Correlation Between Trans-Stenotic Blood Flow Velocity Differences and the Cerebral Venous Pressure Gradient in Transverse Sinus Stenosis: A Prospective 4-Dimensional Flow Magnetic Resonance Imaging Study

BACKGROUND: The relationship between trans-stenotic blood flow velocity differences and the cerebral venous pressure gradient (CVPG) in transverse sinus (TS) stenosis (TSS) has not been studied. OBJECTIVE: To evaluate the hemodynamic manifestations of TSS and the relationship between trans-stenotic blood flow velocity differences and the CVPG. METHODS: Thirty-three patients with idiopathic intracranial hypertension (IIH) or pulsatile tinnitus (PT) and TSS who had undergone diagnostic venography using venous manometry were included in the patient group. Thirty-three volunteers with no stenosis and symptoms were included in the control group. All the 2 groups underwent prospective venous sinus 4-dimensional (4D) flow magnetic resonance imaging (MRI). The average velocity (V(avg)) difference and maximum velocity (V(max)) difference between downstream and upstream of the TS in 2 groups were measured and compared. Correlations between the CVPG and trans-stenotic V(avg) difference/V(max) difference/index of transverse sinus stenosis (ITSS) were assessed in the patient group. RESULTS: The differences in V(avg) difference and V(max) difference between the patient and control groups showed a statistical significance (P < .001). The V(avg) difference and V(max) difference had a strong correlation with CVPG (R = 0.675 and 0.701, respectively, P < .001) in the patient group. Multivariate linear regression using the stepwise method showed that the V(max) difference and ITSS were correlated with the CVPG (R = 0.752 and R(2) = 0.537, respectively; P < .001). CONCLUSION: The trans-stenotic blood flow velocity difference significantly correlates with the CVPG in TSS. As a noninvasive imaging modality, 4D flow MRI may be a suitable screening or complimentary tool to decide which TSS may benefit from invasive venous manometry.