Abstract:
Alterations in dural venous sinus hemodynamics have recently been suggested as the major contributing factors in venous pulsatile tinnitus (PT). Nevertheless, little is known about the association between real-time alterations in hemodynamics and the subjective perception of venous PT. This study aimed to investigate the hydroacoustic correlations among diverticular vortices, mainstream sinus flow, and PT using various Doppler ultrasound techniques. Nineteen venous PT patients with protrusive diverticulum were recruited. The mainstream sinus and diverticular hemodynamics before and after ipsilateral internal jugular vein (IJV) compression were investigated using an innovative retroauricular color-coded Doppler (RCCD) method to examine the correlation between the disappearance of PT and hemodynamic alterations. To reveal the hydroacoustic characteristics of disparate segments of venous return, a computational fluid dynamics (CFD) technique combined with the transcranial color-coded Doppler method was performed. When the ipsilateral IJV was compressed, PT disappeared, as the mean velocity of mainstream sinus flow and diverticular vortex decreased by 51.2 and 50.6%, respectively. The vortex inside the diverticulum persisted in 18 of 19 subjects. The CFD simulation showed that the flow amplitude generated inside the transverse-sigmoid sinus was segmental, and the largest flow amplitude difference was 20.5 dB. The difference in flow amplitude between the mainstream sinus flow and the diverticular flow was less than 1 dB. In conclusion, the sensation of PT is closely associated with the flow of kinetic energy rather than the formation of a vortex, whereby the amplitude of PT is correlated to the magnitude of the flow velocity and pressure gradient. Additionally, the range of velocity reduction revealed by the RCCD method may serve as a presurgical individual baseline curative marker that may potentially optimize the surgical outcomes.
摘要:
最近有人认为硬脑膜静脉窦血流动力学的改变是静脉搏动性耳鸣(PT)的主要因素。然而,对血流动力学的实时改变与静脉PT的主观感知之间的关联知之甚少。本研究旨在研究憩室涡流之间的水声相关性,主流窦流,和PT使用各种多普勒超声技术。招募了19例有憩室突出的静脉PT患者。使用创新的耳后彩色编码多普勒(RCCD)方法研究了同侧颈内静脉(IJV)压迫前后的主流窦和憩室血流动力学,以检查PT消失与血流动力学改变之间的相关性。为了揭示不同段静脉回流的水声特性,采用计算流体力学(CFD)技术结合经颅彩色编码多普勒方法.当同侧IJV被压缩时,PT消失了,随着主流窦流和憩室涡流的平均速度分别下降51.2和50.6%,分别。憩室内部的漩涡持续存在于19名受试者中的18名。CFD模拟显示,横型乙状窦内产生的血流波幅是分段的,最大流量振幅差为20.5dB。主流窦流和憩室流之间的流量幅度差异小于1dB。总之,PT的感觉与动能的流动密切相关,而不是涡流的形成,其中PT的幅度与流速和压力梯度的大小相关。此外,RCCD方法显示的速度降低范围可作为术前个体基线治疗指标,可能优化手术结局.