Separazione delle sorgenti della suscettività magnetica: studio dell'impatto delle metodologie di stima del rilassamento trasversale.

Studying in-vivo cerebral tissues' nature and condition is more and more useful especially in pathological subjects. Using Magnetic Resonance exams allows not only to obtain detailed images of the nervous system, but also to make some estimation about tissues' nature, particularly to identify possible markers that could indicate the progress of a neurodegenerative disease. With this perspective, studying and analysis of magnetic susceptibility sources situated inside the cerebral tissue appears to be very promising and provides a further research field. Different magnetic positive and negative sources are correlated to the presence and nature of lesions in the cerebral tissue in cases of Multiple Sclerosis, where take place demyelination process and alteration of iron accumulation mechanisms. For these reasons, recognize and distinguish these sources is very useful to better comprehend the development of Multiple Sclerosis. The purpose of this work is to exploit an alternative pipeline for the magnetic susceptibility estimation of brain tissues; in order to do that, we decided to estimate the T2 map using an MWIGRASE sequence, rather than a MESE sequence, obtained with a monoexponential fit using qMRLab tool. Qualitative and quantitative evaluation together with the study of the effects of the alternative pipeline showed equivalent results respect to those obtainable using the gold-standard procedure, along with the advantage of having shorter time acquisition and also the possibility of implementation with already existent datasets.

Comprendere la natura dei tessuti cerebrali in-vivo è sempre di maggior utilità, sia con soggetti sani che patologici. Utilizzare la risonanza magnetica permette non solo di ottenere delle immagini dettagliate del sistema nervoso, ma anche di effettuare delle stime sulla natura dei tessuti stessi, dando la possibilità di distinguere le sorgenti di suscettività magnetica presenti al suo interno. Il lavoro svolto aveva il compito di utilizzare i metodi di stima basati sul rilassamento trasversale al fine di analizzare i risultati in pazienti sani ed affetti da sclerosi multipla, per valutare la bontà o meno dei metodi stessi.