called, is computed as the The magnetic resonance imaging is based on very strong magnetic fields and electromagnetic fields change by certain atomic nuclei (usually hydrogen nuclei / protons) in the body are stimulated. By switching on the magnetic field is the axis around which these nuclei rotate (MRI) from their equilibrium deflected. When the magnetic field the nuclei are aiming again to their original position back (= relaxation). These are excited by the atomic nuclei is extremely weak electromagnetic fields emitted, as measured by detectors, and image information to be converted.
An essential basis for the image contrast are the different relaxation times of different tissue types, but also the different levels of hydrogen atoms in the different tissues (eg muscle, bone) contributes to the image contrast for. With the MRT, you can Cutting Images of the human body produce an assessment of the institutions and organs of many pathological changes allow.
By varying parameters of the investigation can be a very high level of detail can be achieved. This exceeds the representability in the X-ray, as well as computed tomography. Through the production of two recording series, with and without administration of contrast medium, there is a further improvement, because in this example by a white coloration intense inflammatory foci or even more vital tumor tissue can be detected.
Besides the possibility of organs and tissues with high soft tissue contrast manner is another benefit of magnetic resonance imaging that this procedure is not X-rays or other ionizing radiation produced or used.
What are contraindications for the MRI?
- Pacemaker
- Metal splinters or vascular clips ferromagnetischem material adverse situation (eg in the eye, brain)
- temporary cava filter
- first trimester (= 1-13 week) pregnancy (relative contraindication)
- Cochleaimplantat (Hearing aid for the deaf)
- implanted insulin pumps (external pump must be stored for examination)
- winding or looping large tattoo in the investigation area (metallic pigments can be warm or burning the skin to cause Grade II
- Claustrophobia (= 'space fear') (relative contra-indication, investigation of possible sedation or anesthesia)
