Abstract #4512

Determinants of T2* Relaxation in White Matter: Insights from Postmortem Analyses

Christian Langkammer^1,2, Nikolaus Krebs², Walter Goessler³, Eva Scheurer², Michaela Soellinger¹, Kathrin Yen², Franz Fazekas¹, Stefan Ropele¹

¹Department of Neurology, Medical University of Graz, Graz, Austria; ²Ludwig Boltzmann Institute for Clinical-Forensic Imaging, Graz, Austria; ³Institute of Chemistry - Analytical Chemistry, University of Graz, Graz, Austria

This study investigated possible contributions of iron deposition, myelin density and fiber orientation on R2* relaxation rates in white matter by using quantitative MRI of postmortem brains in situ and by assessing regional iron concentrations with inductively coupled plasma mass spectrometry. The results suggest that the density of myelin is the dominant determinant of R2* in white matter while the presence of iron additionally has a strong effect. Our results do not support the hypothesis that fiber orientation contributes to the phenomenon of T2* relaxation.