title: Metabolic Activity of Red Nucleus and Its Correlation with Cerebral Cortex and Cerebellum: A Study Using a High-Resolution Semiconductor PET System.
abstract: The red nucleus (RN) is a pair of small gray matter structures located in the midbrain and involved in muscle movement and cognitive functions. This retrospective study aimed to investigate the metabolism of human RN and its correlation to other brain regions.
  
  
  METHODS
  We developed a high-resolution semiconductor PET system to image small brain structures. Twenty patients without neurologic disorders underwent whole-brain scanning after injection of 400 MBq of (18)F-FDG. The individual brain (18)F-FDG PET images were spatially normalized to generate a surface projection map using a 3-dimensional stereotactic surface projection technique. The correlation between the RN and each voxel on the cerebral and cerebellar cortices was estimated with Pearson product-moment correlation analysis.
  
  
  RESULTS
  Both right and left RNs were visualized with higher uptake than that in the background midbrain. The maximum standardized uptake values of RN were 7.64 ± 1.92; these were higher than the values for the dentate nucleus but lower than those for the caudate nucleus, putamen, and thalamus. The voxel-by-voxel analysis demonstrated that the right RN was correlated more with ipsilateral association cortices than contralateral cortices, whereas the left RN was equally correlated with ipsilateral and contralateral cortices. The left RN showed a stronger correlation with the motor cortices and cerebellum than the right RN did.
  
  
  CONCLUSIONS
  Although nonspecific background activity around RNs might have influenced the correlation patterns, these metabolic relationships suggested that RN cooperates with association cortices and limbic areas to conduct higher brain functions.
authors.affiliation: Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California.
authors.forename: Kenji
authors.initials: K
authors.lastname: Hirata
authors.affiliation: Department of Molecular Imaging, Hokkaido University Graduate School of Medicine, Sapporo, Japan nhattori@med.hokudai.ac.jp.
authors.forename: Naoya
authors.initials: N
authors.lastname: Hattori
authors.affiliation: Research and Development Group, Hitachi Ltd., Tokyo, Japan; and.
authors.forename: Wataru
authors.initials: W
authors.lastname: Takeuchi
authors.affiliation: Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Shiga
authors.affiliation: Research and Development Group, Hitachi Ltd., Tokyo, Japan; and.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Morimoto
authors.affiliation: Division of Quantum Science and Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan.
authors.forename: Kikuo
authors.initials: K
authors.lastname: Umegaki
authors.affiliation: Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kobayashi
authors.affiliation: Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Manabe
authors.affiliation: Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Shozo
authors.initials: S
authors.lastname: Okamoto
authors.affiliation: Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Nagara
authors.initials: N
authors.lastname: Tamaki
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging; D001931:Brain Mapping / Q000379:methods; D002531:Cerebellum / Q000000981:diagnostic imaging*; D002540:Cerebral Cortex / Q000000981:diagnostic imaging*; D003072:Cognition Disorders; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D012012:Red Nucleus / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012666:Semiconductors
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: 18F-FDG PET; metabolic correlation; red nucleus; semiconductor detector; voxel-based analysis