MR imaging in cerebral amyloidoses : entering a new phase

Abstract

The general aim of this thesis was to explore the possibility to detect changes related to amyloid deposition in vivo using ultra-high field MRI. The central finding of the work presented in this thesis is the cortical phase change on T2*-weighted sequences that we observed in AD patients using this novel ultra-high field imaging approach at 7T. It has been demonstrated that such phase measurements are a reliable indicator of iron content in the brain. It is known that amyloid depositions co-localize with iron accumulations. However, in autopsy material of AD patients, in addition to amyloid deposition, neurofibrillary tangles as well as tau deficiency were also found to co-localize with neuronal iron accumulation. In addition to iron, myelin and deoxy-hemoglobin can also contribute to phase changes. Although the exact origin of the observed phase changes in AD is not completely clear, these changes could have value for diagnostic purposes and as a biomarker.