Examenspresentation Bahareh Rezaei Arjomand och Tasnim Ahmed

Handledare: Rolf A. Heckemann

Examinator: Andreas Fhager

Opponenter: Sofie Allgöwer och Sofia Ljungdahl

Abstract:
The aim of this master's thesis was to characterize the impact that systemic autoimmune disorders (Graves' disease and rheumatoid arthritis) have on the brain's structure. The focus was on uncovering structural changes via region-wise volumetric analysis of magnetic resonance images of the brain to identify potential imaging biomarkers that can aid in diagnosing and monitoring these disorders. Aside from considering the volumes of individual regions, we also employed two clustering approaches to identify clusters of regions that exhibited similar patterns of impact: natural clustering, where we considered the functional and topological relationships between regions, and affinity propagation, a machine-learning algorithm for clustering. To ensure reliable results and minimize the risk of falsely claiming discoveries, the study employed a meticulous approach that involved bisecting the samples and separating hypothesis generation (exploration dataset) from hypothesis testing (test dataset). The study yielded novel findings: in Graves' disease, for example, the study highlighted that various frontal lobe regions and the insula are affected. The involvement of the medial temporal lobe, which had been identified in earlier work, was confirmed in the present study. The study shed light on the complex relationship between autoimmune conditions and brain structure.

Welcome!
Bahareh, Tasnim and Andreas