Professor Stuart Crozier

Stuart Crozier PhD D.Eng. Professor and Director of Biomedical Engineering at The University of Queensland Australian Research Council Professorial Fellow

Bio

Stuart Crozier, PhD, D.Eng. is currently Professor and Director of Biomedical Engineering at The University of Queensland and Australian Research Council Professorial Fellow. He has published over 130 journal papers, holds 20 patents and has numerous conference papers. Several of his patents have been licensed by MRI suppliers. His research interests include: Magnetic Resonance engineering, applications of MRI for cancer diagnosis and physiological monitoring devices.

He is currently Associate Editor of IEEE Transactions on Biomedical Engineering and sits on two other editorial boards. He is a Fellow of The Institute of Physics (UK) and The Australian Academy for Technological Sciences and Engineering (ATSE).

High Field MRI - potential and pitfalls for new tissue contrast

In this talk we provide an overview of the potential of high field MRI to provide improved resolution and new contrast mechanisms, thus providing potential for the improved use of automated diagnosis. A problem, however, is that at higher field strengths and thus frequencies, there is substantial interaction between tissue and the fields generated in an MRI system. Progress towards understanding and solving this issue for clinical imaging will be detailed.

In MRI image processing it is common to have to consider bias field correction, registration and associated matters before segmentation and subsequent classification can be reliably achieved en route to semi-automated diagnoses. There is a significant push in MRI acquisition towards high field strengths in search of improved signal-to-noise ratios and therefore either better spatial or temporal resolutions. However, the technology needed in order to achieve these improved attributes is challenging, not the least of which is the more substantial interaction of the static, radiofrequency and gradient fields used in MRI with the magnetic and electric properties of tissue in the patient. This has led to a new and stronger class of distortions which must be considered carefully before embarking on bias field correction methods.

We explore the issues surrounding high field MRI with regard to image distortions as well as the progress made in developing new hardware and methods to mitigate the problems. We also provide an overview of some improved and perhaps unexpected contrast mechanisms that have become apparent at high field. The images below show heterogeneous induced current distributions in a patient model (left) and a corrected 7T sagittal brain image.

Induced current in a patient	Corrected 7T FSE image