orals 5th Asia-Pacific NMR Symposium 2013

Technical challenges and clinical applications  in Ultra High Field MRI and MRS (#65)

Peter R Luijten 1
  1. University Medical Center Utrecht, Utrecht, Netherlands

The magnetic field strenghts used for clinical magnetic resonance imaging and spectroscopy over three decennia have followed a similar trend as can be observed for NMR in general: a gradual increase. From 0.3T to 1.5T in the late seventees and early eightees to the current 7T (up 11.7T) systems. The concomittant increase in signal to noise and tissue contrast can be used to develop new applications both in brain and total body imaging. However, at 300 MHz and up, different challenges occur that require special techniques to mitigate the effects that may impede the clinical use of these systems. Restricted use of radiofrequency power may limit the number of applicable pulse sequences, whereas in the regime where the RF wavelengths tends to get smaller than the imaged objects, image quality will become compromised. New approaches will be discussed for the acquisition of clinical  images and spectra that can overcome these challenges. With these new techniques, unprecendented details can be observed using ultra high field clinical imaging, both in regular patient care as well as in neuro-cognitive sciences. The detection of microbleeds and microinfacts in the brain can result in the early detection of signs of neurodegeneration, visualizing small MS lesions in the cortex of the brain may tell us more about the pathophysiology of the disease, we can measure the concentration of the neurotransmitters glutamate and gaba in brain tissue. Also outside the brain ultra high field MRI and MRS may offer clear advantages, e.g. in the detection and characterisation of breastcancer. These and other examples will be described as well.