Magnetic resonance imaging (MRI)
Magnetic resonance imaging (MRI) is a non-invasive imaging technique used to study the structure, function and biochemistry of the brain. At the CIMH, three 3T tomographs (two Siemens PrismaFit, one Siemens Biograph mMR) are available for research studies. MRI is the most commonly used method in the CIMH's imaging studies. It is used since 1996 and has resulted in over 500 publications. In addition to T1 / T2-weighted structural images, most of our studies use functional imaging based on blood oxygen level dependent contrast (BOLD-fMRI). Other options include diffusion-weighted images (DWI, which also allows DTI fiber tracking), proton density maps, arterial spin labeling (ASL), and other less widely used options. Another large field is MR spectroscopy (MRS), which allows us to draw conclusions about the biochemical profile of a volume under investigation, such as the concentration of brain metabolites and neurotransmitters. MRS is not limited to protons, but can also be applied to other so-called X-nuclei such as carbon (13C), phosphorus (31P), sodium (23Na), fluorine (19F), all with different information content. Despite its long history, MR research is still a continuously evolving field and finding new applications.
Advantages / disadvantages compared to other methods
The greatest advantage over most other imaging methods (for example X-ray, CT) is that MR does not use ionizing radiation (X-rays, radioactivity) and the subjects can be examined as often as necessary without any long-term consequences. In addition, the possibilities of use and the potential wealth of information and diversity are very extensive, especially in comparison to other imaging methods.
The operation of MR scanners and subsequent evaluation of the data require a high level of knowledge. Depending on the experiment design, the interaction of all technical components (scanners, stimuli presentation, response evaluation) achieve a high degree of complexity, and are therefore prone to errors.
Risks / Limitations
The biggest risks arise from medical implants (for example pacemakers, artificial joints) or metallic objects in the participants/patients body. Claustrophobia might also be an issue due to restricted space in the scanner. Further restrictions and details are discussed with each participant/patient individually before a measurement.
Zentralinstitut für Seelische Gesundheit (ZI) - https://www.zi-mannheim.de