Magnetic Resonance Imaging Homepage

Magnetic Resonance Imaging (MRI) is a technique for visualizing the internal structure of soft solids, tissues and liquids. Applications range from medicine, e.g. tumor detection, study of blood flow, brain functional mapping, to material science (wetting profiles in drying concrete) and fluid dynamics (rheology of polymer solutions).

The Department of Physics of the University of Notre Dame operates a 7 Tesla Magnetic Resonance Imaging (MRI) facility. While this imager is not suitable for medical applications on humans, because of its limited working volume, its high imaging field and gradients give it a resolution much higher than medical imaging, making it ideal for small animals and condensed mater microimaging. The imager has a vertical, super-wide bore magnet with interchangeable probes and gradient sets. Proton tuned RF probes are available from 3 mm to 64 mm diameter. Proton and separate broadband amplifiers are also available for heteronuclear imaging or non-proton imaging between 6 and 300 MHz.

The system has two gradient sets, the larger one with a gradient strength up to 14 Gauss/cm and a maximum imaging area of up to 60 mm is useful for imaging of live animals (anatomical and functional) or materials research. The smaller gradient set has a gradient strength of up to 100 Gauss/cm and is suitable for MRI microscopy. RF probes with diameters 2.5 mm, 5 mm, 10 mm, 15 mm and 25 mm are available for the small gradient. The sample temperature can be regulated between -50^oC and +100^oC with 0.1^oC accuracy. Both gradients are water cooled allowing high sustainable duty cycles of up to 5%, permitting us to use image methods with very short repetition times (tens of milliseconds) and large gradient strengths. We have achieved resolutions in liquids and tissues below 50 micrometers in single slice and hard pulse three-dimensional acquisitions.

The facility is equipped for in-vivo study of small animals. Respiratory and cardiac gating and animal restraints are available.

Our system can also be used for NMR spectroscopy applications that require multiple gradients, like measurements of diffusion coefficients or volume selective spectroscopy.

Extensive data processing and image analysis capabilities provide our Silicon Graphics workstations running IDL, ParaVision, Voxblast, Matlab. We would be glad to work with researches developing image processing applications related to MRI.

We are also introducing a new course: PHYS 625: "An introduction to MRI." This course will introduce the physics of magnetic resonance and the mathematical principles of image formation, the MRI hardware and the application of MRI to a variety of physical and biomedical problems. It will also include laboratory sessions to provide students with hands-on experience with MRI. Students who complete this course will be qualified to design and conduct further MRI experiments using the Notre Dame facility.

This machine is also available to users outside the Notre Dame Community – if you know anyone with an appropriate application or need, please encourage them to contact us.