The Neuromelanin-related T2* Contrast in Postmortem Human Substantia Nigra with 7T MRI.
High field magnetic resonance imaging (MRI)-based delineation of the substantia nigra (SN) and visualization of its inner cellular organization are promising methods for the evaluation of morphological changes associated with neurodegenerative diseases; however, corresponding MR contrasts must be matched and validated with quantitative histological information. Slices from two postmortem SN samples were imaged with a 7 Tesla (7T) MRI with T1 and T2* imaging protocols and then stained with Perl's Prussian blue, Kluver-Barrera, tyrosine hydroxylase, and calbindin immunohistochemistry in a serial manner. The association between T2* values and quantitative histology was investigated with a co-registration method that accounts for histology slice preparation. The ventral T2* hypointense layers between the SNr and the crus cerebri extended anteriorly to the posterior part of the crus cerebri, which demonstrates the difficulty with an MRI-based delineation of the SN. We found that the paramagnetic hypointense areas within the dorsolateral SN corresponded to clusters of neuromelanin (NM). These NM-rich zones were distinct from the hypointense ventromedial regions with high iron pigments. Nigral T2* imaging at 7T can reflect the density of NM-containing neurons as the metal-bound NM macromolecules may decrease T2* values and cause hypointense signalling in T2* imaging at 7T.
Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea.
Jae-Hyeok
JH
Lee
Department of Anatomy, Pusan National University School of Medicine, Yangsan, South Korea.
Sun-Yong
SY
Baek
Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
YoungKyu
Y
Song
Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
Sujeong
S
Lim
Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
Hansol
H
Lee
School of Electrical and Computer Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
Minh Phuong
MP
Nguyen
Department of Neurology, Pusan National University Hospital, Busan, South Korea.
Eun-Joo
EJ
Kim
Department of Forensic Medicine, Pusan National University School of Medicine, Yangsan, South Korea.
Gi Yeong
GY
Huh
School of Electrical and Computer Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
Se Young
SY
Chun
Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
HyungJoon
H
Cho
D000328:Adult; D003287:Contrast Media / Q000737:chemistry*; D005260:Female; D006801:Humans; D007501:Iron / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D008543:Melanins / Q000378:metabolism*; D008875:Middle Aged; D011180:Postmortem Changes; D013378:Substantia Nigra / Q000378:metabolism* / Q000473:pathology*
D003287:Contrast Media; D008543:Melanins; C014121:neuromelanin; D007501:Iron