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Updated: May 22, 2026
Functional Neuroimaging Using Ultrasonic Blood-brain Barrier Disruption and Manganese-enhanced MRI
Published on: July 12, 2012
New method of manganese-enhanced Magnetic Resonance Imaging (MEMRI) for rat brain research
Keun-Yeong Jeong1, Chulhyun Lee, Jee-Hyun Cho
1Neuroscience Research Institute and Department of Biotechnology and Science, Korea University College of Medicine, Seoul 136-705, Republic of Korea.
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.
Insights
This study optimizes Manganese (Mn2+)-enhanced MRI (MEMRI) by establishing a new intracerebroventricular (ICV) administration method and optimal Mn2+ concentration (20/50 mM/µl) for enhanced rat brain imaging.
Area of Science:
- Neuroimaging
- Biomedical Engineering
- Pharmacology
Background:
- Manganese (Mn2+)-enhanced MRI (MEMRI) offers insights into brain function and anatomy.
- High Mn2+ concentrations can lead to cellular toxicity, necessitating optimized administration protocols.
Purpose of the Study:
- To develop a novel intracerebroventricular (ICV) administration method for Mn2+ contrast agents.
- To determine the optimal Mn2+ concentration and imaging time for MEMRI in rats.
- To mitigate Mn2+ toxicity while maximizing imaging signal.
Main Methods:
- Intracerebroventricular (ICV) cannula implantation in the cisterna magna region of Sprague-Dawley rats.
- Serial dilution of manganese chloride (MnCl2) to test concentrations from 20-80 mM.
- T1-weighted MRI acquisition at various time points post-ICV MnCl2 administration.
Main Results:
- Cannula implantation in the cisterna magna proved effective for ICV contrast agent delivery.
- The optimal Mn2+ concentration for MEMRI was identified as 20/50 mM/µl.
- Maximal signal enhancement was observed between 14-48 hours, with 24 hours being the optimal acquisition time.
Conclusions:
- Optimized parameters for Mn2+ contrast agent injection via ICV administration were established.
- This study provides a foundation for improved rat brain research using MEMRI.
- The findings contribute to safer and more effective application of MEMRI techniques.
