[Magnetic resonance imaging: technical aspects and recent developments]

Abstract

Magnetic resonance imaging (MR) is based on electromagnetic effects of rotating protons in hydrogen of water and organic materials. With a magnetic field and high frequency electromagnetic pulses, MRI generates data sets to be reconstructed as two-dimensional cross-sectional images or three-dimensional volumes of anatomic structures with excellent soft-tissue contrast. Since modern MR techniques have dramatically reduced acquisition times and motion artifacts, breathhold studies of moving organs such as the stomach and intestinum or heart and lung have become part of the daily routine. MRI does not apply ionizing radiation, therefore dynamic studies and repeated controls may be performed. Original contraindications such as metallic implants or electronic devices (pacemakers) have become relative in many cases. Since MR contrast media are considered not nephrotoxic when applied in regular dose, MRI provides a most valuable alter native for imaging studies and angiography in patients with renal insufficiency. The recent developments in the field of internal medicine include functional imaging of stomach, intestinum, heart and lung. Based on these experiences, protocols for whole-body MRI within reasonable acquisition time and at acceptable costs have been developed. In particular for screening and staging, such MRI proto cols might cover an even broader spectrum of applications in the near future. Based on the knowledge of recent trends and technical backgrounds, many perspectives are opened up for the further development of the method in interdisciplinary cooperation.