Advances in magnetic resonance imaging

Abstract

The major advances in clinical MRI relate to the widespread introduction of high field (3.0 Tesla) imaging systems and the development of parallel imaging techniques. The increased signal to noise ratio of high field imaging systems is compromised by the need to compensate for susceptibility, chemical shift and energy deposition. Changes in T1 values at high field strength are tissue specific but in general produce a reduction in contrast. Paramagnetic contrast materials show little change in longitudinal relaxation times at high field strength. The use of frequency specific fat suppression techniques to reduce chemical shift artefacts is of particular value at high field strength. The use of parallel imaging techniques complements increases in field strength by allowing reduction of susceptibility artefacts and reduced blurring in fast spin echo or HASTE acquisitions and reduction in specific absorption rate (SAR).