Intracranial aneurysms are abnormal dilations of brain arteries that may rupture in some patients causing stroke and possibly death. Some treatment modalities are available, but they carry risks to patient health and hence best performed only on aneurysms that are at a high risk of growth or rupture. However, our understanding of factors associated with growth and rupture risk remains poor. Size is considered one factor, but widely acknowledged as a poor indicator. We hypothesize that aneurysm shape is a risk factor for growth and rupture risk on the basis of reported preliminary studies. The proposed project is the testing of this hypothesis. Our overall goal is to enhance understanding of the phenomenon of aneurysm rupture and to develop diagnostic analysis tools to facilitate clinical management of patients with intracranial aneurysms. There are three specific aims.
Aim #1 is to develop the means to quantify the three-dimensional size and shape features of these lesions using techniques in computational geometry, computational hemodynamics and finite element tension analysis using computed tomography angiography (CTA) data.
Aim #2 involves the determination of these indices in a study population of 75 ruptured and 75 unruptured consecutive aneurysms. The indices will then be compared between the two groups to identify the ones that differentiate ruptured from unruptured aneurysms.
Aim #3 involves a five year longitudinal study of unruptured cerebral aneurysms where the indices chosen from specific aim #2 results will be statistically tested for predictability of growth during follow-up in the cohorts. The proposed project would be the first known assessment of three-dimensional geometry of brain aneurysms that integrates geometric, hemodynamic and solid mechanical methods. The computational tools to be developed can be of benefit beyond the scope of this project toward assessment of intracranial aneurysm treatment modalities and the mechanics of other similar disease processes.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
3R01HL083475-02S1
Application #
7839389
Study Section
Special Emphasis Panel (ZRG1-BDCN-K (10))
Program Officer
Goldman, Stephen
Project Start
2009-07-15
Project End
2011-06-30
Budget Start
2009-07-15
Budget End
2011-06-30
Support Year
2
Fiscal Year
2009
Total Cost
$232,992
Indirect Cost
Name
University of Iowa
Department
Biomedical Engineering
Type
Schools of Engineering
DUNS #
062761671
City
Iowa City
State
IA
Country
United States
Zip Code
52242
Ramachandran, Manasi; Retarekar, Rohini; Raghavan, Madhavan L et al. (2016) Assessment of image-derived risk factors for natural course of unruptured cerebral aneurysms. J Neurosurg 124:288-95
Retarekar, Rohini; Ramachandran, Manasi; Berkowitz, Benjamin et al. (2015) Stratification of a population of intracranial aneurysms using blood flow metrics. Comput Methods Biomech Biomed Engin 18:1072-1082
Hoppe, Anna L; Raghavan, Madhavan L; Hasan, David M (2015) Comparison of the association of sac growth and coil compaction with recurrence in coil embolized cerebral aneurysms. PLoS One 10:e0123017
Raghavan, Madhavan L; Sharda, Gaurav V; Huston 3rd, John et al. (2014) Aneurysm shape reconstruction from biplane angiograms in the ISUIA collection. Transl Stroke Res 5:252-9
Dillard, Seth I; Mousel, John A; Shrestha, Liza et al. (2014) From medical images to flow computations without user-generated meshes. Int J Numer Method Biomed Eng 30:1057-83
Miller, Karol; Lu, Jia (2013) On the prospect of patient-specific biomechanics without patient-specific properties of tissues. J Mech Behav Biomed Mater 27:154-66
Ramachandran, Manasi; Retarekar, Rohini; Harbaugh, Robert E et al. (2013) Sensitivity of Quantified Intracranial Aneurysm Geometry to Imaging Modality. Cardiovasc Eng Technol 4:75-86
Lu, Jia; Hu, Shouhua; Raghavan, Madhavan L (2013) A shell-based inverse approach of stress analysis in intracranial aneurysms. Ann Biomed Eng 41:1505-15
Harbaugh, Robert E; Raghavan, Madhavan L; Ramachandran, Manasi (2012) Comments. Neurosurgery 71:45-6
Ramachandran, Manasi; Laakso, Aki; Harbaugh, Robert E et al. (2012) On the role of modeling choices in estimation of cerebral aneurysm wall tension. J Biomech 45:2914-9

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