These magnets are for scientific research on fundamental medical and physiological problems ranging from cognitive science to aging, heart disease and cancer. The opportunities opened by much higher magnetic fields than exist today are tremendous as many human health conditions cannot be approached by any other methods as discussed in the body of this chapter. The technologies focused here upon are initially meant for research and not for routine clinical use. At a clinical level, ca. 40,000 clinical systems will have been installed worldwide

BKM120 manufacturer by 2013. The majority of new installations are for 1.5 T (64%) with the remainder equally divided between 3.0 T and less than 1.5 T. The current distribution of field strengths for magnets at or above 7 T is approximately as follows: 50 at 7 T, 5 at 9.4 T, 2 at 10.5 T, 1 at 11.7 T. One 14 T for human brain imaging is being funded for this website South Korea. Animal research systems with small bores and high field are also in increasing demand world wide. As discussed in previous sections, the field of magnetic resonance spectroscopy (NMR, MRS) is now of major importance particularly to chemistry. In

1972, chemist Paul Lauterbur showed that one can image the spatial distribution of the hydrogen nucleus concentration (mainly water) in objects and this led to magnetic resonance imaging [16]. Magnetic resonance imaging (MRI) initially, and years later functional magnetic resonance imaging (fMRI), eventually became major modalities for research and diagnostic medicine as well as for animal physiology studies – particularly since the mid 1980s. NMR spectroscopy and MRI have followed parallel paths of technological development,

despite their differences in fields and sample sizes (Fig. 1). Throughout the development of MRI and MRS, each substantive increase in field strength has in time led to dramatic improvements in the quality of images and spectra obtainable, and usually to ‘quantum leaps’ in the information available about tissue structure and function (Fig. 2). Each major increase Pyruvate dehydrogenase in field has also introduced new technical challenges and problems that have required creative scientific and engineering solutions in order to realize the potential to improve image quality [18]. The evolution of higher field systems has continued. By 1988 success in development of a whole body 4 T system was reported [19], [20], [21] and [22] and commercial vendors made a small number of 4 T MRI magnets. However, ultimately the main industrial effort focused on developing scanners operating at 3 T, and these systems are replacing 1.5 T systems in many clinical applications. Much of the early 3 T developments emphasized brain imaging, partly motivated by the discovery of the benefits of blood oxygenation level-dependent susceptibility contrast as a measure of brain activity. This phenomenon is also known as functional MRI (fMRI).