[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 T2 * 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.