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CNAA / Theses / 2017 / May /

A comparative imaging study of aneurysms in Willis’ polygon

Author: Arion Marian
Degree:doctor of medicine
Speciality: 14.00.19 - Medical Imagistics
Scientific adviser: Natalia Rotaru
doctor habilitat, associate professor (docent), Nicolae Testemitanu State University of Medicine and Pharmacy of the Republic of Moldova
Scientific consultant: Grigore Zapuhlih
doctor habilitat, professor, Nicolae Testemitanu State University of Medicine and Pharmacy of the Republic of Moldova
Institution: Nicolae Testemitanu State University of Medicine and Pharmacy of the Republic of Moldova


The thesis was presented on the 26 May, 2017
Approved by NCAA on the 11 May, 2018


Adobe PDF document1.40 Mb / in romanian


CZU 616.831-005.1:616.134.97-007.64-001.5-073.756.8

Adobe PDF document 4.10 Mb / in romanian
154 pages


brain aneurysm, Willis polygon, angiography, computed tomography, maximum intensity projection, three-dimensional reconstruction, neuronavigation


The structure of the thesis work is presented on 130 pages of printed text, consists of an introduction, 4 chapters, conclusions, practical recommendations, summaries in Romanian, Russian and English, and bibliography with 178 references, including 36 figures, 8 tables, 7 formulas and 3 annexes. The results were published in 12 scientific papers, including 4 without coauthors and 9 in reviewed editions.

Research area and objectives. The study evaluates the accuracy and efficiency of computed tomography angiography (CTA) in the diagnosis of aneurysm in Willis polygon (AWP). Brain aneurysms characteristics were assessed based on CTA (aspects of epidemiology, localization, evolution, and complications), was evaluated the effectiveness of CTA post-processing methods (axial raw data - ARD, maximum intensity projection - MIP, three-dimensional volume rendering – 3D VR and neuronavigation) in the diagnosis, microsurgical treatment and postoperative outcome in patients with Willis polygon aneurysms.

Scientific novelty and originality of the study consists in brain aneurysm characteristics assessment based on CTA , evaluating the effectiveness of various CTA methods in the diagnosis, treatment and microsurgical postoperative outcome analysis in patients with Willis polygon aneurysms.

Solved scientific problem represents the accuracy and effectiveness assessment of different CTA methods in the diagnosis of Willis polygon aneurysms, which contributed to the diagnostic algorithm improvement and virtual planning of neurosurgical intervention.

Theoretical significance of the study. The effectiveness of the CTA methods ARD, MIP, 3D RV was determined in the diagnosis and planning of virtual neurosurgery in patients with Willis polygon aneurysms, depending on location and size, topography of adjacent brain and vascular structures. Depending on the size, diameter and wall structure of the aneurysm neck, the feeding artery diameter, can be calculated the size and shape of the clip and the clamping pressure on clip’s lips. Depending on the location and morphological characteristics of the aneurysm can be selected surgical access.

Applicative value of study. To establish the effectiveness of the CTA post-processing methods (ARD, MIP, 3D RV) in diagnostics and virtual planning of neurosurgical intervention in patients with Willis polygon aneurysms, the clip’s size and shape calculation, appreciation of clip’s lip clamping pressure for each patient and election of the most effective surgical approach.

Scientific results implementation. The main study results are applied in the didactic process of Radiology and Medical Imaging Department and Neurosurgery Department of the “Nicolae Testemitanu” State University of Medicine and Pharmacy, in clinical practice of Institute of Neurology and Neurosurgery of Moldova.