Intracranial aneurysms present a formidable risk of death or devastating injury either from mass effect or hemorrhage. Aneurysms are detected with a broad range of sizes on first presentation. However, little is known about the rate of progression of aneurysms over time. It has long been suspected that hemodynamic forces play an important role in the genesis and rupture of aneurysms, but there is, to our knowledge, no literature that demonstrates which hemodynamic descriptors of an aneurysm are predictive of future growth. Recent results from the International Study of Unruptured Intracranial Aneurysms demonstrate that the risk of attempting a repair of aneurysms smaller than 7 mm in diameter exceeds the benefit from that intervention. There is now, therefore, a group of patients with saccular intracranial aneurysms who are not being treated, and who can be followed by non-invasive imaging. These patients are part of a broader group of patients with aneurysms of the intracranial circulation for whom there are no safe and effective interventions. The goal of this project is to monitor such patients on a bi-annual basis with non-invasive Magnetic Resonance Imaging. Using boundary values (geometric and velocity) obtained from patient-specific in-vivo imaging, Computational Fluid Dynamics (CFD) simulations will be performed to determine the hemodynamic conditions in each aneurysm. Progression over time in aneurysm lumen volume and/or volume of intraluminal thrombus will be measured from co-registered serial imaging studies. A relationship between different candidate hemodynamic variables and observed aneurysm growth will be sought. Specifically, we hypothesize that, specifying a low wall shear stress threshold value, the larger the surface area is with wall shear stress below that threshold value the greater will be the increase in aneurysm volume over time. In addition to using the standard methodology already established, we will develop new imaging capabilities, and will implement more comprehensive measurements of flow velocities throughout the vascular territory of interest. Our CFD methods will be extended to model non-Newtonian effects, and the in-vivo velocity measurements will be used to select which model is most suitable. As these new tools become available they will be used to improve the accuracy of our methods. This project represents an effort in translational research directed at a important component of neurovascular disorders.

Public Health Relevance

This study will determine the relationship between growth of intracranial aneurysms and hemodynamic forces. That information will be used to guide clinicians as to what interventional treatments might be considered, and when they might best be implemented. The project will provide insight into the underlying mechanisms of aneurysm progression and could help in guiding treatment for this devastating condition.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS059944-03
Application #
8009483
Study Section
Medical Imaging Study Section (MEDI)
Program Officer
Jacobs, Tom P
Project Start
2009-01-01
Project End
2013-12-31
Budget Start
2011-01-01
Budget End
2011-12-31
Support Year
3
Fiscal Year
2011
Total Cost
$331,209
Indirect Cost
Name
University of California San Francisco
Department
Radiation-Diagnostic/Oncology
Type
Schools of Medicine
DUNS #
094878337
City
San Francisco
State
CA
Country
United States
Zip Code
94143
Zhu, Chengcheng; Tian, Bing; Chen, Luguang et al. (2018) Accelerated whole brain intracranial vessel wall imaging using black blood fast spin echo with compressed sensing (CS-SPACE). MAGMA 31:457-467
Haraldsson, Henrik; Kefayati, Sarah; Ahn, Sinyeob et al. (2018) Assessment of Reynolds stress components and turbulent pressure loss using 4D flow MRI with extended motion encoding. Magn Reson Med 79:1962-1971
Kefayati, Sarah; Amans, Matthew; Faraji, Farshid et al. (2017) The manifestation of vortical and secondary flow in the cerebral venous outflow tract: An in vivo MR velocimetry study. J Biomech 50:180-187
Wang, Yan; Seguro, Florent; Kao, Evan et al. (2017) Segmentation of lumen and outer wall of abdominal aortic aneurysms from 3D black-blood MRI with a registration based geodesic active contour model. Med Image Anal 40:1-10
Kao, Evan; Kefayati, Sarah; Amans, Matthew R et al. (2017) Flow patterns in the jugular veins of pulsatile tinnitus patients. J Biomech 52:61-67
Liu, Jing; Feng, Li; Shen, Hsin-Wei et al. (2017) Highly-accelerated self-gated free-breathing 3D cardiac cine MRI: validation in assessment of left ventricular function. MAGMA 30:337-346
Jiang, Yuanliang; Zhu, Chengcheng; Peng, Wenjia et al. (2016) Ex-vivo imaging and plaque type classification of intracranial atherosclerotic plaque using high resolution MRI. Atherosclerosis 249:10-6
Zhu, Chengcheng; Haraldsson, Henrik; Faraji, Farshid et al. (2016) Isotropic 3D black blood MRI of abdominal aortic aneurysm wall and intraluminal thrombus. Magn Reson Imaging 34:18-25
Lawton, Michael T; Abla, Adib A; Rutledge, W Caleb et al. (2016) Bypass Surgery for the Treatment of Dolichoectatic Basilar Trunk Aneurysms: A Work in Progress. Neurosurgery 79:83-99
Zhang, Xuefeng; Zhu, Chengcheng; Peng, Wenjia et al. (2015) Scan-Rescan Reproducibility of High Resolution Magnetic Resonance Imaging of Atherosclerotic Plaque in the Middle Cerebral Artery. PLoS One 10:e0134913

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