Diagnostic imaging

VISTA opens new frontiers in ultra high field MRI research

16 June 2006

The Virtual Institute for Seven Tesla Applications (VISTA) is a Dutch initiative of researchers from the University Medical Centers in Leiden (LUMC), Utrecht (UUMC) and Nijmegen (St Radboud UMC) and from the FC Donders Center for Cognitive Neuroimaging in Nijmegen. The aim of VISTA is to bundle the expertise on ultra high field magnetic resonance imaging (MRI) in The Netherlands into one powerful virtual institute and to give other MRI researchers in the country access to ultra high field MRI expertise and infrastructure.

The center of gravity of VISTA comprises three MRI systems with a field strength of 7Tesla. In Leiden and Utrecht 7Tesla MRI systems manufactured by Philips Medical Systems will be installed during the first quarter of 2007, whereas the Nijmegen teams will have access to a recently installed Siemens 7Tesla system at the University of Duisburg/Essen in Germany.

Over the years, major breakthroughs in the field of MRI have been based on the availability of systems operating at higher field strengths than before, and such breakthroughs have given rise to the development of clinical MRI systems with ever increasing field strengths.

Initially, clinical MRI systems had field strengths of 0.5 Tesla or lower. Presently, MRI systems with a field strength of 1.5 Tesla are the standard for clinical settings in hospitals worldwide. Recently, systems operating at a field strength of 3.0 Tesla started to be installed, mainly in university hospitals and other research institutions. The availability of ultra high field MRI systems with field strengths of 7 Tesla or higher has so far been limited to some research sites where these systems were mostly built by local teams of engineers and physicists.

Ultra high field MRI provides unique advantages that can be used not only to obtain better results for many current diagnostic applications, but opens up new fields of activity, by enabling previously unattainable applications. Researchers are investigating and already showing promising results building on the advantages of ultra high field strength MRI studies for:

  • Structural imaging, morphologic applications such as degenerative neurological diseases like Alzheimer’s disease, Parkinson’s disease and Multiple Sclerosis. New areas of MRI research include high-resolution vascular imaging with opportunities for direct anatomic visualization of angiogenesis of the microvasculature and monitoring the structural effectiveness of anti-angiogenetic and genetic based drugs for the treatment of cancer at an unprecedented level of detail.

  • Physiological and metabolic investigations can be performed at an unmatched level of sensitivity. Activation studies in the brain that utilise the BOLD (Blood Oxygen Level Dependent) contrast mechanism benefit from increased sensitivity and spatial specificity. ASL (Arterial Spin Labelling) techniques are more sensitive, as are studies using exogenous paramagnetic contrast agents. In addition, ultra high field strength substantially improves non invasive metabolic analyses of tissues using MR spectroscopy (MRS).

  • Molecular applications such as quantitative imaging of gene expression, marking stem cells and tracking their evolution or targeting malignant cells with targeted contrast agents will be facilitated due to the tremendous increase in signal-to-noise ratios as well as the new possible contrast mechanisms.

MRI research in The Netherlands has a long and successful tradition. So far an ultra high field MRI system was lacking in the country, which hampered MRI research.

The costs of an ultra high field MRI system are very high, not only because of the costs of the scanner itself, but also because of the costs involved in the housing of such a system (which requires all kinds of expensive adaptations). In addition, at this point in time, 7Tesla research is not ready yet for all kinds of applications. Rather, major work remains to be done, in terms of developing techniques that exploit the theoretical advantages offered by ultra high field, before these systems are ready for all kinds of applications.

For such work, teams of MRI experts with specific experience with ultra high field MRI are needed. The height of the costs involving purchase and installment of a 7Tesla system, and the costs involved in hiring teams of experts prevent most institutions from embarking on human ultra high field MRI research.

VISTA aimed at overcoming such local budgetary limitations by creating a national platform for 7Tesla research comprising human 7 Tesla MRI systems and teams of experts and by seeking national funding. Funding was provided by the national government recently, and VISTA will be a reality by mid 2007.

Mark A. van Buchem, MD, PhD
Professor of Neuroradiology
Department of Radiology
Leiden University Medical Center,
Leiden, The Netherlands

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