Starting with A for "ACE inhibitor" and continuing through to Y for "Yolk Sac Tumour", we give you succinct explanations for scientific and medical terms in clear and simple words.
- Nuclear spin tomographyalso known as magnetic resonance tomography (abbreviation MRT)
Nuclear spin tomography is a computer-based imaging procedure which is based on the principle of magnetic resonance. In contrast to conventional X-ray diagnosis or computer tomography, no ionising radiation is used. A strong magnetic field is applied to the area to be examined. The spin of the nuclei in the sample are then excited by a short high frequency impulse. When the nuclei relax, electromagnetic waves are released and the energy of these is measured. If a field gradient is superimposed on a main homogenous magnetic field, measurements of magnetic resonance are possible which allow conclusions about the origin of the field-dependent signals. Layers of the body can be selected at will and with the help of the computer the signals from these can be assembled into two or three dimensional tomographic images. Superconducting magnets are suitable for the production of particularly stable magnetic field of high flux density. If these are used, very high contrast resolution and the imaging of small anatomical structures is possible, which is usually superior to computer tomography. Nuclear spin tomography is mostly used for diseases of nervous tissue (brain and spinal chord, multiple sclerosis), diagnosis of vertebral discs and imaging of joints and muscles.
Glossary entries: Roche and Walter de Gruyter, Berlin