Hemodynamics of cerebral veins analyzed by 2d and 4d flow mri and ultrasound in healthy volunteers and patients with multiple sclerosis

Abstract

Background: Hemodynamic alterations of extracranial veins are considered an etiologic factor in multiple sclerosis (MS). However, ultrasound and MRI studies could not confirm a pathophysiological link. Because of technical challenges using standard diagnostics, information about the involvement of superficial intracranial veins in proximity to the affected brain in MS is scarce. Purpose: To comprehensively investigate the hemodynamics of intracranial veins and of the venous outflow tract in MS patients and controls. Study Type: Prospective. Population: Twenty-eight patients with relapsing-remitting MS (EDSS1.9 AE 1.1; range 0-3) and 41 healthy controls. Field Strength/Sequence: 3T/2D phase-contrast and time-resolved 4D flow MRI, extra-and transcranial sonography. Assessment: Hemodynamics within the superficial and deep intracranial venous system and outflow tract including the internal, basal, and great cerebral vein, straight, superior sagittal, and transverse sinuses, internal jugular and vertebral veins. Sonography adhered to the chronic cerebrospinal venous insufficiency (CCSVI) criteria. Statistical Tests: Multivariate repeated measure analysis of variance, Student's two-sample t-test, chi-square, Fisher's exact test; separate analysis of the entire cohort and 32 age-and sex-matched participants. Results: Multi-and univariate main effects of the factor group (MS patient vs. control) and its interactions with the factor vessel position (lower flow within dorsal superior sagittal sinus in MS, 3 AE 1 ml/s vs. 3.8 AE 1 ml/s; P < 0.05) in the uncontrolled cohort were attributable to age-related differences. Age-and sex-matched pairs showed a different velocity gradient in a single segment within the deep cerebral veins (great cerebral vein, vena cerebri magna [VCM] 7.6 AE 1.7 cm/s; straight sinus [StS] 10.5 AE 2.2 cm/s vs. volunteers: VCM 9.2 AE 2.3 cm/s; StS 10.2 AE 2.3 cm/s; P = 0.01), reaching comparable velocities instantaneously downstream. Sonography was not statistically different between groups. Data Conclusion: Consistent with previous studies focusing on extracranial hemodynamics, our comprehensive analysis of intracerebral venous blood flow did not reveal relevant differences between MS patients and controls.

4D flow MRI hemodynamic biomarkers for cerebrovascular diseases

“…In cerebral venous thrombosis, 4D flow MRI has been used to detect abnormal flow patterns including stagnant flow, flow velocity acceleration in nonocclusive thrombosis, and reversed flow in the venous drainage that normalized to resemble values obtained in healthy subjects following successful anticoagulation treatment [80]. 4D flow MRI has also played an important role in challenging an influential theory entailing venous insufficiency in multiple sclerosis [81, 82], confirming observations made using conventional 2D phase‐contrast MRI [83].…”

4D flow MRI for non-invasive measurement of blood flow in the brain: A systematic review

“…They found the technique to be effective, highly reliable and accurate by assessing intra- and inter-observer agreement as well as comparing 4D results to 2D blood flow measurements, but state that ‘limited spatial resolution currently precludes flow quantification in small cerebral veins’. In 2019, the same group then used 4D flow to systematically assess the haemodynamics of the brain’s superficial and intracranial venous system with one MRI acquisition 36 (Figure 3(b)). They did this in 28 relapsing–remitting MS patients and 41 controls, finding no relevant differences between the groups.…”

“…In 2015, Schuchardt et al 35 conducted a study using 4D flow on 15 healthy volunteers to examine blood flow in the venous sinuses. They found the technique to be effective, highly reliable and accurate by assessing intra-and inter-observer agreement as well as comparing 4D results to 2D blood flow measurements, but 36 paper on analysing cerebral vein haemodynamics. It can be seen that, by utilising a lower venc, detailed velocities can be encoded from a range of cerebral veins in a single 4D flow scan.…”

Accelerated dual‐venc 4D flow MRI with variable high‐venc spatial resolution for neurovascular applications

“…4D flow MRI has been used to characterize the hemodynamics of neurovascular arterial and venous processes including aneurysms, 1–4 atherosclerotic disease, 5–7 pulsatile tinnitus, 8 intracranial arteriovenous malformations, 9–12 and fistulae 13 among others 14–16 . However, neurovascular vessels are anatomically variable and small relative to the total intracranial volume, and velocities may vary by an order of magnitude between arteries and veins 12 .…”

“…4D flow MRI has been used to characterize the hemodynamics of neurovascular arterial and venous processes including aneurysms, [1][2][3][4] atherosclerotic disease, [5][6][7] pulsatile tinnitus, 8 intracranial arteriovenous malformations, [9][10][11][12] and fistulae 13 among others. [14][15][16] However, neurovascular vessels are anatomically variable and small relative to the total intracranial volume, and velocities may vary by an order of magnitude between arteries and veins. 12 Thus, single-velocity encoded 4D flow does not accurately capture the full range of intracranial blood flow velocities, and conventional anti-aliasing is difficult due to small numbers of voxels within vessel cross-sections.…”