Magnetic resonance imaging with 21.1 T and pathological correlations - Diffuse Lewy body disease

We investigated fixed basal ganglia specimens, including globus pallidus and putamen, with 21.1-Tesla MRI allowing us to achieve a microscopic level resolution from a patient with pathologically confirmed dementia with Lewy bodies (DLB) and a neurologically normal control case. We acquired T₂ and T₂*weighted images that demonstrated diffuse and patchy lower intensities in the basal ganglia compared to control. There are several paramagnetic substances in brain tissue that could potentially reduce both T₂ and T₂*relaxation times, including ferritin, iron (Fe³⁺), manganese, copper and others. Because iron is most abundant, low intensities on T₂ and T₂*weighted images most likely reflect iron deposition. Iron, especially Fe³⁺, deposition was visible in the pathological specimens stained with Prussian blue after images were obtained. Although radiological-pathological comparisons are not straightforward with respect to either the MRI signal or relaxation quantification, there appears to be a correlation between the relative increase in iron as assessed by Prussian blue staining and the decrease in T ²*value between the DLB and control specimens. As such, this exceptionally high field MRI technique may provide details about the role that iron deposition plays either directly or indirectly as a biomarker in neurodegenerative processes.