Mark David Meadowcroft1,2, James R. Connor3, Michael B. Smith1, Qing X. Yang1,3
1Radiology, Pennsylvania State University - College of Medicine, Hershey, PA, USA; 2Neural and Behavioral Sciences, Pennsylvania State University - College of Medicine, Hershey, PA, USA; 3Neurosurgery, Pennsylvania State University - College of Medicine, Hershey, PA, USA
The histo-pathological basis of image contrast associated with Aβ plaques and the connected relaxation mechanism has not been well-understood. T2*-weighted images and R2* parametric maps were compared to histology stains from the same set of AD and APP/PS1 tissue slices. The electronic microscopy and histology images revealed differences in plaque morphology and associated iron concentration between APP/PS1 mice and AD tissue. T2* contrast of Aβ-plaques was associated with the gradation of iron concentration and plaque morphology. These data suggested a duality in the relaxation mechanism where both focal iron concentration and highly compact fibrillar Aβ masses cause rapid proton transverse magnetization decay.
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