H εκτίμηση των μεταβολών του κοιλιακού συστήματος και του μεσολόβιου με μαγνητική τομογραφία στη νόσο Alzheimer
Creators: name: Παπαποστόλου, Παναγιώτα Α.
Publisher: name: Aristotle University of Thessaloniki
Year: 2010
Subjects: Μαγνητική τομογραφία
Κοιλιακό σύστημα
Μεσολόβιο
Ογκομετρία
Νόσος Alzheimer
Volumetric studies
MRI
Ventricular system
Corpus callosum
Alzheimer's disease

description: Η διδακτορική αυτή διατριβή στηριζόμενη στις νεότερες τεχνολογικές εξελίξεις στην Μαγνητική Τομογραφία και στους υπολογιστές ασχολείται με την καταγραφή των μορφολογικών αλλοιώσεων δυο σημαντικών δομών του εγκεφάλου που πλήττονται σημαντικά και μεταβάλλουν το σχήμα και τον όγκο τους στην νόσο του Alzheimer, το μεσολόβιο και το κοιλιακό σύστημα. Η επιλογή αυτών των δομών έγινε με γνώμονα την εύκολη αναγνώριση των δομών από κλινικούς γιατρούς, όπως είναι οι νευρολόγοι, οι ψυχίατροι, αλλά και οι ακτινολόγοι, έτσι ώστε τα συμπεράσματά μας να έχουν πρακτική σημασία και εφαρμογή στην καθημερινή κλινική πράξη.
description: Dementia describes an organic mental disorder that is characterized by a general loss of intellectual abilities such as impairment of memory, judgment and abstract thinking, as well as, personality change. There are many etiologies of dementia but dementia of the Alzheimer type accounts for approximately 50-60% of the cases. The diagnosis of definite Alzheimer Disease requires histopathology, which is generally not available until death, so the diagnosis is made clinically after the exclusion of other causes of dementia. During recent years, the development of new imaging methods such as MR Imaging Tomography and new imaging techniques has lead the study of human brain to new levels. Today these techniques are readily available. Early pathological change in Alzheimer Disease is brain volume loss and whole brain atrophy. The diffuse atrophy of the cerebral cortex, especially temporal lobe, the markedly enlargement of the ventricles and sulci and the severely affected hippocampus are the most prominent imaging findings in Alzheimer Disease. The purpose of this study was to appreciate the changes of the ventricular system and the corpus callosum with Magnetic Resonance Imaging (MRI) examination in Alzheimer’s disease patients. We used reliable methods to calculate the volume of the ventricular system and of the corpus callosum. We produced 3D models of the brain parenchyma from MRI data and then we calculated the volumes of their parts. The extraction procedure of the brain from MR images and the segmentation of these structures is quiet fast and require minimum intervention by the operator. We believe that using this method in patients with Alzheimer disease we can give information more clearly and accurately than single images alone, also those procedures are an important step for the structural and functional investigation of the human brain especially in Alzheimer’s disease patients. During this study we calculated the volume of the ventricular system and of its parts such as 4th ventricle, 3rd ventricle, right lateral ventricle and left lateral ventricle. We also calculated the volume of corpus callosum which was divided in anterior part, middle part, middle posterior part and posterior part. We found that we obtain statistically important volume changes only in the 3rd ventricle, in the lateral ventricles, as well as, in the anterior and posterior part of the corpus callosum. The sensitivity was 72- 87% and the specificity 30-58%. As a conclusion we can say that the ventricular system and the corpus callosum underwent severe changes of its shape and volume in patients with Alzheimer Disease, so the objective calculation of its volume loss gives a great help to clinicians for classification and observation of these patients.