title: New method of manganese-enhanced Magnetic Resonance Imaging (MEMRI) for rat brain research.
abstract: Manganese (Mn(2+))-enhanced MRI (MEMRI) is known to provide insight into functional and anatomical biology. However, this method, which uses Mn(2+) as a MRI-detectable contrast agent, has drawbacks such as the toxicity to cells beyond a certain level of Mn(2+). In this study, we attempt to determine a new method of ICV administration, the optimal concentration of administered Mn(2+) and the optimal MEMRI acquisition time following administration. Male Sprague-Dawley rats were used in the following experimental sessions: (1) intracerebroventricular (ICV) cannula implantation in the region of the cisterna magna, (2) serial dilution of MnCl(2) (20-80 mM), (3) ICV administration of MnCl(2) through the cannula, and (4) T(1)-weighted MRI measurements. We confirmed that cannula implantation in the region of the cisterna magna was a new ICV injection method for the administration of a contrast agent. The optimal concentration for MEMRI was 20/50 mM/µl of MnCl(2). The MEMRI data acquired at different time points indicate that most signal enhancement is maintained during 14-48 h after contrast agent injection, and 24 h was the optimal time to acquire images of the rat brain. The present study offers optimized parameters for contrast agent injection that would be a good basis for studies using MEMRI to research the rat brain.
authors.affiliation: Neuroscience Research Institute and Department of Biotechnology and Science, Korea University College of Medicine, Seoul 136-705, Republic of Korea.
authors.forename: Keun-Yeong
authors.initials: KY
authors.lastname: Jeong
authors.forename: Chulhyun
authors.initials: C
authors.lastname: Lee
authors.forename: Jee-Hyun
authors.initials: JH
authors.lastname: Cho
authors.forename: Ji-Hyuk
authors.initials: JH
authors.lastname: Kang
authors.forename: Heung-Sik
authors.initials: HS
authors.lastname: Na
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001921:Brain / Q000378:metabolism; D001931:Brain Mapping / Q000379:methods*; D002712:Chlorides / Q000008:administration & dosage / Q000633:toxicity; D003287:Contrast Media / Q000008:administration & dosage / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D007089:Image Enhancement; D021621:Imaging, Three-Dimensional / Q000379:methods*; D057967:Infusions, Intraventricular; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D017895:Manganese Compounds / Q000008:administration & dosage; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D002712:Chlorides; D003287:Contrast Media; D017895:Manganese Compounds; C025340:manganese chloride