Growth model for abdominal aortic aneurysms using longitudinal CT images

Download

index.pdf

Date

2020

Author

Akkoyun, Emrah

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

164
views

57
downloads

An Abdominal Aortic Aneurysm (AAA) is diagnosed by an enlargement of the abdominal aorta. The rupture of an AAA, associated with high mortality, is eventually observed if no surgical intervention is performed. Aneurysm repair prior to rupture is thus vital. The decision to intervene is made primarily based on the AAA size measured by a maximum diameter or its growth rate. However, 10 – 24% of aneurysms below the intervention threshold experience rupture in some series. There are many complex interactions involved, from the hemodynamics and geometric properties of the aorta to patient demographic information, affecting the aneurysms’ expansion. Furthermore, the follow-up diameters can be predictable if a patient follows the common growth model of the population. However, a rapid expansion of AAA, often associated with higher rupture risk, might be observed. This study aims to build enhanced Bayesian inference methods to predict maximum aneurysm diameter using 106 CT scans. The utility of master curves and their prediction capabilities in terms of different geometrical parameters were examined. Among all the parameters, the master curve of spherical diameter performed best, predicting the diameter within 0.42 mm in 95% of all scans. Furthermore, a two-step approach based on Bayesian calibration was used and the aneurysm growth model was specified according to individual patient characteristics. Using the enhanced prediction model, 86% of scans were correctly predicted. Thus, the prediction of a measurement at any time-point can be made, along with an associated uncertainty to provide a clinically helpful tool for surgical planning and patient management.

Subject Keywords

Aortic aneurysms., Abdominal aortic aneurysm, clinical decision making, aneurysm growth, probabilistic programming, patient-oriented growth modeling

URI

http://etd.lib.metu.edu.tr/upload/12625366/index.pdf
https://hdl.handle.net/11511/45373

Collections

Graduate School of Informatics, Thesis

Suggestions

OpenMETU
Core

Experimental investigation of hemodynamics in abdominal aortic aneurysm Fathipour, Amirhossein; Yavuz, Mehmet Metin; Department of Mechanical Engineering (2022-9) Abdominal aortic aneurysm (AAA), the enduring enlargement of the aorta, is a serious clinical condition with a very high mortality rate when it ruptures. Even though the precise causes of the dilation and rupture mechanisms of the aorta are still unknown, flow-related structures inside the AAA, including vortex formations and wall shear stresses, are associated with these mechanisms. The present study aims to characterize the flow patterns and their evolutions in two aneurysm models, simplified elliptic geo...
Characterization of wall shear stress in abdominal aortic aneurysm phantom using particle image velocimetry Türk, Semih; Yavuz, Mehmet Metin; Department of Mechanical Engineering (2021-9) Abdominal Aortic Aneurysm (AAA) is defined as the enlargement of the largest artery in the abdominal cavity, the abdominal aorta. The vascular rupture begins to pose a risk after a certain enlargement, and the rupture is described as one of the most critical emergencies in medicine. The disease is labeled as the 14th disease with the highest mortality rate. Thus, predicting the progression of the disease is vitally important. Hence, researchers are trying to identify and standardize all biological and mecha...
Biomechanical Investigation of Disturbed Hemodynamics-Induced Tissue Degeneration in Abdominal Aortic Aneurysms Using Computational and Experimental Techniques Salman, Huseyin Enes; Ramazanlı, Burcu; Yavuz, Mehmet Metin; Yalcin, Huseyin Cagatay (2019-05-31) Abdominal aortic aneurysm (AAA) is the dilatation of the aorta beyond 50% of the normal vessel diameter. It is reported that 4-8% of men and 0.5-1% of women above 50 years of age bear an AAA and it accounts for similar to 15,000 deaths per year in the United States alone. If left untreated, AAA might gradually expand until rupture; the most catastrophic complication of the aneurysmal disease that is accompanied by a striking overall mortality of 80%. The precise mechanisms leading to AAA rupture remains unc...
Characterization of vortex ring in abdominal aortic aneurysm phantom using particle image velocimetry Gökçek, Kerem Tuğ; Yavuz, Mehmet Metin; Department of Mechanical Engineering (2021-9) Abdominal aortic aneurysm (AAA) is the permanent enlargement of the abdominal artery that may even rupture at the end, and it is a critical medical situation with a high mortality rate. Although there are some approaches to model its enlargement and rupture, a complete understanding is far from over. A vortex ring is generated during physiological flow pattern, and its evolution should be analyzed in detail to understand its effect on the flow field. The aim of this study is to investigate and characterize ...
Flow-induced vibration analysis of constricted artery models with surrounding soft tissue Salman, Huseyin Enes; Yazıcıoğlu, Yiğit (2017-10-01) Arterial stenosis is a vascular pathology which leads to serious cardiovascular diseases. Blood flow through a constriction generates sound and vibration due to fluctuating turbulent pressures. Generated vibro-acoustic waves propagate through surrounding soft tissues and reach the skin surface and may provide valuable insight for noninvasive diagnostic purposes. Motivated by the aforementioned phenomena, vibration of constricted arteries is investigated employing computational models. The flow-induced press...

Citation Formats

E. Akkoyun, “Growth model for abdominal aortic aneurysms using longitudinal CT images,” Thesis (Ph.D.) -- Graduate School of Informatics. Health Informatics., Middle East Technical University, 2020.