Introduction
Magnetic resonance imaging (MRI) is an imaging technique used in medical diagnostics, particularly for the visualization of soft tissue and organs. With the help of magnetic resonance imaging, the finest sectional images of the body can be taken. Due to the particularly high-resolution images generated by the MRI, individual changes in organs and soft tissue can be accurately depicted.
General information on MRI can be found under our main topic: Magnetic Resonance ImagingThe functioning of MRI is based on a very strong magnetic field generated within the device, with which certain atomic nuclei (especially hydrogen nucleuss/protons) in the human body are excited. The use of a magnetic field for imaging tissue and organs offers enormous advantages compared to conventional imaging methods. One advantage of MRI compared to imaging procedures (e.g. X-rays) is the possibility of achieving significantly better soft tissue contrasts.
The differences in the imaging of different tissue forms are based on their specific fat and water content. In addition, unlike conventional x-rays, MRI images can be generated without harmful ionizing radiation (X-rays). As a result, there is no radiation exposure even if MRI images are taken repeatedly.
Furthermore, the fact that two different series of images can be obtained with the magnetic resonance tomograph improves the diagnostic possibilities. In this context, a distinction must be made between contrast medium-free and contrast medium MRI. With the help of contrast medium MRI, for example, inflammatory processes or vital tumor tissue can be better depicted by means of a more intensive white coloration.
In addition to conventional MRI, which takes a long time to produce sectional images, so-called “real-time MRIs” are now available for medical diagnostics. With this form of imaging, individual sectional images can be scanned in a fraction of a second. With the help of this procedure, for example, movements of organs can be displayed in a time-true manner.
In addition, the real-time MRI can be used during a surgical procedure to display the exact position of medical instruments. Although magnetic resonance imaging offers a number of advantages, this form of imaging cannot be performed on every patient. Patients who wear a pacemaker or implanted defibrillator usually cannot have an MRI.
The reason for this is that both the pacemaker and the implanted defibrillator could be damaged during the examination. In addition, interactions between these medical devices and the magnetic resonance scanner can cause considerable damage to the patient’s health. Furthermore, persons who have metal splinters and/or vascular clips made of magnetic materials in an unfavorable position (for example, in the area of the eye or brain) cannot be diagnosed with the help of MRI.
Early pregnancy (first trimester; 1st -13th week) is also considered a contraindication for the performance of magnetic resonance imaging. However, in women who are in early pregnancy, it must be decided individually whether there is any risk to the unborn child. In addition, the performance of an MRI examination can be problematic for people who suffer from claustrophobia.
The reason for this is that in some MRI indications (for example, MRI of the head or MRI of the cervical spine) the patient must be placed completely in a closed tube. It is precisely in these patients that the enormous advantages offered by MRI have so far only been used to a limited extent or under sedation. For some time now, however, various radiological institutes have been offering examinations in a so-called open MRI. Thanks to this new form of imaging, patients with claustrophobia can finally take full advantage of the benefits of magnetic resonance imaging.
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