Strukturelle Konnektivität und Diffusionstensor-Bildgebung bei Autismus-Spektrum-Störungen
Abstract
Die Diffusions-Tensor-Bildgebung (DTI) erlangt seit mehreren Jahren in der Erforschung neuropsychiatrischer Krankheitsbilder einen immer höheren Stellenwert. Mit Hilfe dieser Technik können Faserverläufe in vivo dargestellt werden, was bisher anatomischen post-mortem Studien vorbehalten war. Auch bei der Untersuchung neurobiologisch-anatomischer Korrelate kinder- und jugendpsychiatrischer Störungsbilder wie den Autismus-Spektrum-Störungen gewinnt DTI zunehmend an Bedeutung. Die Interpretation dieser Bildgebungsdaten ist allerdings für wissenschaftlich interessierte Kliniker häufig nicht einfach. In vorliegender Übersichtsarbeit sollen daher die Grundlagen der DTI-Bildgebung, wichtige Parameter wie die fraktionelle Anisotropie, radiale, mittlere sowie axiale Diffusivität und ihre zwei wichtigsten Anwendungsmöglichkeiten, das Fibertracking und die Whole Brain-Analyse verständlich erläutert werden. Ferner wird die praktische Anwendung der DTI-Bildgebung bei Autismus-Spektrum-Störungen dargestellt. Dabei sollen sowohl Stärken, aber auch Schwächen und Entwicklungsmöglichkeiten der Technik diskutiert werden.
Over the past years, diffusion tensor imaging (DTI) has become an important brain-imaging technique in neuropsychiatric research. DTI allows noninvasive visualization of white matter tracts. In addition, with DTI it is possible to quantify the structural integrity of the investigated fiber tracts. In child and adolescent psychiatry, DTI has become an increasingly important research tool, especially for conditions like autism spectrum disorders (ASD). Yet, correct interpretation of DTI findings can be challenging, especially for clinicians. Thus, the present review article explains the basic principles of this frequently used imaging technique as well as essential indices, like fractional anisotropy, radial, mean, and axial diffusivity and its two main applications, fibertracking and whole brain analysis. The strengths and weaknesses as well as future perspectives are discussed in light of DTI studies in children and adolescents with ASD.
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