Layer-specific variation of iron content in cerebral cortex as a source of MRI contrast.
Recent advances in high-field MRI have dramatically improved the visualization of human brain anatomy in vivo. Most notably, in cortical gray matter, strong contrast variations have been observed that appear to reflect the local laminar architecture. This contrast has been attributed to subtle variations in the magnetic properties of brain tissue, possibly reflecting varying iron and myelin content. To establish the origin of this contrast, MRI data from postmortem brain samples were compared with electron microscopy and histological staining for iron and myelin. The results show that iron is distributed over laminae in a pattern that is suggestive of each region's myeloarchitecture and forms the dominant source of the observed MRI contrast.
Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA. fukunagm@mail.nih.gov
Masaki
M
Fukunaga
Tie-Qiang
TQ
Li
Peter
P
van Gelderen
Jacco A
JA
de Zwart
Karin
K
Shmueli
Bing
B
Yao
Jongho
J
Lee
Dragan
D
Maric
Maria A
MA
Aronova
Guofeng
G
Zhang
Richard D
RD
Leapman
John F
JF
Schenck
Hellmut
H
Merkle
Jeff H
JH
Duyn
D000328:Adult; D002540:Cerebral Cortex / Q000033:anatomy & histology* / Q000378:metabolism* / Q000648:ultrastructure; D005260:Female; D005293:Ferritins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007501:Iron / Q000737:chemistry / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009186:Myelin Sheath / Q000737:chemistry / Q000378:metabolism
D005293:Ferritins; D007501:Iron