Unit:
Κατεύθυνση Ιατρική Φυσική-ΑκτινοφυσικήLibrary of the School of Health Sciences
Author:
Gianniotis Christos
Supervisors info:
Ιωάννης Σεϊμένης, Καθηγητής, Τμήμα Ιατρικής, Δημοκρίτειο Πανεπιστήμιο Θράκης
Μιχαήλ Μαντατζής, Επίκουρος Καθηγητής, Τμήμα Ιατρικής, Δημοκρίτειο Πανεπιστήμιο Θράκης
Αθανασία Κοτίνη, Αναπληρώτρια Καθηγήτρια, Τμήμα Ιατρικής, Δημοκρίτειο Πανεπιστήμιο Θράκης
Original Title:
Μελέτη μη ραγέντων εγκεφαλικών ανευρυσμάτων με αριθμητική ανάλυση: Σύγκριση γεωμετρικών και αιμοδυναμικών χαρακτηριστικών μετά από μοντελοποιήσεις βασισμένες σε δεδομένα MRA και DSA
Translated title:
Numerical Analysis of the Hemodynamicsin unruptured cerebral aneurysms: A comparison between DSA and MRA derived models
Summary:
A cerebral aneurysm is a vascular disorder characterized by abnormal focal dilation of a brain artery which is considered as a serious and presumably life-threatening condition. Cerebral aneurysms affect around 2%-5% of the general population and they can rupture with an overall mortality rate of more than 50%. By exploiting appropriate Computational Fluid Dynamics tools, we can gain insight into cerebral aneurysm’s behavior and characteristics, such as development, growth and rupture. These tools consist of a set of partial differential equations, the solution of which provides information on a variety of parameters. There has been extensive speculation in the literature about the factors that potentially affect the growth and rupture of brain aneurysms, leading to new aspects of treatment of this disease.
This thesis provides a review of the medical problem of brain aneurysm, as well as of the relevant treatment methods. Moreover, six cerebral aneurysms of the middle cerebral artery, depicted by Magnetic Resonance Angiography (MRA) and Digital Subtraction Angiography (DSA, were studied. Following aneurysm segmentation and modelling from both the MRA and DSA datasets, corresponding hemodynamic fields were simulated and analyzed by employing the computational fluid dynamics method. Geometric and hemodynamic parameters that are considered to be associated with the risk of aneurysm rupture were calculated. A comparison was perfοrmed between corresponding results obtained from MRA- and DSA-derived models. Finally, numerical analyses were carried out in virtual aneurysm occlusion scenarios simulating potential post- endovascular treatment situations. The conclusions of this thesis can be divided in three parts.
First, the maximum values of hemodynamic parameters like pressure, WSS and Area Averaged Wall Shear Stress revealed a difference that ranges from 5 to 57%. This can be attributed to the different geometry derived from the DSA and MRA examinations and suggests that the DSA examination is the gold standard thanks to its better spatial resolution, while MRA can be useful for follow up examinations.
Second, the virtual occlusion scenarios lead to specific hemodynamic changes, which suggest a reduced risk of rupture as is the case in regular clinical practice.
Third, the modelling and simulation process are both highly user dependent. This makes the creation of a general protocol of this process highly recommended, in order to apply Computational Fluid dynamics in daily clinical use.
Main subject category:
Health Sciences
Keywords:
Cerebral, Aneurysm, Computational fluid dynamics, Simulation of hemodynamics, Aneurysm modelling, Aneurysm occlusion, Aneurysm treatment
