Symposium



PATIENT-SPECIFIC CFD ANALYSIS OF FLOW PATTERNS IN THE JUGULAR VEIN


Presenting Author Senior Author
Name: Evan Kao Name: David Saloner
Email: evan.kao@ucsf.edu Email: David.Saloner@ucsf.edu
Presenting Author’s RIG/SRG: Neurovascular/Neurointerventional  
Presenting Author's Lab Location: VAMC   

Abstract Information
Imaging Modality: MR Angiography
Disease Application: Neurovascular/Neurointerventional
Complete author list: Evan Kao,Sarah Kefayati,Farshid Faraji,Matthew Amans,Van Halbach,David Saloner
Abstract highlights: PATIENT-SPECIFIC CFD ANALYSIS OF FLOW PATTERNS IN THE JUGULAR VEIN
 
Introduction
Abnormalities of the venous anatomy are considered to play a role in pulsatile tinnitus. Evaluation of the anatomy is complicated by the large variability in venous outflow patterns even in normal subjects where there is often a one-sided dominant flow distribution. Furthermore, conventional imaging modalities, including catheter-based methods, provide little insight into the complex flow patterns in these tortuous vessels. The aim of this study was to use subject-specific CE-MRA determined anatomy, and MRV-based inlet flow conditions to develop CFD models of flow in normal subjects and in subjects with suspected venous abnormalities to investigate how the geometry of the jugular vein affects the flow field.
 
Methods
10 jugular veins (5 normal, 5 with pulsatile tinnitus) were imaged with CE-MRA. 2D PC-MRV was also acquired transverse to the sigmoid sinus to determine inlet flow conditions. Surfaces were segmented using VMTK (Orobix, Bergamo, Italy) and Geomagic Design X (Geomagic, Rock Hill, USA) and meshed in VMTK. CFD simulations were performed in FLUENT (ANSYS, Canonsburg, USA), using in vivo measurements.1 Flow patterns in the jugular vein were characterized by their vortex core-lines, which were extracted from simulation data using Ensight (CEI, Apex, USA). Additional flow-parameters were calculated in MATLAB (Mathworks, Natick, USA) and visualized using Paraview (Kitware, New York, USA).
 
Results
Patients with suspected venous anomalies conditions had flow patterns that had features that were, in general, quite distinct from those in normal subjects. Normal flow was characterized by vortex cores in the jugular bulb (Figure 1, left), which neatly redirected along the curvature of the bulb straight into the jugular vein. Abnormal flow was characterized by an inability to form these shunting vortex cores due to the geometrical differences, which forced incoming flow directly into the jugular vein at a perpendicular angle, creating larger helical flow structures throughout the proximal jugular vein (Figure 1, right).
 
Conclusions
The geometry of the jugular vein significantly affects the position, size, and length of the vortex cores. Our results suggest a link between geometry, flow, and adverse conditions in the jugular vein, which is an important first step toward determining potential disease mechanisms. References 1. Feng W, Utriainen D, Trifan G, Sethi S, Hubbard D, and Haacke EM. Quantitative Flow Measurements in the Internal Jugular Veins of Multiple Sclerosis Patients Using Magnetic Resonance Imaging. Rev Recent Clinical Trials, 2012; 7: 117-126.