phase contrast imaging was used to quantify blood flow at both the C2/C3 and C5/C6 levels. Total IJV flow (tIJF) was normalized by total arterial flow (tAF). Contrast-enhanced time-resolved 3D MR arteriovenography and 2D time-of-flight MR venography were performed to assess IJV anatomy. Based on this assessment, the MS population was divided into non-stenotic (NST) and stenotic (ST) subjects. RESULTS: Of all the patients, 100 (31%) belonged to the NST group and 223 (69%) belonged to the ST group. At the C2/C3 and C5/C6 levels, the normalized tIJF of the ST group was 56±26% and 51±23%, respectively. This was significantly lower than that of the NST group, 85±13% and 73±12% (P<0·001). Zero percent and 5% of the NST group had a normalized tIJF of less than 50% at the C2/C3 and C5/C6 levels, compared to 37% and 47% for the ST group. The tAF was smaller for the secondary and primary progressive MS patients than the relapsing remitting MS patients (P = 0·02 and 0·01, respectively), while the tIJF was similar among all MS types. CONCLUSION: Total blood flow through the IJVs at both the C2/C3 and C5/C6 levels was reduced in the ST group compared to the NST group.