Neuroimaging
Magnetic Resonance Imaging Facilities at the TCIN
The TCIN houses Ireland's first whole body 3T and small bore 7T MRI scanners. This rare combination of state-of-the-art research-dedicated systems opens up a broad range of interesting applications in physiological, pathophysiological and cognitive research.
The move to the large, whole body 3T magnetic field allow us to conduct complex functional MRI experiments which are extremely difficult if not impossible to perform on conventional 1.5T systems, due to the lower signal sensitivity at such lower field strengths. The even further increased sensitivity possible with the 7T system, coupled with the greater spatial resolution achievable on a small bore (30 cm) system, opens up a wide range of applications across the biological and medical-based sciences.
The MRI systems are located in the basement of the Lloyd Institute, where the TCIN is housed. Each system has its own magnet, operator and technical equipment rooms. A common computing room is located next to the scanning rooms and stocked with several high-end image processing workstations, together with a physics-based laboratory to allow for equipment developments/modifications, coil development, etc.
A team of MR Physicists (headed up by Dr. Christian Kerskens), radiographers and technicians provide technical and scientific support to the activities of the institute, while an active program of MR-based research is also conducted by this group. Applications support is provided by the respective equipment manufacturers (e.g. in the case of the 3T system, a Philips application scientist assists with the implementation of advanced research applications).
3T Whole Body Scanner
The 3T MRI lab houses a Philips Achieva 3T system. Its most important features and technical specifications are:
- Magnet system: Actively shielded, super-conducting magnet, field strength 3 Tesla, whole body (157 cm in length, 60cm bore size), weight 5500 kg
- Gradient system: Quasar Dual High Performance Gradient System: Actively shielded gradient with 80mT/m peak, 200mT/m/ms slew rate, 100% duty cycle.
- RF system: Scalable 32 parallel receiver channels architecture, Philips flex coils, quadrature body and head coils, phased array coils, and 8 and 16 channel array coils.
- Examples of studies which can be carried out on the 3T system include:
- 'Conventional' MR images based on T 1 , T 2 or proton density;
- High resolution anatomical imaging;
- Angiography;
- Venography;
- Arterial spin labeling for measuring blood perfusion through tissue;
- Molecular diffusion of water through tissue such as white matter tracts (tractography and diffusion tensor imaging (DTI));
- Magnetisation transfer contrast;
- Blood Oxygenation Level-Dependent (BOLD) imaging to show areas of brain activated by stimuli - functional MRI (fMRI).
Researchers interested in using the 3T MRI scanner should contact Dr. Christian Kerskens at 01-6088470 or email kerskenc@tcd.ie to discuss potential projects.
7T Small Bore Scanner
The 7T MRI lab houses a Bruker BioSpec 7T system. This state-of-the-art scanner allows for imaging with spatial resolutions less than 40 microns, while the non-invasive nature of MRI permit serial studies to be performed in the living animal. Its most important features and technical specifications are:
- System:
- Bruker BioSpec 70/30 (i.e. 7T, 30 cm bore) with an actively shielded USR Magnet
- Gradients:
- Large (200 mT/m, ID 152 mm)
- Medium (400 mT/m, ID 72mm)
- Small (1000 mT/m, ID 35 mm)
(ID = maximum usable internal diameter)
- RF Coils:
- Variety of volume resonators and surface coils to allow for imaging and spectroscopy of 1 H and a range of other MR-active nuclei such as 31 P, 23 Na, 19 F and 13 C. Parallel imaging capabilities will also be available.
A wide range of pulse sequences and image processing tools are available on the Bruker system, and support is available from an experienced group of MR physicists.
Examples of studies which can be carried out on the 7T system include:
- 'Conventional' MR images based on T 1 , T 2 or proton density, typically used to show anatomical detail;
- Blood flow in arteries or veins (magnetic resonance angiography or MRA);
- Blood perfusion through tissue, giving cerebral blood flow (CBF) and cerebral blood volume (CBV) maps;
- Molecular diffusion of water through tissue such as white matter tracts (tractography and diffusion tensor imaging (DTI));
- Relative degrees of bound and unbound water via magnetisation transfer contrast (MTC);
- Tissue movement, such as motion of the heart to yield measures of ejection fraction and myocardial wall motion;
- Tissue temperature and intracellular pH measurements;
- Oxygenation of blood to show areas of brain activated by stimuli - functional MRI (fMRI);
- Changes in blood perfusion through tissues in response to pharmacological intervention (phMRI);
- Cell tracking following the labeling of cells with magnetic nanoparticles.
Researchers interested in using the 7T MRI scanner should contact Dr. Christian Kerskens at 01-6088470 or email kerskenc@tcd.ie to discuss potential projects.