Flow patterns in the venous sinus of pulsatile tinnitus patients with transverse sinus stenosis and underlying vortical flow as a causative factor. (December 2022)

• Record Type: Journal Article
• Authors: Hong, Zhenxin; Liu, Xin; Ding, Heyu; Zhao, Pengfei; Gong, Shusheng; Wang, Zhenchang; Ghista, Dhanjoo; Fan, Jinsong
• Is Part Of: Computer methods and programs in biomedicine. Volume 227(2022)
• Publication Date: 2022-12
• Subjects: Pulsatile tinnitus (PT) -- Transverse sinus stenosis (TSS) -- Intracranial hypertension -- CFD -- Hemodynamics -- Transverse venous sinus -- Laminar flow -- Turbulent flow -- Vorticity; TSS transverse sinus stenosis -- CVS cerebral venous sinus -- PT pulsatile tinnitus -- IVSS intracranial venous sinus stenosis -- TVS transverse venous sinus -- MVV maximum vortex velocity -- TPR trans-stenotic pressure ratio -- SMV stenosis maximum flow velocity -- TPG trans-stenotic pressure gradient -- SR stenosis ratio -- MCA maximum cross-sectional area -- SSD sigmoid sinus diverticulum -- VSI venous stenotic index -- SCA minimum cross-sectional area at the stenosis -- IIH idiopathic intracranial hypertension -- NL narrow length -- MRV magnetic resonance venography -- TEP model turbulence eddy prediction model -- VSS venous sinus stenosis -- DOS degree of stenosis -- Rmin minimum Reynold's number -- Rmax maximum Reynold's number -- Vor_c calculated vorticity based on turbulent model -- Vor_p predicted vorticity based on the TEP model; Medicine -- Computer programs -- Periodicals; Biology -- Computer programs -- Periodicals; Computers -- Periodicals; Medicine -- Periodicals; Médecine -- Logiciels -- Périodiques; Biologie -- Logiciels -- Périodiques; Biology -- Computer programs; Medicine -- Computer programs; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.cmpb.2022.107203
• Languages: English
• ISSNs: 0169-2607

Abstract

Highlights: The hemodynamics of cerebral venous sinus stenosis with asynchronous drainage was investigated. Simulations using laminar and turbulent flow models were compared and the results indicated that the flow-based analysis could not be sufficient for investigating stenosis-induced turbulent flow patterns. The asynchronous drainage could enhance the occurrence of turbulence. A regression model was proposed for predicting turbulent intensity based on both anatomical and hemodynamics parameters. The prediction model revealed a higher significance of the stenosis-induce turbulence compared to simulations. Abstract: Background: Transverse sinus stenosis (TSS) is commonly found in Pulsatile Tinnitus (PT) patients. Vortex flow is prominent in venous sinus with stenosis, and so it is important to determine the distribution and strength of the vortical flow to understand its influence on the occurrence of PT. Methods: In this study, by using computational fluid dynamics for hemodynamic analysis in patient-specific geometries based on Magnetic Resonance Imaging (MRI), we have investigated the blood flow within the venous sinus of 16 subjects with PT. We have employed both laminar and turbulent flow models for simulations, to obtain (i) streamlines of velocity distribution in the venous sinus, and (ii) pressure distributions of flow patterns in the venous sinus. Then, hemodynamic analysis in the venous sinus recirculation zone was carried out, to determine the flow patterns at the junction of transverse sinuses and sigmoid sinuses. Finally, we have proposed a new model for turbulence evaluation based on the regression analysis of anatomic and hemodynamics parameters. Results: Correlation analysis between the anatomical parameters and the hemodynamic parameters has shown that stenosis at the transverse sinus was the main factor in the local hemodynamics variation in the venous sinus of patients; in this context, it is shown that vorticity can be used as a prime indicator of the severity of the stenosis function. Our results have shown a significant correlation between the vorticity and the stenotic maximum velocity (SMV) ( r = 0.282, p = 0.004). Then, a parameterized prediction model is proposed to determine the vorticity in terms of flow and anatomic variables, termed as the turbulence eddy prediction model (TEP model). Our result have shown that the TEP model is sensitive to the dominant flow distribution, with a high correlation to the flow-based vorticity ( r = 0.809, p = 0.009). Conclusions: The quantification of the vorticity (as both vorticity and MVV) in the downstream of TSS could be a marker for indication of turbulent energy at the transverse-sigmoid sinus, which could potentially serve as a hemodynamic marker for the functional assessment of the PT-related TSS.